OBD System Operation Summary
2007 MY OBD System Operation
Summary for Gasoline Engines
Table of Contents
Introduction – OBD-I, OBD-II and EMD ........................................................... 3
Catalyst Efficiency Monitor................................................................................. 5
Misfire Monitor................................................................................................... 10
AIR System Monitor – Flow Check ................................................................. 18
EVAP System Monitor - 0.040” dia. vacuum leak check ............................... 21
EVAP System Monitor - 0.020” dia. vacuum leak check ............................... 26
EVAP System Monitor - 0.020” dia. engine off natural vacuum leak check. 32
EVAP System Monitor Component Checks ................................................... 39
Fuel System Monitor ........................................................................................ 43
Flex Fuel Operation .......................................................................................... 47
HO2S Monitor ................................................................................................... 49
DPFE EGR System Monitor ............................................................................ 60
ESM DPFE EGR System Monitor................................................................... 66
Stepper Motor EGR System Monitor – Non-intrusive Monitor ...................... 73
PCV System Monitor ........................................................................................ 79
Thermostat Monitor .......................................................................................... 79
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
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Cold Start Emission Reduction Component Monitor ..................................... 80
Cold Start Emission Reduction System Monitor ............................................ 83
Variable Cam Timing System Monitor ............................................................ 86
Electronic Throttle Control................................................................................ 89
Comprehensive Component Monitor - Engine............................................... 94
Comprehensive Component Monitor - Transmission ..................................113
4R75E (RWD) Transmission .........................................................................129
4F50N(AX4N) (FWD) Transmission .............................................................130
CD4E (FWD) Transmission ...........................................................................131
5R44E (RWD) Transmission .........................................................................132
5R55E (RWD) Transmission .........................................................................133
5R55S (RWD) Transmission .........................................................................134
5R110W (RWD) Transmission......................................................................136
6R (RWD) Transmission ................................................................................139
4F27E (FN) (FWD) Transmission .................................................................141
ZF CFT30 (FWD) Continuously Variable Transmission..............................142
ZF 6HP26 (RWD) Transmission ...................................................................146
Aisin F21 (FWD) Transmission......................................................................148
Mazda FNR5 (FWD) Transmission...............................................................150
6F (FWD) Transmission.................................................................................152
On Board Diagnostic Executive.....................................................................155
Exponentially Weighted Moving Average .....................................................156
I/M Readiness Code.......................................................................................158
Catalyst Temperature Model .........................................................................159
Serial Data Link MIL Illumination ...................................................................159
Calculated Load Value ...................................................................................160
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Introduction – OBD-I, OBD-II and EMD
OBD-I Systems
OBD-I vehicles use that same PCM, J1850/CAN serial data communication link, J1962 Data Link Connector, and
PCM software as the corresponding OBD-II vehicle. The only difference is the possible removal of the rear oxygen
sensor(s), fuel tank pressure sensor, canister vent solenoid, and a different PCM calibration. Starting in the 2006
MY, all Federal vehicles from 8,500 to 14,000 lbs. GVWR will have been phased into OBD-II and OBD-I systems
will no longer be utilized in vehicles up to 14,000 lbs GVWR.
OBD-II Systems
California OBD-II applies to all California and "California State" gasoline engine vehicles up to 14,000 lbs. Gross
Vehicle Weight Rating (GVWR) starting in the 1996 MY and all diesel engine vehicles up to 14,000 lbs. GVWR
starting in the 1997 MY.
"California States" are ones that have adopted California emission regulations, starting in the 1998 MY. At this
time, Massachusetts, New York, Vermont and Maine have adopted California's regulations. These States receive
California-certified vehicles for passenger cars and light trucks, and medium-duty vehicles, up to 14,000 lbs.
GVWR."
Federal OBD-II applies to all gasoline engine vehicles up to 8,500 lbs. GVWR starting in the 1996 MY and all
diesel engine vehicles up to 8,500 lbs. GVWR starting in the 1997 MY.
Starting in the 2004 MY, Federal vehicle over 8,500 lbs. are required to phase in OBD-II. Starting in 2004 MY,
gasoline-fueled Medium Duty Passenger Vehicles (MDPVs) are required to have OBD-II. By the 2006 MY, all
Federal vehicles from 8,500 to 14,000 lbs. GVWR will have been phased into OBD-II.
OBD-II system implementation and operation is described in the remainder of this document.
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REVISION DATE: NOVEMBER 12, 2007
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EMD Systems
Engine Manufacturer Diagnostics (EMD) applies to all 2007 MY and beyond California gasoline-fueled and diesel
fueled on-road heavy duty engines used in vehicles over 14,000 lbs Gross Vehicle Weight Rating (GVWR). EMD
systems are required to functionally monitor the fuel delivery system, exhaust gas recirculation system, particulate
matter trap, as well as emission related ECM input inputs for circuit continuity and rationality, and emission-related
outputs for circuit continuity and functionality. For gasoline engines, which have no PM trap, EMD requirements are
very similar to current OBD-I system requirements. As such, OBD-I system philosophy will be employed, the only
change being the addition of some comprehensive component monitor (CCM) rationality and functionality checks.
EMD vehicles use that same PCM, CAN serial data communication link, J1962 Data Link Connector, and PCM
software as the corresponding OBD-II vehicle. The only difference is the possible removal of the rear oxygen
sensor(s), fuel tank pressure sensor, canister vent solenoid, and a different PCM calibration.
The following list indicates what monitors and functions have been altered from OBD-II for EMD calibrations:
Monitor / Feature
Catalyst Monitor
Misfire Monitor
Oxygen Sensor Monitor
EGR Monitor
Fuel System Monitor
Secondary Air Monitor
Evap System Monitor
PCV Monitor
Thermostat Monitor
Comprehensive
Component Monitor
Communication
Protocol and DLC
MIL Control
Calibration
Not required, monitor calibrated out, rear O2 sensors may be deleted.
Calibrated in for service, all DTCs are non-MIL. Catalyst damage misfire criteria
o
calibrated out, emission threshold criteria set to 4%, enabled between 150 F and 220
o
F, 254 sec start-up delay.
Rear O2 sensor test calibrated out, rear O2 sensors may be deleted, front O2 sensor
response test calibrated out.
Same as OBD-II calibration except that P0402 test uses slightly higher threshold.
Same as OBD-II calibration.
Functional (low flow) test calibrated out, circuit codes are same as OBD-II calibration.
Evap system leak check calibrated out, fuel level input circuit checks retained as nonMIL. Fuel tank pressure sensor and canister vent solenoid may be deleted.
Same hardware and function as OBD-II.
Thermostat monitor calibrated out.
All circuit checks, rationality and functional tests same as OBD-II.
Same as OBD-II, all generic and enhanced scan tool modes work the same as OBD-II
but reflect the EMD calibration that contains fewer supported monitors. "OBD
Supported" PID indicates EMD ($11).
Same as OBD-II, it takes 2 driving cycles to illuminate the MIL.
EMD system implementation and operation is a subset of OBD-II and is described in the remainder of this
document.
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REVISION DATE: NOVEMBER 12, 2007
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Catalyst Efficiency Monitor
The Catalyst Efficiency Monitor uses an oxygen sensor before and after the catalyst to infer the hydrocarbon
efficiency based on oxygen storage capacity of the ceria and precious metals in the washcoat. Under normal,
closed-loop fuel conditions, high efficiency catalysts have significant oxygen storage. This makes the switching
frequency of the rear HO2S very slow and reduces the amplitude of those switches as compared to the switching
frequency and amplitude of the front HO2S. As catalyst efficiency deteriorates due to thermal and/or chemical
deterioration, its ability to store oxygen declines. The post-catalyst HO2S signal begins to switch more rapidly with
increasing amplitude, approaching the switching frequency and amplitude of the pre-catalyst HO2S. The
predominant failure mode for high mileage catalysts is chemical deterioration (phosphorus deposition on the front
brick of the catalyst), not thermal deterioration.
All applications utilize an FTP-based (Federal Test Procedure) catalyst monitor. This simply means that the
catalyst monitor must run during a standard FTP emission test as opposed to the 20-second steady-state catalyst
monitor used in 1994 through some 1996 vehicles.
Index Ratio Method
In order to assess catalyst oxygen storage, the catalyst monitor counts front HO2S switches during part-throttle,
closed-loop fuel conditions after the engine is warmed-up and inferred catalyst temperature is within limits. Front
switches are accumulated in up to three different air mass regions or cells. While catalyst monitoring entry
conditions are being met, the front and rear HO2S signal lengths are continually being calculated. When the
required number of front switches has accumulated in each cell (air mass region), the total signal length of the rear
HO2S is divided by the total signal length of front HO2S to compute a catalyst index ratio. An index ratio near 0.0
indicates high oxygen storage capacity, hence high HC efficiency. An index ratio near 1.0 indicates low oxygen
storage capacity, hence low HC efficiency. If the actual index ratio exceeds the threshold index ratio, the catalyst is
considered failed.
General Catalyst Monitor Operation
If the catalyst monitor does not complete during a particular driving cycle, the already-accumulated switch/signallength data is retained in Keep Alive Memory and is used during the next driving cycle to allow the catalyst monitor
a better opportunity to complete, even under short or transient driving conditions.
Rear HO2S sensors can be located in various ways to monitor different kinds of exhaust systems. In-line engines
and many V-engines are monitored by individual bank. A rear HO2S sensor is used along with the front, fuelcontrol HO2S sensor for each bank. Two sensors are used on an in-line engine; four sensors are used on a Vengine. Some V-engines have exhaust banks that combine into a single underbody catalyst. These systems are
referred to as Y-pipe systems. They use only one rear HO2S sensor along with the two front, fuel-control HO2S
sensors. Y-pipe system use three sensors in all. For Y-pipe systems, the two front HO2S sensor signals are
combined by the software to infer what the HO2S signal would have been in front of the monitored catalyst. The
inferred front HO2S signal and the actual single, rear HO2S signal is then used to calculate the switch ratio.
Most vehicles that are part of the “LEV” catalyst monitor phase-in will monitor less than 100% of the catalyst
volume – often the first catalyst brick of the catalyst system. Partial volume monitoring is done on LEV and ULEV
vehicles in order to meet the 1.75 * emission-standard. The rationale for this practice is that the catalysts nearest
the engine deteriorate first, allowing the catalyst monitor to be more sensitive and illuminate the MIL properly at
lower emission standards.
Many applications that utilize partial-volume monitoring place the rear HO2S sensor after the first light-off catalyst
can or, after the second catalyst can in a three-can per bank system. (A few applications placed the HO2S in the
middle of the catalyst can, between the first and second bricks.)
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REVISION DATE: NOVEMBER 12, 2007
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Index ratios for ethanol (Flex fuel) vehicles vary based on the changing concentration of alcohol in the fuel. The
malfunction threshold typically increases as the percent alcohol increases. For example, a malfunction threshold of
0.5 may be used at E10 (10% ethanol) and 0.9 may be used at E85 (85% ethanol). The malfunction thresholds are
therefore adjusted based on the % alcohol in the fuel. (Note: Normal gasoline is allowed to contain up to 10%
ethanol (E10)).
All vehicles employ an Exponentially Weighted Moving Average (EWMA) algorithm to improve the robustness of
the FTP catalyst monitor. During normal customer driving, a malfunction will illuminate the MIL, on average, in 3 to
6 driving cycles. If KAM is reset (battery disconnected), a malfunction will illuminate the MIL in 2 driving cycles. See
the section on EWMA for additional information.
If the catalyst monitor runs to completion during a driving cycle, it will be allowed to run again and collect another
set of data during the same driving cycle. This would allow the catalyst monitor to complete up to a maximum of
two times per driving cycle, however, the in-use performance ratio numerator for the catalyst monitor will only be
allowed to increment once per driving cycle. For example, if the catalyst monitor completes twice during the current
driving cycle, the catalyst monitor in-use performance numerator will be incremented once during the current
driving cycle and will incremented again for the second completion on the following driving cycle, after the catalyst
monitor entry condition have been met.
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REVISION DATE: NOVEMBER 12, 2007
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Index Ratio Catalyst Monitor
START
Inferred catalyst temp.
Vehicle conditions
Engine conditions
(engine warm, steady
drive conditions)
Monitor Entry
Conditions
Met?
No
Accumulate front O2 sensor
signal length.
Accumulate rear O2 sensor
signal length.
Count front O2 sensor switches
for each Air mass cell.
Front O2 Sensor Voltage
Rear O2 Sensor Voltage
Enough O2
switches in
each cell?
No
Divide Rear O2 signal length by
Front O2 signal length to get Index
Ratio.
Input new Index Ratio into EWMA
and calculate new EWMA value.
Yes
Catalyst is deteriorated
EWMA Index
Ratio >
threshold?
No
Catalyst is OK
Fault Management - MIL after
2 Driving Cycles > threshold
END
MIL
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REVISION DATE: NOVEMBER 12, 2007
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CATALYST MONITOR OPERATION:
DTCs
P0420 Bank 1 (or Y-pipe),
P0430 Bank 2
Monitor execution
once per driving cycle
Monitor Sequence
HO2S response test complete and no DTCs (P0133/P0153) prior to
calculating switch ratio, no SAIR pump stuck on DTCs (P0412/P1414), no
evap leak check DTCs (P0442/P0456), no EGR stuck open DTCs (P0402)
Sensors OK
ECT, IAT, TP, VSS, CKP
Monitoring Duration
Approximately 700 seconds during appropriate FTP conditions (approximately
100 to 200 oxygen sensor switches are collected)
TYPICAL INDEX RATIO CATALYST MONITOR ENTRY CONDITIONS:
Entry condition
Minimum
o
Maximum
Time since engine start-up (70 F start)
330 seconds
Engine Coolant Temp
170 F
o
230 F
Intake Air Temp
20 F
o
180 F
Time since entering closed loop fuel
30 sec
Inferred Rear HO2S sensor Temperature
900 F
EGR flow (Note: an EGR fault disables EGR)
1%
12%
Throttle Position
Part Throttle
Part Throttle
o
o
o
Rate of Change of Throttle Position
0.2 volts / 0.050 s
Vehicle Speed
5 mph
Fuel Level
15%
First Air Mass Cell
1.0 lb/min
2.0 lb/min
Engine RPM for first air mass cell
1,000 rpm
1,300 rpm
Engine Load for first air mass cell
15%
35%
o
Monitored catalyst mid-bed temp. (inferred) for first air mass cell
850 F
Number of front O2 switches required for first air mass cell
50
70 mph
o
1,200 F
2.0 lb/min
3.0 lb/min
Engine RPM for second air mass cell
1,200 rpm
1,500 rpm
Engine Load for second air mass cell
20%
35%
Monitored catalyst mid-bed temp. (inferred) for second air mass cell
900 F
Number of front O2 switches required for second air mass cell
70
Second Air Mass Cell
o
o
1,250 F
3.0 lb/min
4.0 lb/min
Engine RPM for third air mass cell
1,300 rpm
1,600 rpm
Engine Load for third air mass cell
20%
40%
Third Air Mass Cell
o
Monitored catalyst mid-bed temp. (inferred) for third air mass cell
950 F
Number of front O2 switches required for third air mass cell
30
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
o
1,300 F
PAGE 8 OF 160
(Note: Engine rpm and load values for each air mass cell can vary as a function of the power-to-weight ratio
of the engine, transmission and axle gearing and tire size.)
TYPICAL MALFUNCTION THRESHOLDS:
Rear-to-front O2 sensor index ratio > 0.75 (bank monitor)
Rear-to-front O2 sensor index-ratio > 0.60 (Y-pipe monitor)
Rear-to-front O2 sensor index ratio > 0.50 for E10 to > 0.90 for E85 (flex fuel vehicles)
J1979 CATALYST MONITOR MODE $06 DATA
Monitor ID
Test ID
Description for CAN
$21
$80
Bank 1 index-ratio and max. limit
unitless
$22
$80
Bank 2 index-ratio and max. limit
unitless
** NOTE: In this document, a monitor or sensor is considered OK if there are no DTCs stored for that component
or system at the time the monitor is running.
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REVISION DATE: NOVEMBER 12, 2007
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Misfire Monitor
There are three different misfire monitoring technologies used in the 2006 MY. They are Low Data Rate (LDR),
High Data Rate (HDR), and Neural Network Misfire (NNM). The LDR system is capable of meeting the FTP
monitoring requirements on most engines and is capable of meeting “full-range” misfire monitoring requirements
on 4-cylinder engines. The HDR system is capable of meeting “full-range” misfire monitoring requirements on 6
and 8 cylinder engines, but not on V-10 or V-12 engines. Neural Network Misfire detection is being used on the
6.8L V-10 in order to achieve "full-range" capability. All software allows for detection of any misfires that occur 6
engine revolutions after initially cranking the engine. This meets the OBD-II requirement to identify misfires within
2 engine revolutions after exceeding the warm drive, idle rpm.
Low Data Rate System
The LDR Misfire Monitor uses a low-data-rate crankshaft position signal, (i.e. one position reference signal at 10
deg BTDC for each cylinder event). The PCM calculates crankshaft rotational velocity for each cylinder from this
crankshaft position signal. The acceleration for each cylinder can then be calculated using successive velocity
values. The changes in overall engine rpm are removed by subtracting the median engine acceleration over a
complete engine cycle. The resulting deviant cylinder acceleration values are used in evaluating misfire in the
“General Misfire Algorithm Processing” section below.
“Profile correction” software is used to “learn” and correct for mechanical inaccuracies in crankshaft tooth spacing
under de-fueled engine conditions (requires three 60 to 40 mph no-braking decels after Keep Alive Memory has
been reset). These learned corrections improve the high-rpm capability of the monitor for most engines. The
misfire monitor is not active until a profile has been learned.
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Low Data Rate Misfire Monitor
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High Data Rate System
The High Data Rate (HDR) Misfire Monitor uses a high data rate crankshaft position signal, (i.e. 18 position
references per crankshaft revolution). This high-resolution signal is processed using two different algorithms. The
first algorithm is optimized to detect “hard” misfires, i.e. one or more continuously misfiring cylinders. The low pass
filter filters the high-resolution crankshaft velocity signal to remove some of the crankshaft torsional vibrations that
degrade signal to noise. Two low pass filters are used to enhance detection capability – a "base" filter and a more
aggressive filter to enhance single-cylinder capability at higher rpm. This significantly improves detection capability
for continuous misfires on single cylinders at redline. During the filter change, new data must propagate through
the single 31 ignition event computational queue on the AICE chip before an accurate misfire determination can be
made. The second algorithm, called pattern cancellation, is optimized to detect low rates of misfire. The algorithm
learns the normal pattern of cylinder accelerations from the mostly good firing events and is then able to accurately
detect deviations from that pattern. Both the hard misfire algorithm and the pattern cancellation algorithm produce
a deviant cylinder acceleration value, which is used in evaluating misfire in the “General Misfire Algorithm
Processing” section below.
Due to the high data processing requirements, the HDR algorithms could not be implemented in the PCM
microprocessor. They are implemented in a separate chip in the PCM called an “AICE” chip. The PCM
microprocessor communicates with the AICE chip using a dedicated serial communication link. The PCM
microprocessor can send different low pass filters to the AICE chip. The AICE chip send the cylinder acceleration
values back to the PCM microprocessor for additional processing as described below. Lack of serial
communication between the AICE chip and the PCM microprocessor, or an inability to synchronize the crank or
cam sensors inputs sets a P1309 DTC. For 2004 MY software, the P1309 DTC is being split into two separate
DTCs. A P0606 will be set if there is a lack of serial communication between the AICE chip and the PCM
microprocessor. A P1336 will be set if there is an inability to synchronize the crank or cam sensors inputs. This
change was made to improve serviceability. A P0606 generally results in PCM replacement while a P1336 points
to a cam sensor that is out of synchronization with the crank.
“Profile correction” software is used to “learn” and correct for mechanical inaccuracies in crankshaft tooth spacing
under de-fueled engine conditions (requires three 60 to 40 mph no-braking decels after Keep Alive Memory has
been reset). If KAM has been reset, the PCM microprocessor initiates a special routine which computes correction
factors for each of the 18 (or 20) position references and sends these correction factors back to the AICE chip to
be used for subsequent misfire signal processing. These learned corrections improve the high rpm capability of the
monitor. The misfire monitor is not active until a profile has been learned.
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High Data Rate Misfire Monitor
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REVISION DATE: NOVEMBER 12, 2007
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Neural Network System
The Neural Net Misfire (NNM) monitor uses a dedicated microprocessor in the PCM along with crankshaft position,
(36–tooth wheel or 40-tooth wheel on a V-10), camshaft position, and engine load to determine engine misfire. A
neural network is different way of computing that uses a large number of simple processing elements with a high
degree of interconnection to process complex information. It is based on the parallel architecture of the brain. The
processing elements have adaptive characteristics (coefficients) that must be learned through a process called
training. During training, the network is fed a sample set of data that consists of the inputs along with the desired
output (e.g. misfire/no misfire). The network coefficients are recursively optimized so that the correct output is
generated from the set of inputs and error is minimized. Once the coefficients have been learned, the network can
process "real" data.
Ford's NNM implementation for California and Green State applications uses a Motorola Star 12 microprocessor in
the PCM to perform the NNM calculations. The PCM is the only difference between California/Green State and
Federal vehicles. The neural network size is 23 nodes and 469 coefficients. Note that the Engine Off Natural
Vacuum evaporative system monitor also uses the same microprocessor. The pilot NNM implementation is on the
2006 MY Econoline van with 4.6L, 5.4L and 6.8L engines.
Inputs to Neural Net
•
Crankshaft acceleration from the crank position (CKP) sensor
•
RPM (calculated from CKP)
•
LOAD (normalized for air mass and rpm)
•
Indication of cam position from camshaft position (CMP) sensor
Output from Neural Net
•
Misfire Call: - 0 (indicating no misfire) or 1 (indicating misfire)
2005 MY NNM System Hardware Design
PCM
MIL
Misfire calls, or ∆t’s
Status Flags
MAF Signal
CID Signal
Main PPC
Processor
LOAD_FG
HCS12
HCS12
CKP - > ACCEL, RPM
CID - > local sync
Signal validation
Profile application
Executes Neural Net
Misfire fault counters
Misfire disable me nts
Profile Learning
CKP Signal
CKP Signal
CID Signal
“Profile correction” software is also used on NNM systems to “learn” and correct for mechanical inaccuracies in
crankshaft tooth spacing under de-fueled engine conditions (requires up to three 60 to 40 mph no-braking decels
after Keep Alive Memory has been reset). These learned corrections improve the high rpm capability of the
monitor. The misfire monitor is not active until a profile has been learned.
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PAGE 14 OF 160
Generic Misfire Algorithm Processing
The acceleration that a piston undergoes during a normal firing event is directly related to the amount of torque that
cylinder produces. The calculated piston/cylinder acceleration value(s) are compared to a misfire threshold that is
continuously adjusted based on inferred engine torque. Deviant accelerations exceeding the threshold are
conditionally labeled as misfires.
The calculated deviant acceleration value(s) are also evaluated for noise. Normally, misfire results in a nonsymmetrical loss of cylinder acceleration. Mechanical noise, such as rough roads or high rpm/light load conditions,
will produce symmetrical acceleration variations. Cylinder events that indicate excessive deviant accelerations of
this type are considered noise. Noise-free deviant acceleration exceeding a given threshold is labeled a misfire.
The number of misfires is counted over a continuous 200 revolution and 1000 revolution period. (The revolution
counters are not reset if the misfire monitor is temporarily disabled such as for negative torque mode, etc.) At the
end of the evaluation period, the total misfire rate and the misfire rate for each individual cylinder is computed. The
misfire rate evaluated every 200 revolution period (Type A) and compared to a threshold value obtained from an
engine speed/load table. This misfire threshold is designed to prevent damage to the catalyst due to sustained
excessive temperature (1600°F for Pt/Pd/Rh conventional washcoat, 1650°F for Pt/Pd/Rh advanced washcoat and
1800°F for Pd-only high tech washcoat). If the misfire threshold is exceeded and the catalyst temperature model
calculates a catalyst mid-bed temperature that exceeds the catalyst damage threshold, the MIL blinks at a 1 Hz
rate while the misfire is present. If the misfire occurs again on a subsequent driving cycle, the MIL is illuminated.
If a single cylinder is determined to be consistently misfiring in excess of the catalyst damage criteria, the fuel
injector to that cylinder will be shut off for 30 seconds to prevent catalyst damage. Up to two cylinders may be
disabled at the same time on 6 and 8 cylinder engines and one cylinder is disabled on 4 cylinder engines. This fuel
shut-off feature is used on all engines starting in the 2005 MY. . After 30 seconds, the injector is re-enabled. If
misfire on that cylinder is again detected after 200 revs (about 5 to 10 seconds), the fuel injector will be shut off
again and the process will repeat until the misfire is no longer present. Note that ignition coil primary circuit failures
(see CCM section) will trigger the same type of fuel injector disablement.
Next, the misfire rate is evaluated every 1000 rev period and compared to a single (Type B) threshold value to
indicate an emission-threshold malfunction, which can be either a single 1000 rev exceedence from startup or four
subsequent 1000 rev exceedences on a drive cycle after start-up. Some vehicles will set a P0316 DTC if the Type
B malfunction threshold is exceeded during the first 1,000 revs after engine startup. This DTC is normally stored in
addition to the normal P03xx DTC that indicates the misfiring cylinder(s). If misfire is detected but cannot be
attributed to a specific cylinder, a P0300 is stored. This may occur on some vehicles at higher engine speeds, for
example, above 3,500 rpm.
Profile Correction
"Profile correction" software is used to "learn" and correct for mechanical inaccuracies in the crankshaft position
o
wheel tooth spacing. Since the sum of all the angles between crankshaft teeth must equal 360 , a correction factor
can be calculated for each misfire sample interval that makes all the angles between individual teeth equal. To
prevent any fueling or combustion differences from affecting the correction factors, learning is done during decelfuel cutout.
The correction factors are learned during closed-throttle, non-braking, de-fueled decelerations in the 60 to 40 mph
range after exceeding 60 mph (likely to correspond to a freeway exit condition). In order to minimize the learning
time for the correction factors, a more aggressive decel-fuel cutout strategy may be employed when the conditions
for learning are present. The corrections are typically learned in a single deceleration, but can be learned during up
to 3 such decelerations. The "mature" correction factors are the average of a selected number of samples. A low
data rate misfire system will typically learn 4 such corrections in this interval, while a high data rate system will learn
36 or 40 in the same interval (data is actually processed in the AICE chip). In order to assure the accuracy of these
corrections, a tolerance is placed on the incoming values such that an individual correction factor must be
repeatable within the tolerance during learning. This is to reduce the possibility of learning corrections on rough
road conditions which could limit misfire detection capability.
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REVISION DATE: NOVEMBER 12, 2007
PAGE 15 OF 160
Since inaccuracies in the wheel tooth spacing can produce a false indication of misfire, the misfire monitor is not
active until the corrections are learned. In the event of battery disconnection or loss of Keep Alive Memory the
correction factors are lost and must be relearned. If the software is unable to learn a profile after three 60 to 40
mph decels, a P0315 DTC is set.
Misfire Monitor Operation:
DTCs
P0300 to P0310 (general and specific cylinder misfire)
P1309 (no cam/crank synchronization, AICE chip malfunction)
P1336 (no cam/crank synchronization)
P0606 (AICE chip malfunction)
P0315 (unable to learn profile)
P0316 (misfire during first 1,000 revs after start-up)
Monitor execution
Continuous, misfire rate calculated every 200 or 1000 revs
Monitor Sequence
None
Sensors OK
CKP, CMP, no EGR stuck open DTCs (P0402)
Monitoring Duration
Entire driving cycle (see disablement conditions below)
Typical misfire monitor entry conditions:
Entry condition
Minimum
Maximum
Time since engine start-up
0 seconds
0 seconds
Engine Coolant Temperature
20 F
250 F
RPM Range (Full-Range Misfire certified, with 2 rev
delay)
2 revs after exceeding
150 rpm below “drive”
idle rpm
redline on tach or fuel
cutoff
Profile correction factors learned in KAM
Yes
Fuel tank level
15%
o
o
Typical misfire temporary disablement conditions:
Temporary disablement conditions:
Closed throttle decel (negative torque, engine being driven)
Fuel shut-off due to vehicle-speed limiting or engine-rpm limiting mode
High rate of change of torque (heavy throttle tip-in or tip out)
Typical misfire monitor malfunction thresholds:
Type A (catalyst damaging misfire rate): misfire rate is an rpm/load table ranging from 40% at idle to 4% at
high rpm and loads
Type B (emission threshold rate): 1% to 2%
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 16 OF 160
J1979 Misfire Mode $06 Data
Monitor ID
Test ID
Description for CAN
A1
$80
Total engine misfire and catalyst damage misfire rate (updated every
200 revolutions)
percent
A1
$81
Total engine misfire and emission threshold misfire rate (updated
every 1,000 revolutions)
percent
A1
$82
Highest catalyst-damage misfire and catalyst damage threshold misfire
rate (updated when DTC set or clears)
percent
A1
$83
Highest emission-threshold misfire and emission threshold misfire rate
(updated when DTC set or clears)
percent
A1
$84
Inferred catalyst mid-bed temperature
o
A2 – AD
$0B
EWMA misfire counts for last 10 driving cycles
events
A2 – AD
$0C
Misfire counts for last/current driving cycle
events
A2 – AD
$80
Cylinder X misfire rate and catalyst damage misfire rate (updated
every 200 revolutions)
percent
A2 – AD
$81
Cylinder X misfire rate and emission threshold misfire rate (updated
every 1,000 revolutions)
percent
C
Profile Correction Operation
DTCs
P0315 - unable to learn profile in three 60 to 40 mph decels
P1309 – AICE chip communication failure
Monitor Execution
once per KAM reset.
Monitor Sequence:
Profile must be learned before misfire monitor is active.
Sensors OK:
CKP, CMP, no AICE communication errors, CKP/CMP in synch
Monitoring Duration;
10 cumulative seconds in conditions
(a maximum of three 60-40 mph defueled decels)
Typical profile learning entry conditions:
Entry condition
Minimum
Maximum
Brakes applied (Brake On/Off Switch)
No
No
Engine RPM
1300 rpm
3700 rpm
Engine in decel-fuel cutout mode for 4 engine cycles
Change in RPM
Vehicle Speed
600 rpm/background
loop
30 mph
Learning tolerance
FORD MOTOR COMPANY
75 mph
1%
REVISION DATE: NOVEMBER 12, 2007
PAGE 17 OF 160
AIR System Monitor – Flow Check
Secondary air systems typically utilize an electric air pump as well as one or two electrically controlled check
valves to deliver air into the exhaust manifold. For the 2006 MY, LEV-II vehicles are required to check for a
decrease in secondary air flow that would cause emissions to exceed 1.5 * std. In addition, the secondary air flow
system must be monitored during normal operation. Previously, a functional check was done on a hot, stabilized
idle.
The vehicles which use secondary air in the 2007 MY are the 2.0L PZEV Focus and the 2.3L PZEV Fusion. Both
use a system with ported air. This means that airflow is delivered to each individual exhaust port. The secondary
air pump is energized soon after start-up while the fuel system is in open loop. After the O2 sensors warm up, the
secondary air pump may continue to be energized while the fuel system goes into closed loop fuel. The
secondary air system may continue to run in closed loop fuel until the air pump is de-energized. The typical time
period during which the AIR pump is energized is approximately 5 to 12 seconds.
In order to meet the 2006 MY monitoring requirements, the air pump inlet hose was routed so as to draw in
airflow that has been metered by the Mass Air Flow (MAF) sensor. When the air pump is energized, the MAF
sensor will show a corresponding increase in air flow. The AIR pump flow check monitors the MAF sensor signal
and two air flow models during normal secondary air system operation to determine if secondary air is being
delivered into the exhaust system. The air pump flow test compares the actual change in MAF during the pump
on and off transitions to the expected change in air flow from the secondary air flow model. (A throttle body flow
model is used to "zero out" errors in the air meter and to compensate for off idle driving conditions.) The actual
air flow is divided by the expected air flow to calculate an "On flow ratio" and an "Off flow ratio". A flow ratio that is
much less than 1.0 means that the air pump has no/low flow, or the inlet hose to the pump is disconnected. If
secondary air system operation extends into closed loop fuel, fuel trim feedback is used to discriminate between
low pump flow and inlet hose disconnection. A low flow ratio with a lean fuel system indicates a disconnected inlet
hose. A flow ratio much higher than 1.0 (and a rich fuel system indication) means that the outlet hose from the
pump is disconnected.
The flow test can set the following three codes: P0491 – Low Pump Flow, P0410 - Pump Inlet Hose Off, or
P2448 - Pump Outlet Hose Off. If the flow ratio is low, the monitor will either set a P0491 or a P0410 if enough
closed loop fuel operation has occurred. If there was insufficient closed loop fuel operation, the monitor will set
both a P0491 and a P0410. If the flow ratio is too high, a P2448 code will be set for outlet hose off.
The electric air pump draws high current and must be energized through a separate relay. Both the primary and
secondary circuits are checked for opens and shorts. First, the output driver within the PCM (primary circuit) is
checked for circuit continuity (P0412). This circuit energizes the relay and the vacuum-operated check and control
valve(s). Next, a feedback circuit from the secondary side of the relay to the PCM is used to check secondary
circuit continuity (P2257, P2258).
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 18 OF 160
PZEV Port Oxidation Secondary Air System
AIR Monitor Flow Check Operation:
DTCs
P0491 Pump Low Flow
P0410 Pump Inlet Hose Off
P2448 Pump Outlet Hose Off
P0412 primary side circuit check
P2257, P2258 secondary side circuit checks
Monitor execution
Flow check - once per driving cycle, circuit checks - continuous
Monitor Sequence
Runs approx. 5 seconds after start during normal SAIR operation
Sensors OK
ECT, IAT, MAF, TP, ETC, and HO2S
Monitoring Duration
From 5 to 12 seconds
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 19 OF 160
Typical AIR flow check entry conditions: (The monitor will run when the air pump runs, the entry
conditions below are secondary air system entry conditions.)
Entry condition
Minimum
Maximum
Time since engine start-up
5 seconds
13 seconds
Engine Coolant Temperature
40 F
Predicted Pump Flow
0.2 lbm/min
Manifold Vacuum
7 in Hg
o
Catalyst Temperature
o
150 F
1200 deg F
Battery Voltage
11 volts
Note: There is a Throttle position stability check that can delay the calculation of the flow ratio. If the throttle is
continuously moving, it is possible, to delay calculation of the flow ratio.
Typical AIR functional check malfunction thresholds:
On and Off Flow ratio < 0.4 (P0491 - Low Flow or, P0410 - Inlet Hose Off)
On Flow ratio > 1.6 (P2448 – Outlet Hose Off)
J1979 Secondary Air Mode $06 Data
Mon ID
Comp ID
Description for CAN
Units
$72
$80
HO2S21 voltage for upstream flow test and rich limit
volts
$72
$81
HO2S lean timer test
$72
$82
On Flow Ratio and limits
unitless
$72
$83
Off Flow Ratio and limits
unitless
$72
$84
Flow Ratio AF indicator and limits PETA_AF_SHIFT
unitless
$72
$85
Timer to indicate if a valid AF shift can be calculated PETA_CL_TMR
seconds
I/M Readiness Indication
o
If the ambient air temperature (IAT) is less than 40 F, or the altitude is greater than 8,000 feet (BARO < 22.5 "Hg),
the Secondary Air system will not be enabled, therefore, the Secondary Air monitor cannot complete. If all the
conditions to run the Secondary Air Monitor are correct except for IAT and BARO, a timer starts to accumulate the
time in these conditions. If the timer reaches the maximum value for Secondary Air enablement (approximately 13
seconds), the Secondary Air Monitor I/M Readiness bit will be set to a “ready” condition after two such driving
cycles.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 20 OF 160
EVAP System Monitor - 0.040” dia. vacuum leak check
Vehicles that meet enhanced evaporative requirements utilize a vacuum-based evaporative system integrity
check. The evap system integrity check uses a Fuel Tank Pressure Transducer (FTPT), a Canister Vent Solenoid
(CVS) and Fuel Level Input (FLI) along with the Vapor Management Valve (VMV) or Electric Vapor Management
Valve (EVMV) to find 0.040” diameter or larger evap system leaks. Federal vehicles can utilize a 0.040" leak
check rather than the 0.020" leak check required for California vehicles.
