HEATER, AIR CONDITIONING AND VENTILATION

HEATER, AIR CONDITIONING AND VENTILATION
55-1
GROUP 55
HEATER, AIR
CONDITIONING AND
VENTILATION
CONTENTS
GENERAL INFORMATION . . . . . . . .
55-3
DIAGNOSTIC FUNCTION. . . . . . . . . . . . . .
55-7
DIAGNOSTIC TROUBLE CODE CHART . .
55-10
55-5
DIAGNOSTIC TROUBLE CODE
PROCEDURES . . . . . . . . . . . . . . . . . . . . . .
55-12
GENERAL SPECIFICATIONS . . . . . .
55-5
SYMPTOM CHART
<VEHICLES WITHOUT A/C> . . . . . . . . . . .
55-96
SERVICE SPECIFICATIONS. . . . . . .
55-5
LUBRICANTS . . . . . . . . . . . . . . . . . .
55-5
SERVICE PRECAUTIONS. . . . . . . . .
55-6
FASTENER TIGHTENING
SPECIFICATIONS . . . . . . . . . . . . . . .
CAUTION LABELS . . . . . . . . . . . . . . . . . . .
AUTO A/C DIAGNOSIS . . . . . . . . . . .
55-6
55-6
INTRODUCTION. . . . . . . . . . . . . . . . . . . . .
55-6
TROUBLESHOOTING STRATEGY . . . . . .
55-6
SYMPTOM PROCEDURES <VEHICLES
WITHOUT A/C>. . . . . . . . . . . . . . . . . . . . . .
55-97
MALFUNCTION OF THE A/C-ECU POWER
SUPPLY SYSTEM
<VEHICLES WITHOUT A/C> . . . . . . . . . . .
55-97
BLOWER FAN AND MOTOR DOES NOT RUN.
<VEHICLES WITHOUT A/C> . . . . . . . . . . . 55-101
BLOWER FAN AND MOTOR DOES NOT STOP
TURNING. <VEHICLES WITHOUT A/C> . . 55-106
INSIDE/OUTSIDE AIR CHANGEOVER IS NOT
POSSIBLE. <VEHICLES WITHOUT A/C> . 55-109
A/C OUTLET AIR TEMPERATURE DOES NOT
INCREASE <VEHICLES WITHOUT A/C>. . 55-112
Continued on next page
WARNINGS REGARDING SERVICING OF SUPPLEMENTAL RESTRAINT SYSTEM (SRS) EQUIPPED VEHICLES
WARNING
Improper service or maintenance of any component of the SRS, or any SRS-related component, can lead to
personal injury or death to service personnel (from inadvertent firing of the air bag) or to the driver and
passenger (from rendering the SRS inoperative).
• Service or maintenance of any SRS component or SRS-related component must be performed only at an
authorized MITSUBISHI dealer.
• MITSUBISHI dealer personnel must thoroughly review this manual, and especially its GROUP 52B - Supplemental
Restraint System (SRS) before beginning any service or maintenance of any component of the SRS or any
SRS-related component.
NOTE
The SRS includes the following components: SRS air bag control unit, SRS warning light, front impact sensors, air bag module,
side-airbag module, curtain air bag module, side impact sensors, seat belt pre-tensioners, clock spring, and interconnecting
wiring. Other SRS-related components (that may have to be removed/installed in connection with SRS service or maintenance)
are indicated in the table of contents by an asterisk (*).
•
55-2
AIR OUTLET VENT CANNOT BE
CHANGED. . . . . . . . . . . . . . . . . . . . . . . . . .
55-114
BLOWER MOTOR POWER SUPPLY SYSTEM
<VEHICLES WITHOUT A/C> . . . . . . . . . . .
55-117
SYMPTOM CHART. . . . . . . . . . . . . . . . . . .
55-121
SYMPTOM PROCEDURES . . . . . . . . . . . .
55-97
WHEN THE IGNITION SWITCH IS "ON,"
THE A/C DOES NOT WORK . . . . . . . . . . .
55-121
MALFUNCTION OF THE A/C-ECU POWER
SUPPLY SYSTEM . . . . . . . . . . . . . . . . . . .
55-124
THE COMPRESSOR DOES NOT WORK .
55-128
BLOWER FAN AND MOTOR DOES NOT
RUN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
55-135
BLOWER FAN AND MOTOR DOES NOT
STOP TURNING. . . . . . . . . . . . . . . . . . . . .
55-140
INSIDE/OUTSIDE AIR CHANGEOVER IS
NOT POSSIBLE.. . . . . . . . . . . . . . . . . . . . .
