DTC P0136 Oxygen Sensor Circuit Malfunction (Bank 1 Sensor 2

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES–165
DTC
P0136
Oxygen Sensor Circuit Malfunction (Bank 1
Sensor 2)
DTC
P0137
Oxygen Sensor Circuit Low Voltage (Bank 1
Sensor 2)
DTC
P0138
Oxygen Sensor Circuit High Voltage (Bank 1
Sensor 2)
DTC
P0156
Oxygen Sensor Circuit Malfunction (Bank 2
Sensor 2)
DTC
P0157
Oxygen Sensor Circuit Low Voltage (Bank 2
Sensor 2)
DTC
P0158
Oxygen Sensor Circuit High Voltage (Bank 2
Sensor 2)
DESCRIPTION
In order to obtain a high purification rate of the carbon monoxide (CO), hydrocarbon (HC) and nitrogen
oxide (NOx) components in the exhaust gas, a TWC is used. For the most efficient use of the TWC, the
air-fuel ratio must be precisely controlled so that it is always close to the stoichiometric air-fuel level. For
the purpose of helping the ECM to deliver accurate air-fuel ratio control, a Heated Oxygen (HO2) sensor
is used.
The HO2 sensor is located behind the TWC, and detects the oxygen concentration in the exhaust gas.
Since the sensor is integrated with the heater that heats the sensing portion, it is possible to detect the
oxygen concentration even when the intake air volume is low (the exhaust gas temperature is low).
When the air-fuel ratio becomes lean, the oxygen concentration in the exhaust gas is rich. The HO2
sensor informs the ECM that the post-TWC air-fuel ratio is lean (low voltage, i.e. less than 0.45 V).
Conversely, when the air-fuel ratio is richer than the stoichiometric air-fuel level, the oxygen concentration
in the exhaust gas becomes lean. The HO2 sensor informs the ECM that the post-TWC air-fuel ratio is
rich (high voltage, i.e. more than 0.45 V). The HO2 sensor has the property of changing its output voltage
drastically when the air-fuel ratio is close to the stoichiometric level.
The ECM uses the supplementary information from the HO2 sensor to determine whether the air-fuel ratio
after the TWC is rich or lean, and adjusts the fuel injection time accordingly. Thus, if the HO2 sensor is
working improperly due to internal malfunctions, the ECM is unable to compensate for deviations in the
primary air-fuel ratio control.
ES
ES–166
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
Atmospheric Air
Housing
Output Voltage Ideal Air-fuel Mixture
Platinum Electrode
Solid Electrolyte
(Zirconia Element)
Heater
ES
Coating (Ceramic)
Cover
Richer - Air-fuel Ratio - Leaner
Exhaust Gas
A115539E07
DTC No.
DTC Detection Condition
•
P0136
P0156
•
•
P0137
P0157
•
•
P0138
P0158
•
Trouble Area
Abnormal voltage output:
During active air-fuel ratio control, following conditions (a)
and (b) met for certain period of time (2 trip detection
logic):
(a) Heated Oxygen (HO2) sensor voltage does not
decrease to less than 0.59 V
(b) HO2 sensor voltage does not increase to more
than 0.21 V
Low impedance:
Sensor impedance less than 5 Ω for more than 30
seconds when ECM presumes sensor to be warmed
up and operating normally (2 trip detection logic)
•
•
•
•
•
•
Open or short in HO2 sensor (sensor 2) circuit
HO2 sensor (sensor 2)
HO2 sensor heater (sensor 2)
Air-fuel Ratio (A/F) sensor (sensor 1)
Integration relay (EFI MAIN relay)
Gas leakage from exhaust system
Low voltage (open):
During active air-fuel ratio control, following conditions (a)
and (b) met for certain period of time (2 trip detection
logic):
(a) HO2 sensor voltage output less than 0.21 V
(b) Target air-fuel ratio rich
High impedance:
Sensor impedance 15 kΩ or more for more than 90
seconds when ECM presumes sensor to be warmed
up and operating normally (2 trip detection logic)
•
•
•
•
•
Open in HO2 sensor (sensor 2) circuit
HO2 sensor (sensor 2)