The evap system integrity test is done under conditions that minimize vapor generation and fuel tank pressure
changes due to fuel slosh since these could result in false MIL illumination. The check is run after a 6 hour cold
engine soak (engine-off timer), during steady highway speeds at ambient air temperatures (inferred by IAT)
o
between 40 and 100 F.
A check for refueling events is done at engine start. A refuel flag is set in KAM if the fuel level at start-up is at least
20% of total tank capacity greater than fuel fill at engine-off. It stays set until the evap monitor completes Phase 0
of the test as described below. Note that on some vehicles, a refueling check may also be done continuously,
with the engine running to detect refueling events that occur when the driver does not turn off the vehicle while
refueling (in-flight refueling).
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 21 OF 160
The evap system integrity test is done in four phases.
(Phase 0 - initial vacuum pulldown):
First, the Canister Vent Solenoid is closed to seal the entire evap system, then the VMV or EVMV is opened to
pull a 8" H2O vacuum. If the initial vacuum could not be achieved, a large system leak is indicated (P0455). This
could be caused by a fuel cap that was not installed properly, a large hole, an overfilled fuel tank,
disconnected/kinked vapor lines, a Canister Vent Solenoid that is stuck open, a VMV that is stuck closed, or a
disconnected/blocked vapor line between the VMV and the FTPT
If the initial vacuum could not be achieved after a refueling event, a gross leak, fuel cap off (P0457) is indicated
and the recorded minimum fuel tank pressure during pulldown is stored in KAM. A “Check Fuel Cap” light may
also be illuminated.
If the initial vacuum is excessive, a vacuum malfunction is indicated (P1450). This could be caused by kinked
vapor lines or a stuck open VMV. If a P0455, P0457, or P1450 code is generated, the evap test does not
continue with subsequent phases of the small leak check, phases 1-4.
Note: Not all vehicles will have the P0457 test or the Check Fuel Cap light implemented. These vehicles will
continue to generate only a P0455. After the customer properly secures the fuel cap, the P0457, Check Fuel Cap
and/or MIL will be cleared as soon as normal purging vacuum exceeds the P0457 vacuum level stored in KAM.
Phase 1 - Vacuum stabilization
If the target vacuum is achieved, the VMV is closed and vacuum is allowed to stabilize for a fixed time. If the
pressure in the tank immediately rises, the stabilization time us bypassed and Phase 2 of the test is entered.
Some software has incorporated a "leaking" VMV test, which will also set a P1450 (excessive vacuum) DTC. This
test is intended to identify a VMV that does not seal properly, but is not fully stuck open. If more than 1 " H2O of
additional vacuum is developed in Phase 1, the evap monitor will bypass Phase 2 and go directly to Phase 3 and
open the canister vent solenoid to release the vacuum. Then, it will proceed to Phase 4, close the canister vent
solenoid and measure the vacuum that develops. If the vacuum exceeds approximately 4 " H2O, a P1450 DTC
will be set.
Phase 2 - Vacuum hold and decay
Next, the vacuum is held for a calibrated time and the vacuum level is again recorded at the end of this time
period. The starting and ending vacuum levels are checked to determine if the change in vacuum exceeds the
vacuum bleed up criteria. Fuel Level Input and ambient air temperature are used to adjust the vacuum bleed-up
criteria for the appropriate fuel tank vapor volume. Steady state conditions must be maintained throughout this
bleed up portion of the test. The monitor will abort if there is an excessive change in load, fuel tank pressure or
fuel level input since these are all indicators of impending or actual fuel slosh. If the monitor aborts, it will attempt
to run again (up to 20 or more times). If the vacuum bleed-up criteria is not exceeded, the small leak test is
considered a pass. If the vacuum bleed-up criteria is exceeded on three successive monitoring events, a 0.040 “
dia. leak is likely and a final vapor generation check is done to verify the leak, phases 3-4. Excessive vapor
generation can cause a false MIL.
Phase 3 - Vacuum release
The vapor generation check is done by releasing any vacuum, then closing the VMV, waiting for a period of time,
and determining if tank pressure remains low or if it is rising due to excessive vapor generation
Phase 4 - Vapor generation
If the pressure rise due to vapor generation is below the threshold limit for absolute pressure and change in
pressure, a P0442 DTC is stored.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 22 OF 160
0.040" Evaporative System Monitor
START 0.040" Test
Refueling
Event?
Fuel Level
Set refuel flag = 1
No
Monitor entry
condition
met?
Vehicle and
engine conditions
Open purge valve and pull evap
system to target vacuum (Phase 0)
Fuel Tank
Pressure Sensor
Yes
Close purge valve (Phase 1)
and measure vacuum after
timer expires (Phase 2)
Vacuum bleedup
> 0.040"
threshold?
Yes
Evap system
vacuum at
target?
Yes
Large leak – Set P0457
if refuel flag = 1 and
vacuum < target
Fuel cap off - Set P0455
if refuel flag = 0 and
vacuum < target
Over vacuum - Set P145
if vacuum > target
No
Open purge valve and release
vacuum (Phase 3), then close
purge valve and measure change
in vacuum (Phase 4)
No
Vacuum bleedup
> 0.020"
threshold?
MIL
Possible 0.020"
leak, set idle test
flag = 1 (if 0.020"
idle test present)
Fault Management - MIL
after 2 Driving Cycles >
threshold
No
Evap System OK
END, Go to 0.020"
test, if present
FORD MOTOR COMPANY
Vacuum increase
< vapor generation
threshold?
No
REVISION DATE: NOVEMBER 12, 2007
Yes
Small leak – Set P0442
when vacuum bleedup >
threshold and no
excessive vapor
generation
PAGE 23 OF 160
0.040” EVAP Monitor Operation:
DTCs
P0455 (gross leak),
P1450 (excessive vacuum),
P0457 (gross leak, cap off),
P0442 (0.040” leak)
Monitor execution
once per driving cycle
Monitor Sequence
HO2S monitor completed and OK
Sensors/Components OK
MAF, IAT, VSS, ECT, CKP, TP, FTP, VMV, CVS
Monitoring Duration
360 seconds (see disablement conditions below)
Typical 0.040” EVAP monitor entry conditions, Phases 0 through 4:
Entry condition
Minimum
Engine off (soak) time
6 hours
Time since engine start-up
330 seconds
Intake Air Temp
40 F
BARO (<8,000 ft altitude)
22.0 “ Hg
Engine Load
20%
70%
Vehicle Speed
40 mph
80 mph
Purge Dutycycle
75%
100%
Purge Flow
0.05 lbm/min
0.10 lbm/min
Fuel Fill Level (may be 30% to 85% for some large, >25 gal tanks)
15%
85%
Fuel Tank Pressure Range
- 17 H2O
1.5 H2O
o
Maximum
1800 to 2700
seconds
o
90 - 100 F
Typical 0.040” EVAP abort (fuel slosh) conditions for Phase 2:
Change in load: > 20%
Change in tank pressure: > 1 “ H2O
Change in fuel fill level: > 15%
Number of aborts: > 20
Typical 0.040 EVAP monitor malfunction thresholds:
P1450 (Excessive vacuum): < -8.0 in H2O over a 30 second evaluation time or > -4. in H2O vapor generation
P0455 (Gross leak): > -8.0 in H2O over a 30 second evaluation time.
P0457 (Gross leak, cap off): > -8.0 in H2O over a 30 second evaluation time after a refueling event.
P0442 (0.040” leak): > 2.5 in H2O bleed-up over a 15 second evaluation time at 75% fuel fill. (Note: bleed-up
and evaluation times vary as a function of fuel fill level and ambient air temperature)
P0442 vapor generation limit: < 2.5 in H2O over a 120 second evaluation time
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 24 OF 160
J1979 Evaporative System Mode $06 Data
Test ID
Comp ID
Description
Units
$61
$00
Phase 0 Initial tank vacuum and minimum vacuum limit (data for
P1450 – excessive vacuum)
in H20
$62
$00
Phase 4 Vapor generation minimum change in pressure and
minimum vacuum limit (data for P1450, VMV stuck open)
in H20
$63
$00
Phase 0 Initial tank vacuum and gross leak maximum vacuum limit
(data for P0455/P0457 – gross leak/cap off)
in H20
$64
$00
Phase 2 0.040” cruise leak check vacuum bleed-up and maximum
vacuum limit (data for P0442 – 0.040" leak)
in H20
Note: Default values (0.0 in H20) will be displayed for all the above TIDs if the evap monitor has never
completed. Each TID is associated with a particular DTC. The TID for the appropriate DTC will be updated
based on the current or last driving cycle, default values will be displayed for any phases that have not
completed.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 25 OF 160
EVAP System Monitor - 0.020” dia. vacuum leak check
Some vehicles that meet enhanced evaporative requirements utilize a vacuum-based evaporative system
integrity check that checks for 0.020” dia leaks. The evap system integrity check uses a Fuel Tank Pressure
Transducer (FTPT), a Canister Vent Solenoid (CVS) and Fuel Level Input (FLI) along with the Vapor
Management Valve (VMV) or Electric Vapor Management Valve (EVMV) to find 0.020” diameter, 0.040”
diameter, or larger evap system leaks.
The evap system integrity test is done under two different sets of conditions - first a cruise test is performed to
detect 0.040” dia leaks and screen for 0.020” leaks. If a 0.020” dia leak is suspected during the cruise test, an idle
test is performed to verify the leak under more restrictive, but reliable, cold-start-idle conditions.
The cruise test is done under conditions that minimize vapor generation and fuel tank pressure changes due to
fuel slosh since these could result in false MIL illumination. The check is run after a 6 hour cold engine soak
(engine-off timer), during steady highway speeds at ambient air temperatures (inferred by IAT) between 40 and
o
100 F.
A check for refueling events is done at engine start. A refuel flag is set in KAM if the fuel level at start-up is at least
20% of total tank capacity greater than fuel fill at engine-off. It stays set until the evap monitor completes Phase 0
of the test as described below. The refueling flag is used to prohibit the 0.020” idle test until the gross leak check
is done during cruise conditions. This is done to prevent potential idle concerns resulting from the high fuel vapor
concentrations present with a fuel cap off/gross leak condition. Note that on some vehicles, a refueling check may
also be done continuously, with the engine running to detect refueling events that occur when the driver does not
turn off the vehicle while refueling (in-flight refueling).
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 26 OF 160
The cruise test is done in four phases.
Phase 0 - initial vacuum pulldown
First, the Canister Vent Solenoid is closed to seal the entire evap system, then the VMV or EVMV is opened to
pull a 8” H2O vacuum.
If the initial vacuum could not be achieved, a large system leak is indicated (P0455). This could be caused by a
fuel cap that was not installed properly, a large hole, an overfilled fuel tank, disconnected/kinked vapor lines, a
Canister Vent Solenoid that is stuck open, a VMV that is stuck closed, or a disconnected/blocked vapor line
between the VMV and the FTPT.
If the initial vacuum could not be achieved after a refueling event, a gross leak, fuel cap off (P0457) is indicated
and the recorded minimum fuel tank pressure during pulldown is stored in KAM. A “Check Fuel Cap” light may
also be illuminated.
If the initial vacuum is excessive, a vacuum malfunction is indicated (P1450). This could be caused by blocked
vapor lines between the FTPT and the Canister Vent Solenoid, or a stuck open VMV. If a P0455, P0457, P1443,
or P1450 code is generated, the evap test does not continue with subsequent phases of the small leak check,
phases 1-4. These codes also prevent the idle portion of the 0.020” dia leak check from executing.
Note: Not all vehicles will have the P0457 test or the Check Fuel Cap light implemented. These vehicles will
continue to generate only a P0455. After the customer properly secures the fuel cap, the P0457, Check Fuel Cap
and/or MIL will be cleared as soon as normal purging vacuum exceeds the P0457 vacuum level stored in KAM.
Phase 1 - Vacuum stabilization
If the target vacuum is achieved, the VMV is closed and vacuum is allowed to stabilize for a fixed time. If the
pressure in the tank immediately rises, the stabilization time is bypassed and Phase2 of the test is entered.
Some software has incorporated a "leaking" VMV test, which will also set a P1450 (excessive vacuum) DTC. This
test is intended to identify a VMV that does not seal properly, but is not fully stuck open. If more than 1 " H2O of
additional vacuum is developed in Phase 1, the evap monitor will bypass Phase 2 and go directly to Phase 3 and
open the canister vent solenoid to release the vacuum. Then, it will proceed to Phase 4, close the canister vent
solenoid and measure the vacuum that develops. If the vacuum exceeds approximately 4 " H2O, a P1450 DTC
will be set.
Phase 2 - Vacuum hold and decay
Next, the vacuum is held for a calibrated time. Two test times are calculated based on the Fuel Level Input and
ambient air temperature. The first (shorter) time is used to detect 0.040” dia leaks, the second (longer) time is
used to detect 0.020” dia leaks. The initial vacuum is recorded upon entering Phase 2. At the end of the 0.040”
dia test time, the vacuum level is recorded. The starting and ending vacuum levels are checked to determine if
the change in vacuum exceeds the 0.040” dia vacuum bleed up criteria. If the 0.040” dia vacuum bleed-up criteria
is exceeded on three successive monitoring attempts, a 0.040” dia leak is likely and a final vapor generation
check is done to verify the leak (phases 3 and 4).
If the 0.040” dia bleed-up criteria is not exceeded, the test is allowed to continue until the 0.020” dia leak test time
expires. The starting and ending vacuum levels are checked to determine if the change in vacuum exceed the
0.020” dia vacuum bleed-up criteria. If the 0.020” dia vacuum bleed-up is exceed on a single monitoring attempt,
a 0.020” dia leak is likely and a final vapor generation check is done to verify the leak (phases 3 and 4).
If the vacuum bleed-up criteria is not exceeded, the leak test (either 0.040” or 0.020” dia is considered a pass. For
both the 0.040” and 0.020” dia leak check, Fuel Level Input and Intake Air Temperature is used to adjust the
vacuum bleed-up criteria for the appropriate fuel tank vapor volume and temperature. Steady state conditions
must be maintained throughout this bleed up portion of the test. The monitor will abort if there is an excessive
change in load, fuel tank pressure or fuel level input since these are all indicators of impending or actual fuel
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 27 OF 160
slosh. If the monitor aborts, it will attempt to run again (up to 20 or more times) until the maximum time-after-start
is reached.
Phase 3 - Vacuum release
The vapor generation check is initiated by opening the Canister Vent Solenoid for a fixed period of time and
releasing any vacuum. The VMV remains closed.
Phase 4 - Vapor generation
In this phase, the sealed system is monitored to determine if tank pressure remains low or if it is rising due to
excessive vapor generation The initial tank pressure is recorded. The pressure is monitored for a change from
the initial pressure, and for absolute pressure. If the pressure rise due to vapor generation is below the threshold
limit for absolute pressure and for the change in pressure, and a 0.040” dia leak was indicated in phase 2, a
P0442 DTC is stored. If the pressure rise due to vapor generation is below the threshold limit for absolute
pressure and for the change in pressure, and a 0.020” dia leak was indicated in phase 2, a 0.020” idle check flag
is set to run the 0.020” leak check during idle conditions.
Idle Check
The long test times required to detect a 0.020” dia leak in combination with typical road grades can lead to false
0.020” leak indications while the vehicle is in motion. The Idle Check repeats Phases 0, 1, and 2 with the vehicle
stationary to screen out leak indications caused by changes in altitude. The 0.020” idle check is done under coldstart conditions to ensure that the fuel is cool and cannot pick up much heat from the engine, fuel rail, or fuel
pump. This minimizes vapor generation. The 0.020” idle check is, therefore, conducted only during the first 10
minutes after engine start.
The 0.020” dia leak test entry conditions, test times and thresholds are used. Unique criteria for excessive
changes in load, fuel tank pressure and fuel level are used to indicate fuel slosh. The test is aborted if vehicle
speed exceeds a calibrated threshold, approx. 10 mph. The initial vacuum pull-down (phase 0) can start with the
vehicle in motion in order to minimize the required time at idle to complete the test. If the vacuum bleed-up is
greater than the 0.020” dia max. criteria during a single monitoring event, a P0456 DTC is stored. If the vacuum
bleed-up is less than the 0.020” dia min. criteria, the pending P0456 DTC may be cleared. If the vacuum bleed-up
is in between, no leak assessment is made. A flowchart of the entire 0.020” test sequence is provided below, on a
subsequent page.
Ford’s 0.020” evaporative system monitor is designed to run during extended, cold-start idle conditions where the
fuel is cool and not likely to generate excessive vapors. These conditions will typically occur at traffic lights or
immediately after start-up, (e.g. idle in the driveway).
As indicated previously, the 0.020” idle test uses two sets of malfunction thresholds to screen out test results in
the area where “leak” and “no-leak” distributions overlap. Loss of vacuum greater than the 0.020” malfunction
criteria is designated as a failure. No/low vacuum loss below the pass criteria is designated a pass. Vacuum loss
that is greater than the pass criteria but less that the failure criteria is indeterminate and does not count as a pass
or a fail.
Test results in this overlap area can stem from high volatility fuel at high ambient temperatures. These situations
are not expected to be encountered routinely by customers. Therefore, this strategy will only temporarily hamper
monitor performance, while effectively preventing false MIL illumination.
A more detailed description of the functional characteristics of the Evaporative Monitor is provided in the
representative calibration submissions to the agency. Additional calibration information is contained on file by
Ford Motor Company and may be obtained via agency request.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 28 OF 160
0.020" Evaporative System Monitor
START 0.020" Test
Vehicle and
engine conditions,
idle flag
No
Monitor entry
condition met
and idle flag =1?
Yes
Yes
Refueling
Event?
Fuel Level
Set refuel flag = 1
Go to 0.040" test
No
Fuel Tank
Pressure Sensor
Open purge valve and pull evap system to target
vacuum (Phase 0) even if vehicle is moving
Evap system
vacuum at target
and vehicle at
idle?
Vehicle speed
Idle condition
No
MIL
Yes
Fault Management - MIL
after 2 Driving Cycles >
threshold
Close purge valve (Phase 1) and measure
vacuum after timer expires (Phase 2)
Yes
Very small leak – Set
P0456 when vacuum
bleedup > threshold
Vacuum bleedup
> 0.020"
threshold?
END
No
Yes
FORD MOTOR COMPANY
END, Leak not confirmed
(no call), Go back to 0.020"
Test on next driving cycle
Vacuum bleedup
< 0.020"
threshold?
Evap System OK
No
REVISION DATE: NOVEMBER 12, 2007
PAGE 29 OF 160
0.020” EVAP Monitor Operation:
DTCs
P0455 (gross leak),
P1450, (excessive vacuum),
P0457 (gross leak, cap off),
P0442 (0.040” leak),
P0456 (0.020” leak)
Monitor execution
once per driving cycle for 0.040” dia leak
once per driving cycle, no refueling event for 0.020” dia leak
Monitor Sequence
HO2S monitor for front sensors completed and OK
Sensors/Components OK
MAF, IAT, VSS, ECT, CKP, TP, FTP, VMV, CVS
Monitoring Duration
360 seconds for 0.040” (see disablement conditions below)
60 seconds for 0.020” (see disablement conditions below)
Typical 0.020” EVAP monitor entry conditions, Phases 0 through 4:
Entry condition
Minimum
Maximum
Engine off (soak) time
6 hours
Time since engine start-up for 0.040”
330 seconds
1800 to 2700
seconds
Time since engine start-up for 0.020” idle test
30 seconds
600 seconds
Refueling event (for 0.020” idle test only)
none
Intake Air Temp for 0.040”
40 F
Intake Air Temp for 0.020”
Vehicle Speed for cruise test, 0.040 and 0.020”
o
90 - 100 F
40 F
o
90 F
40 mph
80 mph
Vehicle Speed for idle test, 0.020”
o
o
3 mph
Fuel Fill Level for 0.040” (may be 30% to 85% for some large, >25 gal
tanks)
15%
85%
Fuel Fill Level for 0.020” (may be 30% to 85% for some large, >25 gal
tanks)
15%
85%
BARO (<8,000 ft altitude)
22.0 “ Hg
Engine Load
20%
70%
Purge Dutycycle
75%
100%
Purge Flow
0.05 lbm/min
0.10 lbm/min
Fuel Tank Pressure Range
- 17 H2O
16.06 H2O
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 30 OF 160
Typical 0.020” EVAP abort (fuel slosh) conditions for Phase 2:
Change in load: > 20% for 0.040”
Change in load: > 10% for 0.020”
Change in tank pressure: > 1 “ H2O for 0.040”
Change in tank pressure: > 1 “ H2O for 0.020”
Change in fuel fill level: > 15% for 0.040”
Change in fuel fill level: > 8% for 0.020”
Number of aborts: > 20 (may be up to 255)
Typical 0.020 EVAP monitor malfunction thresholds:
P1450 (Excessive vacuum): < -8.0 in H2O over a 30 second evaluation time or > -4. in H2O vapor generation.
P0455 (Gross leak): > -8.0 in H2O over a 30 second evaluation time.
P0457 (Gross leak, cap off): > -8.0 in H2O over a 30 second evaluation time after a refueling event.
P0442 (0.040” leak): > 2.5 in H2O bleed-up over a 15 sec. evaluation time at 75% fuel fill.
(Note: bleed-up and evaluation times vary as a function of fuel fill level and ambient temperature).
P0456 (0.020” leak): > 2.5 in H2O bleed-up over a 30 sec. evaluation time at 75% fuel fill.
(Note: bleed-up and evaluation times vary as a function of fuel fill level and ambient temperature)
P0442 vapor generation limit: < 2.5 in H2O over a 100 second evaluation time.
J1979 Evaporative System Mode $06 Data
Monitor ID
Test ID
Description for CAN
Units
$3A
$80
Phase 0 Initial tank vacuum and minimum vacuum limit (data for
P1450 – excessive vacuum)
Pascals
$3A
$81
Phase 4 Vapor generation minimum change in pressure and
minimum vacuum limit (data for P1450, VMV stuck open)
Pascals
$3A
$82
Phase 0 Initial tank vacuum and gross leak maximum vacuum
limit (data for P0455/P0457 – gross leak/cap off)
Pascals
$3B
$80
Phase 2 0.040” cruise leak check vacuum bleed-up and
maximum vacuum limit (data for P0442 – 0.040" leak)
Pascals
$3C
$80
Phase 2 0.020” idle leak check vacuum bleed-up and maximum
vacuum limit (data for P0456 – 0.020" leak)
Pascals
Note: Default values (0.0 in H20) will be displayed for all the above TIDs if the evap monitor has never
completed. Each TID is associated with a particular DTC. The TID for the appropriate DTC will be updated
based on the current or last driving cycle, default values will be displayed for any phases that have not
completed.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 31 OF 160
EVAP System Monitor - 0.020” dia. engine off natural vacuum leak check
Some vehicles that meet enhanced evaporative requirements utilize an engine off natural vacuum (EONV)
evaporative system integrity check that checks for 0.020" dia. leaks while the engine is off and the ignition key is
off. The evap system integrity check uses a Fuel Tank Pressure Transducer (FTPT), a Canister Vent Solenoid
(CVS) and Fuel Level Input (FLI) along with the Vapor Management Valve (VMV) or Electric Vapor Management
Valve (EVMV) to find 0.020” diameter evap system leaks.
The Ideal Gas Law (PV=mRT) defines a proportional relationship between the Pressure and Temperature of a
gas that is contained in a fixed Volume. Therefore, if a sealed container experiences a drop in temperature it will
also experience a drop in pressure. In a vehicle, this happens when a sealed evaporative system cools after the
engine has been run, or if it experiences a drop in temperature due to external environmental effects. This natural
vacuum can be used to perform the leak check, hence the name Engine Off Natural Vacuum (EONV).
Condensation of fuel vapor during cooling can add to the vacuum produced by the Ideal Gas Law.
In contrast the to the vacuum produced by drops in temperature, an additional factor can be heat transfer to the
evaporative system from the exhaust system immediately after key-off. Heat transfer from the exhaust at key-off
aided by fuel vaporization may produce a positive pressure shortly after key-off, which can also be used for leak
detection.
The EONV system is used to perform only the 0.020" leak check while 0.040" dia. leaks and larger (including fuel
cap off) will continue to be detected by the conventional vacuum leak monitor performed during engine running
conditions.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 32 OF 160
Ford's EONV implementation for California and Green State applications uses a Motorola Star-12 microprocessor
in the PCM to process the required inputs and outputs while the rest of the PCM is not powered and the ignition
key is off. The Star-12 microprocessor draws substantially less battery current than the PCM; therefore, powering
only the Star-12 during engine-off conditions extends vehicle battery life and allows the EONV monitor to run more
often. The PCM is the only difference between California/Green State and Federal vehicles.
Note that the Neural Network Misfire Monitor also uses the same microprocessor. The pilot EONV implementation
is on the 2005 MY F-series Super duty truck with the 5.4L and 6.8L engines.
Inputs to EONV Microprocessor
•
Fuel Level Input (via CAN network from Instrument Cluster)
•
Fuel Tank Pressure
•
Battery Voltage
Outputs from EONV Microprocessor
•
Canister Vent Solenoid
•
0.020" leak data
MY2005 EONV System Hardware Design
PCM
Cluster
High-Speed
CAN BUS
Main
Micro
Main
Micro
VBATT
FTPT
Stay-alive
Micro
Intake Manifold
Fuel Level
Indication
VMV
Atmosphere
CVS
Canister
Fuel Tank
Red: Indicates evaporative system
being monitored for leaks.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 33 OF 160
Phase 0- Stabilization Phase
The purpose of the Stabilization Phase is to allow tank pressure to stabilize after vehicle shutdown (i.e. ignition in
the OFF position). During this phase, the Canister Vent Solenoid (CVS) is open, thus allowing the pressure in the
fuel tank to stabilize at atmospheric pressure. The duration of the Stabilization Phase is approximately 2 minutes.
A fuel volatility check is performed just prior to its completion.
The fuel volatility check measures tank pressure and will abort the test if more than 1.5 "H20 is observed in the
tank. Because the CVS is open during this test, it would take a good deal of fuel vaporization to produce this
level of pressure on a vented system. As an example, this condition may occur when a customer performs a long
drive with highly volatile, winter fuel on a 100-deg F day. Note: This feature is not used in some applications.
If the fuel volatility check passes, a Fuel Tank Pressure Transducer (FTPT) offset correction factor is learned as
the last step of this phase. This correction factor is applied to pressure measurements in the next phase to
improve FTPT accuracy.
Phase 1 – First Test Phase
At the start of this phase, the CVS is commanded shut, thus sealing up the entire evaporative system. If the
system is sufficiently sealed, a positive pressure or vacuum will occur during depending on whether the tank
temperature change is positive or negative. Other effects such as fuel vaporization and condensation within the
fuel tank will also determine the polarity of the pressure. As the leak size increases, the ability to develop a
positive pressure or vacuum diminishes. With a 0.020" leak, there may be no measurable positive pressure or
vacuum at all depending on test conditions.
During this phase, tank pressure is continuously measured and compared to calibrated detection thresholds (both
positive pressure and vacuum) that are based on fuel level and ambient temperature. If either the pressure or
vacuum threshold is exceeded, the test will be considered a pass, and the monitor will proceed to "Phase 4 –
Test Complete". If a positive plateau occurs in tank pressure without exceeding the pass threshold, the monitor
will progress to "Phase 2 – Transition Phase". If a vacuum occurs, the monitor will remain in Phase 1 until the
test times out after 45 minutes have elapsed since key-off, or the pass threshold for vacuum is exceeded. In
either case, the monitor will transition to "Phase 4 – Test Complete."
Phase 2- Transition Phase
This phase will occur if a positive pressure plateau occurred in Phase 1 without the positive pass threshold being
exceeded. At the start of the Transition Phase, the CVS is opened and the evaporative system is allowed to
stabilize. The Transition Phase lasts approximately 2 minutes, and a new FTPT offset correction is learned just
prior to its completion. The monitor will then progress to "Phase 3 – Second Test Phase".
Note: This phase is termed the Transition Phase because there is a chance that a vacuum will be seen in the
next phase if a positive pressure plateau occurred in Phase 1. The reason for this is that a positive plateau may
be coincident with vapor temperature starting to decrease, which is favorable for developing a vacuum in the fuel
tank. This is not always the case, and it is possible to see a positive pressure in Phase 3 as well.
Phase 3- Second Test Phase
Upon completion of the Transition Phase, the CVS is commanded shut and the FTPT is monitored for any
positive pressure or vacuum that develops. As with "Phase 1 – First Test Phase", if either the positive pressure
or vacuum pass threshold is exceeded, the test is considered a pass and proceeds to "Phase 4 – Test
Complete". Also, if the test times out after 45 minutes have elapsed since key-off, the test will be considered a fail
(i.e. leak detected) and will also proceed to "Phase 4 – Test Complete".
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 34 OF 160
Phase 4 – Test Complete
In this phase, the EONV test is considered complete for this key-off cycle. The resultant peak pressure and peak
vacuum are stored along with total test time and other information. This information is sent to the main
microprocessor via CAN at the next engine start. During this phase, the CVS is commanded open and the
electrical components performing the EONV test are shutdown to prevent any further power consumption.
Test Aborts
During the EONV test, several parameters are monitored to abort the EONV test under certain conditions. The
primary abort conditions are instantaneous changes in tank pressure and fuel level. They are used to detect
refuel events and rapidly open the CVS upon detection of them. A list of abort conditions is given below.
Fault Filtering
Test results are transferred to the main microprocessor upon detection where they are processed to
determine if MIL illumination should occur. Because of the inherent variability in vapor temperature
changes and fuel volatility, results from multiple EONV runs are normalized and averaged to
determine if a malfunction should be set. Often, an average of four key-off EONV runs are used to
determine a malfunction. If two malfunctions are set in a row, the MIL will be illuminated. Using this
approach, a total of eight, key-off EONV runs will be required to illuminate the MIL. The in-use
performance numerator will be incremented by one after each malfunction is detected.
Alternatively, the fault filtering can be calibrated so that an average of five key-off EONV runs are used
to immediately illuminate the MIL. Using this approach, a total of five, key-off EONV runs will be
required to illuminate the MIL. The in-use performance numerator will be incremented by two after the
MIL is illuminated. Most new 2006 MY and later vehicles will be calibrated in this manner in order to
improve EONV monitor completion frequency in the field.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 35 OF 160
Phases of EONV Test
P0 = Phase 0, Stabilization Phase – With CVS open, Tank Pressure is allowed to stabilize. A fuel volatility test is
performed and FTPT offset correction is learned if volatility test passes.
P1 = Phase 1, First Test Phase – CVS is closed and pressure peaks below positive pass threshold sending test to
Phase 2. If the positive pass threshold were exceeded, the test would have completed and a pass would have
been recorded.
P2 = Phase 2, Transition Phase – CVS is opened and a second stabilization phase occurs. A second FTPT offset
is learned during this time.
P3 = Phase 3, Second Test Phase – CVS is closed again and a vacuum develops that eventually exceeds the
negative pass threshold. When this occurs the test proceeds to Phase 4 test complete.
P4 = Phase 4, Test Compete – CVS opens (not pictured in above data file), results are recorded, and stay-alive
electronics shutdown.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 36 OF 160
0.020” EONV EVAP Monitor Operation:
DTCs
P0456 (0.020” leak)
P260F (Evaporative System Monitoring Processor Performance)
Monitor execution
Once per key-off when entry conditions are met during drive. Monitor will run
up to 2 times per day, or 90 cumulative minutes per day (whichever comes
first)
Monitor Sequence
none
Sensors/Components OK
EONV Processor, Canister Vent Solenoid, Fuel Tank Pressure Sensor, Fuel
Level Input, Vapor Management Valve, CAN communication link
Monitoring Duration
45minutes in key-off state if fault present. Tests will likely complete quicker if
no fault is present.
Typical 0.020” EONV EVAP monitor entry conditions:
Entry conditions seen just prior to engine off
Minimum
Engine off (soak) time
3.5 - 6 hours
Time since engine start-up
20 minutes
o
Ambient Temperature at start-up
40 F
Battery Voltage
11 volts
Maximum
90 minutes
o
95 F
Number of completed tests in 24hr cycle
2
Cumulative test time in 24hr cycle
90 minutes
Fuel level
15%
85%
No severe slosh conditions seen just prior to key-off
Typical 0.020” EONV EVAP key-off abort conditions:
Tank pressure at key-off > 1.5" H20 during stabilization phase (indicates excessive vapor)
Tank pressure not stabilized for tank pressure offset determination
Rapid change in tank pressure > 0.5"H20 (used for refuel/slosh detection)
Rapid change in fuel level > 5% (used for refuel/slosh detection)
Battery voltage < 11 Volts
Rapid change in battery voltage > 1 Volt
Loss of CAN network
Canister Vent Solenoid fault detected
Driver turns key-on
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 37 OF 160
Typical 0.020 EONV EVAP monitor malfunction thresholds:
P0456 (0.020” leak): < 0.75 in H2O pressure build and
< 0.50 in H2O vacuum build over a 45 minute maximum evaluation time
Note: EONV monitor can be calibrated to illuminate the MIL after two malfunctions (an average of four key-off
EONV tests, eight runs in all) or after a single malfunction (an average of five key-off EONV tests, five runs in
all). Most new 2006 MY and later vehicles will use the five-run approach.
J1979 EONV EVAP monitor Mode $06 Data
Monitor ID
Comp ID
Description for CAN
Units
$3C
$81
EONV Positive Pressure Test Result and Limits
in H20
$3C
$82
EONV Negative Pressure (Vacuum) Test Result and Limits
in H20
$3C
$83
Normalized Average of Four EONV Tests Results and Limits
(where 0 = pass, 1 = fail)
unitless
Note: Default values (0.0 in H20) will be displayed for all the above TIDs if the evap monitor has never
completed. The appropriate TID will be updated based on the current or last driving cycle, default values will
be displayed for any phases that have not completed.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 38 OF 160
EVAP System Monitor Component Checks
Additional malfunctions that are be identified as part of the evaporative system integrity check are as follows:
The Vapor Management Valve or Electric Vapor Management Valve (EVMV) (purge solenoid) output circuit is
checked for opens and shorts (P0443)
Note that a stuck closed VMV generates a P0455, a leaking or stuck open VMV generates a P1450.
Vapor Management Valve Check Operation:
DTCs
P0443 – Vapor Management Valve Circuit
Monitor execution
continuous
Monitor Sequence
None
Sensors OK
not applicable
Monitoring Duration
5 seconds to obtain smart driver status
Typical Vapor Management Valve check malfunction thresholds:
P0443 (Vapor Management Valve Circuit): open/shorted at 0 or 100% duty cycle
The Canister Vent Solenoid output circuit is checked for opens and shorts (P1451 or P0446), a stuck closed CVS
generates a P1450, a leaking or stuck open CVS generates a P0455.
Canister Vent Solenoid Check Operation:
DTCs
P1451 or P0446 – Canister Vent Solenoid Circuit
Monitor execution
continuous
Monitor Sequence
None
Sensors OK
not applicable
Monitoring Duration
5 seconds to obtain smart driver status
Typical Canister Vent Solenoid check malfunction thresholds:
P1451 or P0446 (Canister Vent Solenoid Circuit): open/shorted
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 39 OF 160
The Fuel Tank Pressure Sensor input circuit is checked for out of range values (P0452 short, P0453 open), noisy
readings (P0454 noisy) and an offset (P0451 offset).
Note that carryover 2004 MY software and 2003 MY and earlier software will set P0451 for the noisy sensor test.
Note that an open power input circuit or stuck check valve generates a P1450.
Fuel Tank Pressure Sensor Transfer Function
FTP volts = [ Vref * ( 0.14167 * Tank Pressure) + 2.6250 ] / 5.00
Volts
A/D Counts in PCM
Fuel Tank Pressure, Inches H2O
0.100
20
-17.82
0.500
102
-15.0
1.208
247
-10.0
2.625
464
0
3.475.