55-143
A/C OUTLET AIR TEMPERATURE DOES
NOT INCREASE . . . . . . . . . . . . . . . . . . . . .
55-146
AIR OUTLET VENT CANNOT BE
CHANGED. . . . . . . . . . . . . . . . . . . . . . . . . .
55-148
BLOWER MOTOR POWER SUPPLY
SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . .
55-151
DATA LIST REFERENCE TABLE . . . . . . .
55-155
ACTUATOR TEST REFERENCE TABLE. .
55-159
CHECK AT ECU TERMINAL . . . . . . . . . . .
55-160
SPECIAL TOOLS. . . . . . . . . . . . . . . .
55-161
ON-VEHICLE SERVICE. . . . . . . . . . .
55-164
SIGHT GLASS REFRIGERANT LEVEL
TEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
55-164
A/C COMPRESSOR CLUTCH TEST . . . . .
55-164
SIMPLE INSPECTION OF THE A/C
PRESSURE SENSOR . . . . . . . . . . . . . . . .
55-164
COMPRESSOR DRIVE BELT
ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . .
55-165
CHARGING <VEHICLES USING R-134a
REFRIGERANT> . . . . . . . . . . . . . . . . . . . .
55-165
PERFORMANCE TEST <VEHICLES USING
R-134a REFRIGERANT> . . . . . . . . . . . . . .
55-166
REFRIGERANT LEAK REPAIR
PROCEDURE . . . . . . . . . . . . . . . . . . . . . . .
55-167
COMPRESSOR NOISE CHECK . . . . . . . .
55-168
POWER RELAY CHECK . . . . . . . . . . . . . .
55-168
IDLE-UP OPERATION CHECK . . . . . . . . .
55-169
CLEAN AIR FILTER REPLACEMENT
PROCEDURE . . . . . . . . . . . . . . . . . . . . . . .
55-170
HEATER CONTROL UNIT. . . . . . . . .
HEATER CONTROL UNIT REMOVAL AND
INSTALLATION. . . . . . . . . . . . . . . . . . . . . .
55-171
55-171
HEATER UNIT AND BLOWER
ASSEMBLY* . . . . . . . . . . . . . . . . . . . . 55-172
HEATER UNIT AND BLOWER ASSEMBLY
REMOVAL AND INSTALLATION . . . . . . . .
55-172
HEATER UNIT AND BLOWER ASSEMBLY
DISASSEMBLY AND REASSEMBLY . . . . .
55-174
INSPECTION. . . . . . . . . . . . . . . . . . . . . . . .
55-175
MOTORS AND TRANSISTOR . . . . . . 55-176
MOTORS AND TRANSISTOR REMOVAL
AND INSTALLATION . . . . . . . . . . . . . . . . .
55-176
INSPECTION. . . . . . . . . . . . . . . . . . . . . . . .
55-177
AMBIENT AIR TEMPERATURE
SENSOR . . . . . . . . . . . . . . . . . . . . . . . 55-178
AMBIENT AIR TEMPERATURE SENSOR
REMOVAL AND INSTALLATION . . . . . . . .
55-178
INSPECTION. . . . . . . . . . . . . . . . . . . . . . . .
55-178
INTERIOR TEMPERATURE SENSOR 55-179
INTERIOR TEMPERATURE SENSOR
REMOVAL AND INSTALLATION . . . . . . . .
55-179
INSPECTION. . . . . . . . . . . . . . . . . . . . . . . .
55-179
A/C-ECU . . . . . . . . . . . . . . . . . . . . . . . 55-180
A/C-ECU REMOVAL AND INSTALLATION
55-180
COMPRESSOR ASSEMBLY AND
TENSION PULLEY . . . . . . . . . . . . . . . 55-181
COMPRESSOR ASSEMBLY AND TENSION
PULLEY REMOVAL AND INSTALLATION . 55-181
INSPECTION. . . . . . . . . . . . . . . . . . . . . . . .
55-183
COMPRESSOR ASSEMBLY DISASSEMBLY
AND ASSEMBLY. . . . . . . . . . . . . . . . . . . . . 55-183
INSPECTION. . . . . . . . . . . . . . . . . . . . . . . .
55-185
CONDENSER ASSEMBLY. . . . . . . . . 55-186
CONDENSER ASSEMBLY REMOVAL AND
INSTALLATION . . . . . . . . . . . . . . . . . . . . . .
55-186
REFRIGERANT LINE . . . . . . . . . . . . . 55-187
REFRIGERANT LINE REMOVAL AND
INSTALLATION . . . . . . . . . . . . . . . . . . . . . .