HO2 sensor heater (sensor 2)
Integration relay (EFI MAIN relay)
Gas leakage from exhaust system
High voltage (short):
During active air-fuel ratio control, following conditions (a)
and (b) met for certain period of time (2 trip detection
logic):
(a) HO2 sensor voltage output more than 0.59 V
(b) Target air-fuel ratio lean
Extremely high voltage (short):
HO2 sensor voltage output exceeds 1.2 V for more
than 10 seconds (2 trip detection logic)
•
•
•
Short in HO2 sensor (sensor 2) circuit
HO2 sensor (sensor 2)
ECM internal circuit malfunction
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES–167
MONITOR DESCRIPTION
Active Air-Fuel Ratio Control
The ECM usually performs air-fuel ratio feedback control so that the Air-Fuel Ratio (A/F) sensor output
indicates a near stoichiometric air-fuel level. This vehicle includes active air-fuel ratio control in addition to
regular air-fuel ratio control. The ECM performs active air-fuel ratio control to detect any deterioration in
the Three-Way Catalytic Converter (TWC) and Heated Oxygen (HO2) sensor malfunctions (refer to the
diagram below).
Active air-fuel ratio control is performed for approximately 15 to 20 seconds while driving with a warm
engine. During active air-fuel ratio control, the air-fuel ratio is forcibly regulated to become lean or rich by
the ECM. If the ECM detects a malfunction, one of the following DTCs is set: DTC P0136 or P0156
(abnormal voltage output), P0137 or P0157 (open circuit) and P0138 or P0158 (short circuit).
Abnormal Voltage Output of HO2 Sensor (DTC P0136 and P0156)
While the ECM is performing active air-fuel ratio control, the air-fuel ratio is forcibly regulated to become
rich or lean. If the sensor is not functioning properly, the voltage output variation is small. For example,
when the HO2 sensor voltage does not decrease to less than 0.21 V and does not increase to more than
0.59 V during active air-fuel ratio control, the ECM determines that the sensor voltage output is abnormal
and sets DTC P0136 or P0156.
HO2 SENSOR CIRCUIT MALFUNCTION
15 to 20 seconds
(P0136: ABNORMAL VOLTAGE)
Active air-fuel ratio control
Off
Operation
Normal
0.59 V
HO2 sensor voltage
Abnormal
0.21 V
A115540E02
Open or Short in Heated Oxygen (HO2) Sensor Circuit (DTC P0137 and P0157 or P0138 and P0158)
During active air-fuel ratio control, the ECM calculates the Oxygen Storage Capacity (OSC)* of the ThreeWay Catalytic Converter (TWC) by forcibly regulating the air-fuel ratio to become rich or lean. If the HO2
sensor has an open or short, or the voltage output of the sensor decreases significantly, the OSC
indicates an extraordinarily high value. Even if the ECM attempts to continue regulating the air-fuel ratio to
become rich or lean, the HO2 sensor output does not change.
While performing active air-fuel ratio control, when the target air-fuel ratio is rich and the HO2 sensor
voltage output is 0.21 V or less (lean), the ECM interprets this as an abnormally low sensor output voltage
and sets DTC P0137 or P0157. When the target air-fuel ratio is lean and the voltage output is 0.59 V or
more (rich) during active air-fuel ratio control, the ECM determines that the sensor voltage output is
abnormally high, and sets DTC P0138 or P0158.
HINT:
DTC P0138 or P0158 is also set if the HO2 sensor voltage output is more than 1.2 V for 10 seconds or
more.
ES
ES–168
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
*: The TWC has the capability to store oxygen. The OSC and the emission purification capacity of the
TWC are mutually related. The ECM determines whether the catalyst has deteriorated based on the
calculated OSC value (see page ES-234).