712
6.0
4.750
973
15.0
4.90
1004
16.06
Fuel Tank Pressure Sensor Check Operation:
DTCs
P0452 – Fuel Tank Pressure Sensor Circuit Low
P0453 – Fuel Tank Pressure Sensor Circuit High
P0454 – Fuel Tank Pressure Sensor Intermittent/Erratic (noisy)
Monitor execution
continuous
Monitor Sequence
None
Sensors OK
not applicable
Monitoring Duration
5 seconds for electrical malfunctions, 16.7 minutes for noisy sensor test
Typical Fuel Tank Pressure Sensor check malfunction thresholds:
P0452 (Fuel Tank Pressure Sensor Circuit Low): < -17.82 in H2O
P0453 (Fuel Tank Pressure Sensor Circuit High): > 16.06 in H2O
P0454 (Fuel Tank Pressure Sensor Circuit Noisy): > 14 in H2O change between samples, sampled every 10
seconds, more than 100 fault occurrences
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 40 OF 160
Fuel Tank Pressures Sensor Offset Check Operation
DTCs
P0451 – Fuel Tank Pressure Sensor Range/Performance (offset)
Monitor execution
once per driving cycle
Monitor Sequence
No P0443 or P1450 DTCs
Sensors OK
not applicable
Monitoring Duration
< 1 second
Typical Fuel Tank Pressure Sensor Offset Check Entry Conditions:
Entry condition
Minimum
Maximum
Ignition key on, engine off, engine rpm
0 rpm
Purge Duty Cycle
0%
Engine off (soak) time
2 hours
Battery Voltage
11.0 Volts
Typical Fuel Tank Pressure Sensor Offset Check Malfunction Thresholds:
Fuel tank pressure at key on, engine off is 0.0 in H2O +/- 2.0 in H2O
The Fuel Level Input is checked for out of range values (opens/ shorts). The FLI input can be hardwired to the
PCM or be obtained from the serial data link, typically from the instrument cluster. If the FLI signal is open or
shorted, a P0460 is set. Some software will be able to discriminate between an open and short and set the
appropriate DCT (P0462 circuit low and P0463 circuit high).
Finally, the Fuel Level Input is checked for noisy readings. If the FLI input changes from an in-range to out-of-range
value repeatedly, a P0461 DTC is set.
Fuel Level Input Check Operation:
DTCs
P0460 – Fuel Level Input Circuit
P0461 – Fuel Level Input Circuit Noisy
P0462 – Fuel Level Input Circuit Low
P0463 – Fuel Level Input Circuit High
Monitor execution
continuous
Monitor Sequence
None
Sensors OK
not applicable
Monitoring Duration
30 seconds for electrical malfunctions, Fuel Level Stuck test (P0460) can take up
to 120 miles to complete
Typical Fuel Level Input check malfunction thresholds:
P0460 or P0462 (Fuel Level Input Circuit Low): < 5 ohms
P0460 or P0463 (Fuel Level Input Circuit High): > 200 ohms
P0461 (Fuel Level Input Noisy): > 100 circuit low or circuit high exceedences, sampled every 0.100 seconds
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 41 OF 160
The FLI signal is also checked to determine if it is stuck. The PCM calculates the amount of fuel being consumed
by accumulating fuel pulse width. (Fuel consumed and fuel gauge reading range are both stored in KAM and reset
after a refueling event or DTC storage.) If the there is an insufficient corresponding change in fuel tank level, a
P0460 DTC is set.
Different malfunction criteria are applied based on the range in which the fuel level sensor is stuck.
In the range between 15% and 85%, a 30% difference between fuel consumed and fuel used is typical. The actual
value is based on the fuel economy of the vehicle and fuel tank capacity.
In the range below 15%, a 40% difference between fuel consumed and fuel used is typical. The actual value is
based on reserve fuel in the fuel tank and the fuel economy of the vehicle.
In the range above 85%, a 60% difference between fuel consumed and fuel used is typical. The actual value is
based on the overfill capacity of the fuel tank and the fuel economy of the vehicle. Note that some vehicles can be
overfilled by over 6 gallons.
Fuel Level Input Stuck Check Operation:
DTCs
P0460 – Fuel Level Input Circuit Stuck
Monitor execution
continuous
Monitor Sequence
None
Sensors OK
not applicable
Monitoring Duration
Between 15 and 85%, monitoring can take from100 to 120 miles to complete
Typical Fuel Level Input Stuck check malfunction thresholds:
P0460 (Fuel Level Input Stuck):
Fuel level stuck at greater than 85%: > 40% difference in calculated fuel tank capacity consumed versus
change in fuel level input reading
Fuel level stuck at less than 85%: > 40% difference in calculated fuel tank capacity consumed versus change
in fuel level input reading
Fuel level stuck between 15% and 85%: > 60% difference in calculated fuel tank capacity consumed versus
change in fuel level input reading
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 42 OF 160
Fuel System Monitor
The adaptive fuel strategy uses O2 sensors for fuel feedback. The fuel equation includes short and long term fuel
trim modifiers:
FUEL MASS = AIR MASS * SHRTFT * LONGFT
EQUIV_RATIO * 14.64
Where:
Fuel Mass = desired fuel mass
Air Mass = measured air mass, from MAF sensor
SHRTFT = Short Term Fuel Trim, calculated
LONGFT = Long Term Fuel Trim, learned table value, stored in Keep Alive Memory
EQUIV_RATIO = Desired equivalence ratio, 1.0 = stoich, > 1.0 is lean, < 1.0 is rich
14.64 = Stoichiometric ratio for gasoline
A conventional O2 sensor (not a wide-range sensor) can only indicate if the mixture is richer or leaner than
stoichiometric. During closed loop operation, short term fuel trim values are calculated by the PCM using oxygen
sensor inputs in order to maintain a stoichiometric air/fuel ratio. The PCM is constantly making adjustments to the
short term fuel trim, which causes the oxygen sensor voltage to switch from rich to lean around the stoichiometric
point. As long as the short term fuel trim is able to cause the oxygen sensor voltage to switch, a stoichiometric
air/fuel ratio is maintained.
When initially entering closed loop fuel, SHRTFT starts 1.0 and begins adding or subtracting fuel in order to
make the oxygen sensor switch from its current state. If the oxygen sensor signal sent to the PCM is greater than
0.45 volts, the PCM considers the mixture rich and SHRTFT shortens the injector pulse width. When the cylinder
fires using the new injector pulse width, the exhaust contains more oxygen. Now when the exhaust passes the
oxygen sensor, it causes the voltage to switch below 0.45 volts, the PCM considers the mixture lean, and
SHRTFT lengthens the injector pulse width. This cycle continues as long as the fuel system is in closed loop
operation.
O2 sensor voltage
SHRTFT, Short Term
Fuel Trim
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 43 OF 160
As fuel, air, or engine components age or otherwise change over the life of the vehicle, the adaptive fuel strategy
learns deviations from stoichiometry while running in closed loop fuel. Corrections are only learned during closed
loop operation, and are stored in the PCM as long term fuel trim values (LONGFT). They may be stored into an
8x10 rpm/load table or they may be stored as a function of air mass. LONGFT values are only learned when
SHRTFT values cause the oxygen sensor to switch. If the average SHRTFT value remains above or below
stoichiometry, the PCM “learns” a new LONGFT value, which allows the SHRTFT value to return to an average
value near 1.0. LONGFT values are stored in Keep Alive Memory as a function of air mass. The LONGFT value
displayed on the scan tool is the value being used for the current operating condition.
O2 sensor voltage
SHRTFT, Short Term
Fuel Trim, shifted rich
LONGFT, Long Term
Fuel Trim, learning the
rich correction
As components continue to change beyond normal limits or if a malfunction occurs, the long-term fuel trim values
will reach a calibratable rich or lean limit where the adaptive fuel strategy is no longer allowed to compensate for
additional fuel system changes. Long term fuel trim corrections at their limits, in conjunction with a calibratable
deviation in short term fuel trim, indicate a rich or lean fuel system malfunction.
Note that in the PCM, both long and short-term fuel trim are multipliers in the fuel pulse width equation. Scan tools
normally display fuel trim as percent adders. If there were no correction required, a scan tool would display 0%
even though the PCM was actually using a multiplier of 1.0 in the fuel pulse width equation.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 44 OF 160
Fuel System Monitor
START
Engine conditions
(O2 sensors warm, closed
loop fuel requests)
Monitor Entry
Conditions
Met?
No
Continuously monitor short term
fuel trim (SHRTFT) and long
term fuel trim (LONGFT)
corrections.
SRTFT +
LONGFT >
threshold?
Yes
No
Fuel system malfunction
Fault Management - MIL after 2
Driving Cycles w/malfunction
Fuel system OK
END, return to
START
MIL
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 45 OF 160
Fuel Monitor Operation:
DTCs
P0171 Bank 1 Lean, P0174 Bank 2 Lean
P0172 Bank 1 Rich, P0175 Bank 2 Rich
Monitor execution
continuous while in closed loop fuel
Monitor Sequence
none
Sensors OK
Fuel Rail Pressure (if available)
Monitoring Duration
2 seconds to register malfunction
Typical fuel monitor entry conditions:
Entry condition
Minimum
RPM Range
idle
Air Mass Range
0.75 lb/min
Purge Dutycycle
0%
Maximum
0%
Typical fuel monitor malfunction thresholds:
Long Term Fuel Trim correction cell currently being utilized in conjunction with Short Term Fuel Trim:
Lean malfunction: LONGFT > 25%, SHRTFT > 5%
Rich malfunction: LONGFT < 25%, SHRTFT < 10%
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 46 OF 160
Flex Fuel Operation
Ford Motor Company is cooperating with the Department of Energy in providing customers with vehicles capable
of using alcohol-blended fuels. These fuels are renewable and can lower some engine emission byproducts. The
original 1993 Taurus vehicle hardware and calibration was designed for use on any combination of gasoline or
methanol up to 85% methanol. Current flex fuel vehicles, however, are no longer designed for methanol, but are
designed to be compatible with any combination of gasoline and ethanol, up to 85% ethanol.
This flexible fuel capability allows the vehicle to be usable in all regions of the country, even as the alcohol
infrastructure is being built. Operation of a vehicle with the alcohol-blended fuels is intended to be transparent to
the customer. Drivability, NVH, and other attributes are not notably different when using the alcohol-blended fuels.
The higher octane of alcohol-blended fuels allows a small increase in power and performance (approximately 4%),
but this is offset by the lower fuel economy (approximately 33%) due to the lower energy content. Cold starts with
alcohol-blended fuels is somewhat more difficult than with gasoline due to the lower volatility of alcohol-blended
fuels; 10% vaporization occurs at approximately 100 °F for gasoline vs. 160 °F for 85% ethanol. Ethanol requires
approximately 37% more flow than gasoline due to a lower heating value (29.7 vs. 47.3 MJ/kg). Consequently,
Flex Fuel vehicles require higher flow injectors than their gasoline counterparts. This results in smaller fuel pulse
widths with gasoline and makes the task of purging the canister more difficult during idles and decels.
In order to maintain proper fuel control, the PCM strategy needs to know the stoichiometric Air/Fuel Ratio for use in
the fuel pulse width equation. On pre-2000 MY flex fuel vehicles, the percent alcohol in the fuel was determined by
reading the output of the Flex fuel Sensor. The percent alcohol was stored in a register called Percent Methanol
(PM). Although current alcohol-blended fuels only include ethanol, the percent methanol nomenclature has
persisted. On 2000 MY and later vehicles, the Flex Fuel Sensor has been deleted and PM is inferred. The strategy
to infer the correct A/F Ratio (AFR) relies on the oxygen sensor input to maintain stoichiometry after vehicle
refueling occurs.
The relationship between PM and AFR is shown in the table below.
Stoichic Air Fuel Ratio = 14.64 - 5.64 * PM
PM (percent alcohol)
Stoichiometric AFR
0.00 (100 % gasoline)
0.05
0.10 (standard gasoline)
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
0.55
0.60
0.65
0.70
0.75
0.80
0.85 (standard E85)
0.90
0.95
1.00 (100% ethanol)
FORD MOTOR COMPANY
14.64
14.36
14.08
13.79
13.51
13.23
12.95
12.67
12.38
12.10
11.82
11.54
11.26
10.97
10.69
10.41
10.13
9.85
9.56
9.28
9.00
REVISION DATE: NOVEMBER 12, 2007
PAGE 47 OF 160
The fuel level input is used to determine if a refueling event has occurred, either after the initial start or while the
engine is running. If refueling event is detected (typically calibrated as a 10% increase in fuel level), the PCM tracks
the "old" fuel being consumed by the engine. After a calibrated amount of "old" fuel has been consumed from the
fuel lines, fuel rail, etc., the "new" fuel is assumed to have reached the engine. Normal long term fuel trim learning
and purge control are temporarily disabled along with the evaporative system monitor and fuel system monitor to
allow the composition of the fuel to be determined. The filtered value of short-term fuel trim is used during closed
loop to adjust AFR in order to maintain stoichiometry. During learning, all changes in AFR are stored into the
AFRMOD register. As updates are made to the AFRMOD register, the fuel composition register (PM) is updated
and stored in Keep Alive Memory. Learning continues until the inference stabilizes with stabilized engine operating
conditions. The PM inference and engine operating conditions are considered to have stabilized when all of the
following conditions are satisfied:
•
•
•
•
•
ECT indicates the engine has warmed up (typically 170 °F) or an ECT related fault is present.
Enough "new" fuel has been consumed (typically 0.5 lb - vehicle dependant) to insure fuel is adequately
mixed.
The filtered value of short term fuel trim is in tight fuel control around stoichiometry, (typically +/- 2%) for at
least 5 O2 sensor switches or AFRMOD is at a clip.
The engine has been operated for a calibratable length of time, based on ECT temperature at start
(typically 200 sec. at 40 °F and 30 sec at 200 °F) or an ECT related fault is present.
The engine has been operating in closed loop fuel, with the brake off, within a calibratable (off-idle) air
mass region (typically 2.4 to 8 lb/min) for 5 seconds, to minimize the effect of errors such as vacuum
leaks.
Once the value of PM has stabilized (usually about 7 miles of driving), AFRMOD and PM are locked and deemed
to be "mature." After PM is deemed "mature," normal fuel trim learning and purge control are re-enabled along with
the fuel system monitor and evaporative system monitor. Any observed fueling errors from that point on are rolled
into normal long term fuel trim (via adaptive fuel learning).
All remaining OBD-II monitors remain enabled unless AFR is observed to be changing. If AFR is changing, all
monitors (except CCM and EGR) are disabled until the AFR stabilizes. This logic is same as was used for FFV
applications that used a sensor. The AFR rate of change required to disable OBD-II monitor operation is typically
0.1 A/F (rate is based on the difference between a filtered value and the current value). For a fuel change from
gasoline to E85 or vice versa, AFR typically stabilizes after 2 to 3 minutes on an FTP cycle.
If a large refueling event is detected (typically calibrated as a 40% to 50% increase in fuel level), the PCM strategy
tries to assign the "new" fuel as gasoline or ethanol (E85) on the assumption that the only fuels available are either
gasoline or E85. The strategy performs this fuel assignment to gasoline or ethanol (E85) only if the "old" and the
"new" stabilized inferred fuel composition values are within a specified amount of each other (typically 5-10%),
indicating that the fuel in the tank is the same as the fuel that was added and therefore must be either gasoline or
ethanol (E85). If the "old" and "new" stabilized inferred fuel composition values are not near each other, the fuel
added must be different from what was in the tank and the strategy retains the current inferred value of PM until the
next refuel. By assigning the fuel to gasoline or ethanol (E85) in this manner, normal fuel system errors can be
learned into normal long term fuel trip for proper fuel system error diagnosis.
After a battery disconnect or loss of Keep Alive Memory, the strategy will infer AFR immediately after going into
closed loop fuel operation. A vehicle that previously had fuel system errors learned into long term fuel trim will infer
incorrect values of AFR. After the value of AFR is determined, it is fixed until the next refueling event. If the next
refueling event is performed with the same fuel (either E85 or gasoline), the value of AFR will not change. The fuel
is then assigned to be E85 or gasoline as explained above. The long term fuel trim will again be a reliable
indication of normal fuel system errors.
Only one large tank fill is required to assign the fuel as being either gasoline or ethanol, if the inferred AFR did not
change significantly. If AFR did change significantly, several tank fills with the same fuel may be necessary to
assign the fuel as gasoline or ethanol.
As the vast majority of vehicles are expected to be operated with gasoline, the initial value of AFR is set to
gasoline. This is the starting point for the AFR after a battery disconnect and will allow for normal starting. Some
vehicles may have E85 in the fuel tank after having a battery disconnect, and may not have a good start or drive
away. The startability of alcohol-blended fuels at extreme cold temperatures (< 0 °F) is difficult under normal
conditions; these vehicles may be required to be towed to a garage for starting if a battery disconnect occurs.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 48 OF 160
HO2S Monitor
Front HO2S Signal
The time between HO2S switches is monitored after vehicle startup when closed loop fuel has been requested,
during closed loop fuel conditions and when open loop fuel has been requested due to an HO2S fault. Excessive
time between switches with short term fuel trim at its limits (up to +/- 40%), or no switches since startup indicate a
malfunction. Since “lack of switching” malfunctions can be caused by HO2S sensor malfunctions or by shifts in the
fuel system, DTCs are stored that provide additional information for the “lack of switching” malfunction. Different
DTCs indicate whether the sensor was always indicates lean/disconnected (P1131 or P2195, P1151 or P2197), or
always indicates rich (P1132 or P2196, P1152 or P2198).
Characteristic Shift Downward (CSD) is a deviation from the normal positive voltage output of the HO2S signal to
negative voltage output. During a full CSD, the HO2S signal shifts downward (negative) by 1 volt. CSD occurs
when the reference chamber of the HO2S becomes contaminated, causing negative HO2S voltage to be
generated. Even though CSD can occur in both front and rear HO2S signals, only the front HO2S are
compensated for CSD. The CSD compensation algorithm must not be in the process of driving fuel to bring the
HO2S out of CSD before running some of the HO2S monitors.
2005 MY and later vehicles will monitor the HO2S signal for high voltage, in excess of 1.1 volts and store a
(P0132, P0152) DTC. An over voltage condition is caused by a HO2S heater or battery power short to the HO2S
signal line.
HO2S “Lack of Switching” Operation:
DTCs
P1131 or P2195 - Lack of switching, sensor indicates lean, Bank 1
P1132 or P2196 - Lack of switching, sensor indicates rich, Bank 1
P0132 Over voltage, Bank 1
P1151 or P2197 - Lack of switching, sensor indicates lean, Bank 2
P1152 or P2198 - Lack of switching, sensor indicates rich, Bank 2
P0152 Over voltage, Bank 2
Monitor execution
continuous, from startup and while in closed loop fuel or open loop fuel due to
HO2S fault
Monitor Sequence
None
Sensors OK
ECT, IAT, MAF, MAP, VSS, CKP, TP, FRP, no misfire DTCs, no system failures
affecting fuel, FTP, HO2S heaters OK, no HO2S over voltage
Monitoring Duration
30 seconds to register a malfunction
Typical HO2S “Lack of Switching” entry conditions:
Entry condition
Minimum
Maximum
Closed Loop or Open Loop Requested due to HO2S fault
o
Inferred Ambient Temperature
-40 F
Time within entry conditions
10 seconds
Fuel Tank Pressure
10 in H2O
Fuel Level
15%
Inferred O2 sensor temperature (for overvoltage test only)
400 F
FORD MOTOR COMPANY
o
REVISION DATE: NOVEMBER 12, 2007
PAGE 49 OF 160
Typical HO2S “Lack of Switching” malfunction thresholds:
< 5 switches since startup for > 30 seconds in test conditions or > 30 seconds since last switch while closed
loop fuel;
> 1.1 volts for 30 seconds for over voltage test
The HO2S is also tested functionally. The response rate is evaluated by entering a special 1.5 Hz. square wave,
fuel control routine. This routine drives the air/fuel ratio around stoichiometry at a calibratable frequency and
magnitude, producing predictable oxygen sensor signal amplitude. A slow sensor will show reduced amplitude.
Oxygen sensor signal amplitude below a minimum threshold indicates a slow sensor malfunction. (P0133 Bank 1,,
P0153 Bank 2). If the calibrated frequency was not obtained while running the test because of excessive purge
vapors, etc., the test will be run again until the correct frequency is obtained.
HO2S Response Rate Operation:
DTCs
P0133 (slow response Bank 1)
P0153 (slow response Bank 2)
Monitor execution
once per driving cycle
Monitor Sequence
> 30 seconds time in lack of switch test
Sensors OK
ECT, IAT, MAF, MAP, VSS, CKP, TP, FRP, no misfire DTCs, no fuel
system DTCs, CMP, no HO2S over voltage or lack of switch DTCs
Monitoring Duration
6 seconds
Typical HO2S response rate entry conditions:
Entry condition
Minimum
Engine Coolant Temp
150 F
o
o
240 F
o
Intake Air Temp
140 F
Time since entering closed loop fuel
10 seconds
o
1600 F
Inferred Catalyst Midbed Temperature
Fuel Level
15%
Short Term Fuel Trim Range
90%
Short Term Fuel Trim Absolute Change while in monitor
Engine Load
20%
Vehicle Speed
Maximum change in vehicle speed while in monitor
REVISION DATE: NOVEMBER 12, 2007
60 mph
3 mph
1000 rpm
Maximum change in engine rpm while in monitor
50%
0.13
30 mph
Engine RPM
110%
10%
Maximum change in engine load while in monitor
FORD MOTOR COMPANY
Maximum
2000 rpm
150 rpm
PAGE 50 OF 160
Typical HO2Sresponse rate malfunction thresholds:
Voltage amplitude: < 0.5 volts
J1979 Front HO2S Mode $06 Data
Monitor ID
Test ID
Description for CAN
$01
$80
HO2S11 voltage amplitude and voltage threshold
Volts
$01
$01
H02S11 sensor switch-point voltage
Volts
$05
$80
HO2S21 voltage amplitude and voltage threshold
Volts
$05
$01
H02S21 sensor switch-point voltage
Volts
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 51 OF 160
HO2S Monitor
START
Switching Test
Entry
Conditions
Met?
Closed Loop Fuel, O2
sensor temperature, fuel
pressure, fuel level
No
Yes
Front O2 Sensor Signal
Status - rich/lean
Short Term Fuel Trim
at limits
No
Monitor HO2S
voltage and heater
current and voltage
Response
Test Entry
Conditions
Met?
Front O2 Sensor Voltage
Heater Voltage and
Current
Initiate 1.5 Hz fuel square
wave and monitor HO2S
voltage amplitude
Front O2 Sensor
Voltage
Voltage or
current >
threshold?
Yes
Time between
O2 switches >
30 sec?
Yes
Amplitude <
threshold?
No
END
No
MIL
Yes
Fault Management - MIL after 2
Driving Cycles w/malfunction
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 52 OF 160
Rear HO2S Signal
A functional test of the rear HO2S sensors is done during normal vehicle operation. The peak rich and lean
voltages are continuously monitored. Voltages that exceed the calibratable rich and lean thresholds indicate a
functional sensor. If the voltages have not exceeded the thresholds after a long period of vehicle operation, the
air/fuel ratio may be forced rich or lean in an attempt to get the rear sensor to switch. This situation normally occurs
only with a green catalyst (< 500 miles). If the sensor does not exceed the rich and lean peak thresholds, a
malfunction is indicated.
2005 MY and beyond vehicles will monitor the rear HO2S signal for high voltage, in excess of 1.1 volts and store a
unique DTC. (P0138, P0158). An over voltage condition is caused by a HO2S heater or battery power short to the
HO2S signal line.
Some Partial Zero Emission Vehicles (PZEV Focus) may utilize three sets of HO2S sensors. The front sensors
(HO2S11/HO2S21) are the primary fuel control sensors. The next sensors downstream in the exhaust are utilized
to monitor the light-off catalyst (HO2S12/HO2S22). The last sensors downstream in the exhaust
(HO2S13/Ho2S23) are utilized for very long term fuel trim in order to optimize catalyst efficiency (Fore Aft Oxygen
Sensor Control). Ford's first PZEV vehicle uses a 4-cylinder engine so only the Bank 1 DTCs are utilized.
Rear HO2S Functional Check Operation:
DTCs Sensor 2
P0136 HO2S12 No activity or
P2270 HO2S12 Signal Stuck Lean
P2271 HO2S12 Signal Stuck Rich
P0138 HO2S12 Over voltage
P0156 HO2S22 No activity or
P2272 HO2S22 Signal Stuck Lean
P2273 HO2S22 Signal Stuck Rich
P0158 HO2S22 Over voltage
DTCs Sensor 3
P2274 HO2S13 Signal Stuck Lean
P2275 HO2S13 Signal Stuck Rich
P0144 HO2S13 Over voltage
P2276 HO2S23 Signal Stuck Lean
P2277 HO2S23 Signal Stuck Rich
P0164 HO2S23 Over voltage
Monitor execution
once per driving cycle for activity test, continuous for over voltage test
Monitor Sequence
HO2S 1 response test, HO2S 2 and 3 functional tests
Sensors OK
ECT, IAT, MAF, MAP, VSS, CKP, TP, FRP, no misfire DTCs, no system
failures affecting fuel, CMP, no HO2S 1 signal failures, no HO2S 2/3 over
voltage failures
Monitoring Duration
continuous until monitor completed
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 53 OF 160
Typical Rear HO2S functional check entry conditions:
Entry condition
Minimum
o
Engine Coolant Temp
150 F
Maximum
o
240 F
o
Intake Air Temp
140 F
Time since entering closed loop fuel
10 seconds
o
1600 F
Inferred Catalyst Midbed Temperature
o
Heater-on Inferred Sensor(s) 2/3 HO2S Temperature Range
400 F
Sensor(s) 2/3 HO2S heater-on time
90 seconds
Short Term Fuel Trim Range
90%
Fuel Level (forced excursion only)
15%
Inferred exhaust temperature range
400 F
Rear HO2S heater-on time
120 seconds
Throttle position
Part throttle
Engine RPM (forced excursion only)
1000 rpm
o
Inferred O2 Sensor 2/3 Temperature (for over voltage test only)
o
1400 F
110%
o
1400 F
2000 rpm
o
400 F
Typical Rear HO2S functional check malfunction thresholds:
Does not exceed rich and lean threshold envelope:
Rich < 0.42 volts
Lean > 0.48 volts
> 1.1 volts for 25 seconds for over voltage test
J1979 Rear HO2S Functional Check Mode $06 Data
Monitor ID
Test ID
Description for CAN
$02
$01
HO2S12 sensor switch-point voltage
volts
$06
$01
HO2S22 sensor switch-point voltage
volts
$03
$01
HO2S13 sensor switch-point voltage
volts
$07
$01
HO2S23 sensor switch-point voltage
volts
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 54 OF 160
Starting with the 2007 MY, the rear/downstream HO2S is also tested for proper response. A two stage test
performed once per driving cycle. First, a passive test is performed. If the passive test "passes", the rear HO2S
response monitor is complete. If the passive test does not complete in time, the monitor proceeds to the active test.
Passive Test Overview:
The diagnostic monitors the voltage slew rate during a passive rear O2 sensor "switch" to determine if the
sensor has slowed down.
The sensor slew rate is tracked continuously during normal vehicle operation
The monitor will complete if a rear sensor switch of sufficient voltage magnitude is detected in the rich to
lean and lean to rich directions and the sensor slew rate is above a calibrated value.
If the front sensor response rate test has completed, but there has not been sufficient rear sensor activity
(i.e. sensor slew rate is slow), an intrusive mode will be entered.
•
•
•
•
Active Test Overview:
The intrusive mode test involves inducing an air fuel modulation at slowly increasing magnitudes.
The sensor will pass the diagnostic if sufficiently fast switches are seen.
The sensor will fail the diagnostic if:
o the modulation has reached its limits by calibrated number of events, or
o the time in intrusive mode has exceeded and high slew rate switches were still not detected
•
•
•
Slew rate is calculated from the delta voltage and delta time between the last sample before crossing the 0.6 volt
threshold and the first sample after crossing the 0.3 volt threshold. Slew rates are tracked as a function of bank and
direction. Threshold voltages can be calibrated differently for each direction. Minimum slew rate required to pass is
calibrated differently for each direction.
Slew Rate Calculation
1
Slew rate is calculated
from the delta voltage
and delta time between the
last sample before crossing
one threshold and the
first sample after crossing
the other threshold.
0.9
0.8
Downstream Sensor Voltages
0.7
High Voltage Threshold 0.6 V
0.6
0.5
0.4
Delta
Voltage
Low Voltage Threshold 0.3 V
0.3
Delta Time
0.2
0.1
136
136.5
FORD MOTOR COMPANY
137
137.5
Time, Seconds
REVISION DATE: NOVEMBER 12, 2007
138
138.5
139
PAGE 55 OF 160
Rear HO2S Response Rate Operation:
DTCs
P0139 (slow response Bank 1)
P0159 (slow response Bank 2)
Monitor execution
once per driving cycle
Monitor Sequence
HO2S 1 response test complete, HO2S 2 and 3 functional tests
complete, HO2S heater voltage and current checks complete
Sensors OK
ECT, IAT, MAF, MAP, VSS, CKP, TP, FRP, no misfire DTCs, no
fuel system DTCs, CMP, no HO2S 1 signal DTCs, no HO2S 2
functional DTCs
Monitoring Duration
100 seconds or 50 lean/rich and rich/lean commanded
modulations to register a malfunction
Typical Rear HO2S response rate entry conditions:
Entry condition
Minimum
Engine Coolant Temperature
150 F
o
Maximum
o
240 F
o
Intake Air Temperature
140 F
Time since entering closed loop fuel
10 seconds
o
1600 F
Inferred Catalyst Temperature
o
Inferred HO2S 2/3 Temperature
400 F
HO2S 2/3 heater-on time
90 seconds
Fuel Level (forced excursion only)
15%
Short Term Fuel Trim Range (forced excursion only)
90%
Short Term Fuel Trim absolute change (forced excursion only)
o
1400 F
110%
10%
Vehicle Speed (forced excursion only)
30 mph
680 mph
Engine RPM (forced excursion only)
1000 rpm
2000 rpm
Time since engine start (forced excursion only)
0 seconds
Inferred HO2S 2 Temperature (forced excursion only)
850 F
Air Mass Range (forced excursion only)
1.7 lbs/min
Abort time if air mass is out of range (forced excursion only)
1 second
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
o
7 lbs/min
PAGE 56 OF 160
Typical Rear HO2S response rate malfunction thresholds:
Rich to lean slew rate thresholds: = <1.25 mV volts/msec (NTK Thimble)
= < 1.0 mV/msec (Bosch Thimble)
= < 0.75 mV/msec (Bosch Planar)
Lean to rich slew rate thresholds: = < 1.67 mV/msec (NTK Thimble)
= < 1.0 mV/msec (Bosch Thimble)
= < 1.5 mV/msec (Bosch Planar)
J1979 Rear HO2S response rate Mode $06 Data
Monitor ID
Test ID
Description for CAN
$02
$82
HO2S12 sensor Lean to Rich Response Rate
Volts/msec
$02
$83
HO2S12 sensor Rich to Lean Response Rate
Volts/msec
$06
$82
HO2S22 sensor Lean to Rich Response Rate
Volts/msec
$06
$83
HO2S22 sensor Rich to Lean Response Rate
Volts/msec
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 57 OF 160
HO2S Heaters, front and rear
The HO2S heaters are monitored for proper voltage and current. A HO2S heater voltage fault is determined by
turning the heater on and off and looking for corresponding voltage change in the heater output driver circuit in the
PCM.
A separate current-monitoring circuit monitors heater current once per driving cycle. The heater current is actually
sampled three times. If the current value for two of the three samples falls below a calibratable threshold, the
heater is assumed to be degraded or malfunctioning. (Multiple samples are taken for protection against noise on
the heater current circuit.)
HO2S Heater Monitor Operation:
DTCs Sensor 1
P0135 O2 Heater Circuit, Bank 1
P0155 O2 Heater Circuit, Bank 2
P0053 HO2s Heater Resistance, Bank 1
P0059 HO2s Heater Resistance, Bank 2
DTCs Sensor 2
P0141 O2 Heater Circuit, Bank 1
P0161 O2 Heater Circuit, Bank 2
P0054 HO2s Heater Resistance, Bank 1
P0060 HO2s Heater Resistance, Bank 2
DTCs Sensor 3
P0147 O2 Heater Circuit, Bank 1
P0167 O2 Heater Circuit, Bank 2
P0055 HO2s Heater Resistance, Bank 1
P0061 HO2s Heater Resistance, Bank 2
Monitor execution
once per driving cycle for heater current, continuous for voltage monitoring
Monitor Sequence
HO2S 1 response test complete, HO2S 2 and 3 functional tests complete,
HO2S heater voltage check complete
Sensors OK
ECT, IAT, MAF, MAP, VSS, CKP, TP, FRP, no misfire DTCs, no fuel system
DTCs, no HO2S heater voltage DTCs
Monitoring Duration
< 10 seconds for heater voltage check, < 5 seconds for heater current check
Typical HO2S heater monitor entry conditions:
Entry condition
Minimum
Maximum
o
1250 F
o
1400 F
o
1250 F
o
1400 F
o
1400 F
Inferred HO2S 1 Temperature
150 F
Inferred HO2S 2/3 Temperature
400 F
Inferred HO2S 1 Temperature (heater current check only)
250 F
Inferred HO2S 2 Temperature (heater current check only)
250 F
Inferred HO2S 3 Temperature (heater current check only)
250 F
HO2S 1/2/3 heater-on time (heater current check only)
30 seconds
o
o
o
o
o
Engine RPM (heater current check only)
5000 rpm
Battery Voltage (heater voltage check only)
18.9 Volts
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 58 OF 160
Typical HO2S heater check malfunction thresholds:
Smart driver status indicated malfunction
Heater current outside limits:
< 0.220 amps or > 3 amps, (NTK)
< 0.400 amps or > 3 amps, (Bosch)
< 0.465 amps or > 3 amps, (NTK Fast Light Off)
< 0.230 amps or > 3 amps, (Bosch Fast Light Off)
Number monitor retries allowed for malfunction > = 30
J1979 HO2S Heater Mode $06 Data
Monitor ID
Test ID
Description for CAN
Units
$01
$81
HO2S11 Heater Current
Amps
$05
$81
HO2S21 Heater Current
Amps
$02
$81
HO2S12 Heater Current
Amps
$06
$81
HO2S22 Heater Current
Amps
$03
$81
HO2S13 Heater Current
Amps
$07
$81
HO2S23 Heater Current
Amps
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 59 OF 160
DPFE EGR System Monitor
The Delta Pressure Feedback EGR system is a closed loop EGR control system that uses Delta Pressure
Feedback EGR sensor (DPFE) to measure EGR flow across an orifice in the EGR tube. When the EGR valve is
open, a pressure differential is created across the orifice and measured by the DPFE sensor. This DPFE
measurement is used to control the EGR vacuum regulator (EVR), which provides vacuum to open and modulate
the EGR valve itself.
CONVENTIONAL
DPFE EGR SYSTEM
PCM
FRESH AIR INLET
EVR
EGR
VALVE
INTAKE
DPFE
SENSOR
DOWNSTREAM (P2)
UPSTREAM (P1)
EXHAUST
FORD MOTOR COMPANY
FLOW CONTROL
ORIFICE
DELTA P = P1 - P2
REVISION DATE: NOVEMBER 12, 2007
PAGE 60 OF 160
DPFE EGR Monitor
Start
DPFE Voltage
> High Flow
threshold?
Yes
Engine Conditions,
(idle)
No
Monitor DPFE
sensor voltage and
EVR output current.
Hose Check
Entry
Conditions
Met?
Engine Conditions, (no
EGR, part throttle)
Yes
DPFE Sensor Voltage
EVR Current
DPFE
voltage
outside
thresholds?
Yes
DPFE Voltage
No
Flow Check
Conditions
Met?
Voltage or
current >
threshold?
End
No
DPFE
voltage > low
flow
threshold?
Yes
Engine Conditions,
(Part Throttle)
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 61 OF 160
The Delta Pressure Feedback EGR Monitor is a series of electrical tests and functional tests that monitor various
aspects of EGR system operation.
First, the Delta Pressure Feedback EGR (DPFE) sensor input circuit is checked for out of range values (P1400 or
P0405, P1401 or P0406). The Electronic Vacuum Regulator (EVR) output circuit is checked for opens and shorts
(P1409 or P0403).