55-187
DUCTS*. . . . . . . . . . . . . . . . . . . . . . . . 55-189
DUCT REMOVAL AND INSTALLATION . . .
55-189
VENTILATORS . . . . . . . . . . . . . . . . . . 55-190
VENTILATOR (INSTRUMENT PANEL AND
FLOOR) REMOVAL AND INSTALLATION .
55-190
HEATER, AIR CONDITIONING AND VENTILATION
GENERAL INFORMATION
GENERAL INFORMATION
The blower, heater, and evaporator have been integrated with the heater and A/C system to achieve
greater fan power and noise reduction.
Item
Specification
Heater control assembly
Dial type
Compressor mode
MSC90CAS
Compressor type
Scroll type
Refrigerant and quantity g (oz)
R-134a (HFC-134a), 480 −520 (16.9 −18.3)
SAFETY PRECAUTIONS
WARNING
Wear safety goggles and gloves when servicing the refrigeration system to prevent
severe damage to eyes and hands.
Because R-134a refrigerant is a hydro fluorocarbon
(HFC) which contains hydrogen atoms in place of
chlorine atoms, it will not cause damage to the ozone
layer.
Ozone filters out harmful radiation from the sun. To
assist in protecting the ozone layer, Mitsubishi
Motors Corporation recommends an R-134a refrigerant recycling device.
Refrigerant R-134a is transparent and colorless in
both the liquid and vapor state. Since it has a boiling
point of −29.8° C (−21.64° F) at atmospheric pressure,
it will be a vapor at all normal temperatures and pressures. The vapor is heavier than air, non-flammable,
and non-explosive. The following precautions must
be observed when handling R-134a.
WARNING
Do not heat R-134a above 40° C (104.0° F) or
it may catch fire and explode.
R-134a evaporates so rapidly at normal atmospheric
pressures and temperatures that it tends to freeze
anything it contacts. For this reason, extreme care
must be taken to prevent any liquid refrigerant from
contacting the skin and especially the eyes. Always
wear safety goggles when servicing the refrigeration
part of the A/C system. Keep a bottle of sterile mineral oil handy when working on the refrigeration system.
1. Should any liquid refrigerant get into your eyes,
use a few drops of mineral oil to wash them out.
R-134a is rapidly absorbed by the oil.
2. Next, splash your eyes with plenty of cold water.
3. Call your doctor immediately even if irritation has
ceased.
M1552023500112
CAUTION
Keep R-134a containers upright when charging
the system.
In most instances, moderate heat is required to bring
the pressure of the refrigerant in its container above
the pressure of the system when charging or adding
refrigerant.
A bucket or large pan of hot water not over 40° C
(104.0° F) is all the heat required for this purpose. Do
not heat the refrigerant container with a blow torch or
any other means that would raise temperature and
pressure above this temperature. Do not weld or
steam-clean on or near the system components or
refrigerant lines.
WARNING
The leak detector for R-134a should be used
to check for refrigerant gas leaks.
CAUTION
Do not allow liquid refrigerant to touch bright
metal or it will be stained.
When metering R-134a into the refrigeration system,
keep the supply tank or cans in an upright position. If
the refrigerant container is on its side or upside
down, liquid refrigerant will enter the system and
damage the compressor.
Refrigerant will tarnish bright metal and chrome surfaces, and in combination with moisture can severely
corrode all metal surfaces.
OPERATION
.
CONDENSER FAN AND RADIATOR FAN
CONTROL
The ECM judges the required revolution speed of
radiator fan motor and condenser fan motor using
the input signals transmitted from A/C switch or vehicle speed sensor (VSS) <M/T> and engine coolant
temperature sensor.
.
TSB Revision
55-3
55-4
HEATER, AIR CONDITIONING AND VENTILATION
GENERAL INFORMATION
COMPRESSOR CONTROL
• When the fin thermo sensor is activated, and the
ignition switch, blower switch, and A/C switch are
ON, the A/C compressor clutch relay is energized.
When operating the A/C switch
• The fin thermo sensor, which senses the temperature of the air flowing out of the evaporator,
deactivates the compressor at 1° C (33.8° F) or
below.
• The dual pressure switch turns OFF when the
refrigerant pressure becomes excessively high or
low, thus protecting the compressor circuit (See
Table below).
When operating the mode selection dial
• The A/C will work when the mode selection dial is
set to the "Defroster" or "Defroster/foot" position,
or the temperature control dial is set to the "MAX
A/C" position. In other dial positions, when the
A/C switch is turned on, the A/C will work.