HO2 SENSOR CIRCUIT LOW VOLTAGE
(P0137 and P0157: OPEN)
15 to 20 seconds
Active air-fuel ratio control
Operation
Off
Abnormal
Normal
ES
Target air-fuel ratio
Stoichiometric
Air-Fuel Level
Rich
Normal
HO2 sensor voltage
0.21 V
Abnormal
HO2 SENSOR CIRCUIT HIGH VOLTAGE
(P0138 and P0158: SHORT)
Operation
Active air-fuel ratio control
Target air-fuel ratio
Off
Stoichiometric
Air-Fuel Level
Lean
Abnormal
0.59 V
HO2 sensor voltage
A115541E06
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES–169
High or Low Impedance of Heated Oxygen (HO2) Sensor (DTC P0136 and P0156 or P0137 and
P157)
Relationship between element
temperature and impedance:
(Ω)
15,000
DTC Detection Area
1,000
100
10
5
300 400 500 600 700 800
(572) (752) (932)(1,112)(1,292)(1,472)
°C (°F)
A076841E04
During normal air-fuel ratio feedback control, there are small variations in the exhaust gas oxygen
concentration. In order to continuously monitor the slight variations in the HO2 sensor signal while the
engine is running, the impedance* of the sensor is measured by the ECM. The ECM determines that there
is a malfunction in the sensor when the measured impedance deviates from the standard range.
*: The effective resistance in an alternating current electrical circuit.
HINT:
• The impedance cannot be measured using an ohmmeter.
• DTC P0136 and P0156 indicate the deterioration of the HO2 sensor. The ECM sets this DTC by
calculating the impedance of the sensor when the typical enabling conditions are satisfied (2 driving
cycles).
• DTC P0137 and P0157 indicate an open or short circuit in the HO2 sensor (2 driving cycles). The ECM
sets this DTC when the impedance of the sensor exceeds the threshold 15 kΩ.
MONITOR STRATEGY
Related DTCs
P0136: Heated oxygen sensor (bank 1) output voltage (Abnormal
voltage output)
P0136: Heated oxygen sensor (bank 1) impedance (Low)
P0137: Heated oxygen sensor (bank 1) output voltage (Low voltage)
P0137: Heated oxygen sensor (bank 1) impedance (High)
P0138: Heated oxygen sensor (bank 1) output voltage (High voltage)
P0138: Heated oxygen sensor (bank 1) output voltage (Extremely
high)
P0156: Heated oxygen sensor (bank 2) output voltage (Abnormal
voltage output)
P0156: Heated oxygen sensor (bank 2) impedance (Low)
P0157: Heated oxygen sensor (bank 2) output voltage (Low voltage)
P0157: Heated oxygen sensor (bank 2) impedance (High)
P0158: Heated oxygen sensor (bank 2) output voltage (High voltage)
P0158: Heated oxygen sensor (bank 2) output voltage (Extremely
high)
Required Sensors/Components (Main)
Heated oxygen sensor
Required Sensors/Components (Related)
Crankshaft position sensor, engine coolant temperature sensor, mass
air flow meter and throttle position sensor
Frequency of Operation
Once per driving cycle: Active air-fuel ratio control detection
Continuous: Other
Duration
20 seconds: Active air-fuel ratio control detection
90 seconds: Heated oxygen sensor impedance (High)
30 seconds: Heated oxygen sensor impedance (Low)
10 seconds: Output voltage (Stuck high)
MIL Operation
2 driving cycles
ES
ES–170
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
Sequence of Operation
None
TYPICAL ENABLING CONDITIONS
All:
Monitor runs whenever following DTCs not present
ES
P0031, P0032, P0051, P0052 (A/F Sensor heater - Sensor 1)
P0037, P0038, P0057, P0058 (O2 Sensor heater - Sensor 2)
P0100 - P0103 (MAF meter)
P0110 - P0113 (IAT sensor)