DPFE EGR Electrical Check Operation:
DTCs
P1400 or P0405 - DPFE Circuit Low
P1401 or P0406 - DPFE Circuit High
P1409 or P0403 - EVR circuit open or shorted
Monitor execution
Continuous, during EGR monitor
Monitor Sequence
None
Sensors OK
Monitoring Duration
4 seconds to register a malfunction
Typical DPFE EGR electrical check entry conditions:
EGR system enabled
Typical DPFE EGR electrical check malfunction thresholds:
DPFE sensor outside voltage: > 4.96 volts, < 0.0489 volts
EVR solenoid smart driver status indicates open/short
The DPFE sensor is a ceramic, capacitive-type pressure transducer that monitors the differential pressure across a
metering orifice located in the orifice tube assembly. The differential pressure feedback sensor receives this signal
through two hoses referred to as the downstream pressure hose (REF SIGNAL) and upstream pressure hose (HI
SIGNAL). The HI and REF hose connections are marked on the aluminum DPFE sensor housing for identification
(note that the HI signal uses a larger diameter hose). There are two styles of DPFE sensors. The newer, plastic
housing utilizes a 1.0-volt offset (zero reading) whereas the older, aluminum housing utilizes either a 0.5-volt or
1.0-volt offset. See the ESM EGR section for the 0.5-volt offset transfer function. The slopes for either offset are
identical.
DPFE Sensor Transfer Function
DPFE volts = Vref [( 0.683 * Delta Pressure) + 20 ] / 100
Volts
A/D Counts in PCM
Delta Pressure, Inches H2O
0.0489
10
-27.9
0.76
156
-7.0
1.0
204
0
1.24
254
7.0
2.02
415
30
3.05
624
60
4.07
834
90
4.96
1015
116
Note: EGR normally has large amounts of water vapor that are the result of the engine combustion process. During
cold ambient temperatures, under some circumstances, water vapor can freeze in the DPFE sensor, hoses, as
well as other components in the EGR system. In order to prevent MIL illumination for temporary freezing, the
following logic is used:
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 62 OF 160
o
If an EGR system malfunction is detected above 32 F, the EGR system and the EGR monitor is disabled for the
current driving cycle. A DTC is stored and the MIL is illuminated if the malfunction has been detected on two
consecutive driving cycles.
o
If an EGR system malfunction is detected below 32 F, only the EGR system is disabled for the current driving
cycle. A DTC is not stored and the I/M readiness status for the EGR monitor will not change. The EGR monitor,
however, will continue to operate. If the EGR monitor determined that the malfunction is no longer present (i.e., the
ice melts), the EGR system will be enabled and normal system operation will be restored.
The differential pressure indicated by the DPFE sensor is also checked at idle with zero requested EGR flow to
perform the high flow check. If the differential pressure exceeds a calibratable limit, it indicates a stuck open EGR
valve or debris temporarily lodged under the EGR valve seat (P0402).
DPFE EGR Stuck open Check Operation:
DTCs
P0402
Monitor execution
once per driving cycle
Monitor Sequence
Done after electrical tests
Sensors OK
CPS, ECT, IAT, MAF, TP
Monitoring Duration
10 seconds to register a malfunction
Typical DPFE EGR stuck open check entry conditions:
Entry Condition
Minimum
Maximum
EVR dutycycle (EGR commanded off)
0%
0%
Engine RPM (after EGR enabled)
at idle
Idle
Typical DPFE EGR stuck open check malfunction thresholds:
DPFE sensor voltage at idle versus engine-off signal: > 0.6 volts
J1979 DPFE EGR Stuck Open Mode $06 Data
Monitor ID
Test ID
Description for CAN Conventional DPFE
Units
$31
$84
Delta pressure for stuck open test and threshold
kPa
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 63 OF 160
On conventional Delta PFE systems, after the vehicle is started, during vehicle acceleration, the differential
pressure indicated by the DPFE sensor at zero EGR flow is checked to ensure that both hoses to the DPFE
sensor are connected. Under this condition, the differential pressure should be zero. If the differential pressure
indicated by the DPFE sensor exceeds a maximum positive threshold, a downstream DPFE hose malfunction is
indicated (P1406). If the differential pressure falls below a minimum negative threshold, an upstream DPFE hose
malfunction is indicated (P1405).
DPFE EGR Hose Check Operation:
DTCs
P1405 - Upstream Hose Off or Plugged
P1406 – Downstream Hose Off or Plugged
Monitor execution
once per driving cycle
Monitor Sequence
After P0402 test completed
Sensors OK
MAF
Monitoring Duration
4 seconds to register a malfunction
Typical DPFE EGR hose check entry conditions:
Entry Condition
Minimum
Maximum
EVR dutycycle (EGR commanded off)
0%
0%
Mass Air Flow
8 lb/min
Inferred exhaust backpressure
13 in H2O
Typical DPFE EGR hose check malfunction thresholds:
DPFE sensor voltage: < 7 in H2O, > 7 in H2O
J1979 DPFE EGR Hose Check Mode $06 Data
Monitor ID
Test ID
Description for CAN Conventional DPFE
$31
$80
Delta pressure for upstream hose test and threshold
kPa
$31
$81
Delta pressure for downstream hose test and threshold
kPa
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 64 OF 160
After the vehicle has warmed up and normal EGR rates are being commanded by the PCM, the low flow check is
performed. Since the EGR system is a closed loop system, the EGR system will deliver the requested EGR flow as
long as it has the capacity to do so. If the EVR duty cycle is very high (greater than 80% duty cycle), the differential
pressure indicated by the DPFE sensor is evaluated to determine the amount of EGR system restriction. If the
differential pressure is below a calibratable threshold, a low flow malfunction in indicated (P0401).
EGR Flow Check Operation:
DTCs
P0401 – Insufficient Flow
Monitor execution
once per driving cycle
Monitor Sequence
Done after hose tests for conventional DPFE, after P0402 for ESM
Sensors OK
CPS, ECT, IAT, MAF, TP
Monitoring Duration
70 seconds to register a malfunction
Typical EGR flow check entry conditions:
Entry Condition
Minimum
Maximum
EVR Dutycycle
80%
100%
Engine RPM
2500 rpm
Mass Air Flow Rate of Change
6% program loop
Inferred manifold vacuum
6 in Hg
10 in Hg
Typical EGR flow check malfunction thresholds:
DPFE sensor voltage: < 6 in H2O
J1979 EGR Flow Check Mode $06 Data
Monitor ID
Test ID
Description for CAN Conventional DPFE
Units
$31
$85
Delta pressure for flow test and threshold
kPa
I/M Readiness Indication
o
o
If the inferred ambient temperature is less than 32 F, or greater than 140 F, or the altitude is greater than 8,000
feet (BARO < 22.5 "Hg), the EGR monitor cannot be run reliably. In these conditions, a timer starts to accumulate
the time in these conditions. If the vehicle leaves these extreme conditions, the timer starts decrementing, and, if
conditions permit, will attempt to complete the EGR flow monitor. If the timer reaches 500 seconds, the EGR
monitor is disabled for the remainder of the current driving cycle and the EGR Monitor I/M Readiness bit will be set
to a “ready” condition after one such driving cycle. Starting in the 2002 MY, vehicles will require two such driving
cycles for the EGR Monitor I/M Readiness bit to be set to a "ready" condition.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 65 OF 160
ESM DPFE EGR System Monitor
In the 2002.5 MY, Ford introduced a revised DPFE system. It functions in the same manner as the conventional
DPFE system, however, the various system components have been combined into a single component called the
EGR System Module (ESM). This arrangement increases system reliability while reducing cost. By relocating the
EGR orifice from the exhaust to the intake, the downstream pressure signal measures Manifold Absolute
Pressure (MAP). The ESM will provide the PCM with a differential DPFE signal, identical to the conventional
DPFE system. The DPFE signal is obtained by electrically subtracting the MAP and P1 pressure signals and
providing this signal to the DPFE input on the PCM. 2003 MY and later implementations of the ESM system has
a separate input to the PCM for the MAP sensor signal.
New ESM
DPFE EGR SYSTEM
PCM
EGR System Module
(ESM) Components
FRESH AIR INLET
MAP SIGNAL
EVR
DPFE
signal
EGR
VALVE
VREF
Sig Rtn
EGR DC
P1
INTAKE
(MAP)
MAP
DPFE
SENSOR
DELTA P = P1 - MAP
EXHAUST
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 66 OF 160
ESM DPFE EGR Monitor
No
Hose Check
Entry
Conditions
Met?
Start
Engine Conditions, (no
EGR, part throttle)
Yes
Monitor DPFE
sensor voltage and
EVR output current.
DPFE
voltage
outside
thresholds?
Yes
DPFE Voltage
Yes
DPFE Sensor Voltage
EVR Current
DPFE Voltage
> High Flow
threshold?
Yes
Engine Conditions,
(idle)
No
Flow Check
Conditions
Met?
Voltage or
current >
threshold?
No
Yes
End
No
DPFE
voltage > low
flow
threshold?
Engine Conditions,
(Part Throttle)
Yes
MIL
Fault Management – MIL after 2 Driving
Cycles w/malfunction
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 67 OF 160
The ESM Delta Pressure Feedback EGR Monitor is a series of electrical tests and functional tests that monitor
various aspects of EGR system operation.
First, the Delta Pressure Feedback EGR (DPFE) sensor input circuit is checked for out of range values (P1400 or
P0405, P1401 or P0406). The Electronic Vacuum Regulator (EVR) output circuit is checked for opens and shorts
(P1409 or P0403).
EGR Electrical Check Operation:
DTCs
P1400 or P0405 - DPFE Circuit Low
P1401 or P0406 - DPFE Circuit High
P1409 or P0403 - EVR circuit open or shorted
Monitor execution
Continuous, during EGR monitor
Monitor Sequence
None
Sensors OK
Monitoring Duration
4 seconds to register a malfunction
Typical EGR electrical check entry conditions:
EGR system enabled
Typical EGR electrical check malfunction thresholds:
DPFE sensor outside voltage: > 4.96 volts, < 0.0489 volts
EVR solenoid smart driver status indicates open/short
DPFE Sensor Transfer Function
ESM DPFE volts = Vref [( 0.683 * Delta Pressure) + 10 ] / 100
Volts
A/D Counts in PCM
Delta Pressure, Inches H2O
0.0489
10
-13.2
0.26
53
-7.0
0.5
102
0
0.74
151
7.0
1.52
310
30
2.55
521
60
3.57
730
90
4.96
1015
130.7
Note: EGR normally has large amounts of water vapor that are the result of the engine combustion process. During
cold ambient temperatures, under some circumstances, water vapor can freeze in the DPFE sensor, hoses, as
well as other components in the EGR system. In order to prevent MIL illumination for temporary freezing, the
following logic is used:
o
If an EGR system malfunction is detected above 32 F, the EGR system and the EGR monitor is disabled for the
current driving cycle. A DTC is stored and the MIL is illuminated if the malfunction has been detected on two
consecutive driving cycles.
o
If an EGR system malfunction is detected below 32 F, only the EGR system is disabled for the current driving
cycle. A DTC is not stored and the I/M readiness status for the EGR monitor will not change. The EGR monitor,
however, will continue to operate. If the EGR monitor determined that the malfunction is no longer present (i.e., the
ice melts), the EGR system will be enabled and normal system operation will be restored.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 68 OF 160
The ESM may provide the PCM with a separate, analog Manifold Absolute Pressure Sensor (MAP) signal. For the
2006 MY, the MAP signal has limited use within the PCM. It may be used to read BARO (key on, then updated at
high load conditions while driving) or to modify requested EGR rates. Note that if the MAP pressure-sensing
element fails in the ESM fails, the DPFE signal is also affected. Therefore, this MAP test is only checking the circuit
from the MAP sensing element to the PCM.
The MAP sensor is checked for opens, shorts, or out-of-range values by monitoring the analog-to-digital (A/D)
input voltage.
MAP Sensor Check Operation
DTCs
P0107 (low voltage), P0108 (high voltage)
Monitor execution
continuous
Monitor Sequence
None
Sensors OK
not applicable
Monitoring Duration
5 seconds to register a malfunction
MAP electrical check entry conditions:
Battery voltage > 11.0 volts
Typical MAP sensor check malfunction thresholds:
Voltage < 0.024 volts or voltage > 4.96 volts
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 69 OF 160
On ESM DPFE systems, after the vehicle is started, the differential pressure indicated by the ESM DPFE sensor at
idle, at zero EGR flow is checked to ensure that both hoses to the ESM DPFE sensor are connected. At idle, the
differential pressure should be zero (both hoses see intake manifold pressure). If the differential pressure indicated
by the ESM DPFE sensor exceeds a maximum threshold or falls below a minimum threshold, an upstream or
downstream hose malfunction is indicated (P1405, P1406).
ESM DPFE EGR Hose Check Operation:
DTCs
P1405 - Upstream Hose Off or Plugged
P1406 – Downstream Hose Off or Plugged
Monitor execution
once per driving cycle
Monitor Sequence
after electrical checks completed
Sensors OK
MAF
Monitoring Duration
10 seconds to register a malfunction
Typical ESM DPFE EGR hose check entry conditions:
Entry Conditions
Minimum
Maximum
EVR dutycycle (EGR commanded off)
0%
0%
Closed throttle (warm engine idle)
o
Engine Coolant Temperature
150 F
o
220 F
Typical ESM EGR hose check malfunction thresholds:
DPFE sensor voltage: < -0.122 volts (-11.06 in H2O), > 4.69 volts (122.82 in H2O)
J1979 Mode $06 Data
Monitor ID
Test ID
Description for CAN ESM DPFE
$32
$82
Delta pressure for upstream hose test and threshold
kPa
$32
$83
Delta pressure for downstream hose test and threshold
kPa
Note: OBD monitor ID $32, Test ID $82 (upstream hose test) may erroneously show a failing test result when no
P1405 DTC is present. This is cause by in incorrect max limit in the software. The incorrect max limit will show a
negative value (approx -32 kPa). The correct max limit will show a positive value (approx. +32 kPa). Early
production vehicles may exhibit this issue until the software is corrected by a production running change or service
fix.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 70 OF 160
Next, the differential pressure indicated by the DPFE sensor is also checked at idle with zero requested EGR flow
to perform the high flow check. If the differential pressure exceeds a calibratable limit, it indicates a stuck open
EGR valve or debris temporarily lodged under the EGR valve seat (P0402).
EGR Stuck open Check Operation:
DTCs
P0402
Monitor execution
once per driving cycle
Monitor Sequence
done after hose tests completed
Sensors OK
CPS, ECT, IAT, MAF, TP, MAP (P0106/7/8)
Monitoring Duration
10 seconds to register a malfunction
Typical EGR stuck open check entry conditions:
Entry Condition
Minimum
Maximum
EVR dutycycle (EGR commanded off)
0%
0%
Engine RPM (after EGR enabled)
at idle
Idle
Typical EGR stuck open check malfunction thresholds:
DPFE sensor voltage at idle versus engine-off signal: > 0.6 volts
J1979 Mode $06 Data
Monitor ID
Test ID
Description for CAN ESM DPFE
Units
$32
$84
Delta pressure for stuck open test and threshold
kPa
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 71 OF 160
After the vehicle has warmed up and normal EGR rates are being commanded by the PCM, the low flow check is
performed. Since the EGR system is a closed loop system, the EGR system will deliver the requested EGR flow as
long as it has the capacity to do so. If the EVR duty cycle is very high (greater than 80% duty cycle), the differential
pressure indicated by the DPFE sensor is evaluated to determine the amount of EGR system restriction. If the
differential pressure is below a calibratable threshold, a low flow malfunction is indicated (P0401).
EGR Flow Check Operation:
DTCs
P0401 – Insufficient Flow
Monitor execution
once per driving cycle
Monitor Sequence
done after P0402 completed
Sensors OK
CPS, ECT, IAT, MAF, TP, MAP (P0106/7/8)
Monitoring Duration
70 seconds to register a malfunction
Typical EGR flow check entry conditions:
Entry Condition
Minimum
Maximum
EVR Dutycycle
80%
100%
Engine RPM
2500 rpm
Mass Air Flow Rate of Change
6% program loop
Inferred manifold vacuum
6 in Hg
10 in Hg
Typical EGR flow check malfunction thresholds:
DPFE sensor voltage: < 6 in H2O
J1979 Mode $06 Data
Monitor ID
Test ID
Description for CAN ESM DPFE
Units
$32
$85
Delta pressure for flow test and threshold
kPa
I/M Readiness Indication
o
o
If the inferred ambient temperature is less than 32 F, or greater than 140 F, or the altitude is greater than 8,000
feet (BARO < 22.5 "Hg), the EGR monitor cannot be run reliably. In these conditions, a timer starts to accumulate
the time in these conditions. If the vehicle leaves these extreme conditions, the timer starts decrementing, and, if
conditions permit, will attempt to complete the EGR flow monitor. If the timer reaches 500 seconds, the EGR
monitor is disabled for the remainder of the current driving cycle and the EGR Monitor I/M Readiness bit will be set
to a “ready” condition after one such driving cycle. Starting in the 2002 MY, vehicles will require two such driving
cycles for the EGR Monitor I/M Readiness bit to be set to a "ready" condition.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 72 OF 160
Stepper Motor EGR System Monitor – Non-intrusive Monitor
The Electric Stepper Motor EGR System uses an electric stepper motor to directly actuate an EGR valve rather
than using engine vacuum and a diaphragm on the EGR valve. The EGR valve is controlled by commanding
from 0 to 52 discreet increments or “steps” to get the EGR valve from a fully closed to fully open position. The
position of the EGR valve determines the EGR flow. Control of the EGR valve is achieved by a non-feedback,
open loop control strategy. Because there is no EGR valve position feedback, monitoring for proper EGR flow
requires the addition of a MAP sensor.
Stepper Motor EGR System
PCM
FRESH AIR INLET
Map
Sensor
Intake Manifold
Stepper Motor
EGR Valve
0403
0400
Note: Some configurations may differ slightly
Exhaust
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
Gates
PAGE 73 OF 160
The Non-Intrusive Stepper Motor EGR Monitor consists of an electrical and functional test that checks the
stepper motor and the EGR system for proper flow.
The stepper motor electrical test is a continuous check of the four electric stepper motor coils and circuits to the
PCM. A malfunction is indicated if an open circuit, short to power, or short to ground has occurred in one or more
of the stepper motor coils for a calibrated period of time. If a malfunction has been detected, the EGR system will
be disabled, and additional monitoring will be suspended for the remainder of the driving cycle, until the next
engine start-up.
EGR Stepper Monitor Electrical Check Operation:
DTCs
P0403
Monitor execution
continuous
Monitor Sequence
none
Sensors OK
Monitoring Duration
4 seconds to register a malfunction
Stepper motor electrical check entry conditions:
Battery voltage > 11.0 volts
Typical EGR electrical check malfunction thresholds:
“Smart” Coil Output Driver status indicates open or short to ground, or short to power
EGR flow is monitored using an analog Manifold Absolute Pressure Sensor (MAP). If a malfunction has been
detected in the MAP sensor, the EGR monitor will not perform the EGR flow test.
The MAP sensor is checked for opens, shorts, or out-of-range values by monitoring the analog-to-digital (A/D)
input voltage.
MAP Sensor Check Operation
DTCs
P0107 (low voltage), P0108 (high voltage)
Monitor execution
continuous
Monitor Sequence
none
Sensors OK
not applicable
Monitoring Duration
5 seconds to register a malfunction
MAP electrical check entry conditions:
Battery voltage > 11.0 volts
Typical MAP sensor check malfunction thresholds:
Voltage < 0.024 volts or voltage > 4.96 volts
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 74 OF 160
The MAP sensor is also checked for rational values. The value of inferred MAP is checked against the actual value
of MAP at idle and non-idle engine operating conditions.
MAP Sensor Rationality Check Operation
DTCs
P0106
Monitor execution
continuous
Monitor Sequence
None
Sensors OK
not applicable
Monitoring Duration
10 seconds to register a malfunction
Typical MAP Rationality check entry conditions:
Entry Conditions
Minimum
Change in load
Maximum
5%
500 rpm
Engine rpm
1800 rpm
Typical MAP Rationality check malfunction thresholds:
Difference between inferred MAP and actual MAP > 10 in Hg
The MAP sensor is also checked for intermittent MAP faults.
MAP Sensor Intermittent Check Operation
DTCs
P0109 (non-MIL)
Monitor execution
Continuous
Monitor Sequence
None
Sensors OK
not applicable
Monitoring Duration
2 seconds to register a malfunction
Typical MAP Intermittent check malfunction thresholds:
Voltage < 0.024 volts or voltage > 4.96 volts
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 75 OF 160
After the vehicle has warmed up and normal EGR rates are being commanded by the PCM, the EGR flow test is
performed. The flow test is performed once per drive-cycle after the remaining entry conditions required to initiate
the test are satisfied.
The EGR flow test is done by observing the behavior of two different values of MAP - the analog MAP sensor
reading, and inferred MAP, (MAP calculated from the Mass Air Flow Sensor, throttle position, rpm, BARO, etc.).
The calculation of inferred MAP is not compensated for EGR flow and, therefore, does not account for the effects
of EGR flow whereas measured MAP does respond to the effects of EGR flow. The amount of EGR flow can
therefore be calculated by looking at the difference between measured MAP and inferred MAP.
Measured MAP can be thought of as consisting of three contributors: fresh air drawn into the intake manifold, EGR
flow, and a noise/variability term. The following equation describes this:
Pmap = Pmaf + Pegr + Pnoise
Where: Pmap = pressure in manifold measured by the MAP sensor
Pmaf = fresh air pressure without EGR flow, inferred from the MAF sensor, also known as
inferred MAP
Pegr = EGR flow pressure due to EGR flow
Pnoise = any discrepancy between measured MAP and inferred MAP, without EGR
Pmaf (inferred MAP) is determined by the amount of fresh air drawn into manifold as measured by the Mass Air
Flow (MAF) sensor. Inferred MAP is determined during the engine mapping process with no EGR, as a function of
rpm and load
Pegr , the pressure due to EGR contribution can be modeled in the following equation:
Pegr = K * (Actual EGR / Desired EGR) * Desired EGR
Where: K = converts EGR pressure to a percent EGR flow rate
By rearranging the equation:
Actual EGR / Desired EGR = Pegr / (K * Desired EGR)
The ratio of actual to desired EGR will eventually be calculated by the EGR monitor and will reflect how accurately
EGR is being delivered to the engine.
Some differences will always exist between measured MAP and inferred MAP due to hardware variations. Within
steady engine operating conditions without EGR, it is reasonable to model any differences between inferred and
measured MAP as an offset and slope that is a function of load. The offset and slope are learned at various loads.
This correction can be represented as:
MAP correction = Pnoise = M * LOAD + B
Where: B = offset between measured MAP and inferred MAP
M = slope which accounts for the difference between measured MAP and inferred MAP as a
function of load
The terms B and M are learned and compensate for differences between measured MAP and inferred MAP.
Rearranging and substituting in the equations above results in the following system model:
Actual EGR / Desired EGR = (measured MAP – inferred MAP – MAP correction) / (K * Desired EGR)
The Actual EGR / Desired EGR is called the "degradation index". A value near one indicates the system is
functioning properly whereas a value near zero reflects severe flow degradation.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 76 OF 160
When the entry conditions for the flow test have been satisfied, a calibrated number of samples of the difference
between measured MAP and inferred MAP are taken at low, medium and high load regions, with and without
EGR, to learn the MAP correction terms and then calculate the degradation index. When the number of samples in
each load region is complete, a degradation index value from zero to one is computed. A value near one indicates
the system is functioning properly whereas a value near zero reflects EGR severe flow degradation.
The degradation index is compared to a calibrated threshold to determine if a low flow malfunction has occurred.
Once the EGR monitor has been completed, the counter for the number of samples in each load region is reset to
zero. If an EGR flow malfunction has occurred, the P0400 DTC flow malfunction is registered.
Note: BARO is inferred at engine startup using the KOEO MAP sensor reading. It is updated during high, partthrottle, engine operation.
This monitor employs an Exponentially Weighted Moving Average (EWMA) algorithm to improve the robustness
threshold of the degradation index. During normal customer driving, a malfunction will illuminate the MIL, on
average, in 3 to 6 driving cycles. If KAM is reset (battery disconnected), a malfunction will illuminate the MIL in 2
driving cycles. See the section on EWMA for additional information.
EGR Flow Check Operation:
DTCs
P0400
Monitor execution
once per driving cycle
Monitor Sequence
None
Sensors OK
CPS, ECT, IAT, MAF, MAP (P0106/7/8), TP, BARO not available yet
Monitoring Duration
200 seconds (600 data samples)
Typical EGR flow check entry conditions:
Entry Condition
Minimum
Maximum
Engine RPM
1400 rpm
2600 rpm
o
140 F
o
250 F
Inferred Ambient Air Temperature
32 F
Engine Coolant Temperature
80 F
o
o
Engine RPM Steady (change/0.050 sec)
100 rpm
MAP Steady (change/0.050 sec)
0.5 in Hg
Engine Load Steady (change/0.050 sec)
1.5 %
BARO
22.5 " Hg
Typical EGR flow check malfunction thresholds:
< 0.50 degradation index
J1979 Mode $06 Data
Monitor ID
Test ID
Description for CAN
Units
$33
$82
EGR Degradation Index
unitless
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 77 OF 160
I/M Readiness Indication
o
o
If the inferred ambient temperature is less than 20 F, greater than 130 F, or the altitude is greater than 8,000 feet
(BARO < 22.5 "Hg), the EGR flow test cannot be reliably done. In these conditions, the EGR flow test is
suspended and a timer starts to accumulate the time in these conditions. If the vehicle leaves these extreme
conditions, the timer starts decrementing, and, if conditions permit, will attempt to complete the EGR flow monitor.
If the timer reaches 800 seconds, the EGR flow test is disabled for the remainder of the current driving cycle and
the EGR Monitor I/M Readiness bit will be set to a “ready” condition after one such driving cycle. Two such
consecutive driving cycles are required for the EGR Monitor I/M Readiness bit to be set to a "ready" condition.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 78 OF 160
PCV System Monitor
The PCV valve is installed into the rocker cover using a quarter-turn cam-lock design to prevent accidental
disconnection. High retention force molded plastic lines will be used from the PCV valve to the intake manifold.
The diameter of the lines and the intake manifold entry fitting will be increased to 0.625" so that inadvertent
disconnection of the lines after a vehicle is serviced will cause either an immediate engine stall or will not allow
the engine to be restarted. In the event that the vehicle does not stall if the line between the intake manifold and
PCV valve is inadvertently disconnected, the vehicle will have a large vacuum leak that will cause the vehicle to
run lean at idle. This will illuminate the MIL after two consecutive driving cycles and will store one or more of the
following codes: Lack of O2 sensor switches, Bank1 (P1131 or P2195), Lack of O2 sensor switches Bank 2
(P1151 or P2197), Fuel System Lean, Bank1 (P0171),, Fuel System Lean, Bank 2 (P0174)
Thermostat Monitor
Ford complies with the thermostat-monitoring requirement by using a slightly-modified version of the current
“Insufficient temperature for closed-loop” test (P0125 or P0128). If the engine is being operated in a manner that
is generating sufficient heat, the engine coolant temperature (ECT) or cylinder head temperature (CHT) should
warm up in a predictable manner. A timer is incremented while the engine is at moderate load and vehicle speed
is above a calibrated limit. The target/minimum timer value is based on ambient air temperature at start-up. If the
timer exceeds the target time and ECT/CHT has not warmed up to the target temperature, a malfunction is
indicated. The test runs if the start-up IAT temperature is below the target temperature. A 2-hour engine-off soak
time is required to erase a pending or confirmed DTC. This feature prevents false-passes where engine coolant
temperature rises after the engine is turned off during a short engine-off soak. The target temperature is
o
o
calibrated to the thermostat regulating temperature minus 20 F. For a typical 195 F thermostat, the warm-up
o
temperature would be calibrated to 175 F.
Insufficient Temperature for Closed Loop Check Operation:
DTCs
P0125 or P0128
Monitor execution
Once per driving cycle
Monitor Sequence
None
Monitoring Duration
300 to 800 seconds within test entry conditions, based on ambient temperature
Typical P0125/P0128 check entry conditions:
Entry Condition
Minimum
Vehicle speed
15 mph
Intake Air Temp at Start-up
20 F
Engine Load
30%
Engine off (soak) time to clear pending/confirmed DTC
2 hours
o
Maximum
Target ECT temp.
Typical P0125/P0128 check malfunction thresholds:
o
Time period expired without reaching 175 F target ECT temperature.
Time period is 300 to 800 seconds based on ambient temperature at start-up.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 79 OF 160
Cold Start Emission Reduction Component Monitor
The Cold Start Emission Reduction Component Monitor was introduced for the 2006 MY on vehicles that meet the
LEV-II emission standards. The monitor works by validating the operation of the components of the system
required to achieve the cold start emission reduction strategy, namely retarded spark timing and elevated idle
airflow.
Low Idle Airflow Test – Systems with Bypass Air Solenoid
When the CSER strategy is enabled, the idle air control system will request a higher idle rpm, elevating engine
airflow. While this CSER elevated airflow is requested, the low airflow test compares the measured idle airflow from
the MAF sensor to the commanded idle airflow from the idle air control strategy. For the purpose of detecting low
airflow failures, the low airflow test uses the measured airflow and the commanded airflow to create a low airflow
index as follows:
Low airflow index = 1 – (average measured airflow / average commanded airflow)
For a good system, the average measured airflow approximately equals the average commanded airflow
low airflow index ~ 0.
For a failed system, the average measured airflow is much less than the average commanded airflow
low airflow index ~ 1.
CSER low airflow test operation:
DTCs
P050A – Cold Start Idle Air Control System Performance
Monitor execution
Once per driving cycle, from startup with CSSRE active
Monitor Sequence
None
Sensors OK
Monitoring Duration
~ 7 seconds
CSER typical low airflow test entry conditions:
Entry Condition
Minimum
o
Maximum
o
Engine Coolant Temperature
40 F
180 F
Barometric pressure
22.5 " Hg
31.0 " Hg
Throttle at closed position
Engine off (soak) time
50 minutes
CSER typical low airflow test malfunction thresholds:
Low Airflow Index > 0.45
For the 2007 MY, only the Freestar/Monterey utilizes the CSER Component monitor with bypass air.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 80 OF 160
Low Idle Airflow Test – Systems with Electronic Throttle Control
When the CSER strategy is enabled, the Electronic Throttle Control system will request a higher idle rpm, elevating
engine airflow. Vehicles that have ETC and do not have a separate airflow test (P050A). Any fault that would not
allow the engine to operate at the desired idle rpm during a cold start would be flagged by one of three ETC DTCs:
P2111 (throttle actuator control system stuck open),
P2112 throttle actuator control system stuck closed)
P2107 (throttle actuator control module processor/circuit test).
All three DTCs will illuminate the MIL in 2 driving cycles, and immediately illuminate the "ETC" light. These DTCS
are also documented in the ETC section of this document.
For the 2007 MY, only the Fusion/Milan and Explorer/Sport Trac utilize the CSER Component monitor with ETC.
Throttle Plate Controller and Actuator Operation:
DTCs
P2107 – processor test (MIL)
P2111 – throttle actuator system stuck open (MIL)
P2112 – throttle actuator system stuck closed (MIL)
Note: For all the above DTCs, in addition to the MIL, the ETC light will be on for
the fault that caused the FMEM action.
Monitor execution
Continuous
Monitor Sequence
None
Monitoring Duration
60 msec for processor fault, 500 msec for stuck open/closed fault
Throttle Plate Controller and Actuator malfunction thresholds:
P2111 - Desired throttle angle vs. actual throttle angle > 6 degrees
P2112 - Desired throttle angle vs. actual throttle angle < 6 degrees
P2107 - Internal processor fault, lost communication with main CPU
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 81 OF 160
Spark Timing Monitor
The powertrain control module is equipped with a "spark conduction capture" circuit which measures the timing
and duration of the spark delivered by processing the flyback voltage signal from the primary side of the ignition
coil. With CSER enabled, the spark control strategy will request retarded spark timing. While retarded spark
timing is requested, the spark timing monitor compares the measured spark timing from the spark conduction
capture circuit to the commanded spark timing from the spark control strategy. For the purpose of detecting spark
timing failures, the spark timing monitor increments a fault filter if the measured spark timing is advanced by more
than 5 degrees from the commanded spark timing. A failure is indicated if the fault filter exceeds a value of 200
(equivalent to a failure duration of approximately 4 seconds).
CSER spark timing test Operation:
DTCs
P050B – Cold Start Ignition timing Performance
Monitor execution
Once per driving cycle, from startup with CSSRE active
Monitor Sequence
None
Sensors OK
Monitoring Duration
~ 7 seconds
CSER typical spark timing test entry conditions:
Entry Condition
Minimum
Maximum
Engine RPM
400 RPM
2000 RPM
No coil primary faults
Engine position synchronized
Cylinder identification synchronized
CSRE typical spark timing test malfunction thresholds:
Spark advanced from desired > 5 deg.
Fault present for 4 seconds
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 82 OF 160
Cold Start Emission Reduction System Monitor
The Cold Start Emission Reduction System Monitor is being introduced for the 2007 MY on vehicles that meet the
LEV-II emission standards. It will eventually replace the Cold Start Emission Reduction Component Monitor. The
Cold Start Emission Reduction (CSER) Monitor detects the lack of catalyst warm up resulting from a failure to
apply sufficient CSER during a cold start. It does this by using the inferred catalyst temperature model to
determine how closely the actual catalyst temperature follows the expected catalyst temperature during a cold
start. How closely the actual temperature follows the expected temperature is reflected in a ratio which is
compared with a calibratable threshold.
Temperatures Used
The actual catalyst temperature is the same inferred catalyst temperature that is used by other portions of the
engine control system, including the CSER control system. The inputs to this actual temperature are measured
engine speed, measured air mass, and commanded spark.
The expected catalyst temperature is calculated using the same algorithm as the actual catalyst temperature, but
the inputs are different. Desired engine speed replaces measured engine speed, desired air mass replaces
measured air mass, and desired cold start spark replaces commanded spark. The resulting temperature
represents the catalyst temperature that is expected if CSER is functioning properly.
Ratio Calculation
A ratio is calculated to reflect how closely the actual temperature has followed the expected temperature. This
ratio is the difference between the two temperatures at a certain time-since-start divided by the increase in
expected temperature over the same time period. The ratio, then, provides a measure of how much loss of
catalyst heating occurred over that time period.
This ratio correlates to tailpipe emissions. Therefore applying a threshold to it allows illumination of the MIL at the
appropriate emissions level. The threshold is a function of ECT at engine start.
General CSER Monitor Operation
During the first 15 seconds of a cold start, the monitor checks the entry conditions, counts time in idle, and
observes catalyst temperature.
If the expected change in catalyst temperature is large enough, the monitor calculates the ratio as described
above. Otherwise the monitor does not make a call.
The monitor then begins the waiting period, which lasts from the time the ratio is calculated (15 seconds after
engine start) until 300 seconds after engine start. This 5-minute wait allows time to diagnose other components
and systems that affect the validity of the catalyst temperature model. During this waiting period, there are no
constraints on drive cycle and the monitor cannot be disabled without turning off the key.
At the end of the waiting period, if no other faults that could compromise the validity the catalyst temperature model
are found, the monitor compares the ratio to the threshold.
If the ratio exceeds the threshold, the monitor considers the test a fail, and the monitor is complete.
If the ratio falls below the threshold, the monitor determines whether the idle time was sufficient. If so, it considers
the test a pass and the monitor is complete. If idle time was not sufficient, the monitor does not make a call and
does not complete. This prevents tip-ins from resulting in false passes.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 83 OF 160
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 84 OF 160
CSER MONITOR OPERATION
DTC
P050E: Cold Start Engine Exhaust Temperature Out Of Range
Monitor Execution
Once per driving cycle, during a cold start
Monitor Sequence
Monitor data collection takes place during first 15 seconds of cold start
Sensors OK
No fault is present in any of the sensors or systems affecting the catalyst
temperature model: MAF (P0102, P0103), TP (P0122, P0123, P0222, P0223),
Misfire (P0316, P0300-P0312), Injectors (P0201-P0212), Fuel System (P0171,
P0172, P0174, P0175), Secondary Air (P0412, P2258), CPS (P0320), Ignition
Coil (P0351-P0360), IAT (P0112, P0113), ECT/CHT (P0117, P0118, P1289,
P1290), VCT (P0010, P0020, P0011, P0012, P0021, P0022), IMRC (P2008).
Monitoring Duration
Monitor completes 300 seconds after initial engine start
TYPICAL CSER MONITOR ENTRY AND COMPLETION CONDITIONS
Entry condition
Minimum
Barometric Pressure
Maximum
22 in. Hg
Engine Coolant Temperature at Start
35 °F
100 °F
Catalyst Temperature at Start
35 °F
125 °F
Fuel Level
15%
No Torque Reduction by Injector Cutout
Power Takeout Not Active
Completion condition
Minimum
Length of Time Entry Conditions are Satisfied
Expected Change in Catalyst Temperature
Maximum
11 sec.