A/C Compressor Clutch Relay ON Conditions
Ignition switch (IG2)
ON
Blower switch
ON
A/C switch, mode selection dial defroster,
defroster/foot position or temperature control MAX
A/C
ON
Fin thermo sensor
*
Pressure detected
by A/C pressure
sensor
2.94 MPa (427psi) or less (If
ON
the refrigerant pressure
exceeds 2.94 MPa (427psi),
A/C compressor clutch relay is
not ON condition until the
refrigerant pressure has been
measured up to 2.35 MPa
(341psi) a or less.)
0.19 MPa (27psi) or more (If
the refrigerant pressure falls
short of 0.19 MPa (27psi), A/C
compressor clutch relay is not
ON condition until the
refrigerant pressure has been
measured up to 0.22 MPa
(32psi) or more.)
A/C compressor clutch relay driving transistor (within ON
powertrain control module)
TSB Revision
NOTE: A/C compressor clutch relay is
de-energized when any one switch, sensor
or control unit shown on the left turns off.
NOTE: The components marked by *
communicate with the ECM. If the air thermo
sensor detects a temperature of 1° C
(33.8° F), the A/C-ECU will turn off the A/C
compressor clutch relay.
55-5
HEATER, AIR CONDITIONING AND VENTILATION
FASTENER TIGHTENING SPECIFICATIONS
FASTENER TIGHTENING SPECIFICATIONS
M1552012100370
Item
Specification
Armature plate mounting bolt
16 ± 1 N⋅ m (11.8 ± 0.7 ft-lb)
Discharge flexible hose mounting bolt (compressor side)
25 ± 4 N⋅ m (18 ± 3 ft-lb)
Discharge flexible hose mounting nut (condenser side)
4.9 ± 0.9 N⋅ m (43 ± 8 in-lb)
Connection between the liquid pipe A and B
13 ± 1 N⋅ m (115 ± 9 in-lb)
Liquid pipe A mounting bolt (condenser side)
4.9 ± 0.9 N⋅ m (43 ± 8 in-lb)
Suction flexible hose mounting bolt (compressor side)
25 ± 4 N⋅ m (18 ± 3 ft-lb)
Suction flexible hose mounting nut (heater unit side)
4.9 ± 0.9 N⋅ m (43 ± 8 in-lb)
Front deck crossmember mounting bolt (left side)
23 ± 6 N⋅ m (17 ± 4 ft-lb)
Front deck crossmember mounting bolt (right side)
20 ± 5 N⋅ m (15 ± 3 ft-lb)
Front deck crossmember mounting bolt (front deck side)
20 ± 5 N⋅ m (15 ± 3 ft-lb)
GENERAL SPECIFICATIONS
Item
Standard value
Heater control assembly
Rotary type
A/C switch
Push-button type
Compressor model, type
MSC90CAS, Scroll type
Refrigerant
Type
R134a (HFC-134a)
Amount g (oz)
480 −520 (16.9 −18.3)
M1552000200336
SERVICE SPECIFICATIONS
Item
Standard value
Idle speed r/min
700 ± 100
Idle-up speed r/min
800 ± 100
Air gap (A/C compressor clutch) mm (in)
0.3 −0.5 (0.012 −0.020)
M1552000300678
LUBRICANTS
Item
Each connection of refrigerant line
3
Compressor refrigerant unit lubricant cm (fl.oz)
TSB Revision
M1552000400567
Specified lubricant
Quantity
SUN PAG 56
As required
SUN PAG 56
80 −100 (2.7 −3.4)
55-6
HEATER, AIR CONDITIONING AND VENTILATION
SERVICE PRECAUTIONS
SERVICE PRECAUTIONS
CAUTION LABEL
M1552017400387
The refrigerant gas caution label must be affixed in the location
shown in the figure on the left. Follow the instructions on the
label when servicing.
AC708364AB
1
3
2
2
3
No.
Content
1
Name of A/C manufacturer
2
Amount of refrigerant
3
Name of compressor oil
AC200079AC
AUTO A/C DIAGNOSIS
INTRODUCTION TO HEATER, A/C AND VENTILATION DIAGNOSIS
Air is drawn into the heater assembly from either the
outside, or from the inside of the passenger cabin if
DEFROST, maximum cooling or RECIRCULATION
are selected. The air is then forced through the evaporator where heat is removed, cooling and de-humidifying the air. Depending on the temperature
selected, a portion of this air is then forced through
the heater core to achieve the selected discharge
temperature.
M1552012200418
If the system does not cool properly, look for a problem with the refrigerant, blower or air distribution systems. If the system does not heat properly, look for a
problem with the coolant, blower or air distribution
systems. In either case all system fuses, circuit
breaker and relays should be checked.