P0115 - P0118 (ECT sensor)
P0120 - P0223, P2135 (TP sensor)
P0125 (Insufficient ECT for Closed Loop)
P0171, P0172 (Fuel system)
P0300 - P0304 (Misfire)
P0335 (CKP sensor)
P0340 (CMP sensor)
P0455, P0456 (EVAP system)
P0500 (VSS)
P2196, P2198 (A/F Sensor - rationality)
P2A00, P2A03 (A/F Sensor - slow response)
Heated Oxygen Sensor Output Voltage (Abnormal Voltage Output, High Voltage and Low Voltage):
Active air-fuel ratio control
Executing
Active air-fuel ratio control begins when all of following conditions met:
-
Battery voltage
11 V or more
Engine coolant temperature
75°C (167°F) or more
Idling
OFF
Engine RPM
Less than 3,200 rpm
A/F sensor status
Activated
Fuel system status
Closed loop
Fuel cut
OFF
Engine load
10 to 70%
Shift position
4th
Heated Oxygen Sensor Impedance (Low):
Battery voltage
11 V or more
Estimated rear HO2 sensor temperature
Less than 700°C (1,292°F)
ECM monitor
Completed
DTC P0606
Not set
Heated Oxygen Sensor Impedance (High):
Battery voltage
11 V or more
Estimated rear HO2 sensor temperature
450°C (842°F) or more
ECM monitor
Completed
DTC P0606
Not set
Heated Oxygen Sensor Output Voltage (Extremely High):
Battery voltage
11 V or more
Time after engine start
2 seconds or more
TYPICAL MALFUNCTION THRESHOLDS
Heated Oxygen Sensor Output Voltage (Abnormal Voltage Output):
Either of following conditions met:
1 or 2
1. All of following conditions (a), (b) and (c) met
-
(a) Commanded air-fuel ratio
14.3 or less
(b) Rear HO2 sensor voltage
0.21 to 0.59 V
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
(c) OSC (Oxygen Storage Capacity of Catalyst)
2 g or more
2. All of following conditions (d), (e) and (f) met
-
(d) Commanded air-fuel ratio
14.9 or more
(e) Rear HO2 sensor voltage
0.21 to 0.59 V
(f) OSC
2 g or more
ES–171
Heated Oxygen Sensor Output Voltage (Low):
All of following conditions (a), (b) and (c) met
-
(a) Commanded air-fuel ratio
14.3 or less
(b) Rear HO2 sensor voltage
Less than 0.21 V
(c) OSC
2 g or more
Heated Oxygen Sensor Output Voltage (High):
All of following conditions (a), (b) and (c) met
-
(a) Commanded air-fuel ratio
14.9 or more
(b) Rear HO2 sensor voltage
More than 0.59 V
(c) OSC
2 g or more
Heated Oxygen Sensor Impedance (Low):
Duration of following condition met
30 seconds or more
Heated oxygen sensor impedance
Less than 5 Ω
Heated Oxygen Sensor Impedance (High):
Duration of following condition met
90 seconds or more
Heated oxygen sensor impedance
15 kΩ or more
Heated Oxygen Sensor Output Voltage (Extremely High):
Duration of following condition met
10 seconds or more
Heated oxygen sensor voltage
1.2 V or more
COMPONENT OPERATING RANGE
Duration of following condition met
30 seconds or more
Heated oxygen sensor voltage
Varies between 0.1 and 0.9 V
MONITOR RESULT
Refer to CHECKING MONITOR STATUS (see page ES-19).
ES
ES–172
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
WIRING DIAGRAM
Integration Relay
E35
Heated Oxygen Sensor (for Bank 1)
ECM
EFI MAIN
1 +B
EFI MAIN
48
HT1B
B30
HT1B 2
EFI NO. 1
Shielded
3 E2
OX1B 4
ES
88
B30 OX1B
65
B30 EX1B
P/I
B19
Heated Oxygen Sensor
(for Bank 2)
2 +B
HT2B 1
47
HT2B
B30
4 E2
OX2B 3
87
B30 OX2B
FL MAIN
Shielded
Battery
64
B30 EX2B
44
MREL
A9
A136304E01
CONFIRMATION DRIVING PATTERN
HINT:
• This confirmation driving pattern is used in the "PERFORM CONFIRMATION DRIVING PATTERN"
procedure of the following diagnostic troubleshooting procedure.