50 °F
Time in Idle
10 sec.
Selected Gear
Neutral
Drive
TYPICAL MALFUNCTION THRESHOLD
Cold start warm-up temperature ratio > 0.4
J1979 CSER MONITOR MODE $06 DATA
Monitor ID
Test ID
Description for CAN
Units
$F0
$80
Cold start warm-up temperature ratio
unitless
$F0
$80
Cold start warm-up temperature ratio threshold
unitless
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 85 OF 160
Variable Cam Timing System Monitor
Variable Cam Timing (VCT) enables rotation of the camshaft(s) relative to the crankshaft (phase-shifting) as a
function of engine operating conditions. There are four possible types of VCT with DOHC engines:
•
Intake Only (phase-shifting only the intake cam);
•
Exhaust Only (phase-shifting only the exhaust cam);
•
Dual Equal (phase-shifting the intake and exhaust cams equally);
•
Dual Independent (phase-shifting the intake and exhaust cams independently).
All four types of VCT are used primarily to increase internal residual dilution at part throttle to reduce NOx, and to
improve fuel economy. This allows for elimination the external EGR system.
With Exhaust Only VCT, the exhaust camshaft is retarded at part throttle to delay exhaust valve closing for
increased residual dilution and to delay exhaust valve opening for increased expansion work.
With Intake Only VCT, the intake camshaft is advanced at part throttle and WOT (at low to mid-range engine
speeds) to open the intake valve earlier for increased residual dilution and close the intake valve earlier in the
compression stroke for increased power. When the engine is cold, opening the intake valve earlier warms the
charge which improves fuel vaporization for less HC emissions; when the engine is warm, the residual burned
gasses limit peak combustion temperature to reduce NOx formation.
With Dual Equal VCT, both intake and exhaust camshafts are retarded from the default, fully advanced position to
increase EGR residual and improve fuel economy by reducing intake vacuum pumping losses. The residual
charge for NOx control is obtained by backflow through the late-closing exhaust valve as the piston begins its
intake stroke.
The VCT system hardware consists of a control solenoid and a pulse ring on the camshaft. The PCM calculates
relative cam position using the CMP input to process variable reluctance sensor pulses coming from the pulse ring
mounted on the camshaft. Each pulse wheel has N + 1 teeth where N = the number of cylinders per bank. The N
equally spaced teeth are used for cam phasing; the remaining tooth is used to determine cylinder # 1 position.
Relative cam position is calculated by measuring the time between the rising edge of profile ignition pickup (PIP)
and the falling edges of the VCT pulses.
The PCM continually calculates a cam position error value based on the difference between the desired and actual
position and uses this information to calculate a commanded duty cycle for the VCT solenoid valve. When
energized, engine oil is allowed to flow to the VCT unit thereby advancing and retarding cam timing. The variable
cam timing unit assembly is coupled to the camshaft through a helical spline in the VCT unit chamber. When the
flow of oil is shifted from one side of the chamber to the other, the differential change in oil pressure forces the
piston to move linearly along the axis of the camshaft. This linear motion is translated into rotational camshaft
motion through the helical spline coupling. A spring installed in the chamber is designed to hold the camshaft in the
low-overlap position when oil pressure is too low (~15 psi) to maintain adequate position control. The camshaft is
allowed to rotate up to 30 degrees.
Although the VCT system has been monitored under Comprehensive Component Monitoring requirements for
many years, a new, emission-based VCT monitor is being introduced for the 2006 MY on vehicles that meet LEV-II
emission standards. The intent of the new VCT monitoring requirements is to detect slow VCT system response
that could cause emissions to increase greater than 1.5 * std. in addition to detecting functional problems (target
errors).
The new logic calculates the instantaneous variance in actual cam position (the squared difference between actual
cam position and commanded cam position), then calculates the long term variance using a rolling average filter
(Exponentially Weighted Moving Average). Continued, slow response from the VCT system will eventually
accumulate large variances.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 86 OF 160
This same logic will also detect target errors that were detected by the previous CCM monitor. If the VCT system is
stuck in one place, the monitor will detect a variance which will quickly accumulate.
There are three variance indices that monitor cam variance in the retard direction, the advance direction, and for Vengines, the difference between banks. If any variance index is greater than the malfunction threshold, a VCT slow
response/target error malfunction will be indicated (P0011, P0012 Bank 1, 0021, P0022 Bank 2). Target errors will
tend to generate only a single over-advanced or over-retarded code while slow response will tend to generate both
codes.
In addition, logic has been added to determine whether the camshaft and crankshaft are misaligned by one or
more teeth. This test calculates the absolute offset between one of the camshaft teeth and the crankshaft missing
tooth at idle when that can is at its stop. If the error is greater than the malfunction threshold, a cam/crank
misalignment error will be indicated (P0016 Bank 1, P0018 Bank 2).
The in-use performance ratio numerator for the VCT monitor can be incremented only if the VCT system has been
monitored for both functional and response faults. If the vehicle is operated in a manner that does not ask the VCT
actuators to change position, it may not be possible to evaluate whether they are working properly. As a result, the
in-use ratio numerator checks to see if the commanded VCT position changes sufficiently to detect possible target
errors and with a sufficiently high rate to detect possible slow response. For each drive cycle in which both criteria
are met, the VCT in-use performance numerator will be incremented.
Similar to the previous CCM monitor, the VCT solenoid output driver in the PCM is checked electrically for opens
and shorts (P0010 Bank 1, P0020 Bank 2).
VCT Monitor Operation:
DTCs
P0010 - Camshaft Position Actuator Circuit (Bank 1)
P0011 - Cam Position Actuator Over Advanced (Bank 1)
P0012 - Cam Position Actuator Over Retarded (Bank 1)
P0016 - Crank/Cam Position Correlation (Bank 1)
P0020 - Camshaft Position Actuator Circuit (Bank 2)
P0021 - Cam Position Actuator Over Advanced (Bank 2)
P0022 - Cam Position Actuator Over Retarded (Bank 2)
P0018 - Crank/Cam Position Correlation (Bank 2)
Monitor execution
continuous
Monitor Sequence
None
Sensors OK
IAT, ECT, EOT, IMRC, TP, MAF, CKP, and CMP
Monitoring Duration
5 seconds for circuit faults, 300 seconds for target error
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 87 OF 160
Typical VCT response/functional monitor entry conditions:
Entry condition
Minimum
Maximum
Engine RPM (for P0016/P0018 only)
500
4500
Engine Coolant Temperature
32 F
o
o
Engine Oil Temperature
280 F
VCT control enabled and commanded to advance or
retard cam **
n/a
n/a
** VCT control of advance and retard by the engine is disabled in crank mode, when engine oil is cold (< 150
o
F), while learning the cam/crank offset, while the control system is "cleaning" the solenoid oil passages,
throttle actuator control in failure mode, and if one of the following sensor failures occur: IAT, ECT, EOT,
MAF, TP, CKP, CMP, or IMRC.
Typical VCT monitor malfunction thresholds:
VCT solenoid circuit: Open/short fault set by the PCM driver
Cam/crank misalignment: > or = one tooth difference, or 17 crank degrees
Response/target error - VCT over-advance variance too high: 40 to 700 degrees squared
Response/target error - VCT over-retard variance too high: 40 to 700 degrees squared
Response/target error - Cam bank-to-bank variance too high: 40 to 700; degrees squared
Typical In-Use Performance monitoring thresholds:
Monitoring thresholds to increment the numerator:
Amount of cam change required for target error fault: > 160 degrees squared
Amount of rate of change required for slow response fault: > 5 degrees squared
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 88 OF 160
Electronic Throttle Control
The Gen 2 Electronic Throttle Control system uses a strategy that delivers engine or output shaft torque, based
on driver demand, utilizing an electronically controlled throttle body. Gen 2 ETC strategy was developed mainly to
improve fuel economy. This is possible by decoupling throttle angle (produces engine torque) from pedal position
(driver demand). This allows the powertrain control strategy to optimize fuel control and transmission shift
schedules while delivering the requested engine or wheel torque. Gen 2 ETC is being used on most Ford
products.
Because safety is a major concern with ETC systems, a complex safety monitor strategy (hardware and
software) was developed. The monitor system is distributed across two processors: the main powertrain control
processor and a monitoring processor called an Enhanced-Quizzer (E-Quizzer) processor.
The primary monitoring function is performed by the Independent Plausibility Check (IPC) software, which resides
on the main processor. It is responsible for determining the driver-demanded torque and comparing it to an
estimate of the actual torque delivered. If the generated torque exceeds driver demand by specified amount, the
IPC takes appropriate mitigating action.
Since the IPC and main controls share the same processor, they are subject to a number of potential, commonfailure modes. Therefore, the E-Quizzer processor was added to redundantly monitor selected PCM inputs and to
act as an intelligent watchdog and monitor the performance of the IPC and the main processor. If it determines
that the IPC function is impaired in any way, it takes appropriate Failure Mode and Effects Management (FMEM)
actions.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 89 OF 160
ETC System Failure Mode and Effects Management:
Effect
Failure Mode
No Effect on Driveability
A loss of redundancy or loss of a non-critical input could result in a fault that does not affect
driveability. The ETC light will turn on, but the throttle control and torque control systems will
function normally.
RPM Guard w/ Pedal
Follower
In this mode, torque control is disabled due to the loss of a critical sensor or PCM fault. The
throttle is controlled in pedal-follower mode as a function of the pedal position sensor input
only. A maximum allowed RPM is determined based on pedal position (RPM Guard.) If the
actual RPM exceeds this limit, spark and fuel are used to bring the RPM below the limit. The
ETC light and the MIL are turned on in this mode and a P2106 or other ETC component
causal code is set. EGR, VCT, and IMRC outputs are set to default values.
RPM Guard w/ Default
Throttle
In this mode, the throttle plate control is disabled due to the loss of Throttle Position, the
Throttle Plate Position Controller, or other major Electronic Throttle Body fault. A default
command is sent to the TPPC, or the H-bridge is disabled. Depending on the fault detected,
the throttle plate is controlled or springs to the default (limp home) position. A maximum
allowed RPM is determined based on pedal position (RPM Guard.) If the actual RPM
exceeds this limit, spark and fuel are used to bring the RPM below the limit. The ETC light
and the MIL are turned on in this mode and a P2110 is set. EGR, VCT, and IMRC outputs
are set to default values.
RPM Guard w/ Forced
High Idle
This mode is caused by the loss of 2 or 3 pedal position sensor inputs due to sensor, wiring,
or PCM faults. The system is unable to determine driver demand, and the throttle is controlled
to a fixed high idle airflow. There is no response to the driver input. The maximum allowed
RPM is a fixed value (RPM Guard.) If the actual RPM exceeds this limit, spark and fuel are
used to bring the RPM below the limit. The ETC light and the MIL are turned on in this mode
and a P2104 is set. EGR, VCT, and IMRC outputs are set to default values.
Shutdown
If a significant processor fault is detected, the monitor will force vehicle shutdown by disabling
all fuel injectors. The ETC light is turned on in this mode and a P2105 is set.
Note: Vehicle shutdown does not increase emissions; therefore the MIL is not required to be
illuminated for this fault.
Note: ETC illuminates or displays a message on the message center immediately, MIL
illuminates after 2 driving cycles
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 90 OF 160
Electronic Throttle Monitor
Electronic Throttle Monitor Operation:
DTCs
P2106 – ETC FMEM – forced limited power; sensor fault: MAF, one TP, CKP, TSS,
OSS, stuck throttle, throttle actuator circuit fault (MIL, ETC light)
P2110 – ETC FMEM – forced limited rpm; two TPs failed; TPPC detected fault (MIL,
ETC light)
P2104 – ETC FMEM – forced idle, two or three pedal sensors failed (MIL, ETC light)
P2105 – ETC FMEM – forced engine shutdown; EQuizzer detected fault (MIL, ETC
light)
U0300 – ETC software version mismatch, IPC, EQuizzer or TPPC (non-MIL, ETC
light)
P0600 – Serial Communication Link (non-MIL, ETC light)
P060A – Internal control module monitoring processor performance (non-MIL, ETC
light)
P060B – Internal control module A/D processing performance (MIL, ETC light)
P060C – Internal control module main processor performance (MIL, ETC light)
P061B – Internal control module torque calculation performance (MIL, ETC light)
P061C – Internal control module engine rpm performance (MIL, ETC light)
P061D – Internal control module engine airmass performance (MIL, ETC light)
P061F – Internal control module throttle actuator controller performance (MIL, ETC
light)
P062C – Internal control module vehicle speed performance (MIL, ETC light)
P1674 – Internal control module software corrupted (non-MIL, ETC light)
Monitor execution
Continuous
Monitor Sequence
None
Sensors OK
not applicable
Monitoring Duration
< 1 seconds to register a malfunction
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 91 OF 160
Accelerator and Throttle Position Sensor Inputs
Accelerator Pedal Position Sensor Check Operation:
DTCs
P2122, P2123 – APP D circuit continuity (ETC light, non-MIL)
P2121 – APP D range/performance (ETC light, non-MIL)
P2127, P2128 – APP E circuit continuity (ETC light, non-MIL)
P2126 – APP E range/performance (ETC light, non-MIL)
P2132, P2133 – APP F circuit continuity (ETC light, non-MIL)
P2131 – APP F range/performance (ETC light, non-MIL)
Monitor execution
continuous
Monitor Sequence
none
Sensors OK
not applicable
Monitoring Duration
< 1 seconds to register a malfunction
APP sensor check malfunction thresholds:
Circuit continuity - Voltage < 0.25 volts or voltage > 4.75 volts
Range/performance – sensor disagreement between processors (PCM and EQuizzer)
Throttle Position Sensor Check Operation:
DTCs
P0122, P0123 – TP A circuit continuity (MIL, ETC light)
P0121 – TP A range/performance (non-MIL)
P2135 – TP A / TP B correlation (ETC light, non-MIL)
P0222, P0223 – TP B circuit continuity (MIL, ETC light)
P0221 – TP B range/performance (non-MIL)
Monitor execution
Continuous
Monitor Sequence
None
Sensors OK
not applicable
Monitoring Duration
< 1 seconds to register a malfunction
TP sensor check malfunction thresholds:
Circuit continuity - Voltage < 0.25 volts or voltage > 4.75 volts
Correlation and range/performance – sensor disagreement between processors (PCM and EQuizzer), TP
inconsistent with TPPC throttle plate position
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 92 OF 160
Throttle Plate Position Controller (TPPC) Outputs
The purpose of the TPPC is to control the throttle position to the desired throttle angle. It is a separate chip
embedded in the PCM. The desired angle is communicated from the main CPU via a 312.5 Hz duty cycle signal.
The TPPC interprets the duty cycle signal as follows:
0% <= DC < 4% - Out of range, limp home default position.
4% <= DC < 6% - Commanded default position, closed.
6% <= DC < 7% - Commanded default position. Used for key-on, engine off.
7% <= DC < 8% - Ice Breaker Mode.
8% <= DC < 10% - Closed against hard-stop. Used to learn zero throttle angle position (hard-stop) after
key-up
10% <= DC <=92% - Normal operation, between 0 degrees (hard-stop) and 82%, 10% duty cycle = 0
degrees throttle angle, 92% duty cycle = 82 degrees throttle angle.
92% < DC <= 96% - Wide Open Throttle, 82 to 86 degrees throttle angle.
96% < DC <= 100% - Out of Range, limp home default position
The desired angle is relative to the hard-stop angle. The hard-stop angle is learned during each key-up process
before the main CPU requests the throttle plate to be closed against the hard-stop. The output of the TPPC is a
voltage request to the H-driver (also in PCM). The H driver is capable of positive or negative voltage to the
Electronic Throttle Body Motor.
Throttle Plate Controller and Actuator Operation:
DTCs
P2107 – processor test (MIL)
P2111 – throttle actuator system stuck open (MIL)
P2112 – throttle actuator system stuck closed (MIL)
P2100 – throttle actuator circuit open, short to power, short to ground (non-MIL)
P2101 – throttle actuator range/performance test (MIL)
P2072 – throttle body ice blockage (non-MIL)
P115E – throttle actuator airflow trim at max limit (non-MIL)
Note: For all the above DTCs, in addition to the MIL, the ETC light will be on for
the fault that caused the FMEM action.
Monitor execution
Continuous
Monitor Sequence
None
Monitoring Duration
< 5 seconds to register a malfunction
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 93 OF 160
Comprehensive Component Monitor - Engine
Engine Temperature Sensor Inputs
Analog inputs such as Intake Air Temperature (P0112, P0113), Engine Coolant Temperature (P0117, P0118),
Cylinder Head Temperature (P1289. P1290), Mass Air Flow (P0102, P0103) and Throttle Position (P0122, P0123,
P1120), Fuel Temperature (P0182, P0183), Engine Oil Temperature (P0197, P0198), Fuel Rail Pressure (p0192,
P0193) are checked for opens, shorts, or rationality by monitoring the analog -to-digital (A/D) input voltage.
Engine Coolant Temperature Sensor Check Operation:
DTCs
P0117 (low input), P0118 (high input)
Monitor execution
continuous
Monitor Sequence
None
Sensors OK
not applicable
Monitoring Duration
5 seconds to register a malfunction
Typical ECT sensor check malfunction thresholds:
Voltage < 0.244 volts or
voltage > 4.96 volts
The ECT rationality test checks to make sure that ECT is not stuck in a range that causes other OBD to be
o
disabled. If after a long (6 hour) soak, ECT is very high (> 230 F) and is also much higher than IAT at start, it is
o
assumed that ECT is stuck high. If after a long (6 hour) soak, ECT is stuck midrange between 175 F (typical
o
thermostat monitor threshold temperature) and 230 F and is also much higher than IAT at start, it is assumed that
ECT is stuck mid range.
ECT Sensor Rationality Check Operation:
DTCs
P0116 (ECT stuck high or midrange)
Monitor execution
Once per driving cycle
Monitor Sequence
None
Sensors OK
ECT, CHT, IAT
Monitoring Duration
100 seconds to register a malfunction
Typical ECT Sensor Rationality check entry conditions:
Entry Condition
Minimum
Engine-off time (soak time)
360 min
Maximum
50 deg
Difference between ECT and IAT
o
Engine Coolant Temperature for stuck high condition
230 F
Engine Coolant Temperature for stuck midrange condition
175 F
o
o
230 F
Typical ECT Sensor Rationality check malfunction thresholds:
ECT stuck high for > 100 seconds and Catalyst, Misfire, Fuel System or HO2S Monitors have not run this
drive cycle for stuck high condition OR ECT stuck midrange for > 100 seconds
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 94 OF 160
Currently, vehicles use either an ECT sensor or CHT sensor, not both. The CHT sensor measures cylinder head
metal temperature as opposed to engine coolant temperature. At lower temperatures, CHT temperature is
equivalent to ECT temperature. At higher temperatures, ECT reaches a maximum temperature (dictated by
coolant composition and pressure) whereas CHT continues to indicate cylinder head metal temperature. If there is
a loss of coolant or air in the cooling system, the CHT sensor will still provides an accurate measure of cylinder
head metal temperature. If a vehicle uses a CHT sensor, the PCM software calculates both CHT and ECT values
for use by the PCM control and OBD systems.
Cylinder Head Temperature Sensor Check Operation:
DTCs
P1289 (high input), P1290 (low input), P1299 (fail-safe cooling activated)
Monitor execution
continuous
Monitor Sequence
none
Sensors OK
not applicable
Monitoring Duration
5 seconds to register a malfunction
Typical CHT sensor check malfunction thresholds:
Voltage < 0.244 volts or voltage > 4.96 volts
o.
For P1299, MIL illuminates immediately if CHT > 270 Fuel shut-off is activated to reduce engine and coolant
temperature
Intake Air Temperature Sensor Check Operation:
DTCs
P0112 (low input), P0113 (high input)
Monitor execution
continuous
Monitor Sequence
none
Sensors OK
not applicable
Monitoring Duration
5 seconds to register a malfunction
Typical IAT sensor check malfunction thresholds:
Voltage < 0.244 volts or
voltage > 4.96 volts
Engine Oil Temperature Sensor Check Operation:
DTCs
P0197 (low input), P0198 (high input)
Monitor execution
continuous
Monitor Sequence
none
Sensors OK
not applicable
Monitoring Duration
5 seconds to register a malfunction
Typical EOT sensor check malfunction thresholds:
Voltage < 0.20 volts or
FORD MOTOR COMPANY
voltage > 4.96 volts
REVISION DATE: NOVEMBER 12, 2007
PAGE 95 OF 160
ECT, IAT, EOT Temperature Sensor Transfer Function
Volts
A/D counts in PCM
Temperature, degrees F
4.89
1001
-40
4.86
994
-31
4.81
983
-22
4.74
970
-13
4.66
954
-4
4.56
934
5
4.45
910
14
4.30
880
23
4.14
846
32
3.95
807
41
3.73
764
50
3.50
717
59
3.26
666
68
3.00
614
77
2.74
561
86
2.48
508
95
2.23
456
104
1.99
407
113
1.77
361
122
1.56
319
131
1.37
280
140
1.20
246
149
1.05
215
158
0.92
188
167
0.80
165
176
0.70
144
185
0.61
126
194
0.54
110
203
0.47
96
212
0.41
85
221
0.36
74
230
0.32
65
239
0.28
57
248
0.25
51
257
0.22
45
266
0.19
40
275
0.17
35
284
0.15
31
293
0.14
28
302
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 96 OF 160
The Cylinder Head Temp Sensor uses a switchable input circuit to create two transfer functions for cold and hot
range temperatures
CHT Temperature Sensor Transfer Function, Cold End
Volts
A/D counts in PCM
Temperature, degrees F
4.899
1002
-40
4.861
995
-31
4.812
985
-22
4.75
972
-14
4.671
956
-4
4.572
936
4
4.452
911
14
4.309
882
22
4.14
847
32
3.95
808
40
3.737
765
48
3.508
717
58
3.26
666
68
3.00
614
77
2.738
560
87
2.478
507
96
2.226
455
105
1.985
406
114
1.759
360
122
1.551
317
132
1.362
279
141
1.193
244
149
1.043
213
159
0.91
186
168
0.794
162
176
0.693
142
186
0.604
124
194
0.528
108
203
0.462
95
204
CHT Temperature Sensor Transfer Function, Hot End
Volts
A/D counts in PCM
Temperature, degrees F
4.235
866
168
4.119
843
168
3.993
817
176
3.858
789
185
3.714
760
194
3.563
729
203
3.408
697
212
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 97 OF 160
3.244
664
221
3.076
629
230
2.908
595
239
2.740
561
248
2.575
527
257
2.411
493
266
2.252
461
275
2.099
430
284
1.953
400
294
1.813
371
303
1.680
344
312
1.556
318
320
1.439
294
329
1.329
272
338
1.228
251
347
1.133
232
356
1.046
214
366
0.965
197
375
0.891
182
383
0.822
168
392
0.760
155
401
0.701
144
408
0.648
133
415
0.599
123
422
0.555
113
428
0.513
105
433
0.476
97
438
0.441
90
442
0.409
84
447
0.380
78
450
0.353
72
454
0.328
67
457
0.306
63
460
0.285
58
463
0.265
54
465
0.248
51
468
0.231
47
470
0.216
44
472
0.202
41
474
0.190
39
475
0.178
36
477
0.167
34
478
0.156
32
480
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 98 OF 160
IAT Rationality Test
The IAT rationality test determines if the IAT sensor is producing an erroneous temperature indication within the
normal range of IAT sensor input. The IAT sensor rationality test is run only once per power-up. The IAT sensor
input is compared to the CHT sensor input (ECT sensor input on some applications) at key-on after a long (6 hour)
soak. If the IAT sensor input and the CHT (ECT) sensor input agree within a tolerance (+/- 30 deg F), no
malfunction is indicated and the test is complete. If the IAT sensor input and the CHT (ECT) sensor input differ by
more than the tolerance, the vehicle must be driven over 35 mph for 5 minutes to confirm the fault. This is intended
to address noise factors like sun load that can cause the IAT sensor to indicate a much higher temperature than
the CHT (ECT) sensor after a long soak. Driving the vehicle attempts to bring the IAT sensor reading within the
test tolerance. If the IAT sensor input remains outside of the tolerance after the vehicle drive conditions have been
met, the test indicates a malfunction and the test is complete.
Intake Air Temperature Sensor Range/Performance Check Operation:
DTCs
P0111 (range/performance)
Monitor execution
Once per driving cycle, at start-up
Monitor Sequence
None
Sensors OK
ECT/CHT, IAT, VSS
Monitoring Duration
Immediate or up to 30 minutes to register a malfunction
Typical Intake Air Temperature Sensor Range/Performance Entry Conditions
Entry condition
Minimum
Engine off (soak) time
Maximum
6 hours
Battery Voltage
11.0 Volts
Time since engine start (if driving req'd)
Vehicle speed (if driving req'd)
30 min
35 mph
Time above minimum vehicle speed (if driving req'd)
5 min
IAT - ECT at start (block heater inferred)
-30 °F
-90 °F
Typical IAT sensor check malfunction thresholds:
IAT and ECT/CHT error at start-up > +/-30 deg F
The IAT rationality test employs alternate statistical MIL illumination. This protocol allows up to 6 trips before MIL
illumination based on the magnitude of the measured error. The greater the error the fewer number of trips before
a DTC will be indicated. In the case of the IAT rationality test the measured error is the difference between the IAT
input and the CHT (ECT) input.
The error space is divided into bands. Each band represents a range of error. There are two bands for each of; 5
trips to pending DTC, 4 trips to pending DTC, 3 trips to pending DTC, 2 trips to pending DTC and 1 trip to pending
DTC. There are two bands for each because there is one band for positive error and one band for negative error
of the same magnitude range.
Counters are maintained that keep track of how many trips a malfunction has occurred within each band. When a
sufficient number of trips with a malfunction has been achieved in any band, a P0111 DTC will be set.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 99 OF 160
If an IAT error, trip to trip, remains just above the IAT-out-of-range error threshold, it will take 6 trips to illuminate the
MIL. If the IAT-out-of-range error, trip to trip, is much larger (80 deg F), the MIL will illuminate in the standard 2
trips.
Note that immediately after an KAM clear/battery disconnect, the MIL will be set after two trips regardless of the
amount the IAT error exceeds the threshold.
IAT - ECT at start
(deg F)
80
75
2 Trip MIL
3 Trip MIL
65
4 Trip MIL
50
5 Trip MIL
30
6 Trip MIL
0
No Fault
-30
6 Trip MIL
-50
-65
-75
-80
FORD MOTOR COMPANY
5 Trip MIL
No Call Block Heater
4 Trip MIL
3 Trip MIL
2 Trip MIL
REVISION DATE: NOVEMBER 12, 2007
PAGE 100 OF 160
Fuel Rail Pressure Sensor
Fuel Rail Pressure Sensor Check Operation:
DTCs
P0192 (low input), P0193 (high input)
Monitor execution
continuous
Monitor Sequence
None
Sensors OK
not applicable
Monitoring Duration
8 seconds to register a malfunction
Typical FRP sensor check malfunction thresholds:
Voltage < 0.049 volts or
voltage > 4.88 volts
Fuel Rail Pressure Sensor Transfer Function
FRP volts = [ Vref * ( 4 * Fuel Pressure / 70) + 0.50 ] / 5.00
Volts
A/D counts in PCM
Pressure, psi
4.85
993
76.125
4.50
922
70
4.00
820
61.25
3.50
717
52.5
3.00
614
43.75
2.50
512
35
2.00
410
26.25
1.50
307
17.5
1.00
205
8.75
0.50
102
0
0.15
31
-6.125
The FRP range/performance test checks to make sure that fuel rail pressure can be properly controlled by the
electronic returnless fuel system. The FPS sensor is also checked for in-range failures that can be caused by loss
of Vref to the sensor. Note that the FRP is referenced to manifold vacuum (via a hose) while the fuel rail pressure
sensor is not referenced to manifold vacuum. It uses gage pressure. As a result, a mechanical gage in the fuel rail
will display a different pressure than the FPR PID on a scan tool. The scan tool PID will read higher because of
manifold vacuum.
FRP Range/Performance Check Operation:
DTCs
P0191 (FRP range/performance), P1090 (stuck in range)
Monitor execution
Continuous
Monitor Sequence
None
Sensors OK
FRP
Monitoring Duration
8 seconds to register a malfunction
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 101 OF 160
Typical FRP Sensor Range/Performance check entry conditions:
Entry Condition
Minimum
Maximum
Demand pressure reasonable
35 psig
60 psig
Fuel level
15%
Typical FRP Range/Performance check malfunction thresholds:
Fuel pressure error (demand – actual pressure) > 20 psig
Typical FRP Sensor Stuck check entry conditions:
Entry Condition
Minimum
Maximum
FRP sensor input
0 psig
46 psig
1 psig / sec
FRP input not moving
Typical FRP Stuck check malfunction thresholds:
Fuel pressure error (demand – actual pressure) > 5 psig
Throttle Position Sensor
Throttle Position Sensor Check Operation:
DTCs
P0122 (low input), P0123 (high input), P1120 (closed throttle too low)
Monitor execution
continuous
Monitor Sequence
none
Sensors OK
not applicable
Monitoring Duration
5 seconds to register a malfunction
Typical TP sensor check malfunction thresholds:
Voltage < 0.20 volts or
FORD MOTOR COMPANY
voltage > 4.80 volts or
voltage < 0.488
REVISION DATE: NOVEMBER 12, 2007
PAGE 102 OF 160
Mass Air Flow Sensor
MAF Sensor Check Operation:
DTCs
P0102 (low input), P0103 (high input)
Monitor execution
continuous
Monitor Sequence
none
Sensors OK
not applicable
Monitoring Duration
5 seconds to register a malfunction
Typical MAF sensor check malfunction thresholds:
Voltage < 0.244 volts and engine running or
voltage > 4.785 volts engine rpm < 4,000 rpm
MAF/TP Rationality Test
The MAF and TP sensors are cross-checked to determine whether the sensor readings are rational and
appropriate for the current operating conditions. (P1121/P0068)
MAF/TP Rationality Check Operation:
DTCs
P1121 or P0068
Monitor execution
Continuous
Monitor Sequence
None
Sensors OK
Monitoring Duration
3 seconds within test entry conditions
Typical MAF/TP rationality check entry conditions:
Entry Condition
Minimum
Maximum
Engine RPM
1000 rpm
minimum of 3800 rpm
Engine Coolant Temp
o
100 F
Typical MAF/TP rationality check malfunction thresholds:
Load > 60% and TP < 2.4 volts or Load < 30% and TP > 2.4 volts
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 103 OF 160
Miscellaneous CPU Tests
Loss of Keep Alive Memory (KAM) power (a separate wire feeding the PCM) results is a P1633 DTC and
immediate MIL illumination.
Vehicles that require tire/axle information and VIN to be programmed into the Vehicle ID block (VID) will store a
P1639 if the VID block is not programmed or corrupted.
Additional DTCs will be stored to indicate various internal PCM hardware malfunctions:
P0602 - Powertrain Control Module Programming Error indicates that the Vehicle ID block check sum test failed.
P0603 - Powertrain Control Module Keep Alive Memory (KAM) Error indicates the Keep Alive Memory check sum
test failed.
P0604 - Powertrain Control Module Random Access Memory (RAM) Error indicates the Random Access Memory
read/write test failed.
P0605 - Powertrain Control Module Read Only Memory (ROM) Error indicates a Read Only Memory check sum
test failed.
P0607 - Powertrain Control Module Performance indicates incorrect CPU instruction set operation, or excessive
CPU resets.
The PCM "engine off" or "soak" timer is tested to ensure that it is functional. The value of engine coolant
temperature decays after the engine is turned off. This decay is modeled as a function of ECT, IAT and soak time.
If, during a cold start, (difference between ECT and IAT is low), the actual ECT at start is much lower than the
predicted ECT at start, it means that the soak timer is not functioning and a P0606 DTC is stored. (If the timer fails,
it will read zero seconds and the model will predict that ECT will be the same temperature as when the engine was
last turned off.)
Ignition System Tests
EDIS Ignition
The EDIS system uses a chip to process the 36 (or 40) tooth crankshaft position signal, generate a low data rate
PIP signal for the PCM microprocessor and control a 4 or 6 terminal coil pack which fires a pair of spark plugs. One
of these sparkplugs is on the compression stroke, while the other is on the exhaust stroke. The EDIS chip can be
incorporated within the PCM or in a separate ignition control module. The COP system also uses an EDIS chip in
the same way as described above, however, each sparkplug has it’s own coil which is fired only once on the
compression stroke.
The EDIS ignition system is checked by monitoring three ignition signals during normal vehicle operation:
Profile Ignition Pickup (CKP, commonly known as PIP), the timing reference signal derived from the
crankshaft 36-tooth wheel and processed by the EDIS chip. PIP is a 50% duty cycle, square wave signal
that has a rising edge at 10 deg BTDC.
Camshaft IDentification (CMP, commonly known at CID), a signal derived from the camshaft to identify the
#1 cylinder
Ignition Diagnostic Monitor (IDM), a signal that indicates that the primary side of the coil has fired. This
signal is received as a digital pulsewidth signal from the EDIS chip. The EDIS chip determines if the
current flow to the ignition coil reaches the required current (typically 5.5 Amps for COP, 3.0 to 4.0 Amps
for DIS) within a specified time period (typically > 200 microseconds for both COP and DIS). The EDIS
chip also outputs status information when the engine is not running.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 104 OF 160
First, the relationship between successive PIP events is evaluated to determine whether the PIP signal is rational.
Too large a change in 3 successive PIP indicates a missing or noisy PIP signal (P0320).
Next, the CMP edge count is compared to the PIP edge count. If the proper ratio of CMP events to PIP events is
not being maintained (for example, 1 CMP edge for every 8 PIP edges for an 8-cylinder engine), it indicates a
missing or noisy CMP signal (P0340).
Finally, the relationship between IDM edges and PIP edges is evaluated. If there is not an IDM edge (coil firing) for
every PIP edge (commanded spark event), the PCM will look for a pattern of failed IDM events to determine which
ignition coil has failed. If the ignition coil cannot be identified or if the engine is running and there are no IDM edges,
the IDM circuit is malfunctioning (P1351).
Power PC Ignition
New "Power PC" processors no longer use an EDIS chip for ignition signal processing. The signals are now
directly processed by the PCM using a special interface chip called a Time Processing Unit or TPU. The 36-tooth
crankshaft and camshaft position signals come directly into the TPU. The signals to fire the ignition coil drivers also
come from the TPU.
The PowerPC ignition system is checked by monitoring three ignition signals during normal vehicle operation:
CKP, the signal from the crankshaft 36-1-tooth wheel. The missing tooth is used to locate the cylinder pair
associated with cylinder # 1 The TPU also generates the Profile Ignition Pickup (PIP) signal, a 50% duty
cycle, square wave signal that has a rising edge at 10 deg BTDC.
Camshaft IDentification (CMP, commonly known at CID), a signal derived from the camshaft to identify the
#1 cylinder
NOMI, a signal that indicates that the primary side of the coil has achieved the nominal current required for
proper firing of the spark plug. This signal is received as a digital signal from the coil drivers to the TPU.
The coil drivers determine if the current flow to the ignition coil reaches the required current (typically 5.5
Amps for COP, 3.0 to 4.0 Amps for DIS) within a specified time period (typically > 200 microseconds for
both COP and DIS).
First, several relationships are checked on the 36-1 tooth CKP signal. The TPU looks for the proper number of
teeth (35 or 39) after the missing tooth is recognized; time between teeth too low (< 30 rpm or > 9,000 rpm); or the
missing tooth was not where it was expected to be. If an error occurs, the TPU shuts off fuel and the ignition coils
and attempts to resynchronize itself. It takes on revolution to verify the missing tooth, and another revolution to
verify cylinder #1 using the CMP input. Note that if a P0320 DTC is set on a vehicle with Electronic Throttle Control,
(ETC), the ETC software will also set a P2106.
If the proper ratio of CMP events to PIP events is not being maintained (for example, 1 CMP edge for every 8 PIP
edges for an 8-cylinder engine), it indicates a missing or noisy CMP signal (P0340). On applications with Variable
Cam Timing (VCT), the CMP wheel has five teeth to provide the VCT system with more accurate camshaft control.