HEATER, A/C AND VENTILATION DIAGNOSTIC TROUBLESHOOTING STRATEGY
Use these steps to plan your diagnostic strategy. If
you follow them carefully, you will be sure that you
have exhausted most of the possible ways to find a
heater, A/C and ventilation fault.
1. Gather information from the customer.
TSB Revision
M1552009600494
2. Verify that the condition described by the
customer exists.
3. Find the malfunction by following the Symptom
Chart.
4. Verify that the malfunction is eliminated.
55-7
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
DIAGNOSTIC FUNCTION
M1552019800295
HOW TO CONNECT THE SCAN TOOL (M.U.T.-III)
Required Special Tools:
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
Data link connector
MB991910
MB991824
MB991827
AC608435 AB
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
1. Ensure that the ignition switch is at the "LOCK" (OFF)
position.
2. Start up the personal computer.
3. Connect special tool MB991827 to special tool MB991824
and the personal computer.
4. Connect special tool MB991910 to special tool MB991824
5. Connect special tool MB991910 to the data link connector.
6. Turn the power switch of special tool MB991824 to the "ON"
position.
NOTE: When the special tool MB991824 is energized, the
special tool MB991824 indicator light will be illuminated in a
green color.
7. Start the M.U.T.-III system on the personal computer.
NOTE: Disconnecting the scan tool special tool MB991824 is
the reverse of the connecting sequence, making sure that the
ignition switch is at the "LOCK" (OFF) position.
HOW TO READ AND ERASE DIAGNOSTIC
TROUBLE CODES
Required Special Tools:
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
TSB Revision
55-8
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
Data link connector
MB991910
MB991824
MB991827
AC608435 AB
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
NOTE: If the battery voltage is low, diagnostic trouble codes will
not be output. Check the battery if scan tool MB991958 does
not display.
1. Connect the scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Select "System select" from the start-up screen.
4. Select "From 2006 MY" of "Model Year." When the "Vehicle
Information" is displayed, check the contents.
5. Select "AUTO A/C" from "System List," and press the "OK"
button.
NOTE: When the "Loading Option Setup" list is displayed,
check the applicable item.
6. Select "Diagnostic Trouble Code" to read the DTC.
7. If a DTC is set, it is shown.
8. Choose "Erase DTCs" to erase the DTC.
HOW TO DIAGNOSE THE CAN BUS LINE
Required Special Tools:
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
Data link connector
MB991910
MB991824
MB991827
AC608435 AB
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Select "CAN bus diagnosis" from the start-up screen.
4. When the vehicle information is displayed, confirm that it
matches the vehicle whose CAN bus lines will be
diagnosed.
• If they match, go to step 8.
• If not, go to step 5.
5. Select "view vehicle information" button.
6. When the vehicle information is displayed, confirm again
that it matches the vehicle which is diagnosed CAN bus line.
• If they match, go to step 8.
• If not, go to step 5.
7. Press the "OK" button.
8. When the options are displayed, choose the options (mark
the check) and then select "OK".
TSB Revision
55-9
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
CHECK OF FREEZE FRAME DATA
The freeze frame data can be checked by using the
scan tool (GROUP 00, How to Cope with Intermittent
Malfunction P.00-15).
.
Display item list
Item No.
Item name
When detecting fault and storing the DTC, the ECU
connected to CAN bus line obtains the data before
the determination of the DTC and the data when the
DTC is determined, and then stores the ECU status
of that time. By analyzing the data from scan tool, the
troubleshooting can be performed more efficiently.
The displayed items are as shown in the table below.
Content item
Unit
mile*
01
Odometer
Total driving distance after the diagnostic trouble
code is generated
02
Ignition cycle
Number of times the ignition switch is turned "ON" or Number of
"LOCK (OFF)" after the past failure transition
counts is
displayed.
04
Current trouble
accumulative time
Cumulative time for current malfunction of
diagnostic trouble code
NOTE: .
min
• *: If a failure occurs to both the ABS-ECU and
ETACS-ECU, 0000 mile or FFFF km is displayed
to the scan tool MB991958.
TSB Revision
55-10
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
DIAGNOSTIC TROUBLE CODE CHART
M1554004901756
CAUTION
During diagnosis, a DTC code associated with
other system may be set when the ignition switch
is turned on with connector(s) disconnected. On
completion of repairs, check all systems for DTC
code(s). If DTC code(s) are set, erase them all.
<VEHICLES WITHOUT A/C>
Diagnostic
Diagnostic item
trouble code No.