• Performing this confirmation pattern will activate the Heated Oxygen (HO2) sensor monitor. (The
catalyst monitor is performed simultaneously.) This is very useful for verifying the completion of a
repair.
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
Vehicle Speed
(h)
Between 64 km/h and
113 km/h (40 mph and
70 mph)
ES–173
NOTICE:
This test will not be completed
if the vehicle is driven at
absolutely constant speed
such as with cruise control
activated.
(g)
Idling
ES
Ignition Switch OFF
Warm up
10 minutes
Time
(Note: Even if vehicle stops during driving pattern, test can be resumed)
A115372E26
A098191E02
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch ON.
(c) Turn the tester ON.
(d) Clear DTCs (if set) (see page ES-39).
(e) Select the following menu items: DIAGNOSIS / CARB OBD II / READINESS TESTS.
(f) Check that O2S EVAL is INCMPL (incomplete).
(g) Start the engine and warm it up.
(h) Drive the vehicle at between 64 km/h and 113 km/h (40 mph and 70 mph) for at least 10 minutes.
(i) Note the state of the Readiness Tests items. Those items will change to COMPL (complete) as the O2S
EVAL monitor operates.
(j) On the tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO /
PENDING CODES. Then check if any DTCs (any pending DTCs) are set.
HINT:
If O2S EVAL does not change to COMPL, and any pending DTCs fail to set, extend the driving time.
INSPECTION PROCEDURE
HINT:
Sensor 2 refers to the sensor mounted behind the Three-Way Catalytic Converter (TWC) and located far
from the engine assembly.
HINT:
Intelligent tester only:
ES–174
ES
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
Malfunctioning areas can be identified by performing the A/F CONTROL function provided in the ACTIVE
TEST. The A/F CONTROL function can help to determine whether the Air-Fuel Ratio (A/F) sensor, Heated
Oxygen (HO2) sensor and other potential trouble areas are malfunctioning.
The following instructions describe how to conduct the A/F CONTROL operation using the intelligent
tester.
(a)Connect the intelligent tester to the DLC3.
(b)Start the engine and turn the tester ON.
(c) Warm up the engine at an engine speed of 2,500 rpm for approximately 90 seconds.
(d)On the tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/
F CONTROL.
(e)Perform the A/F CONTROL operation with the engine idling (press the RIGHT or LEFT button to
change the fuel injection volume).
(f) Monitor the voltage outputs of the A/F and HO2 sensors (AFS B1 S1 and O2S B1 S2 or AFS B2 S1
and O2S B2 S2) displayed on the tester.
HINT:
• The A/F CONTROL operation lowers the fuel injection volume by 12.5% or increases the injection
volume by 25%.
• The sensors react in accordance with increases and decreases in the fuel injection volume.
Standard
Tester Display
(Sensor)
Injection Volume
Status
Voltage
AFS B1 S1
(A/F)
+25%
Rich
Less than 3.0
-12.5%
Lean
More than 3.35
AFS B2 S1
(A/F)
+25%
Rich
Less than 3.0
-12.5%
Lean
More than 3.35
O2S B1 S2
(HO2)
+25%
Rich
More than 0.55
-12.5%
Lean
Less than 0.4
O2S B2 S2
(HO2)
+25%
Rich
More than 0.55
-12.5%
Lean
Less than 0.4
NOTICE:
The A/F sensor has an output delay of a few seconds and the HO2 sensor has a maximum output
delay of approximately 20 seconds.