The TPU checks the CMP signal for an intermittent signal by looking for CMP edges where they would not be
expected to be. If an intermittent is detected, the VCT system is disabled and a P0344 (CMP Intermittent Bank 1)
or P0349 (CMP intermittent Bank 2) is set.
Finally, the relationship between NOMI events and PIP events is evaluated. If there is not an NOMI signal for every
PIP edge (commanded spark event), the PCM will look for a pattern of failed NOMI events to determine which
ignition coil has failed.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 105 OF 160
CKP Ignition System Check Operation:
DTCs
P0320 (CKP)
Monitor execution
continuous
Monitor Sequence
none
Sensors OK
Monitoring Duration
< 5 seconds
Typical CKP ignition check entry conditions:
Entry Condition
Minimum
Engine RPM for CKP
200 rpm
Maximum
Typical CKP ignition check malfunction thresholds:
EDIS:
For PIP: Time between PIP edges: > 350 milliseconds
Ratio of current PIP period to last two periods: < 0.75, > 1.75
PowerPC: Incorrect number of teeth after the missing tooth is recognized,
Time between teeth too low (< 30 rpm or > 9,000 rpm)
Missing tooth was not where it was expected to be.
CMP Ignition System Check Operation:
DTCs
P0340 (CMP)
P0344 (CMP Intermittent Bank 1)
P0349 (CMP Intermittent Bank 2)
Monitor execution
continuous
Monitor Sequence
none
Sensors OK
Monitoring Duration
< 5 seconds
Typical CMP ignition check entry conditions:
Entry Condition
Minimum
Engine RPM for CMP
200 rpm
Maximum
Typical CMP ignition check malfunction thresholds:
EDIS: Ratio of PIP events to CMP events: 4:1, 6:1, 8:1 or 10:1 based on engine cyl.
PowerPC: Ratio of PIP events to CMP events: 4:1, 6:1, 8:1 or 10:1 based on engine cyl.,
Intermittent CMP signal – CMP signal in unexpected location
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 106 OF 160
Coil Primary Ignition System Check Operation:
DTCs
P0351 – P0360 (Coil primary)
Monitor execution
Continuous
Monitor Sequence
None
Sensors OK
Monitoring Duration
< 5 seconds
Typical Coil primary ignition check entry conditions:
Entry Condition
Minimum
Maximum
Engine RPM for coil primary
200 rpm
Minimum of 3200 rpm
Positive engine torque
Positive torque
Typical Coil primary ignition check malfunction thresholds:
Ratio of PIP events to IDM or NOMI events 1:1
If an ignition coil primary circuit failure is detected for a single cylinder or coil pair, the fuel injector to that cylinder or
cylinder pair will be shut off for 30 seconds to prevent catalyst damage. Up to two cylinders may be disabled at the
same time on 6 and 8 cylinder engines and one cylinder is disabled on 4 cylinder engines. After 30 seconds, the
injector is re-enabled. If an ignition coil primary circuit failure is again detected, (about 0.10 seconds), the fuel
injector will be shut off again and the process will repeat until the fault is no longer present. Note that engine misfire
can trigger the same type of fuel injector disablement.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 107 OF 160
Engine Outputs
The Idle Air Control (IAC) solenoid is checked electrically for open and shorts (P1504 or P0511) and is functionally
checked by monitoring the closed loop idle speed correction required to maintain the desired idle rpm. If the proper
idle rpm cannot be maintained and the system has a high rpm (+100) or low rpm error (-200) greater than the
malfunction threshold, an IAC malfunction is indicated. (P1506 or P0507, P1507or P0506)
IAC Check Operation:
DTCs
P1504/P0511 (opens/shorts)
P1506/P0507 (functional - overspeed)
P1507/P0506 (functional - underspeed)
Monitor execution
once per driving cycle
Monitor Sequence
None
Sensors OK
Monitoring Duration
30 seconds
Typical IAC functional check entry conditions:
Entry Condition
Minimum
Engine Coolant Temp
150 F
Time since engine start-up
30 seconds
Closed loop fuel
Yes
Throttle Position (at idle, closed throttle, no dashpot)
Closed
Maximum
o
Closed
Typical IAC functional check malfunction thresholds:
For underspeed error: Actual rpm 100 rpm below target, closed-loop IAC correction > 1 lb/min
For overspeed error: Actual rpm 200 rpm above target, closed-loop IAC correction < .2 lb/min
The PCM monitors the "smart" driver fault status bit that indicates either an open circuit, short to power or short to
ground.
Injector Check Operation:
DTCs
P0201 through P0210 (opens/shorts)
Monitor execution
Continuous within entry conditions
Monitor Sequence
None
Monitoring Duration
10 seconds
Typical injector circuit check entry conditions:
Entry Condition
Minimum
Battery Voltage
11.0 volts
Maximum
o
Engine Coolant Temp
240 F
Intake Air Temp
150 F
FORD MOTOR COMPANY
o
REVISION DATE: NOVEMBER 12, 2007
PAGE 108 OF 160
Electronic Returnless Fuel Systems (ERFS) utilize a Fuel Pump Driver Module (FPDM) to control fuel pressure.
The PCM uses a Fuel Rail Pressure Sensor (FRP) for feedback. The PCM outputs a duty cycle to the FPDM to
maintain the desired fuel rail pressure. During normal operation, the PCM will output a FP duty cycle from 5% to
51%. The FPDM will run the fuel pump at twice this duty cycle, e.g. if the PCM outputs a 42% duty cycle, the
FPDM will run the fuel pump at 84%. If the PCM outputs a 75% duty cycle, the FPDM will turn off the fuel pump.
The FPDM returns a duty cycled diagnostic signal back to the PCM on the Fuel Pump Monitor (FPM) circuit to
indicate if there are any faults in the FPDM.
If the FPDM does not out any diagnostic signal, (0 or 100% duty cycle), the PCM sets a P1233 DTC. This DTC is
set if the FPDM loses power. This can also occur if the Inertia Fuel Switch is tripped.
If the FPDM outputs a 25% duty cycle, it means that the fuel pump control duty cycle is out of range. This may
occurs if the FPDM does not receive a valid control duty cycle signal from the PCM. The FPDM will default to
100% duty cycle on the fuel pump control output. The PCM sets a P1235 DTC.
If the FPDM outputs a 75% duty cycle, it means that the FPDM has detected an open or short on the fuel pump
control circuit. The PCM sets a P1237 DTC.
If the FPDM outputs a 50% duty cycle, the FPDM is functioning normally.
Fuel Pump Driver Module Check Operation:
DTCs
P1233 – FPDM disabled of offline
P1235 – Fuel pump control out of range
P1237 – Fuel pump secondary circuit
Monitor execution
Continuous, voltage > 11.0 volts
Monitor Sequence
None
Monitoring Duration
3 seconds
Some vehicle applications (2.3L Ranger) use an electric thermostat heater. These vehicles use a high temperature
o
o
thermostat (220 F versus 192 F) to achieve faster warm-up times. The heater circuit can be energized by the
PCM whenever additional cooling is required. (The PCM energizes the heater based primarily on ECT/CHT, but
can allow for additional cooling based on inputs from rpm, load, IAT and TFT.) The heat generated by the heater
o
causes the thermostat to open at a lower temperature than the rated temperature of the thermostat (up to 50 F
lower), thereby, providing additional engine and transmission cooling. The PCM duty cycles the heater output at
100% to open the open the thermostat, 70% to keep it open and 0% to provided rated thermostat function. The
PCM monitors the "smart" driver fault status bit that indicates either an open circuit, short to power or short to
ground. If the heater circuit fails such that it is always off, the vehicle can run hotter than normal. If the heater fails
such that it is always on, the vehicle may also fail the thermostat test (P0125/P0128).
Thermostat Heater Check Operation:
DTCs
P1432 or P0597 (opens/shorts)
Monitor execution
Continuous at 0 and 100% dutycycle
Monitor Sequence
None
Monitoring Duration
5 seconds
Typical thermostat heater check entry conditions:
Entry Condition
Minimum
Battery Voltage
11.0 volts
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
Maximum
PAGE 109 OF 160
There are several different styles of hardware used to control airflow within the engine air intake system. In general,
the devices are defined based on whether they control in-cylinder motion (charge motion) or manifold dynamics
(tuning).
Systems designed to control charge motion are defined to be Intake Manifold Runner Controls. IMRC systems
generally have to modify spark when the systems are active because altering the charge motion affects the burn
rate within the cylinder.
Systems designed to control intake manifold dynamics or tuning are defined to be Intake Manifold Tuning Valves.
IMTV systems generally do not require any changes to spark or air/fuel ratio because these systems only alter the
amount of airflow entering the engine.
Intake Manifold Runner Control Systems
The Intake Manifold Runner Control (IMRC) consists of a remote mounted, electrically motorized actuator with an
attaching cable for each housing on each bank. Some applications will use one cable for both banks. The cable or
linkage attaches to the housing butterfly plate levers. (The Focus IMRC uses a motorized actuator mounted directly
to a single housing without the use of a cable.)
The IMRC housing is an aluminum casting with two intake air passages for each cylinder. One passage is always
open and the other is opened and closed with a butterfly valve plate. The housing uses a return spring to hold the
butterfly valve plates closed. The motorized actuator houses an internal switch or switches, depending on the
application, to provide feedback to the PCM indicating cable and butterfly valve plate position.
Below approximately 3000 rpm, the motorized actuator will not be energized. This will allow the cable to fully
extend and the butterfly valve plates to remain closed. Above approximately 3000 rpm, the motorized actuator will
be energized. The attaching cable will pull the butterfly valve plates into the open position. (Some vehicles will
activate the IMRC near 1500 rpm.)
The Intake Manifold Swirl Control used on the 2.3L Ranger consists of a manifold mounted vacuum actuator and a
PCM controlled electric solenoid. The linkage from the actuator attaches to the manifold butterfly plate lever. The
IMSC actuator and manifold are composite/plastic with a single intake air passage for each cylinder. The passage
has a butterfly valve plate that blocks 60% of the opening when actuated, leaving the top of the passage open to
generate turbulence. The housing uses a return spring to hold the butterfly valve plates open. The vacuum
actuator houses an internal monitor circuit to provide feedback to the PCM indicating butterfly valve plate position.
Below approximately 3000 rpm, the vacuum solenoid will be energized. This will allow manifold vacuum to be
applied and the butterfly valve plates to remain closed. Above approximately 3000 rpm, the vacuum solenoid will
be de-energized. This will allow vacuum to vent from the actuator and the butterfly valve plates to open.
IMRC System Check Operation:
DTCs
P1516/P2014 - IMRC input switch electrical check, Bank 1
P1517/P0219 - IMRC input switch electrical check, Bank 2
P1520/P2008 - IMRC output electrical check
P1518/P2004 - IMRC stuck open, electric operated
P1537/P2004 – IMRC stuck open, vacuum operated, Bank 1
P1538/P2005 – IMRC stuck open, vacuum operated, Bank 2
Monitor execution
Continuous, after ECT > 40 deg F
Monitor Sequence
None
Sensors OK
Monitoring Duration
FORD MOTOR COMPANY
5 seconds
REVISION DATE: NOVEMBER 12, 2007
PAGE 110 OF 160
Typical IMRC functional check malfunction thresholds
IMRC plates do not match commanded position (functional)
IMRC switches open/shorted (electrical)
Intake Manifold Tuning Valve Systems
The intake manifold tuning valve (IMTV) is a motorized actuated unit mounted directly to the intake manifold. The
IMTV actuator controls a shutter device attached to the actuator shaft. There is no monitor input to the PCM with
this system to indicate shutter position.
The motorized IMTV unit will not be energized below approximately 2600 rpm or higher on some vehicles. The
shutter will be in the closed position not allowing airflow blend to occur in the intake manifold. Above approximately
2600 rpm or higher, the motorized unit will be energized. The motorized unit will be commanded on by the PCM
initially at a 100 percent duty cycle to move the shutter to the open position and then falling to approximately 50
percent to continue to hold the shutter open.
IMTV Check Operation:
DTCs
P1549 or P0660 - IMTV output electrical check (does not illuminate MIL)
Monitor execution
continuous
Monitor Sequence
None
Sensors OK
Monitoring Duration
5 seconds
Variable Cam Timing Systems
Variable Cam Timing (VCT) enables rotation of the camshaft(s) relative to the crankshaft (phase-shifting) as a
function of engine operating conditions. There are four possible types of VCT with DOHC engines:
•
Intake Only (phase-shifting only the intake cam);
•
Exhaust Only (phase-shifting only the exhaust cam);
•
Dual Equal (phase-shifting the intake and exhaust cams equally);
•
Dual Independent (phase-shifting the intake and exhaust cams independently).
All four types of VCT are used primarily to increase internal residual dilution at part throttle to reduce NOx, and to
improve fuel economy. This allows for elimination the external EGR system.
With Exhaust Only VCT, the exhaust camshaft is retarded at part throttle to delay exhaust valve closing for
increased residual dilution and to delay exhaust valve opening for increased expansion work.
With Intake Only VCT, the intake camshaft is advanced at part throttle and WOT (at low to mid-range engine
speeds) to open the intake valve earlier for increased residual dilution and close the intake valve earlier in the
compression stroke for increased power.
The VCT system hardware consists of a control solenoid and a pulse ring on the camshaft. The PCM calculates
relative cam position using the CMP input to process variable reluctance sensor pulses coming from the pulse ring
mounted on the camshaft. Each pulse wheel has N + 1 teeth where N = the number of cylinders per bank. The N
equally spaced teeth are used for cam phasing; the remaining tooth is used to determine cylinder # 1 position.
Relative cam position is calculated by measuring the time between the rising edge of profile ignition pickup (PIP)
and the falling edges of the VCT pulses.
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REVISION DATE: NOVEMBER 12, 2007
PAGE 111 OF 160
The PCM continually calculates a cam position error value based on the difference between the desired and actual
position and uses this information to calculate a commanded duty cycle for the VCT solenoid valve. When
energized, engine oil is allowed to flow to the VCT unit thereby advancing and retarding cam timing. The variable
cam timing unit assembly is coupled to the camshaft through a helical spline in the VCT unit chamber. When the
flow of oil is shifted from one side of the chamber to the other, the differential change in oil pressure forces the
piston to move linearly along the axis of the camshaft. This linear motion is translated into rotational camshaft
motion through the helical spline coupling. A spring installed in the chamber is designed to hold the camshaft in the
low-overlap position when oil pressure is too low (~15 psi) to maintain adequate position control. The camshaft is
allowed to rotate up to 30 degrees.
The VCT output driver in the PCM is checked electrically for opens and shorts (P1380/P0010, P1385/P0020). The
VCT system is checked functionally by monitoring the closed loop cam position error correction. If the proper cam
position cannot be maintained and the system has an advance or retard error greater than the malfunction
threshold, a VCT control malfunction is indicated (P1381/P0011, P1383/P0012, P1386/P0021, P1388/P0022).
Camshaft Position Control System Check Operation:]
DTCs
P1380/P0010 Camshaft Position Actuator Circuit (Bank 1)
P1381/P0011 Cam Position Actuator Over Advanced (Bank 1)
P1383/P0012 Cam Position Actuator Over Retarded (Bank 1)
P1385/P0020 - Camshaft Position Actuator Circuit (Bank 2)
P1386/P0021 - Cam Position Actuator Over Advanced (Bank 2)
P1388/P0022 - Cam Position Actuator Over Retarded (Bank 2)
Monitor execution
Continuous
Monitor Sequence
ECT > 150 F
o
Sensors OK
Monitoring Duration
5 seconds
Typical CPC functional check malfunction thresholds:
timing over-advanced/over-retarded by > 10 crankshaft degrees
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 112 OF 160
Comprehensive Component Monitor - Transmission
General
The MIL is illuminated for all emissions related electrical component malfunctions. For malfunctions attributable to
a mechanical component (such as a clutch, gear, band, valve, etc.), some transmissions are capable of not
commanding the mechanically failed component and providing the remaining maximum functionality (functionality
is reassessed on each power up)- in such case a non-MIL Diagnostic Trouble Code (DTC) will be stored and, if
so equipped, a Transmission Control Indicator Light (TCIL) will flash.
Transmission Inputs
Transmission Range Sensor Check Operation:
DTCs
P0708, P0705 Open/invalid pattern for digital TRS
P0707, P0708 Opens/shorts for analog TRS
P0705 Out of range signal frequency for PWM TRS
P0706, P0707 Low /High duty cycle for PWM TRS
P0705 Open/invalid pattern for 4- bit digital TRS – 6HP26, CFT30
P0707, P0708 Opens/shorts for dual analog TRS – F21
P0706 Range/performance for dual analog TRS – F21
Monitor execution
Continuous
Monitor Sequence
None
Sensors OK
Monitoring Duration
Up to 30 seconds for pattern recognition, 5 seconds for analog faults
Typical TRS check entry conditions:
Auto Transmission Entry Conditions
Minimum
Maximum
Gear selector position
each position for up to 30 seconds
480 seconds
Typical TRS malfunction thresholds:
Digital TRS:
Invalid pattern from 3 or 5 digital inputs and/or 1 analog circuit open for 5 seconds
4-bit digital TRS: Invalid pattern for 200 ms
Analog TRS:
Voltage > 4.8 volts or < 0.2 volts for 5 seconds
Dual analog TRS: Voltage > 4.84 volts or < 0.127 volts for 200 ms or
Sum of both inputs is outside the range of 5.0 volts +/- 0.29 volts for 200 ms
PWM TRS:
Frequency > 160 Hz or < 100 Hz,
Duty Cycle > 90% or < 10%
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 113 OF 160
Most vehicle applications no longer have a standalone vehicle speed sensor input. The PCM sometimes obtains
vehicle speed information from another module on the vehicle, i.e. ABS module. In most cases, however, vehicle
speed is calculated in the PCM by using the transmission output shaft speed sensor signal and applying a
conversion factor for axle ratio and tire programmed into the Vehicle ID block. A Vehicle Speed Output pin on the
PCM provides the rest of the vehicle with the standard 8,000 pulses/mile signal.
Note: If the Vehicle ID block has not been programmed or has been programmed with an out-of-range (uncertified)
tire/axle ratio, a P1639 DTC will be stored and the MIL will be illuminated immediately.
Vehicle Speed Sensor Functional Check Operation:
DTCs
P0500 – VSS circuit
Monitor execution
Continuous
Monitor Sequence
None
Sensors OK
Monitoring Duration
30 seconds
Typical VSS functional check entry conditions:
Auto Transmission Entry Conditions
Minimum
Gear selector position
drive
Engine rpm (above converter stall speed) OR
3000 rpm
Turbine shaft rpm (if available) OR
1500 rpm
Output shaft rpm
650 rpm
Vehicle speed (if available)
15 mph
Maximum
Manual Transmission Entry Conditions
Engine load
50 %
Engine rpm
2400 rpm
Typical VSS functional check malfunction thresholds:
Vehicle is inferred to be moving with positive driving torque and VSS is < 1 - 5 mph for 5 seconds
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 114 OF 160
Output Shaft Speed Sensor Functional Check Operation:
DTCs
P0720 – OSS circuit
P0721 – OSS range/performance -F-21, 6HP26
P0722 – OSS no signal
P0723 – OSS intermittent/erratic – 6HP26
Monitor execution
Continuous
Monitor Sequence
None
Sensors OK
TSS, Wheel Speed
Monitoring Duration
30 seconds
Typical OSS functional check entry conditions:
Auto Transmission Entry Conditions
Minimum
Gear selector position
drive
Engine rpm (above converter stall speed) OR
3000 rpm
Primary Pulley Speed (CFT30) OR
400 rpm
Turbine shaft rpm (if available) OR
1500 rpm
Output shaft rpm
300 - 650 rpm
Vehicle speed (if available)
12.5 - 15 mph
Maximum
Typical OSS functional check malfunction thresholds:
Circuit/no signal - vehicle is inferred to be moving with positive driving torque and OSS < 100 to 200 rpm for 5
to 30 seconds
6HP26 Circuit/no signal: open or short circuit for > 0.6 seconds
6HP Range/Performance: > 200 rpm difference between OSS and wheel speed and > 250 rpm difference
between OSS and input shaft speed
F21 Range/Performance: TSS, ABS wheel speed and engine rpm correlate properly, but OSS error is
greater than 15% for 10 seconds
CFT30 Range/Performance: ABS wheel speed indicates a 6.24 mph difference with OSS calculated wheel
speed
6HP26 Intermittent/Erratic: > -1000 rpm instantaneous change with locked torque converter clutch
CFT30 Intermittent/Erratic: > 6000 rpm/sec change
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 115 OF 160
Intermediate Shaft Speed Sensor Functional Check Operation:
DTCs
P0791 – ISS circuit
Monitor execution
Continuous
Monitor Sequence
None
Sensors OK
Monitoring Duration
30 seconds
Typical ISS functional check entry conditions:
Auto Transmission Entry Conditions
Minimum
Gear selector position
drive
Engine rpm (above converter stall speed) OR
3000 rpm
Turbine shaft rpm (if available) OR
1500 rpm
Output shaft rpm
650 rpm
Vehicle speed (if available)
15 mph
Maximum
Typical ISS functional check malfunction thresholds:
Vehicle is inferred to be moving with positive driving torque and ISS < 250 rpm for 5 seconds
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 116 OF 160
Turbine Shaft Speed Sensor Functional Check Operation:
DTCs
P0715 – TSS circuit
P0716 – TSS range/performance - F-21, 6HP26, CFT30
P0717 – TSS no signal
Monitor execution
Continuous
Monitor Sequence
None
Sensors OK
OSS, Wheel Speed
Monitoring Duration
30 seconds
Typical TSS functional check entry conditions:
Auto Transmission Entry Conditions
Minimum
Gear selector position
Forward range
Engine rpm (above converter stall speed) OR
3000 rpm
Output shaft rpm OR
600 - 650 rpm
Vehicle speed (if available)
12.5 - 15 mph
Maximum
Typical TSS functional check malfunction thresholds:
Circuit/no signal - vehicle is inferred to be moving with positive driving torque and TSS < 200 rpm for 5 – 30
seconds
F21 Range/Performance – OSS, ABS wheel speed and engine rpm correlate properly, but TSS error is
greater than 15% for 10 seconds
F21, 6HP26 Circuit/no signal – open or short circuit for > 0.6 seconds
6HP26 Range/Performance - - vehicle is inferred to be moving with positive driving torque and TSS < 20 rpm
for 0.6 seconds
CFT30 Intermittent/Erratic: > 11,000 rpm/sec change
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 117 OF 160
Primary Pulley Speed Sensor Functional Check Operation:
DTCs
P2765 – ISS circuit – CFT30
P2766 – ISS Range/Performance – CFT30
Monitor execution
Continuous
Monitor Sequence
None
Sensors OK
Monitoring Duration
30 seconds
Typical Primary Pulley functional check entry conditions:
Entry Conditions
Minimum
Maximum
Gear selector position
drive
Vehicle speed OR
4 mph
Engine rpm = Turbine rpm w/converter locked OR
300 rpm
300 rpm
Output shaft rpm
650 rpm
1000 rpm
Typical Primary Pulley functional check malfunction thresholds:
Circuit/no signal: Vehicle is inferred to be moving with positive driving torque and PPS = 0 rpm for .25
seconds or
Intermittent/Erratic: > 7,500 rpm/sec change
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 118 OF 160
Transmission Fluid Temperature Sensor Functional Check Operation:
DTCs (non-MIL)
P0712, P0713 or P0710 Opens/shorts
P1713 Stuck low, P1718 Stuck high, or P0711 Stuck low/high
P0714 Intermittent/Erratic – 6HP26
Monitor execution
continuous
Monitor Sequence
none
Sensors OK
ECT substituted if TFT has malfunction
TFT inferred from pressure solenoids on CFT30
Monitoring Duration
5 seconds for electrical, 600 seconds for functional check
Typical TFT Stuck Low/High check entry conditions:
Auto Transmission Entry Conditions
Minimum
Engine Coolant Temp (hot or cold, not midrange)
> 100 F
Time in run mode
500 – 600 sec
Time in gear, vehicle moving, positive torque
150 sec
Vehicle Speed
15 mph
Time with engine off (cold start) OR
420 min
o
Engine Coolant Temp AND Trans Fluid Temp (inferred cold start)
Maximum
o
< 20 F
o
122 F
Typical TFT malfunction thresholds:
Opens/shorts: TFT voltage <0.05 or > 4.6 volts for 5 – 12 seconds
TFT Stuck low/high, i.e. TFT stuck at high temperature or stuck at low temperature):
Old Logic (pre 2006 MY):
o
< 6 F rise or fall in TFT after extended vehicle driving
New Logic (phase in between 2006 and 2008 MY):
Stores a fault code if TFT stabilizes (stops increasing if temperature < 70 deg F, stops
decreasing if temperature > 225 deg F) before reaching the temperature region where all
MIL tests are enabled (70 to 225 deg F). If TFT remains constant (+/- 2 deg F) for
approximately 2.5 minutes of vehicle driving outside the 70 to 225 deg F zone a P0711 fault
code will be stored. Old logic used to indicate a "pass" for a single delta, and not test until
the normal operating region (70-225 deg F) was reached.
6HP26 Stuck low/high: > 77 deg F difference between TFT and internal TCM temperature sensor.
CFT30 Stuck low/high: > 54 deg F difference between TFT and inferred TFT.
6HP26 Intermittent/Erratic check: > 68 deg F change between successive readings
CFT30 Intermittent/Erratic Check: > 180 deg F change per second
o
F21 Stuck: < 2 F rise or fall in TFT after extended vehicle driving
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 119 OF 160
Secondary Pulley Pressure Sensor Check Operation:
DTCs
P0840 Low or high input – CFT30
Monitor execution
Continuous
Monitor Sequence
None
Sensors OK
not applicable
Monitoring Duration
0.200 seconds to register a malfunction
Typical Secondary Pulley pressure sensor check malfunction thresholds:
Voltage < 1.5 volts or
voltage > 4.8 volts
Main Pressure Sensor Check Operation:
DTCs
P0845 Low or high input – CFT30
Monitor execution
Continuous
Monitor Sequence
None
Sensors OK
not applicable
Monitoring Duration
0.200 seconds to register a malfunction
Typical Main pressure sensor check malfunction thresholds:
Voltage < 1.5 volts or
FORD MOTOR COMPANY
voltage > 4.8 volts
REVISION DATE: NOVEMBER 12, 2007
PAGE 120 OF 160
Transmission Outputs
Shift Solenoid Check Operation:
DTCs
SS A - P0750 electrical,
P1714 ISIG functional, or P0751 mechanical functional
P0973, P0974 opens/shorts – 6HP26, F21
P0972 current range – 6HP26
SS B - P0755 electrical,
P1715 ISIG functional, or P0756 mechanical functional
P0976, P0977 opens/shorts – 6HP26
P0975 current range – 6HP26
SS C - P0760 electrical,
P1716 ISIG functional, or P0761 mechanical functional
P0979, P0980 opens/shorts – 6HP26, F21
P0978 current range – 6HP26, F21
SS D - P0765 electrical,
P1717 ISIG functional, or P0766 mechanical functional
P0982, P0983 opens/shorts – 6HP26, F21
P0981 current range – 6HP26, F21
SS E - P0770 electrical, or P0771 mechanical functional
P0985, P0986 opens/shorts – 6HP26, F21
P0984 current range – 6HP26, F21
SS F - P0998, P0999 opens/shorts – F21
P0997 current range – F21
Monitor execution
electrical - continuous, functional - during off to on solenoid transitions
Monitor Sequence
None
Sensors OK
Monitoring Duration
0.5 to 5 seconds for electrical checks, 10 solenoid events for functional
check
Typical Shift Solenoid ISIG functional check entry conditions:
Entry Conditions
Minimum
Transmission Fluid Temp
70 F
Throttle position
positive drive torque (actual TP
varies)
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o
REVISION DATE: NOVEMBER 12, 2007
Maximum
o
225 F
PAGE 121 OF 160
Typical Shift Solenoid mechanical functional check entry conditions:
Entry Conditions (with turbine speed)
Minimum
Gear ratio calculated
each gear
Throttle position
positive drive torque
Maximum
Typical Shift Solenoid mechanical functional check entry conditions:
Entry Conditions (without turbine speed)
Minimum
Rpm drop is obtained
each shift
Throttle position
positive drive torque
Maximum
Typical Shift Solenoid malfunction thresholds:
Electrical circuit check: Output driver feedback circuit does not match commanded driver state for 0.5 – 5.0
seconds
Electrical current check: Feedback current out of range for 0.5 seconds
ISIG functional check: ISIG chip hardware circuit does not detect characteristic current dip and rise produced
by solenoid movement.
Mechanical functional check: Actual obtained gear or shift pattern indicates which shift solenoid is stuck on or
off.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 122 OF 160
Gear Ratio Check Operation:
DTCs
P0731 incorrect gear 1 ratio – 6HP26, F21
P0732 incorrect gear 2 ratio – 6HP26, F21
P0733 incorrect gear 3 ratio – 6HP26, F21
P0734 incorrect gear 4 ratio – 6HP26, F21
P0735 incorrect gear 5 ratio – 6HP26, F21
P0729 incorrect gear 6 ratio – 6HP26, F21
P0736 incorrect reverse ratio – 6HP26
P1700 incorrect neutral ratio – F21
Monitor execution
Continuous, in each gear
Monitor Sequence
None
Sensors OK
TSS, OSS, wheel speed
Monitoring Duration
12 seconds
Typical Forward Gear Ratio check entry conditions:
Entry Conditions
Minimum
Gear selector position
forward range,
Maximum
> 8 seconds
Engine Torque
100 NM
Throttle position
10%
Not shifting
> 0.5 seconds
Engine/input Speed
550 rpm
Output Shaft Speed
250 rpm
1350 rpm
Entry Conditions
Minimum
Maximum
Gear selector position
forward range,
Typical Neutral Gear Ratio check entry conditions:
> 1 second
Absolute value of Engine rpm – Turbine rpm
150 rpm
Output Shaft Speed
500 rpm
Typical Gear Ratio malfunction thresholds:
F21 Forward gear check: > 20% error in commanded ratio for > 12 seconds
F21 Neutral gear check: TSS > (OSS * Gear 1 ratio) + 400 rpm for > 1 second
6HP26 Forward and reverse gear check: > 400 to 640 rpm difference between calculated input and output
shaft speeds for 3 monitoring events
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REVISION DATE: NOVEMBER 12, 2007
PAGE 123 OF 160
Shift Completion Check Operation:
DTCs
P0781 incorrect 1-2 shift – 6HP26
P0782 incorrect 2-3 shift – 6HP26
P0783 incorrect 3-4 shift – 6HP26
P0784 incorrect 4-5 shift – 6HP26
P0829 incorrect 5-6 shift – 6HP26
Monitor execution
During up-shifts and down-shifts
Monitor Sequence
None
Sensors OK
TSS, OSS
Monitoring Duration
5 shift events
Typical Shift Completion check entry conditions:
Entry Conditions
Minimum
Gear selector position
forward range
Transmission Fluid Temp
50 F
Engine/input Speed
1200 rpm
Output Shaft Speed
256 rpm
Maximum
o
Typical Shift Completion malfunction thresholds:
Up-shift rpm check:
rpm does not drop by > 30 rpm
Down-shift rpm check: rpm does not increase by > 30 rpm
Up-shift rpm check:
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rpm increases (flares) by > 300 rpm
REVISION DATE: NOVEMBER 12, 2007
PAGE 124 OF 160
Torque Converter Clutch Check Operation:
DTCs
P0740, P2763, P2764, P0742, P0743 Opens/shorts
P0744 Intermittent – 5R110
P2762 current range – 6HP26, F21
P1740 ISIG functional
P1744 mechanical functional - 4R100
P0741 mechanical functional, stuck off
P1742 mechanical functional, stuck on – CD4E
P2758 mechanical functional, stuck on - F21
P2757 mechanical functional, stuck off - F21
Monitor execution
electrical - continuous,
mechanical - during lockup
Monitor Sequence
None
Sensors OK
TSS, OSS
Monitoring Duration
Electrical – 5 seconds, Functional - 5 lock-up events
Typical TCC ISIG functional check entry conditions:
Entry Conditions
Minimum
Maximum
Transmission Fluid Temp
70 F
Engine Torque
positive drive torque
Commanded TCC duty cycle for 0 rpm slip
60%
90%
Entry Conditions
Minimum
Maximum
Throttle Position
steady
Engine Torque
positive drive torque
Transmission Fluid Temp
70 F
225 F
Commanded TCC duty cycle (0 rpm slip)
60%
100%
o
o
225 F
Typical TCC mechanical functional check stuck off entry conditions:
o
o
Not shifting
Typical TCC malfunction thresholds:
Electrical circuit check: Output driver feedback circuit does not match commanded driver state for 0.5 – 5.0
seconds
Electrical current check: Feedback current out of range for 0.5 seconds
ISIG functional check: ISIG chip hardware circuit does not detect characteristic current dip and rise produced
by solenoid movement.
Mechanical check, stuck off: Slip across torque converter > 100 – 200 rpm or speed ratio < 0.93
Mechanical check, stuck on: Slip across torque converter < 20 rpm with converter commanded off
Mechanical check, stuck on: engine rpm < 100 after drive engagement (engine stall)
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REVISION DATE: NOVEMBER 12, 2007
PAGE 125 OF 160
Pressure Control Solenoid Check Operation:
DTCs
P1747 or P0962 PC A shorted low
P1789 or P0966 PC A shorted low
P0797 or P0970 PC C shorted low
P0745, P0775, P0795 mechanical functional
P0960, P0962, P0963 PC A opens/shorts - 6HP26, F21
P0961 PC A curent range – 6HP26, F21
P0964, P0966, P0967 PC B opens/shorts - CFT30
P0968, P0970, P0971 PC C opens/shorts - CFT30
Monitor execution
Continuous
Monitor Sequence
none
Sensors OK
Monitoring Duration
Electrical: 5 seconds,
Mechanical functional: up to 30 seconds
Typical Pressure Control Solenoid mechanical functional check entry conditions:
Entry Conditions
Minimum
Maximum
Gear ratio calculated
each gear
Transmission Fluid Temperature
70 F
Throttle Position
positive drive torque
o
o
225 F
Typical Pressure Control Solenoid malfunction thresholds:
Electrical circuit check: Output driver feedback circuit does not match commanded driver state for 0.5 – 5.0
seconds
Electrical current check: Feedback current out of range for 0.5 seconds
Mechanical functional check: Actual obtained gear pattern indicates Pressure Control solenoid fault
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REVISION DATE: NOVEMBER 12, 2007
PAGE 126 OF 160
Inductive Signature Chip Communication Check Operation:
DTCs
P1636 ISIG chip loss of communication
Monitor execution
off-to-on solenoid transitions
Monitor Sequence
none
Sensors OK
Monitoring Duration
< 100 solenoid events
Typical Inductive Signature Chip Communication Check entry conditions:
Entry Conditions
Minimum
o
Transmission Fluid Temp
70 F
Solenoid commanded off duration
Maximum
o
225 F
< 2 seconds
Typical Inductive Signature Communication Chip malfunction thresholds:
Checksum error, chip not responding
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 127 OF 160
Forward Clutch/Reverse Clutch Solenoid Check Operation:
DTCs
P0900, P0902, P0903 Opens/shorts – CFT30
P0810 functional, sticking – CFT30
P0811 functional, slippage – CFT30
Monitor execution
Continuous
Monitor Sequence
None
Sensors OK
Monitoring Duration
Electrical: 0.040 seconds,
Mechanical functional: 0.500 seconds
Typical Forward Clutch/Reverse Clutch slipping check entry conditions:
Entry Conditions
Minimum
Maximum
0.62 mph
Vehicle Speed OR
Vehicle Speed
16 mph
Gear selector
Drive or Reverse
Typical Forward Clutch/Reverse Clutch stuck check entry conditions:
Entry Conditions
Minimum
Maximum
0.62 mph
Vehicle Speed OR
Vehicle Speed
16 mph
Gear selector
Park or Neural
Typical Forward Clutch/Reverse Clutch Solenoid malfunction thresholds:
Electrical current check: Feedback current out of range for 0.040 seconds
Slipping Check: Turbine Speed is > 100 rpm higher than Pulley Speed for 200 ms.
Stuck Check: Turbine Speed is within 40 rpm of Pulley Speed for 500 ms.