Reference
page
B1000
Control panel communication error <Vehicles without A/C>
P.55-15
B1003
Mode dial SW error <Vehicles without A/C>
P.55-24
B1018
Temperature control dial SW error <Vehicles without A/C>
P.55-31
B1021
Fan dial SW error <Vehicles without A/C>
P.55-37
B1031
Fin thermo sensor system (short circuit) <Vehicles without A/C>
P.55-43
B1032
Fin thermo sensor system (open circuit) <Vehicles without A/C>
P.55-43
B1034*
Ambient air temperature sensor system (short circuit)
P.55-49
B1035*
Ambient air temperature sensor system (open circuit)
P.55-49
B2214
Control panel failure <Vehicles without A/C>
P.55-56
B223B
Control panel improperly assembled <Vehicles without A/C>
P.55-63
U1415
Coding not completed
P.55-69
U0019
Bus off (CAN1)
P.55-71
U0141
ETACS-ECU time-out
P.55-72
U0151
SRS-ECU time-out
P.55-75
U0154
Occupant classification-ECU time-out
P.55-77
U0155
Combination meter time-out
P.55-80
U0168
WCM time-out
P.55-82
U0184
Audio time-out
P.55-85
U0195
Satellite radio tuner time-out
P.55-87
U0197
Hands free module time-out
P.55-90
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55-11
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
<VEHICLES WITH A/C>
Diagnostic
Diagnostic item
trouble code No.
Reference
page
B10C0
Interior temperature sensor system (short circuit)
P.55-12
B10C1
Interior temperature sensor system (open circuit)
P.55-12
B1000
Control panel communication error
P.55-20
B1003
Mode dial SW error
P.55-28
B1018
Temperature control dial SW error
P.55-34
B1021
Fan dial SW error
P.55-40
B1031
Fin thermo sensor system (short circuit)
P.55-46
B1032
Fin thermo sensor system (open circuit)
P.55-46
B1034*
Ambient air temperature sensor system (short circuit)
P.55-49
B1035*
Ambient air temperature sensor system (open circuit)
P.55-49
B1079
Refrigerant leaks
P.55-52
B2214
Control panel failure
P.55-60
B223B
Control panel improperly assembled
P.55-66
U1415
Coding not completed
P.55-69
U0019
Bus off (CAN1)
P.55-71
U0141
ETACS-ECU time-out
P.55-72
U0151
SRS-ECU time-out
P.55-75
U0154
Occupant classification ECU time-out
P.55-77
U0155
Combination meter time-out
P.55-80
U0168
WCM time-out
P.55-82
U0184
Audio time-out
P.55-85
U0195
Satellite radio tuner time-out
P.55-87
U0197
Hands free module time-out
P.55-90
U0245
Audio visual navigation unit CAN time-out
P.55-93
NOTE: The diagnostic trouble codes marked by * are
set from the ETACS-ECU.
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55-12
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
DIAGNOSTIC TROUBLE CODE PROCEDURES
DTC B10C0, B10C1: Interior Temperature Sensor System
Interior Temperature Sensor Circuit
A/C-ECU
JOINT
CONNECTOR (2)
INTERIOR
TEMPERATURE
SENSOR
AC804911
Connectors: C-06, C-102
C-102 (B)
Connector: C-22
C-06
C-22 (B)
AC708950AP
AC708951AI
.
DTC SET CONDITION
• DTC B10C0 is set if there is a short circuit in the interior
temperature sensor input circuit.
• DTC B10C1 is set if there is a defective connector connection, or if there is an open circuit in the harness.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• The A/C-ECU, the interior temperature sensor, or connector(s) or wiring between the two may be defective.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-13
Past trouble
• If DTC B10C0 or B10C1 is stored as a past trouble, carry
out diagnosis with particular emphasis on wiring and connector(s) between the A/C-ECU and the interior temperature sensor. If the connectors and wiring are normal, and
obviously the ECU is the cause of the trouble, replace the
ECU. If in doubt, do not replace the ECU.
.
TROUBLESHOOTING HINT
•
•
•
•
Malfunction of connector.
Malfunction of the harness.
Malfunction of the interior temperature sensor.
Malfunction of the A/C-ECU.
DIAGNOSIS
Required Special Tool:
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line.
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
Use scan tool MB991958 to diagnose the CAN bus lines.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to "ON" position.
(3) Diagnose the CAN bus line.
Q: Is the check result satisfactory?
YES : Go to Step 2.
NO : Repair the CAN bus lines. Repair the CAN bus lines
(Refer to GROUP 54C, Diagnosis-Can Bus
Diagnostic Chart P.54C-15).
STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the check result satisfactory?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
NO : Go to Step 3.