Case
1
2
A/F Sensor (Sensor 1)
Output Voltage
HO2 Sensor (Sensor 2)
Output Voltage
Injection Volume
+25%
-12.5%
Injection Volume
+25%
-12.5%
Output Voltage
More than 3.35 V
Less than 3.0 V
Output Voltage
More than 0.5 V
Less than 0.4 V
Injection Volume
+25%
-12.5%
Injection Volume
+25%
-12.5%
Output Voltage
Almost
no reaction
Output Voltage
More than 0.5 V
Less than 0.4 V
Main Suspected
Trouble Area
-
•
•
•
A/F sensor
A/F sensor heater
A/F sensor circuit
ES–175
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
Case
3
4
A/F Sensor (Sensor 1)
Output Voltage
HO2 Sensor (Sensor 2)
Output Voltage
Injection Volume
+25%
-12.5%
Injection Volume
+25%
-12.5%
Output Voltage
More than 3.35 V
Less than 3.0 V
Output Voltage
Almost
no reaction
Injection volume
+25%
-12.5%
Injection Volume
+25%
-12.5%
Output Voltage
Almost
no reaction
Output Voltage
Almost
no reaction
Main Suspected
Trouble Area
•
•
•
HO2 sensor
HO2 sensor heater
HO2 sensor circuit
•
•
•
Injector
Fuel pressure
Gas leakage from
exhaust system
(Air-fuel ratio
extremely lean or
rich)
Following the A/F CONTROL procedure enables technicians to check and graph the voltage outputs of
both the A/F and HO2 sensors.
To display the graph, select the following menu items on the tester: DIAGNOSIS / ENHANCED OBD II /
ACTIVE TEST / A/F CONTROL / USER DATA / AFS B1 S1 and O2S B1 S2 or AFS B2 S1 and O2S B2
S2; then press the YES button and then the ENTER button followed by the F4 button.
HINT:
• Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition
when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the
vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or
rich, and other data from the time the malfunction occurred.
• If the OX1B wire from the ECM connector is short-circuited to the +B wire, DTC P0138 will be set.
• If the OX2B wire from the ECM connector is short-circuited to the +B wire, DTC P0158 will be set.
1
READ OUTPUT DTC
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch ON and turn the tester ON.
(c) Select the following menu items: DIAGNOSIS /
ENHANCED OBD II / DTC INFO / CURRENT CODES.
(d) Read DTCs.
Result
Display (DTC output)
Proceed to
P0138 or P0158
A
P0137 or P0157
B
P0136 or P0156
C
B
Go to step 14
C
Go to step 7
A
2
READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF HEATED OXYGEN
SENSOR)
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch ON and turn the tester ON.
ES
ES–176
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
(c) Select the following menu items: DIAGNOSIS /
ENHANCED OBD II / DATA LIST / PRIMARY / O2S B1
S2 or O2S B2 S2.
(d) Allow the engine to idle.
(e) Read the Heated Oxygen (HO2) sensor output voltage
while idling.
Result
HO2 Sensor Output Voltage
Proceed to
More than 1.2 V
A
Less than 1.0 V
B
B
Go to step 5
A
ES
3
CHECK WIRE HARNESS (CHECK FOR SHORT)
(a) Turn the ignition switch OFF and wait for 5 minutes.
(b) Disconnect the B30 ECM connector.
(c) Measure the resistance.
Standard resistance
Wire Harness Side:
B30
ECM
Tester Connection
B30-48 (HT1B) - B30-88 (OX1B)
10 kΩ or higher
B30-47 (HT2B) - B30-87 (OX2B)
10 kΩ or higher
(d) Reconnect the ECM connector.
OK
OX2B
HT2B
OX1B
HT1B
A107892E99
NG
Specified Condition
REPLACE ECM
ES–177
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
4
INSPECT HEATED OXYGEN SENSOR (CHECK FOR SHORT)
(a) Disconnect the B19 or E35 HO2 sensor connector.
(b) Measure the resistance.
Standard resistance (bank 1)
Component Side:
HO2 Sensor (bank 1)
+B
HT1B
Tester Connection
Specified Condition
1 (+B) - 3 (E2)
10 kΩ or higher
1 (+B) - 4 (OX1B)
10 kΩ or higher
Standard resistance (bank 2)
Tester Connection
E2
OX1B
Specified Condition
2 (+B) - 4 (E2)
10 kΩ or higher
2 (+B) - 3 (OX2B)
10 kΩ or higher
(c) Reconnect the HO2 sensor connector.