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REVISION DATE: NOVEMBER 12, 2007
PAGE 128 OF 160
4R75E (RWD) Transmission
4R75E is the replacement for the 4R70W. The 4R75E transmission is essentially a 4R70W with a Turbine Speed
Sensor (TSS)
Transmission Inputs
The Digital Transmission Range (DTR) sensor provides a single analog and three digital inputs to the PCM. The
PCM decodes the inputs to determine the driver-selected gear position (Park, Rev, Neutral, OD, 2, 1). This input
device is checked for opens and invalid input patterns. (P0708 P0705)
The Vehicle Speed Sensor (VSS), Output Shaft Speed (OSS) sensor, and Turbine Speed Sensor (TSS) if
equipped, are inputs that are checked for rationality. If the engine rpm is above the torque converter stall speed
and engine load is high, it can be inferred that the vehicle must be moving. If there is insufficient output from the
VSS sensor, a malfunction is indicated (P0500). If there is insufficient output from the OSS sensor, a malfunction
is indicated (P0720). If there is insufficient output from the TSS sensor, a malfunction is indicated (P0715).
Transmission Outputs
Shift Solenoids
The Shift Solenoid (SSA and SSB) output circuits are checked for opens and shorts by the PCM by monitoring
the status of a feedback circuit from the output driver (P0750 SSA, P0755 SSB).
All vehicle applications will utilize an inductive signature circuit to monitor the shift solenoids functionally. The ISIG
circuit monitors the current signature of the shift solenoid as the solenoid is commanded on. A solenoid that
functions properly will show a characteristic decrease in current as the solenoid starts to move. If the solenoid is
malfunctioning, the current will not change (P1714 SSA, P1715 SSB). The lack of communication between the
ISIG chip and the PCM microprocessor is also monitored (P1636).
Torque Converter Clutch
The Torque Converter Clutch (TCC) output circuit is a duty-cycled output that is checked electrically for opens
and shorts by the PCM by monitoring the status of a feedback circuit from the output driver (P0743).
All vehicle applications will utilize an inductive signature circuit to monitor the torque converter clutch. The ISIG
circuit monitors the current signature of the TCC solenoid as the solenoid is commanded on. A solenoid that
functions properly will show a characteristic decrease in current as the solenoid starts to move. If the solenoid is
malfunctioning, the current will not change (P1740). In some applications, the ISIG test is run in conjunction with
the other transmission functional tests. The lack of communication between the ISIG chip and the PCM
microprocessor is also monitored (P1636).
Electronic Pressure Control
The EPC solenoid is a variable force solenoid that controls line pressure in the transmission. The EPC solenoid
has a feedback circuit in the PCM that monitors EPC current. If the current indicates a short to ground (low
pressure), engine torque may be reduced to prevent damage to the transmission. (P0962, PCA)
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4F50N(AX4N) (FWD) Transmission
Transmission Inputs
The Digital Transmission Range (DTR) sensor provides a single analog and three digital inputs to the PCM. The
PCM decodes the inputs to determine the driver-selected gear position (Park, Rev, Neutral, OD, D, 1). This input
device is checked for opens and invalid input patterns. (P0708 P0705)
The Turbine Shaft Speed (TSS) sensor and Output Shaft Speed (OSS) sensor, if equipped, are analog inputs that
are checked for rationality. If the engine rpm is above the torque converter stall speed and engine load is high, it
can be inferred that the vehicle must be moving. If there is insufficient output from the TSS sensor, a malfunction is
indicated (P0715). If there is insufficient output from the OSS sensor, a malfunction is indicated (P0720).
Transmission Outputs
Shift Solenoids
The Shift Solenoid (SSA SSB and SSC) output circuits are checked for opens and shorts by the PCM by
monitoring the status of a feedback circuit from the output driver (P0750 SSA, P0755 SSB, P0760 SSC).
All vehicle applications will utilize an inductive signature circuit to monitor the shift solenoids functionally. The ISIG
circuit monitors the current signature of the shift solenoid as the solenoid is commanded on. A solenoid that
functions properly will show a characteristic decrease in current as the solenoid starts to move. If the solenoid is
malfunctioning, the current will not change (P1714 SSA, P1715 SSB, P1716 SSC). The ISIG test runs in
conjunction with the other transmission functional tests. The lack of communication between the ISIG chip and the
PCM microprocessor is also monitored (P1636).
Torque Converter Clutch
The Torque Converter Clutch (TCC) output circuit is a duty-cycled output that is checked electrically for opens and
shorts by the PCM by monitoring the status of a feedback circuit from the output driver (P0743).
All vehicle applications will utilize an inductive signature circuit to monitor the torque converter clutch. The ISIG
circuit monitors the current signature of the TCC solenoid as the solenoid is commanded on. A solenoid that
functions properly will show a characteristic decrease in current as the solenoid starts to move. If the solenoid is
malfunctioning, the current will not change (P1740). The ISIG test runs in conjunction with the other transmission
functional tests. The lack of communication between the ISIG chip and the PCM microprocessor is also monitored
(P1636).
Electronic Pressure Control
The EPC solenoid is a variable force solenoid that controls line pressure in the transmission. The EPC solenoid
has a feedback circuit in the PCM that monitors EPC current. If the current indicates a short to ground (low
pressure), engine torque may be reduced to prevent damage to the transmission. (P1747, PCA)
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CD4E (FWD) Transmission
Transmission Inputs
The Analog Transmission Range (TR) sensor provides a single analog input to the PCM. The voltage corresponds
to the driver-selected gear position (Park, Rev, Neutral, OD, 2, 1). This input is checked for opens and shorts.
(P0707, P0708)
The Turbine Shaft Speed (TSS) sensor and Output Shaft Speed (OSS) sensors are analog inputs that are
checked for rationality. If the engine rpm is above the torque converter stall speed and engine load is high, it can be
inferred that the vehicle must be moving. If there is insufficient output from the TSS sensor, a malfunction is
indicated (P0715). If there is insufficient output from the OSS sensor, a malfunction is indicated (P0720).
Transmission Outputs
Shift Solenoids
The Shift Solenoid (SSA and SSB) output circuits are checked for opens and shorts by the PCM by monitoring the
status of a feedback circuit from the output driver (P0750 SSA, P0755 SSB).
All vehicle applications will utilize an inductive signature circuit to monitor the shift solenoids functionally. The ISIG
circuit monitors the current signature of the shift solenoid as the solenoid is commanded on. A solenoid that
functions properly will show a characteristic decrease in current as the solenoid starts to move. If the solenoid is
malfunctioning, the current will not change (P1714 SSA, P1715 SSB). The ISIG test runs in conjunction with the
other transmission functional tests. The lack of communication between the ISIG chip and the PCM
microprocessor is also monitored (P1636).
Torque Converter Clutch
The Torque Converter Clutch (TCC) output circuit is a duty-cycled output that is checked electrically for opens and
shorts by the PCM by monitoring the status of a feedback circuit from the output driver (P0743).
The PWM used to control CD4E's TCC does not have sufficient inductive signature, therefore on these
applications the TCC solenoid is functionally tested by monitoring converter slip. If the TCC is failed on when
commanded off, a P1742 fault code will be stored. If the TCC is failed off when commanded on, a P0741 fault code
will be stored.
Electronic Pressure Control
The EPC solenoid is a variable force solenoid that controls line pressure in the transmission. The EPC solenoid
has a feedback circuit in the PCM that monitors EPC current. If the current indicates a short to ground (low
pressure), engine torque may be reduced to prevent damage to the transmission. (P0962, PCA)
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5R44E (RWD) Transmission
Transmission Inputs
The Digital Transmission Range (DTR) sensor provides a single analog and three digital inputs to the PCM. The
PCM decodes these inputs to determine the driver-selected gear position (Park, Rev, Neutral, OD, 2, 1).
This input device is checked for opens and invalid input patterns. (P0708 P0705)
The Turbine Shaft Speed (TSS) sensor and Output Speed Sensor (OSS) are inputs that are checked for
rationality. Provided one of the two speed sensors has sufficient signal and engine load is high enough and the
engine speed is above the torque converter stall speed, it can be inferred that the vehicle must be moving. If there
is insufficient output from the TSS sensor, a malfunction is indicated (P0715). If there is insufficient output from the
OSS sensor, a malfunction is indicated (P0720).
Transmission Outputs
Shift Solenoids
The Shift Solenoid (SSA, SSB, SSC, and SSD) output circuits are checked for opens and shorts by the PCM by
monitoring the status of a feedback circuit from the output driver (P0750 SSA, P0755 SSB, P0760 SSC, and
P0765 SSD).
All vehicle applications will utilize an inductive signature circuit to monitor the shift solenoids functionally. The ISIG
circuit monitors the current signature of the shift solenoid as the solenoid is commanded on. A solenoid that
functions properly will show a characteristic decrease in current as the solenoid starts to move. If the solenoid is
malfunctioning, the current will not change (P1714 SSA, P1715 SSB, P1716 SSC, P1717 SSD). The ISIG test
runs in conjunction with the other transmission functional tests. The lack of communication between the ISIG chip
and the PCM microprocessor is also monitored (P1636).
Torque Converter Clutch
The Torque Converter Clutch (TCC) output circuit is a duty-cycled output that is checked electrically for opens and
shorts by the PCM by monitoring the status of a feedback circuit from the output driver (P0743).
These vehicle applications will utilize an inductive signature circuit to monitor the torque converter clutch. The ISIG
circuit monitors the current signature of the TCC solenoid as the solenoid is commanded on. A solenoid that
functions properly will show a characteristic decrease in current as the solenoid starts to move. If the solenoid is
malfunctioning, the current will not change (P1740). The ISIG test is run in conjunction with the other transmission
functional tests. The lack of communication between the ISIG chip and the PCM microprocessor is also monitored
(P1636).
Electronic Pressure Control Output
The EPC solenoid is a variable force solenoid that controls line pressure in the transmission. The EPC solenoid
has a feedback circuit in the PCM that monitors EPC current. If the current indicates a short to ground (low
pressure), engine torque may be reduced to prevent damage to the transmission. (P1747, PCA)
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5R55E (RWD) Transmission
Transmission Inputs
The Digital Transmission Range (DTR) sensor provides a single analog and three digital inputs to the PCM. The
PCM decodes these inputs to determine the driver-selected gear position (Park, Rev, Neutral, OD, 2, 1). This input
device is checked for opens and invalid input patterns. (P0708, P0705)
The Turbine Shaft Speed (TSS) and Output Shaft Speed (OSS) sensors are inputs that are checked for rationality.
Provided one of the twp speed sensors has sufficient signal and engine load is high enough and the engine rpm is
above the torque converter stall speed, it can be inferred that the vehicle must be moving. If there is insufficient
output from the TSS sensor, a malfunction is indicated (P0715). If there is insufficient output from the OSS sensor,
a malfunction is indicated (P0720).
Transmission Outputs
Shift Solenoids
The Shift Solenoid (SSA, SSB, SSC and SSD) output circuits are checked for opens and shorts by the PCM by
monitoring the status of a feedback circuit from the output driver (P0750 SSA, P0755 SSB, P0760 SSC, P0765
SSD).
These vehicle applications will utilize an inductive signature circuit to monitor the shift solenoids functionally. The
ISIG circuit monitors the current signature of the shift solenoid as the solenoid is commanded on. A solenoid that
functions properly will show a characteristic decrease in current as the solenoid starts to move. If the solenoid is
malfunctioning, the current will not change (P1714 SSA, P1715 SSB, P1716 SSC, P1717 SSD). The ISIG test is
run in conjunction with the other transmission functional tests. The lack of communication between the ISIG chip
and the PCM microprocessor is also monitored (P1636).
Torque Converter Clutch
The Torque Converter Clutch (TCC) output circuit is a duty-cycled output that is checked electrically for opens and
shorts by the PCM by monitoring the status of a feedback circuit from the output driver (P0743).
These vehicle applications will utilize an inductive signature circuit to monitor the torque converter clutch. The ISIG
circuit monitors the current signature of the TCC solenoid as the solenoid is commanded on. A solenoid that
functions properly will show a characteristic decrease in current as the solenoid starts to move. If the solenoid is
malfunctioning, the current will not change (P1740). The ISIG test runs in conjunction with the other transmission
functional tests. The lack of communication between the ISIG chip and the PCM microprocessor is also monitored
(P1636).
Electronic Pressure Control Output
The EPC solenoid is a variable force solenoid that controls line pressure in the transmission. The EPC solenoid
has a feedback circuit in the PCM that monitors EPC current. If the current indicates a short to ground (low
pressure), engine torque may be reduced to prevent damage to the transmission. (P0962, PCA)
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5R55S (RWD) Transmission
Transmission Inputs
The Digital Transmission Range (DTR) sensor provides a single analog and three digital inputs to the PCM. The
PCM decodes these inputs to determine the driver-selected gear position. This input device is checked for opens
and invalid input patterns. (P0708, P0705)
Turbine Shaft Speed (TSS) and Output Shaft Speed (OSS) sensors are analog inputs that are checked for
rationality. If the engine rpm is above the torque converter stall speed and engine load is high, it can be inferred
that the vehicle must be moving. If there is insufficient output from the TSS sensor, a malfunction is indicated
(P0715). If there is insufficient output from the OSS sensor, a malfunction is indicated (P0720).
Transmission Outputs
Shift Solenoids
The Shift Solenoid (SSA, SSB, SSC, SSD) output circuits are checked for opens and shorts by the PCM by
monitoring the status of a feedback circuit from the output driver (P0750 SSA, P0755 SSB, P0760 SSC, P0765
SSD).
These vehicle applications will utilize an inductive signature circuit to monitor the shift solenoids functionally. The
ISIG circuit monitors the current signature of the shift solenoid as the solenoid is commanded on. A solenoid that
functions properly will show a characteristic decrease in current as the solenoid starts to move. If the solenoid is
malfunctioning, the current will not change (P1714 SSA, P1715 SSB, P1716 SSC, P1717 SSD). The ISIG test
runs in conjunction with the other transmission functional tests. The lack of communication between the ISIG chip
and the PCM microprocessor is also monitored (P1636).
Electronic Pressure Control Outputs
The VFS solenoids are variable force solenoids that control line pressure and gear selection in the transmission.
The VFS solenoids have a feedback circuit in the PCM that monitors VFS current. If the current indicates a short to
ground (low pressure), engine torque may be reduced to prevent damage to the transmission. (P0962, P0966,
P0970).
The VFS solenoids are also checked for functionality by utilizing a rationality test that looks at gear ratios. If
VFS/shift solenoid electrical faults and shift solenoid ISIG faults are not present, then actual ratios versus expected
ratios are used to infer VFS failures. (P0745 PCA, P0775 PCB, P0795 PCC)
Torque Converter Clutch
The Torque Converter Clutch (TCC) output circuit is a duty-cycled output that is checked electrically for opens and
shorts by the PCM by monitoring the status of a feedback circuit from the output driver (P0743).
These vehicle applications will utilize an inductive signature circuit to monitor the torque converter clutch. The ISIG
circuit monitors the current signature of the TCC solenoid as the solenoid is commanded on. A solenoid that
functions properly will show a characteristic decrease in current as the solenoid starts to move. If the solenoid is
malfunctioning, the current will not change (P1740). The ISIG test runs in conjunction with the other transmission
functional tests. The lack of communication between the ISIG chip and the PCM microprocessor is also monitored
(P1636).
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Direct One Way Clutch
The Direct One Way Clutch is checked for functionality by utilizing a rationality test that looks at transmission input
st
rd
th
torque relative to commanded throttle position while in 1 , 3 , or 4 gear. If a direct one way clutch fault is present,
st
rd
th
then the transmission will not be able to carry torque at high throttle angles in 1 , 3 , or 4 gears. (P1700)
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5R110W (RWD) Transmission
Transmission Inputs
Transmission Range Sensor
The Non-contacting Pulse Width Modulated Transmission Range Sensor (TRS) provides a duty cycle signal for
each position. This signal is transmitted at a frequency of 125 Hz. The PCM decodes the duty cycle to determine
the driver-selected gear position (Park, Rev, Neutral, OD, 3, 2, 1). This input device is checked for out of range
frequency, low duty cycle and high duty cycle input signals. (P0706, P0707, P0708)
Speed Sensors
The Turbine Shaft Speed (TSS) sensor, Intermediate Shaft Speed (ISS) sensor and Output Shaft Speed (OSS)
sensor, if equipped, are hall effect inputs that are checked for rationality. The vehicle speed signal is provided from
the ABS system to the PCM. If the engine rpm is above the torque converter stall speed and engine load is high, it
can be inferred that the vehicle must be moving. If there is insufficient output from the VSS sensor, a malfunction is
indicated (P0500). If there is insufficient output from the TSS sensor, a malfunction is indicated (P0715). If there is
insufficient output from the ISS sensor, a malfunction is indicated (P0791). If there is insufficient output from the
OSS sensor, a malfunction is indicated (P0720).
Transmission Fluid Temperature
st
nd
5R110W has a feature called "Cold mode". If TFT is below 0 deg F, the transmission will limit operation to 1 , 2 ,
rd
th
th
th
3 , and 4 gears (5 and 6 gears are disabled). Cold mode remains in effect until TFT rises above 0 deg F or
vehicle operation (based on shift times or heat generated by driving) indicates that TFT should not be in the cold
mode range, at which point normal operation is enabled.
Direct clutch apply times cold have forced the addition of this cold mode (DC takes excessive times to apply below
–10 deg F), and require revisions to TFT failure management – if TFT is failed at start up the transmission will be
placed in cold mode and remain there until TFT is no longer failed and above 0 deg F or the vehicle operating
conditions listed above trigger an exit from cold mode.
Once out of cold mode a TFT failure will not trigger cold mode (can only go into cold mode once/power-up); but this
mode is new to 5R110W.
TFT is monitored for circuit faults (P0712, P0713) and in-range failures (P0711)
For this reason all TFT diagnostics illuminate the MIL on 5R110W.
Transmission Outputs
Shift Solenoids
The Shift Solenoid (SSA, SSB, SSC, SSD, and SSE) output circuits are checked for opens and shorts by the PCM
by monitoring the status of a feedback circuit from the output driver (SSA P0750, P0973, P0974; SSB P0755,
P0976, P0977; SSC P0760, P0979, P0980; SSD P0765, P0982, P0983; SSE P0770, P0985, P0986).
The shift solenoids will be tested for function. This is determined by vehicle inputs such as gear command, and
gear. Shift solenoid malfunction codes actually cover the entire clutch system (using ratio there is no way to isolate
the solenoid from the rest of the clutch system. Diagnostics will isolate the fault into clutch functionally (nonelectrical) failed off (SSA P0751, SSB P0756, SSC P0761, SSD P0766, SSE P0771) and clutch functionally failed
on (SSA: P0752, SSB: P0757, SSC: P0762, SSD: P0767, SSE: P0772). These fault codes replace the P2700
level clutch fault codes previously used since the additional information of the failed state of the clutch adds value
for service.
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Torque Converter Clutch
The Torque Converter Clutch (TCC) output circuit is a duty-cycled output that is checked electrically for opens and
shorts internally in the PCM by monitoring the status of a feedback circuit from the output driver (P0740, P0742,
P0744).
The TCC solenoid is checked functionally by evaluating torque converter slip under steady state conditions when
the torque converter is fully applied. If the slip exceeds the malfunction thresholds when the TCC is commanded
on, a TCC malfunction is indicated (P0741).
Electronic Pressure Control
The EPC solenoid is a variable force solenoid that controls line pressure in the transmission. The EPC solenoid
has a feedback circuit in the PCM that monitors EPC current. If the current indicates a short to ground (low
pressure), a high side switch will be opened. This switch removes power from all 7 VFS's, providing Park, Reverse,
Neutral, and 5M (in all forward ranges) with maximum line pressure based on manual lever position. This solenoid
is tested for open (P0960), short to ground (P0962), and short to power (P0963) malfunctions.
High Side Switch
5R110W has a high side switch that can be used to remove power from all 7 VFS's simultaneously. If the high side
switch is opened, all 7 solenoids will be electrically off, providing Park, Reverse, Neutral, and 5M (in all forward
ranges) with maximum line pressure based on manual lever position. The switch is tested for open faults (switch
failed closed will provide normal control). If the switch fails, a P0657 fault code will be stored.
CAN Communications error
The TCM receives critical information from the ECM via CAN. If the CAN link fails, the TCM no longer has torque
or engine speed information available – the high side switch will be opened. The TCM will store a U0100 fault code
if unable to communicate with the TCM.
Requirements for Heavy-Duty Engine Testing
Beginning in 2005, Ford is introducing a new TorqShift (5R110W) transmission for all HDGE automatic
transmission applications. This new transmission uses direct electronic shift control technology (DESC) to actuate
transmission mechanisms to achieve the desired gear changes. The DESC architecture requires more extensive
monitoring within the PCM of transmission components, speeds, and gear ratios to ensure that the transmission is
operating within expected ranges. Without the transmission hardware present during engine dyno testing, the
transmission diagnostics will presume a transmission/sensor failure, and default to self-protective operating mode.
As in past years, this requires special test procedures to be used during HDGE testing to assure a representative
test by simulating key signals typically generated from the transmission system. The methodology used to
generate these signals has been modified for the 2005MY.
For dynamometer testing on engines using this new transmission, the function of the previously used simulator box
is now incorporated as part of the transmission OBD code included in the power-train control module (PCM). The
new simulator strategy expands on the old strategy and uses engine rpm, commanded gear, and manual lever
position to model transmission control system responses, e.g. representative, scheduled shift points and torque
modulation during shifts. The PCM will enter this 'dyno cert' mode if, at start up, the transmission OBD senses that
the seven transmission variable force solenoids, the turbine speed sensor, the intermediate speed sensor, and the
output speed sensor are all absent. In this mode, transmission diagnostics are disabled, a MIL code is set, and the
PCM generates simulated signals that typically come from the transmission.
During the running of the transient dyno cycle, the engine follows a set path of normalized engine rpm and
normalized torque as prescribed in the regulations. This simulator strategy allows the engine to perform this cycle,
with the PCM reacting as if the transmission were present and the vehicle were operating on the road, resulting in
representative shift events and torque modulation. These shift events follow the calibrated shift schedule, but
require the input of specific transmission signals. These signals include Turbine Shaft Speed (TSS), Intermediate
Shaft Speed (ISS), Output Shaft Speed (OSS), and Vehicle Speed (VSS). Since there is no transmission
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PAGE 137 OF 160
hardware, these signals must be simulated. The model for the simulation strategy is based on fixed mechanical
gear ratios of the transmission, scheduled shift points, small losses of efficiency in the torque converter, and
approximations of transmission characteristics during transition periods (i.e. shift transition between 1st & 2nd
gears). Simulated characteristics during shifts are based on extensive experience with real world transmission and
vehicle operation. The initial inputs to the simulator are engine speed and transmission lever position (e.g. park,
drive), these signals determine the status of the Torque Converter Clutch, and in turn output the TSS. In park, TSS
equals engine rpm. In drive with the engine speed less than an approximate engine speed of 1000 rpm, the TSS
equal zero. As the engine accelerates (or decelerates), the model ramps the TSS signal to respond as closely as
possible to the way the turbine shaft would respond on the road. The TSS in turn, along with the status of the
overdrive gear set, is used to generate the ISS. This is based on the commanded gear, and fixed gear ratios.
During shift events, the model ramps the ISS signal between gear ratios. Likewise, ISS is then used, with the
status of the simpson gear set, to generate the OSS, based on the fixed gear ratios. OSS is in turn used by the
PCM to establish commanded gear. VSS is calculated from the OSS, using tire size and axle ratio. VSS is used
within the PCM for vehicle speed limiting and as an entry condition to some of the engine on-board diagnostics.
The goal of this new 'simulator' strategy is to ensure proper function of the PCM without transmission hardware.
Only the transmission OBD recognizes that the engine is in 'dyno cert' mode, the rest of the transmission control
systems react as if the transmission hardware is present and is running normally as it would on the road.
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6R (RWD) Transmission
Transmission Control System Architecture
The 6R is a 6-speed, step ratio transmission that is controlled by a standalone Transmission Control Module
(TCM), The TCM communicates to the Engine Control Module (ECM), ABS Module, Instrument Cluster and
Transfer Case Control Module using the high speed CAN communication link. The TCM incorporates a standalone
OBD-II system. The TCM independently processes and stores fault codes, freeze frame, supports industrystandard PIDs as well as J1979 Mode 09 CALID and CVN. The TCM does not directly illuminate the MIL, but
requests the ECM to do so. The TCM is located inside the transmission assembly. It is not serviceable with the
exception of reprogramming.
Transmission Inputs
Transmission Range Sensor
The non-contacting, Hall effect Transmission Range (TR) sensor provides four digital inputs to the TCM. Each 4-bit
pattern corresponds to the driver-selected gear position (Park, Rev, Neutral, D6, D4, 3, 2, 1). The 4-bit pattern is
checked for invalid combinations (P0705).
Speed Sensors
The Turbine Shaft Speed (TSS) sensor and Output Shaft Speed (OSS) sensor are Hall effect sensors.
The Turbine Shaft Speed sensor is monitored for circuit faults and rationality (P0715, P0717). If turbine shaft speed
exceeds a maximum calibrated speed (7,700 rpm), a fault is stored (P0716). If engine speed and output shaft
speed are high and a gear is engaged, it can be inferred that the vehicle is moving. If there is insufficient output
from the TSS sensor a fault is stored (P0716).
The Output Shaft Speed sensor is monitored for circuit faults and rationality (P0720, P0722). If output shaft speed
exceeds a maximum calibrated speed (7,450 rpm), a fault is stored (P0721). If output shaft speed does not
correlate with turbine shaft speed and wheel speed while a gear is engaged and the vehicle is moving, a fault is
stored (P0721). If the output shaft speed decreases at an erratic/unreasonable rate, a fault is stored (P0723).
Transmission Fluid Temperature
The Transmission Fluid Temperature Sensor is checked for open circuit, short circuit to ground, short circuit to
power, and short circuit of the sensor (P0711, P0712, P0713, P0714). The transmission fluid temperature is
checked for an erratic signal (P0714) and is also compared with the internal TCM temperature sensor as a
rationality check (P0711). The internal TCM temperature sensor is monitored for opens and shorts (P0667) and
over temperature conditions (P0634).
Transmission Outputs
Shift Solenoids
The Shift Solenoid output circuits are duty-cycled outputs that are checked electrically for open circuit, short circuit
to ground and short circuit to power by monitoring the status of a feedback circuit from the output driver (SSA P0973, P0974; SSB - P0976, P0977; SSC - P0979, P0980; SSD - P0982, P0983; SSE - P0770, P0985, P0986).
In addition, during steady states, the current flow through the Variable Force Shift Solenoids is calculated based on
a current feedback signal and compared with a target current value (SSA low current - P0972; SSB high current P0975; SSC low current - P0978; SSD high current - P0981).
The shift solenoids are functionally monitored through gear ratio and shift monitoring. The actual gear ratio versus
st
nd
rd
the expected gear ratio is monitored. If there is a mismatch, a fault is stored (1 gear - P0731; 2 gear - P0732; 3
th
th
th
gear - P0733; 4 gear - P0734; 5 gear - P0735; 6 gear - P0729; reverse gear - P0736). Shifts are also
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monitored. If the ratio characteristics do not change properly during a shift (rpm does not go down during an upshift, rpm does not go up during a down-shift, or rpm flares during an up-shift), a fault is stored (1-2/2-1 shift P0781; 2-3/3-2 shift - P0782; 3-4/4-3 shift - P0783; 4-5/5-4 shift - P0784; 5-6/6-5 shift - P0829).
Torque Converter Clutch
The Torque Converter Clutch (TCC) Solenoid output circuit is a duty-cycled output that is checked electrically for
open circuit, short circuit to ground, and short circuit to power by monitoring the status of a feedback circuit from the
output driver (P0740, P2763, P2764). If the TCC pressure is high and the engine torque is low, the TCC should be
fully applied or have a controlled amount of slippage. If the slip exceeds a threshold, a fault is stored (P0741).
Pressure Control
The Pressure Control solenoid is a variable force solenoid that controls line pressure in the transmission. The
Pressure Control solenoid output circuit is a duty-cycled output that is checked electrically for short circuit to ground
or short circuit to battery by monitoring the status of a feedback circuit from the output driver (P0962, P0963).
Note that the Pressure Control Solenoid failures P0960 and P0963 do not illuminate the MIL because the
diagnostic action (maximum line pressure) does not affect emissions.
High Side Actuator Control Circuit
The TCM has a high side actuator supply control circuit that can be used to remove power from all 7 solenoids and
the external Reverse Light Relay simultaneously. If the high side actuator control circuit is deactivated, all 7
solenoids and the external Reverse Light Relay will be electrically turned off, providing Park, Reverse, Neutral, and
3M/5M (in all forward ranges) with maximum line pressure, based on the selected transmission range. The
actuator control circuit is tested for open and short circuits to power and ground. (P0657, P0658, P0659).
Transmission Control Module (TCM)
The TCM monitors itself by using a watchdog circuit and by various software monitoring functions. If there is a fault,
a P0613 is stored. The flash ROM is checked using a checksum calculation. If the checksum is incorrect, a P0605
fault will be stored. The EEPROM is emulated in the flash ROM. If it is not possible to store information in the
EEPROM emulation or if the verification fails, a P062F fault is stored and the ECM is requested to illuminate the
MIL immediately. If the diagnostic software tries to enter two contradictory failure mode strategies or if there are
contradictory output states commanded versus the expected output states, a P0701 fault is stored.
CAN Communications Error
The TCM receives information from the ECM via the high speed CAN network. If the CAN link or network fails, the
TCM no longer has torque or engine speed information available. The TCM will store a U0073 fault code and will
illuminate the MIL immediately (missing engine speed) if the CAN Bus is off. The TCM will store a U0100 fault code
and will illuminate the MIL immediately (missing engine speed) if it stops receiving CAN messages from the ECM.
If the engine speed from the ECM is unreasonably high (> 6,000 rpm), a P0219 fault will be stored.
Internal Over Temperature
If the TCM internal temperature sensor indicates an over temperature condition, the TCM will shut down and a fault
will be stored (P0634). The MIL will be illuminated immediately.
Internal TCM Power Supply
If the power supply voltage is outside of the specified 9 to 16 volt range, a fault will be stored (P0562, P0563).
Sensor Supply Voltage
If the sensor supply voltage is too high or too low, a fault will be stored (P0641).
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PAGE 140 OF 160
4F27E (FN) (FWD) Transmission
Transmission Inputs
The Transmission Range Sensor (TRS) provides five digital inputs, one for Park and Neutral, one for Reverse, one
for Drive, one for Second and one for First. These inputs are monitored for opens and shorts (P0705).
The Turbine Shaft Speed (TSS) sensor and Output Shaft Speed (OSS) sensors are analog inputs that are
checked for rationality. If the engine rpm is above the torque converter stall speed or one of the two speed sensors
has sufficient signal and engine load is high enough, it can be inferred that the vehicle must be moving. If there is
insufficient output from the TSS sensor, a malfunction is indicated (P0715). If there is insufficient output from the
OSS sensor, a malfunction is indicated (P0720).
Transmission Outputs
Shift Solenoids
The Shift Solenoid (SSA, SSB, SSC, SSD, and SSE) output circuits are checked for opens and shorts by the PCM
by monitoring the status of a feedback circuit from the output driver (P0750, P0755, P0760, P0765 and P0770
respectively).
The shift solenoids are functionally (mechanically) checked by means of a comprehensive malfunction pattern test.
This monitor examines learned gear states and the TCC function to determine if a shift solenoid mechanical failure
has occurred
(P0751, P0756, P0761, P0766 and P0771 respectively).
Torque Converter Clutch
No single solenoid controls the TCC in the FN. Electrical checks for all shift solenoids are performed as indicated
above. The TCC is checked functionally by evaluating torque converter slip under steady state conditions when the
torque converter is fully applied. If the slip exceeds the malfunction thresholds when the TCC is commanded on, a
TCC malfunction is indicated (P0741). If slip is below an open converter threshold when the TCC is commanded
off, a TCC malfunction is indicated through the shift solenoid functional test (P0756).
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PAGE 141 OF 160
ZF CFT30 (FWD) Continuously Variable Transmission
Transmission Control System Architecture
The ZF CFT30 is a continuously variable transmission that is controlled by a standalone Transmission Control
Module (TCM), The TCM communicates to the Engine Control Module (ECM), ABS Module, Instrument Cluster
and Transfer Case Control Modules using the high speed CAN communication link. The TCM incorporates a
standalone OBD-II system. The TCM independently processes and stores fault codes, freeze frame, supports
industry-standard PIDs as well as J1979 Mode 09 CALID and CVN. The TCM does not directly illuminate the MIL,
but requests the ECM to do so. The TCM is located inside the transmission assembly. It is not serviceable with the
exception of reprogramming.
CFT 30 Power Flow Diagram
CFT 30 Sensors and Actuators
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CFT 30 Mechatronic Illustration
Transmission Inputs
Transmission Range Sensor
The Hall effect Transmission Range (TR) sensor provides four digital inputs to the TCM. The 4-bit bit pattern
corresponds to the driver-selected gear position (Park, Rev, Neutral, Drive, Low). The 4-bit pattern is checked for
invalid bit combinations. (P0705).
Speed Sensors
The Turbine Shaft Speed (TSS) sensor, Primary Pulley Speed Sensor and Output Shaft Speed (OSS) sensors are
Hall effect sensors.
The Turbine Shaft Speed sensor is monitored for circuit rationality (P0716, speed too high (>7,500 rpm) or erratic)
and insufficient output/no signal (P0715).
The Output Shaft Speed sensor actually consists of two sensors. They are both monitored for circuit rationality,
(P0721, speed too high (> 2,500 rpm) or erratic) and insufficient output/no signal (P0720).
The Primary Pulley Speed sensor is monitored for circuit rationality (P2766, speed too high (> 7,500 rpm) or
erratic) and insufficient output/no signal (P2765). If any one of these sensors fails, normal function continues by
substituting information from other sensors.
The CFT30 uses two analog pressure sensors for feedback. One sensor is for main pressure; the second sensor
is for secondary pulley pressure. (There is no primary pulley pressure sensor.) The Secondary Pulley Pressure
sensor is checked for opens and shorts (P0840). The Main Pressure Sensor is checked for opens and shorts
(P0845).
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PAGE 143 OF 160
Transmission Fluid Temperature
The Transmission Fluid Temperature Sensor is checked for open circuit, short circuit to ground, and short circuit to
power (P0710). The transmission fluid temperature is checked for an erratic signal and is also checked for rational
values versus inferred TFT (P0711, P0714). Pressure control solenoids have a known resistance versus
temperature characteristic. TFT is inferred by measuring the voltage and current of the pressure control solenoids
to get resistance, then temperature.
Note that TFT failures are do not illuminate the MIL because TFT failures result in substituted the inferred value of
TFT. Normal transmission control continues, and all emission-related diagnostic tests continue to run.
If the transmission fluid temperature exceeds 212 deg F, a P0218 fault will be stored.
Transmission Outputs
Pressure Control Solenoids
The CFT30 uses 5 pressure control solenoids. Each solenoid is checked electrically for opens, shorts to ground,
and shorts to power by monitoring the status of a feedback circuit from the output driver. They are the Main
Pressure Control Solenoid (P0960, P0962, P0963), Primary Pulley Pressure Control Solenoid (P0964, P0966,
P0967), Secondary Pulley Pressure Control Solenoid (P0968, P0970, P0971), Forward/Reverse Clutch Pressure
Control Solenoid (P0900, P0902, P0903), and the Torque Converter Clutch Solenoid (P0740, P0742, P0743).
The forward/reverse clutch, torque converter clutch (TCC), and ratio control solenoids are functionally monitored. If
the TCC is released and the speed ratio of the converter is out of physical range, a fault P0741 will be stored. If the
TCC is fully applied, and the converter clutch is slipping, a P0741 fault will be stored.
The forward/reverse clutch is checked tested for slippage by comparing the turbine speed and primary pulley
speed. If the difference between TSS and primary pulley speed exceeds a calibrated threshold, a P0811 fault will
be stored. If the clutch is stuck, a P0810 fault will be set.
The ratio control check detects if the variator belt is slipping by comparing primary pulley speed (PSS) to
secondary pulley speed (TSS). If the ratio is out of the expected range of 0.28 to 2.7, or is changing at a rate
greater than a ratio of 0.5/second, then a P0730 fault will be stored.