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55-14
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 3. Check interior temperature sensor connector C-06
and A/C-ECU connector C-22 for loose, corroded or
damaged terminals, or terminals pushed back in the
connector.
Q: Are interior temperature sensor connector C-06 and
A/C-ECU connector C-22 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
STEP 4. Check the wiring harness between A/C-ECU
connector C-22 (terminals 17 and 19) and interior
temperature sensor connector C-06 (terminals 2 and 1).
NOTE: Also check joint connector C-102 for loose, corroded, or
damaged terminals, or terminals pushed back in the connector.
If joint connector C-102 is damaged, repair or replace the connector as described in GROUP 00E, Harness Connector
Inspection P.00E-2.
• Check the sensor signal line and ground line for open and
short circuit.
Q: Is the wiring harness between A/C-ECU connector C-22
(terminals 17 and 19) and interior temperature sensor
connector C-06 (terminals 1 and 2) in good condition?
YES : Go to Step 5.
NO : Repair the wiring harness.
STEP 5. Check the interior temperature sensor.
Measure the resistance between connector terminals 2 and 1
under at least two different temperatures. The resistance values should generally match those in the graph.
NOTE: The temperature at the check should not exceed the
range in the graph.
RESISTANCE
20
(kΩ)
Q: Is the interior temperature sensor in good condition?
YES : Replace the A/C-ECU. Then go to Step 6.
NO : Replace the interior temperature sensor. Then go to
Step 6.
15
10
5
0
-10
10
0
(50)
(14)
(32)
TEMPERATURE ºC (ºF)
20
(68)
30
(86)
40
(104)
AC609165AB
STEP 6. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Connect scan tool MB991958 to the data link connector
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result satisfactory?
YES : The procedure is complete.
NO : Return to Step 1.
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55-15
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
DTC B1000: Control panel communication error <Vehicles without A/C>
Heater Control Panel Circuit
ETACS-ECU
CPU
POWER
SUPPLY
HEATER
CONTROL
PANEL
INTERFACE
CIRCUIT
HEATER
CONTROL MODULE
AC901564
Connectors: C-53, C-138
Connector: C-317
Junction block
C-53 (B)
C-138
AC708951CK
AC708972AB
.
DTC SET CONDITION
DTC B1000 will be set when the communication between
heater control module and heater control panel cannot be performed.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• The heater control module, the heater control panel, or connector(s) or wiring between the two may be defective.
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55-16
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
Past trouble
• If DTC B1000 is stored as a past trouble, carry out diagnosis with particular emphasis on wiring and connector(s)
between the heater control module and the heater control
panel. If the connectors and wiring are normal, and obviously the ECU is the cause of the trouble, replace the ECU.
If in doubt, do not replace the ECU.
.
TROUBLESHOOTING HINT
•
•
•
•
Malfunction of connector.
Malfunction of the harness.
Malfunction of the heater control panel.
Malfunction of the heater control module.
DIAGNOSIS
Required Special Tool:
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line.
Use scan tool MB991958 to diagnose the CAN bus lines.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to "ON" position.
(3) Diagnose the CAN bus line.
Data link connector
Q: Is the check result satisfactory?
YES : Go to Step 2.
NO : Repair the CAN bus lines. Repair the CAN bus lines
(Refer to GROUP 54C, Diagnosis-Can Bus
Diagnostic Chart P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-17
STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Go to Step 3.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
STEP 3. Check heater control panel connector C-138 for
loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Is heater control panel connector C-138 in good
condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
STEP 4. Measure the voltage at heater control panel
connector C-138.
(1) Disconnect heater control panel connector C-138, and
measure the voltage at the harness side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 6 and ground.
• The measured value should be approximately 12 volts
(battery positive voltage).
CONNECTOR C-138
(HARNESS SIDE)
Q: Is the measured voltage approximately 12 volts?
YES : Go to Step 6.
NO : Go to Step 5.
AC608254ET
STEP 5. Check the wiring harness between heater control
panel connector C-138 (terminal 6) and ETACS-ECU
connector C-317 (terminal 5).
• Check the heater control panel power supply line for open
circuit.
Q: Is the wiring harness between heater control panel
connector C-138 (terminal 6) and ETACS-ECU connector
C-317 (terminal 5) in good condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
NO : Repair the wiring harness.
TSB Revision
55-18
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 6. Measure the resistance at heater control panel
connector C-138.
(1) Disconnect heater control panel connector C-138, and
measure the resistance at the wiring harness side.
(2) Measure the resistance value between terminal 7 and
ground.
• The measured value should be 2 ohms or less.