HO2 Sensor (bank 2)
+B
2
4
E2
NG
REPLACE HEATED OXYGEN SENSOR
HT2B
1
3
OX2B
A136185E01
OK
REPAIR OR REPLACE HARNESS AND CONNECTOR
5
PERFORM CONFIRMATION DRIVING PATTERN
NEXT
6
CHECK WHETHER DTC OUTPUT RECURS (DTC P0138 OR P0158)
(a) On the intelligent tester, select the following menu items:
DIAGNOSIS / ENHANCED OBD II / DTC INFO /
CURRENT CODES.
(b) Read DTCs.
Result
Display (DTC Output)
Proceed to
P0138 or P0158
A
No output
B
B
A
REPLACE HEATED OXYGEN SENSOR
CHECK FOR INTERMITTENT PROBLEMS
ES
ES–178
7
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF HEATED OXYGEN
SENSOR)
(a)
(b)
(c)
(d)
Connect the intelligent tester to the DLC3.
Turn the ignition switch ON and turn the tester ON.
Start the engine.
Select the following menu items: DIAGNOSIS /
ENHANCED OBD II / DATA LIST / PRIMARY / O2S B1
S2 or O2S B2 S2.
(e) After warming up the engine, run the engine at an engine
speed of 2,500 rpm for 3 minutes.
(f) Read the output voltage of the HO2 sensor when the
engine rpm is suddenly increased.
HINT:
Quickly accelerate the engine to 4,000 rpm 3 times using
the accelerator pedal.
Standard voltage:
Fluctuates between 0.4 V or less and 0.5 V or more.
ES
NG
Go to step 14
OK
8
PERFORM CONFIRMATION DRIVING PATTERN
NEXT
9
CHECK WHETHER DTC OUTPUT RECURS (DTC P0136 OR P0156)
(a) On the intelligent tester, select the following menu items:
DIAGNOSIS / ENHANCED OBD II / DTC INFO /
CURRENT CODES.
(b) Read DTCs.
Result
Display (DTC Output)
Proceed to
P0136 or P0156
A
No output
B
B
A
10
NEXT
REPLACE HEATED OXYGEN SENSOR
CHECK FOR INTERMITTENT PROBLEMS
ES–179
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
11
PERFORM CONFIRMATION DRIVING PATTERN
NEXT
12
CHECK WHETHER DTC OUTPUT RECURS (DTC P0136 OR P0156)
(a) On the intelligent tester, select the following menu items:
DIAGNOSIS / ENHANCED OBD II / DTC INFO /
CURRENT CODES.
(b) Read DTCs.
Result
Display (DTC Output)
Proceed to
P0136 or P0156
A
No output
B
B
ES
REPAIR COMPLETE
A
13
PERFORM ACTIVE TEST USING INTELLIGENT TESTER (INJECTION VOLUME)
Injection Volume
+12%
Malfunction
-12%
A/F Sensor
Output
Normal
3.3 V
HO2 Sensor Output
Malfunction
1V
0V
A121606E03
(a)
(b)
(c)
(d)
Connect the intelligent tester to the DLC3.
Start the engine and turn the tester ON.
Warm up the engine.
Select the following menu items: DIAGNOSIS /
ENHANCED OBD II / ACTIVE TEST / INJ VOL.
ES–180
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
(e) Change the fuel injection volume using the tester, and
monitor the voltage output of Air-Fuel Ratio (A/F) and
HO2 sensors displayed on the tester.
HINT:
• Change the fuel injection volume within the range of -12%
and +12%. The injection volume can be changed in 1%
graduations within the range.
• The A/F sensor is displayed as AFS B1 S1 or AFS B2 S1,
and the HO2 sensor is displayed as O2S B1 S2 or O2S B2
S2, on the intelligent tester.