High Side Actuator Control Circuit
The TCM has a high side actuator supply control circuit that can be used to remove power from all solenoids
simultaneously. The actuator control circuit is tested for open and short circuits to power and ground. (P0657,
P0658, P0659).
Transmission Control Module (TCM)
The TCM monitors itself by using various software monitoring functions. If there is an EEPROM fault on power up,
a P0613 fault will be stored. If there is a power up or continuous RAM fault, a P0604 fault will be stored. The flash
ROM is continuously checked using a checksum calculation. If the checksum is incorrect, a P0605 fault will be
stored. If there is a watchdog timer failure, a P0702 fault will be stored. If the diagnostic software tries to enter two
contradictory failure mode strategies or if there are contradictory output states commanded versus the expected
output states, a P0701 fault is stored.
CAN Communications Error
The TCM receives information from the ECM via the high speed CAN network. If the CAN link or network fails, the
TCM no longer has torque or engine speed information available. The TCM will store a U0073 fault code if the
CAN Bus is off or a U0001 if no acknowledgement to an outgoing message is received. The TCM will store a
U0100 fault code if it stops receiving CAN messages from the ECM. If the engine speed from the ECM is
unreasonably high (> 7500 rpm), a P0219 fault will be stored. The TCM will store a P186D fault code if the
Transfer Case Control Module is unable to control the four-wheel drive clutch.
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PAGE 144 OF 160
Internal TCM Power Supply
If the power supply voltage is outside of the specified 8.5 to 16.9 volt range, a fault will be stored (P0562, P0563).
Sensor Supply Voltage
If the sensor supply voltage is outside of the specified 6.0 to 10.7 volt range, a fault will be stored (P0641). If the
low side solenoid driver voltage is out of range, a P1710 fault is stored.
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PAGE 145 OF 160
ZF 6HP26 (RWD) Transmission
Transmission Control System Architecture
The ZF 6HP26 is a 6-speed, step ratio transmission that is controlled by a standalone Transmission Control
Module (TCM), The TCM communicates to the Engine Control Module (ECM), ABS Module, Instrument Cluster
and Transfer Case Control Module using the high speed CAN communication link. The TCM incorporates a
standalone OBD-II system. The TCM independently processes and stores fault codes, freeze frame, supports
industry-standard PIDs as well as J1979 Mode 09 CALID and CVN. The TCM does not directly illuminate the MIL,
but requests the ECM to do so. The TCM is located inside the transmission assembly. It is not serviceable with the
exception of reprogramming.
Transmission Inputs
Transmission Range Sensor
The non-contacting, Hall effect Transmission Range (TR) sensor provides four digital inputs to the TCM. Each 4-bit
pattern corresponds to the driver-selected gear position (Park, Rev, Neutral, D6, D4, 3, 2, 1). The 4-bit pattern is
checked for invalid combinations (P0705).
Speed Sensors
The Turbine Shaft Speed (TSS) sensor and Output Shaft Speed (OSS) sensor are Hall effect sensors.
The Turbine Shaft Speed sensor is monitored for circuit faults and rationality (P0715, P0717). If turbine shaft speed
exceeds a maximum calibrated speed (7,700 rpm), a fault is stored (P0716). If engine speed and output shaft
speed are high and a gear is engaged, it can be inferred that the vehicle is moving. If there is insufficient output
from the TSS sensor a fault is stored (P0716).
The Output Shaft Speed sensor is monitored for circuit faults and rationality (P0720, P0722). If output shaft speed
exceeds a maximum calibrated speed (7,450 rpm), a fault is stored (P0721). If output shaft speed does not
correlate with turbine shaft speed and wheel speed while a gear is engaged and the vehicle is moving, a fault is
stored (P0721). If the output shaft speed decreases at an erratic/unreasonable rate, a fault is stored (P0723).
Transmission Fluid Temperature
The Transmission Fluid Temperature Sensor is checked for open circuit, short circuit to ground, short circuit to
power, and short circuit of the sensor (P0711, P0712, P0713, P0714). The transmission fluid temperature is
checked for an erratic signal (P0714) and is also compared with the internal TCM temperature sensor as a
rationality check (P0711). The internal TCM temperature sensor is monitored for opens and shorts (P0667) and
over temperature conditions (P0634).
Transmission Outputs
Shift Solenoids
The Shift Solenoid output circuits are duty-cycled outputs that are checked electrically for open circuit, short circuit
to ground and short circuit to power by monitoring the status of a feedback circuit from the output driver (SSA P0973, P0974; SSB - P0976, P0977; SSC - P0979, P0980; SSD - P0982, P0983; SSE - P0770, P0985, P0986).
In addition, during steady states, the current flow through the Variable Force Shift Solenoids is calculated based on
a current feedback signal and compared with a target current value (SSA low current - P0972; SSB high current P0975; SSC low current - P0978; SSD high current - P0981).
The shift solenoids are functionally monitored through gear ratio and shift monitoring. The actual gear ratio versus
st
nd
rd
the expected gear ratio is monitored. If there is a mismatch, a fault is stored (1 gear - P0731; 2 gear - P0732; 3
th
th
th
gear - P0733; 4 gear - P0734; 5 gear - P0735; 6 gear - P0729; reverse gear - P0736). Shifts are also
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PAGE 146 OF 160
monitored. If the ratio characteristics do not change properly during a shift (rpm does not go down during an upshift, rpm does not go up during a down-shift, or rpm flares during an up-shift), a fault is stored (1-2/2-1 shift P0781; 2-3/3-2 shift - P0782; 3-4/4-3 shift - P0783; 4-5/5-4 shift - P0784; 5-6/6-5 shift - P0829).
Torque Converter Clutch
The Torque Converter Clutch (TCC) Solenoid output circuit is a duty-cycled output that is checked electrically for
open circuit, short circuit to ground, and short circuit to power by monitoring the status of a feedback circuit from the
output driver (P0740, P2763, P2764). If the TCC pressure is high and the engine torque is low, the TCC should be
fully applied or have a controlled amount of slippage. If the slip exceeds a threshold, a fault is stored (P0741).
Pressure Control
The Pressure Control solenoid is a variable force solenoid that controls line pressure in the transmission. The
Pressure Control solenoid output circuit is a duty-cycled output that is checked electrically for short circuit to ground
or short circuit to battery by monitoring the status of a feedback circuit from the output driver (P0962, P0963).
Note that the Pressure Control Solenoid failures P0960 and P0963 do not illuminate the MIL because the
diagnostic action (maximum line pressure) does not affect emissions.
High Side Actuator Control Circuit
The TCM has a high side actuator supply control circuit that can be used to remove power from all 7 solenoids and
the external Reverse Light Relay simultaneously. If the high side actuator control circuit is deactivated, all 7
solenoids and the external Reverse Light Relay will be electrically turned off, providing Park, Reverse, Neutral, and
3M/5M (in all forward ranges) with maximum line pressure, based on the selected transmission range. The
actuator control circuit is tested for open and short circuits to power and ground. (P0657, P0658, P0659).
Transmission Control Module (TCM)
The TCM monitors itself by using a watchdog circuit and by various software monitoring functions. If there is a fault,
a P0613 is stored. The flash ROM is checked using a checksum calculation. If the checksum is incorrect, a P0605
fault will be stored. The EEPROM is emulated in the flash ROM. If it is not possible to store information in the
EEPROM emulation or if the verification fails, a P062F fault is stored and the ECM is requested to illuminate the
MIL immediately. If the diagnostic software tries to enter two contradictory failure mode strategies or if there are
contradictory output states commanded versus the expected output states, a P0701 fault is stored.
CAN Communications Error
The TCM receives information from the ECM via the high speed CAN network. If the CAN link or network fails, the
TCM no longer has torque or engine speed information available. The TCM will store a U0073 fault code and will
illuminate the MIL immediately (missing engine speed) if the CAN Bus is off. The TCM will store a U0100 fault code
and will illuminate the MIL immediately (missing engine speed) if it stops receiving CAN messages from the ECM.
If the engine speed from the ECM is unreasonably high (> 6,000 rpm), a P0219 fault will be stored.
Internal Over Temperature
If the TCM internal temperature sensor indicates an over temperature condition, the TCM will shut down and a fault
will be stored (P0634). The MIL will be illuminated immediately.
Internal TCM Power Supply
If the power supply voltage is outside of the specified 9 to 16 volt range, a fault will be stored (P0562, P0563).
Sensor Supply Voltage
If the sensor supply voltage is too high or too low, a fault will be stored (P0641).
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Aisin F21 (FWD) Transmission
Transmission Control System Architecture
The Aisin F21 is a 6-speed, step ratio transmission that is controlled by a standalone Transmission Control Module
(TCM), The TCM communicates to the Engine Control Module (ECM), ABS Module, and Instrument Cluster using
the high speed CAN communication link. The TCM incorporates a standalone OBD-II system. The TCM
independently processes and stores fault codes, freeze frame, supports industry-standard PIDs as well as J1979
Mode 09 CALID and CVN. The TCM does not directly illuminate the MIL, but requests the ECM to do so. The TCM
is located inside the transmission assembly. It is not serviceable with the exception of reprogramming.
Transmission Inputs
Transmission Range Sensor
The Hall effect Transmission Range (TR) sensor provides 2 analog voltage inputs to the Transmission Control
Module (TCM). The voltages correspond to the driver-selected gear position (Park, Rev, Neutral, D, L). One input
is high in Park, and decreases thru the ranges. The other input is the inverse of the first. These inputs are checked
for opens and shorts (P0707, P0708) and invalid voltage sum (the 2 inputs should sum to 5 V +/- 0.29 V, a P0706
is stored if the sum is out of range).
Speed Sensors
The Turbine Shaft Speed (TSS) sensor and Output Shaft Speed (OSS) sensors are hall effect sensors that are
checked for rational readings between each other, and with the vehicle speed signal over CAN.
If the TSS sensor is open or shorted, or in 2-nd gear and above, OSS indicates a gear-adjusted speed over 600
rpm, or the CAN VSS signal indicates a vehicle speed over 12.5 mph, a P0717 fault will be stored. If engine speed,
CAN wheel speed and OSS speeds correlate but TSS error exceeds 15%, a P0716 fault will be stored.
If the OSS sensor is open or shorted, or in 2-nd gear and above, OSS calculated from wheel speed indicates a
speed over 300 rpm, or the CAN VSS signal indicates a vehicle speed over 12.5 mph, a P0722 fault will be stored.
If engine speed, CAN wheel speed and TSS speeds correlate but OSS error exceeds 15%, a P0721 fault will be
stored.
Transmission Fluid Temperature
The Transmission Fluid Temperature Sensor (TFT) is monitored for open and short circuit faults (P0712, P0713)
and for stuck in-range faults (P0711) where TFT does not change from its initial cold-start value after extended
driving and end up at a reasonable temperature (> 20 deg C).
Transmission Outputs
Shift Solenoids
The on/off Shift Solenoid (SSA and SSB) output circuits are checked for open/short to power (SSA: P0974, SSB:
P0977) and short to ground (SSA: P0973, SSB: P0976) by monitoring the status of a feedback circuit from the
output driver.
The Variable Force Solenoid (VFS) Shift Solenoid (SSC, SSD, SSE, and SSF) output circuits are checked for short
to power (SSC: P0980, SSD: P0983, SSE: P0986, SSF: P0999), open/short to ground (SSC: P0979, SSD: P0982,
SSE: P0985, SSF: P0998) and stuck control current (SSC: P0978, SSD: P0981, SSE: P0984, SSF: P0997) by
monitoring the status of a feedback circuit from the output driver.
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PAGE 148 OF 160
st
nd
The shift solenoids are monitored functionally through gear ratio monitoring (P0731 for 1 gear, P0732 for 2 gear,
rd
th
th
th
P0733 for 3 gear, P0734 for 4 gear, P0735 for 5 gear, and P0729 for 6 gear), or if the drive range is failed to
Neutral (P1700 fault code).
Torque Converter Clutch
The Torque Converter Clutch (TCC) output circuit is checked for short to power (P2763), open/short to ground
(P2764) and stuck control current (P2762) by monitoring the status of a feedback circuit from the output driver.
The TCC solenoid is also functionally monitored for stuck on and stuck off malfunctions. If the TCC is failed on
when commanded off, engine rpm will drop to zero during a drive engagement or when coming to a stop and a
P2758 fault code will be stored. If the TCC is failed off when commanded on, excessive slip (>100 rpm) will occur
and a P2757 fault code will be stored.
Pressure Control Solenoid
The Pressure Control Solenoid (PCA, controls line pressure) output circuit is checked for short to power (P0963)
open/short to ground (P0962) and stuck control current (P0961) by monitoring the status of a feedback circuit from
the output driver.
Transmission Control Module (TCM)
The TCM monitors itself by using various software monitoring functions. The flash ROM is checked using a
checksum calculation. If the checksum is incorrect during initialization, a P0601 fault will be stored. The EEPROM
is emulated in the flash ROM. If it is not possible to store information in the EEPROM emulation or if the verification
fails, a P0603 fault is stored and the ECM is requested to illuminate the MIL immediately. If a RAM Read/Write
error is detected during initialization, a P0604 fault code will be stored.
CAN Communications error
The TCM receives information from the ECM via CAN. If the CAN link fails the TCM no longer has torque or
engine speed information available. The TCM will store a U0073 fault code if the CAN Bus is off. The TCM will
store a U0100 fault code if it doesn’t receive any more CAN messages from the ECM. Fault codes will be stored if
the ECM received invalid/faulted information for the following CAN message items: Engine Torque (P2544),
Engine Speed (P1920), and pedal position (P1576).
The TCM receives wheel speed from the Antilock Brake System (ABS) module, a U0121 fault code will be stored if
communication with the ABS module is lost. If the wheel speed signal is invalid or failed, a U0415 fault code will be
stored.
Power Supply
If the power supply is outside of the specified 9 to 18 volt range, a fault will be stored (P0562, P0563).
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PAGE 149 OF 160
Mazda FNR5 (FWD) Transmission
FNR5 is mechanically similar to the FN transmission; with an add-on gear set increasing it from a four-speed to a
five-speed transmission.
Transmission Inputs
The Transmission Range Sensor (TRS) provides a single analog input to the TCM. This input voltage is monitored
for mis-adjustment (P0706), opens (P0708) and shorts (P0707).
The Turbine Shaft Speed (TSS) sensor is a variable reluctance sensor; with rationality check for opens and shorts
(P0715).
Intermediate Shaft Speed (ISS) and Output Shaft Speed (OSS) sensors are analog inputs that are checked for
rationality. If the engine rpm is above the torque converter stall speed or one of the two speed sensors has
sufficient signal, it can be inferred that the vehicle must be moving. If there is insufficient output from the ISS
sensor, a malfunction is indicated (P0791). If there is insufficient output from the OSS sensor, or a disconnected
sensor a malfunction is indicated (P0720).
Transmission Fluid Temperature Sensor is checked for stuck (P0711), Low input or Short (P0712) and High input
or open (P0713).
Transmission Outputs
Shift Solenoids
The three On/Off Shift Solenoids (SSD, SSE, SSF) output circuits are checked for opens and shorts by the TCM
by monitoring the status of a feedback circuit from the output driver (P0768, P0773, P2709 respectively). The shift
solenoids are functionally (mechanically) checked by means of a comprehensive malfunction pattern test. This
monitor examines gear ratios to determine if a shift solenoid failure is stuck on (P0767, P0772, P2708) or stuck off
(P0766, P0771, P2707 respectively).
The four Duty Cycle Solenoids (SSA, SSB, SSC, PCB) are functionally checked by means of comprehensive
malfunction patterns for stuck on (P0752, P0757, P0762, and P0777), for stuck off (P0751, P0756, P0761, no
code for PCB), and have a continuity check for open or shorted (P0753, P0758, P0763, P0778).
Torque Converter Clutch
Multiple solenoids control the TCC in the FNR5 transmission. Electrical checks for all shift solenoids are performed
as indicated above. The TCC is checked functionally by evaluating torque converter slip under steady state
conditions when the torque converter is fully applied. If the slip exceeds the malfunction thresholds when the TCC
is commanded on, a TCC malfunction is indicated (P0741). If slip is below an open converter threshold when the
TCC is commanded off, a TCC malfunction is indicated through the shift solenoid functional test (P0742). The TCC
also has a check for intermittent slip detection (P0744).
Pressure Control Solenoid
The Pressure Control Solenoid A is a linear solenoid. This solenoid has a continuity check for shorts and opens
(P0745).
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Transmission Control Module (TCM)
Power Supply
If the TCM input power voltage is low a code is set (P0882).
CAN Communications
The TCM receives information from the ECM via the high speed CAN connection. If the CAN link or network fails
the TCM no longer has engine information available. The TCM will store a U0073 fault code if the CAN Bus is off or
a U0100 fault code if the TCM stops receiving CAN messages from the ECM.
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PAGE 151 OF 160
6F (FWD) Transmission
Transmission Inputs
Transmission Range Sensor
The 6F Digital Transmission Range (DTR) sensor provides four digital inputs to the PCM. Unlike the Ford standard
digital TRS that has 1 analog and 3 digital inputs, this sensor uses 4 digital inputs, and all switches open (sensor
disconnect) is an invalid bit pattern. The PCM decodes these inputs to determine the driver-selected gear position
(Park, Rev, Neutral, OD, Low). This input device is checked for all switches open (P0708), invalid input patterns
(P0705), and a stuck in transition zone between valid positions (P0706).
Speed Sensors
The Turbine Shaft Speed (TSS) sensor and Output Shaft Speed (OSS) sensor are Hall Effect inputs that are
checked for rationality. The vehicle speed signal is provided from the ABS system (if present) to the PCM, or is
derived from OSS. If the engine rpm is above the torque converter stall speed and engine load is high, it can be
inferred that the vehicle must be moving. If there is insufficient output from the VSS sensor (if present), a
malfunction is indicated (P0500). If there is insufficient output from the TSS sensor, a malfunction is indicated
(P0715). If there is insufficient output from the OSS sensor, a malfunction is indicated (P0720).
Transmission Fluid Temperature
st
6F has a feature called "Cold mode" (1 implemented in 5R110W in 2003 MY). If TFT is below -20 deg F, the
st
nd
rd
th
th
th
transmission will limit operation to 1 , 2 , 3 , and 4 gears (5 and 6 gears are disabled). Cold mode remains in
effect until TFT rises above -20 deg F or vehicle operation (based on shift times or heat generated by driving)
indicates that TFT should not be in the cold mode range, at which point normal operation is enabled.
if TFT is failed at start up the transmission will be placed in cold mode and remain there until TFT is no longer failed
and above -20 deg F or the vehicle operating conditions listed above trigger an exit from cold mode.
Once out of cold mode a TFT failure will not trigger cold mode (can only go into cold mode once/power-up); this
mode is the same as implemented on 5R110W in 2003.5 MY.
TFT is monitored for circuit faults (P0712, P0713) and in-range failures (P0711)
For this reason all TFT diagnostics illuminate the MIL on 6F.
Transmission Outputs
Shift Solenoids
6F has 5 shift solenoids:
1. SSA – a Variable Force Solenoid (VFS) that controls CB1234 (a brake clutch, grounds an element to the
st
nd
rd
th
case, that is on in 1 , 2 , 3 and 4 gear)
rd
th
2. SSB – a VFS that controls C35R (a rotating clutch on in 3 , 5 and Reverse)
nd
th
3. SSC – a VFS that controls CB26 (a brake clutch on in 2 and 6 gear)
st
4. SSD – a VFS that controls either CBLR (a brake clutch on in 1 gear with engine braking and Reverse) or
th
th
th
C456 (a rotating clutch on in 4 , 5 and 6 gear)
5. SSE – an On/Off solenoid that controls the multiplexing of SSD between CBLR and C456.
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Output circuits are checked for opens, short to ground and short to power faults (codes listed in that order) by the
PCM by monitoring the status of a feedback circuit from the output driver (SSA P0750, P0973, P0974; SSB P0755,
P0976, P0977; SSC P0760, P0979, P0980; SSD P0765, P0982, P0983; SSE P0770).
The shift solenoids are also functional tested for stuck on and stuck off failures. This is determined by vehicle
inputs such as gear command, and achieved gear (based on turbine and output speed). In general the shift
solenoid malfunction codes actually cover the entire clutch system (solenoid, valves, and the clutch itself since
using ratio there is no way to isolate the solenoid from the rest of the clutch system), BUT due to the hydraulic
controls arrangement on 6F it is possible to isolate two specific solenoid failures from clutch system faults:
a) SSB stuck on from C35R stuck on - due to hydraulic interlock between CBLR and C35R we can isolate
st
st
SSB stuck on from C35R by turning SSE on in 1 gear without engine braking (get 1 if SSB stuck on, get
rd
3 if C35R is stuck on)
b) SSD stuck off. Since SSD is multiplexed (controls both CBLR and C456) we can isolate CBLR stuck off
and C456 stuck off from SSD stuck off since the latter impacts both clutch systems.
For SSA thru SSD Diagnostics will isolate the fault into clutch functionally (non-electrical) failed off (SSA P0751,
SSB P0756, SSC P0761, SSD P0766) and clutch functionally failed on (SSA: P0752, SSB: P0757, SSC: P0762,
SSD: P0767). The On/Off solenoid (SSE) controls the multiplexing of SSD between CBLR and C456 clutches.
Using ratio we can determine if the multiplex valve is in the wrong position, but cannot be sure if the failure is due to
the solenoid or a stuck valve. The multiplex valve is tested for stuck in default position (P0771, includes SSE stuck
off) and stuck in spring compressed position (P0772, includes SSE stuck on) failures.
Torque Converter Clutch
The Torque Converter Clutch (TCC) solenoid is a Variable Force Solenoid. TCC solenoid circuit is checked
electrically for open, short to ground and short to power circuit faults internally in the PCM by monitoring the status
of a feedback circuit from the output driver (P0740, P0742, P0744).
The TCC solenoid is checked functionally by evaluating torque converter slip under steady state conditions when
the torque converter is fully applied. If the slip exceeds the malfunction thresholds when the TCC is commanded
on, a TCC malfunction is indicated (P0741).
For 6F the TCC is controlled by a 2 valve system - TCC reg apply and TCC control valve. Normally the TCC VFS
controls the positions of these valves - turning on the TCC VFS moves both valves from the release to the apply
position. If the TCC control valve sticks in the apply position then there will be no flow thru the TCC (both apply and
release sides exhausted) when commanded open, which will cause the converter to overheat.
A method to detect this failure was designed into the hardware - SSE pressure is routed to the TCC reg apply
valve (SSE has no effect on TCC control valve). In 3rd gear or higher if TCC is open SSE can be turned on,
moving the TCC reg apply valve to the apply position. If the TCC control valve is in the wrong (apply) position this
rd
th
th
th
will cause the TCC to apply. If the TCC applies when SSE is turned on in 3 , 4 , 5 or 6 gear while TCC is
commanded open (TCC VFS pressure low) the failure will be detected, a P2783 DTC fault code stored. Even
though this test only detects failures of the control valve, the FMEM actions alter the shift and TCC lock schedules
to keep the TCC applied as much as possible, so this failure has been made MIL.
Electronic Pressure Control
The EPC solenoid is a variable force solenoid that controls line pressure in the transmission. The EPC solenoid
has a feedback circuit in the PCM that monitors EPC current. If the current indicates a short to ground (low
pressure), a high side switch will be opened. This switch removes power from all 6 VFS's and the on/off shift
solenoid, providing Park, Reverse, Neutral, and 5M (in all forward ranges) with maximum line pressure based on
manual lever position. This solenoid is tested for open (P0960), short to ground (P0962), and short to power
(P0963) malfunctions.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 153 OF 160
High Side Switch
6F has a high side switch that can be used to remove power from all 7 solenoids simultaneously. If the high side
switch is opened, all 7 solenoids will be electrically off, providing Park, Reverse, Neutral, and 5M (in all forward
ranges) with maximum line pressure based on manual lever position. The switch is tested for open faults (switch
failed closed will provide normal control). If the switch fails, a P0657 fault code will be stored.
ADLER (chip that controls all 7 solenoids) diagnostics:
The solenoids are controlled by an ADLER chip. The main micro sends commanded solenoid states to the
ADLER, and receives back solenoid circuit fault information.
If communication with the ADLER is lost a P1636 fault code will be stored. If this failure is detected the states of the
solenoids are unknown, so the control system will open the high side switch (removes power from all the
solenoids), providing P, R, N and 5M with open TCC and max line pressure.
TRID Block
The TRID block is a portion of flash memory that contains solenoid characterization data tailored to the specific
transmission to improve pressure accuracy.
The TRID block is monitored for two failures:
a) TRID block checksum error / incorrect version of the TRID (P163E)
b) TRID block not programmed (P163F)
st
rd
If the TRID block is unavailable FMEM action limits operation to 1 and 3 gear until the issue is correct.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 154 OF 160
On Board Diagnostic Executive
The On-Board Diagnostic (OBD) Executive is a portion of the PCM strategy that manages the sequencing
and execution of all diagnostic tests. It is the "traffic cop" of the diagnostic system. Each test/monitor can be
viewed as an individual task, which may or may not be able to run concurrently with other tasks. The
Diagnostic Executive enables/disables OBD monitors in order to accomplish the following:
•
•
•
•
•
•
•
Sequence the OBD monitors such that when a test runs, each input that it relies upon has already
been tested.
Controls and co-ordinates the execution of the individual OBD system monitors: Catalyst, Misfire,
EGR, O2, Fuel, AIR, EVAP and, Comprehensive Component Monitor (CCM).
Stores freeze frame and "similar condition" data
Manages storage and erasure of Diagnostic Trouble Codes as well as MIL illumination
Controls and co-ordinates the execution of the On-Demand tests: Key On Engine Off (KOEO), Key
On Engine Running (KOER), and the Output Test Mode (OTM).
Performs transitions between various states of the diagnostic and powertrain control system to
minimize the effects on vehicle operation.
Interfaces with the diagnostic test tools to provide diagnostic information (I/M readiness, various J1979 test
modes) and responds to special diagnostic requests (J1979 Mode 08 and 09).
The diagnostic also executive controls several overall, global OBD entry conditions.
•
•
•
•
The Diagnostic Executive waits for 4 seconds after the PCM is powered before initiating any OBD
monitoring. For the 2001 MY and beyond, this delay has been eliminated to meet the "zero startup delay"
misfire monitoring requirements.
The engine must be started to initiate a driving/monitoring cycle.
The Diagnostic Executive suspends OBD monitoring when battery voltage falls below 11.0 volts.
The Diagnostic Executive suspends monitoring of fuel-system related monitors (catalyst, misfire, evap,
O2, AIR and fuel system) when fuel level falls below 15%
The diagnostic executive controls the setting and clearing of pending and confirmed DTCs.
•
•
•
•
A pending DTC and freeze frame data is stored after a fault is confirmed on the first monitoring cycle. If the
fault recurs on the next driving cycle, a confirmed DTC is stored, freeze frame data is updated, and the
MIL is illuminated. If the fault did not recur on the next driving cycle, the pending DTC and freeze frame
data is erased on the next power-up.
For the 2005 MY and later, pending DTCs will be displayed as long as the fault is present. Note that OBDII regulations required a complete fault-free monitoring cycle to occur before erasing a pending DTC. In
practice, this means that a pending DTC is erased on the next power-up after a fault-free monitoring cycle.
For clearing comprehensive component monitoring (CCM) pending DTCs, the specific monitor must
determine that no fault is present, and a 2-hour engine off soak has occurred prior to starting the vehicle.
The 2-hour soak criteria for clearing CCM confirmed and pending DTCs has been utilized since the 2000
MY.
After a confirmed DTC is stored and the MIL has been illuminated, three consecutive fault-free monitoring
cycles must occur before the MIL can be extinguished on the next (fourth) power-up. After 40 engine
warm-ups, the DTC and freeze frame data is erased.
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REVISION DATE: NOVEMBER 12, 2007
PAGE 155 OF 160
Exponentially Weighted Moving Average
Exponentially Weighted Moving Averaging is a well-documented statistical data processing technique that is used
to reduce the variability on an incoming stream of data. Use of EWMA does not affect the mean of the data,
however, it does affect the distribution of the data. Use of EWMA serves to “filter out” data points that exhibit
excessive and unusual variability and could otherwise erroneously light the MIL.
The simplified mathematical equation for EWMA implemented in software is as follows:
New Average = [New data point * “filter constant”] + [( 1 - “filter constant” ) * Old Average]
This equation produces an exponential response to a step-change in the input data. The "Filter Constant"
determines the time constant of the response. A large filter constant (i.e. 0.90 ) means that 90% of the new data
point is averaged in with 10% of the old average. This produces a very fast response to a step change.
Conversely, a small filter constant (i.e. 0.10 ) means that only 10% of the new data point is averaged in with 90%
of the old average. This produces a slower response to a step change.
When EWMA is applied to a monitor, the new data point is the result from the latest monitor evaluation. A new
average is calculated each time the monitor is evaluated and stored in Keep Alive Memory (KAM). This normally
occurs each driving cycle. The MIL is illuminated and a DTC is stored based on the New Average store in KAM.
In order to facilitate repair verification and DDV demonstration, 2 different filter constants are used. A “fast filter
constant” is used after KAM is cleared/DTCs are erased and a “normal filter constant” is used for normal
customer driving. The “fast filter” is used for 2 driving cycles after KAM is cleared/DTCs are erased, and then the
“normal filter” is used. The “fast filter” allows for easy repair verification and monitor demonstration in 2 driving
cycles, while the normal filter is used to allow up to 6 driving cycles, on average, to properly identify a malfunction
and illuminate the MIL.
In order to relate filter constants to driving cycles for MIL illumination, filter constants must be converted to time
constants. The mathematical relationship is described below:
Time constant = [ ( 1 / filter constant ) - 1 ] * evaluation period
The evaluation period is a driving cycle. The time constant is the time it takes to achieve 68% of a step-change to
an input. Two time constants achieve 95% of a step change input.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 156 OF 160
Catalyst Monitor and EGR Monitor EWMA
EWMA has been incorporated in the catalyst monitor and the non-intrusive stepper motor EGR monitor. There are
3 calibrateable parameters that determine the MIL illumination characteristics.
“Fast” filter constant, used for 2 driving cycles after DTCs are cleared or KAM is reset
“Normal” filter constant, used for all subsequent, “normal” customer driving
Number of driving cycles to use fast filter after KAM clear (normally set to 2 driving cycles)
Several examples for a typical catalyst monitor calibration are shown in the tables below. Specific calibration
information can be obtained from the parameter listing provided for each strategy.
Monitor
evaluation
EWMA Filter Calculation,
“normal” filter constant
Weighted
Average
(“new data”)
set to 0.4
(“new
average”)
Malfunction threshold = .75
0.15
.15 * (0.4) + .15 * ( 1 - 0.4)
Driving
cycle
number
0.15
Action/Comment
normal 100K system
1.0
1.0
* (0.4) + .15 * ( 1 - 0.4)
0.49
1
1.0
1.0
* (0.4) + .49 * ( 1 - 0.4)
0.69
2
catastrophic failure
1.0
1.0
* (0.4) + .69 * ( 1 - 0.4)
0.82
3
exceeds threshold
1.0
1.0
* (0.4) + .82 * ( 1 - 0.4)
0.89
4
MIL on
0.15
.15 * (0.4) + .15 * ( 1 - 0.4)
0.15
normal 100K system
0.8
0.8 * (0.4) + .15 * ( 1 - 0.4)
0.41
1
0.8
0.8 * (0.4) + .41 * ( 1 - 0.4)
0.57
2
0.8
0.8 * (0.4) + .57 * ( 1 - 0.4)
0.66
3
0.8
0.8 * (0.4) + .66 * ( 1 - 0.4)
0.72
4
0.8
0.8 * (0.4) + .72 * ( 1 - 0.4)
0.75
5
exceeds threshold
0.8
0.8 * (0.4) + .75 * ( 1 - 0.4)
0.77
6
MIL on
1.5 * threshold failure
Note: For the catalyst and EGR monitor, the "fast filter" is normally set to 1.0
For the catalyst monitor, the "fast filter" is normally used to 2 driving cycles, for the EGR monitor, "fast filter" is
normally used for 1 driving cycle.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 157 OF 160
I/M Readiness Code
The readiness function is implemented based on the J1979 format. A battery disconnection or clearing codes
using a scan tool results in the various I/M readiness bits being set to a “not-ready” condition. As each noncontinuous monitor completes a full diagnostic check, the I/M readiness bit associated with that monitor is set to a
“ready” condition. This may take one or two driving cycles based on whether malfunctions are detected or not.
The readiness bits for comprehensive component monitoring, misfire and fuel system monitoring are considered
complete once all the non-continuous monitors have been evaluated. Because the evaporative system monitor
o
requires ambient conditions between 40 and 100 F and BARO > 22.5 " Hg (< 8,000 ft.) to run, special logic can
“bypass” the running the evap monitor for purposes of clearing the evap system I/M readiness bit due to the
continued presence of these extreme conditions.
Evap bypass logic for new 1999 MY, 2000 MY, and beyond vehicles:
o
If the evaporative system monitor conditions are met with the exception of the 40 to 100 F ambient temperatures
or BARO range, a timer is incremented. The timer value is representative of conditions where the Evap monitor
could have run (all entry conditions met except IAT and BARO) but did not run due to the presence of those
extreme conditions. If the timer continuously exceeds 30 seconds during a driving cycle in which all continuous
and non-continuous monitors were evaluated, the evaporative system monitor is then considered complete. If the
above conditions are repeated during a second driving cycle, the I/M readiness bit for the evaporative system is
set to a “ready” condition.
Power Take Off Mode
While PTO mode is engaged, the I/M readiness bits are set to a “not-ready” condition. When PTO mode is
disengaged, the I/M readiness bits are restored to their previous states prior to PTO engagement. During PTO
mode, only CCM circuit checks continue to be performed.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 158 OF 160
Catalyst Temperature Model
A catalyst temperature model is currently used for entry into the catalyst and oxygen sensor monitors. The
catalyst temperature model uses various PCM parameters to infer exhaust/catalyst temperature. For the 1998
MY, the catalyst temperature model has been enhanced and incorporated into the Type A misfire monitoring
logic. The model has been enhanced to include a misfire-induced exotherm prediction. This allows the model to
predict catalyst temperature in the presence of misfire.
The catalyst damage misfire logic (Type A) for MIL illumination has been modified to require that both the catalyst
damage misfire rate and the catalyst damage temperature is being exceeded prior to MIL illumination. This
change is intended to prevent the detection of unserviceable, unrepeatable, burst misfire during cold engine startup while ensuring that the MIL is properly illuminated for misfires that truly damage the catalyst.
Beginning with the 2007 MY, the catalyst temperature model is also used to generate the primary inputs to the
CSER Monitor as described in that section of this document.
Serial Data Link MIL Illumination
The OBD-II diagnostic communication messages utilize an industry standard 500 kbps CAN communication link.
The instrument cluster on some vehicles uses the same CAN data link to receive and display various types of
information from the PCM. For example, the engine coolant temperature information displayed on the instrument
cluster comes from the same ECT sensor used by the PCM for all its internal calculations.
These same vehicles use the CAN data link to illuminate the MIL rather than a circuit, hard-wired to the PCM.
The PCM periodically sends the instrument cluster a message that tells it to turn on the MIL, turn off the MIL or
blink the MIL. If the instrument cluster fails to receive a message within a 5-second timeout period, the instrument
cluster itself illuminates the MIL. If communication is restored, the instrument cluster turns off the MIL after 5
seconds. Due to its limited capabilities, the instrument cluster does not generate or store Diagnostic Trouble
Codes.
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 159 OF 160
Calculated Load Value
LOAD_PCT (PID $04) =
current airflow
(peak airflow at [email protected] as a function of rpm) * (BARO/29.92) * SQRT(298/(AAT+273))
o
Where: STP = Standard Temperature and Pressure = 25 C, 29.92 in Hg BARO,
SQRT = square root,
WOT = wide open throttle,
o
AAT = Ambient Air Temperature and is in C
MAF Sensor Voltage
current airflow
(peak airflow at [email protected] as a function of rpm) * (BARO/29.92) * SQRT(298/(AAT+273))
Calibration Table:
Airflow as a function of rpm
BARO (inferred from
MAF sensor) or MAP
sensor voltage
Ambient Air Temp,
inferred from IAT
sensor voltage
engine rpm
FORD MOTOR COMPANY
REVISION DATE: NOVEMBER 12, 2007
PAGE 160 OF 160
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