Result
Tester Display (Sensor)
AFS B1 S1 (A/F)
AFS B2 S1 (A/F)
ES
Voltage Variation
Proceed to
Alternates between more and less than 3.3
V
OK
Remains at more than 3.3 V
NG
Remains at less than 3.3 V
NG
HINT:
A normal HO2 sensor voltage (O2S B1 S2 or O2S B2 S2)
reacts in accordance with increases and decreases in fuel
injection volumes. When the A/F sensor voltage remains
at either less or more than 3.3 V despite the HO2 sensor
indicating a normal reaction, the A/F sensor is
malfunctioning.
NG
REPLACE AIR-FUEL RATIO SENSOR
OK
CHECK AND REPAIR EXTREMELY RICH OR LEAN ACTUAL AIR-FUEL RATIO (INJECTOR, FUEL
PRESSURE, GAS LEAKAGE FROM EXHAUST SYSTEM, ETC.)
14
CHECK FOR EXHAUST GAS LEAK
OK:
No gas leakage.
NG
REPAIR OR REPLACE EXHAUST GAS
LEAKAGE POINT
OK
15
INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE) (See page ES-117)
NG
REPLACE HEATED OXYGEN SENSOR
OK
16
INSPECT INTEGRATION RELAY (EFI MAIN RELAY) (See page ES-118)
NG
REPLACE INTEGRATION RELAY
ES–181
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
OK
17
CHECK WIRE HARNESS (HEATED OXYGEN SENSOR - ECM)
(a) Disconnect the B19 or E35 HO2 sensor connector.
(b) Turn the ignition switch ON.
(c) Measure the voltage between the +B terminal of the HO2
sensor connector and body ground.
Standard voltage
Wire Harness Side:
HO2 Sensor (for Bank 1)
+B
HT1B
E35
OX1B
HO2 Sensor (for Bank 2)
+B
B19
E2
OX2B
HT2B
EX2B
OX2B
B30
ECM
EX1B
OX1B
Specified Condition
9 to 14 V
B19-2 (+B) - Body ground
9 to 14 V
(d) Turn the ignition switch OFF.
(e) Disconnect the B30 ECM connector.
(f) Measure the resistance.
Standard resistance
E2
HT2B
Tester Connection
E35-1 (+B) - Body ground
HT1B
A136188E03
ES
Tester Connection
Specified Condition
E35-2 (HT1B) - B30-48 (HT1B)
Below 1 Ω
E35-4 (OX1B) - B30-88 (OX1B)
Below 1 Ω
E35-3 (E2) - B30-65 (EX1B)
Below 1 Ω
B19-1 (HT2B) - B30-47 (HT2B)
Below 1 Ω
B19-3 (OX2B) - B30-87 (OX2B)
Below 1 Ω
B19-4 (E2) - B30-64 (EX2B)
Below 1 Ω
E35-2 (HT1B) or B30-48 (HT1B) Body ground
10 kΩ or higher
E35-4 (OX1B) or B30-88 (OX1B) Body ground
10 kΩ or higher
E35-3 (E2) or B30-65 (EX1B) - Body
ground
10 kΩ or higher
B19-1 (HT2B) or B30-47 (HT2B) Body ground
10 kΩ or higher
B19-3 (OX2B) or B30-87 (OX2B) Body ground
10 kΩ or higher
B19-4 (E2) or B30-64 (EX2B) - Body
ground
10 kΩ or higher
(g) Reconnect the HO2 sensor connector.
(h) Reconnect the ECM connector.
ES–182
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
Reference (System Diagram of Bank 1 Sensor 2):
ECM
HO2 Sensor
EFI MAIN
Heater
EFI MAIN
+B
from
Battery
EFI NO. 1
E2
HT1B
HT1B
OX1B
OX1B
Sensor
EX1B
ES
MREL
Ground
A137607E01
NG
OK
REPLACE HEATED OXYGEN SENSOR
REPAIR OR REPLACE HARNESS AND
CONNECTOR