CONNECTOR C-138
(HARNESS SIDE)
Q: Does the measured resistance value correspond with
this range?
YES : Go to Step 8.
NO : Go to Step 7.
AC608255DB
STEP 7. Check the wiring harness between heater control
panel connector C-138 (terminal 7) and ground.
• Check the heater control panel ground line for open circuit.
Q: Is the wiring harness between heater control panel
connector C-138 (terminal 7) and ground in good
condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
NO : Repair the wiring harness.
STEP 8. Check heater control module connector C-53 for
loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Is heater control module connector C-53 in good
condition?
YES : Go to Step 9.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
STEP 9. Check the wiring harness between heater control
module connector C-53 (terminal 9) and heater control
panel connector C-138 (terminal 9).
• Check the heater control panel signal line and ground line
for open and short circuit.
Q: Is the wiring harness between heater control module
connector C-53 (terminal 9) and heater control panel
connector C-138 (terminal 9) in good condition?
YES : Go to Step 10.
NO : Repair the wiring harness.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-19
STEP 10. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the heater control panel. Then go to Step 11.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
STEP 11. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the heater control module.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
TSB Revision
55-20
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
DTC B1000: Control Panel Communication Error
A/C Control Panel Circuit
ETACS-ECU
A/C
CONTROL
PANEL
CPU
POWER
SUPPLY
INTERFACE
CIRCUIT
A/C-ECU
AC901387
Connectors: C-22, C-123
Connector: C-317
Junction block
C-22 (B)
C-123
AC708972AB
AC708951AJ
.
DTC SET CONDITION
DTC B1000 will be set when the communication between
A/C-ECU and A/C control panel cannot be performed.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• The A/C-ECU, the A/C control panel, or connector(s) or wiring between the two may be defective.
TSB Revision
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-21
Past trouble
• If DTC B1000 is stored as a past trouble, carry out diagnosis with particular emphasis on wiring and connector(s)
between the A/C-ECU and the A/C control panel. If the connectors and wiring are normal, and obviously the ECU is the
cause of the trouble, replace the ECU. If in doubt, do not
replace the ECU.
.
TROUBLESHOOTING HINT
•
•
•
•
Malfunction of connector.
Malfunction of the harness.
Malfunction of the A/C control panel.
Malfunction of the A/C-ECU.
DIAGNOSIS
Required Special Tool:
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line.
Use scan tool MB991958 to diagnose the CAN bus lines.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to "ON" position.
(3) Diagnose the CAN bus line.
Data link connector
Q: Is the check result satisfactory?
YES : Go to Step 2.
NO : Repair the CAN bus lines. Repair the CAN bus lines
(Refer to GROUP 54C, Diagnosis-Can Bus
Diagnostic Chart P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
TSB Revision
55-22
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Go to Step 3.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
STEP 3. Check A/C control panel connector C-123 for
loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Is A/C control panel connector C-123 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
STEP 4. Measure the voltage at A/C control panel
connector C-123.
(1) Disconnect A/C control panel connector C-123, and
measure the voltage at the harness side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 6 and ground.
• The measured value should be approximately 12 volts
(battery positive voltage).
Connector C-123
(Harness side)
Q: Is the measured voltage approximately 12 volts?
YES : Go to Step 6.
NO : Go to Step 5.
AC608254CI
STEP 5. Check the wiring harness between A/C control
panel connector C-123 (terminal 6) and ETACS-ECU
connector C-317 (terminal 5).
• Check the A/C control panel power supply line for open circuit.
Q: Is the wiring harness between A/C control panel
connector C-123 (terminal 6) and ETACS-ECU connector
C-317 (terminal 5) in good condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
NO : Repair the wiring harness.
TSB Revision
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-23
STEP 6. Measure the resistance at A/C control panel
connector C-123.
(1) Disconnect A/C control panel connector C-123, and
measure the resistance at the wiring harness side.
(2) Measure the resistance value between terminal 7 and
ground.
• The measured value should be 2 ohms or less.
Connector C-123
(Harness side)
Q: Does the measured resistance value correspond with
this range?
YES : Go to Step 8.
NO : Go to Step 7.
AC608255BP
STEP 7. Check the wiring harness between A/C control
panel connector C-123 (terminal 7) and ground.
• Check the A/C control panel ground line for open circuit.
Q: Is the wiring harness between A/C control panel
connector C-123 (terminal 7) and ground in good
condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
NO : Repair the wiring harness.
STEP 8. Check A/C-ECU connector C-22 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is A/C-ECU connector C-22 in good condition?
YES : Go to Step 9.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
STEP 9. Check the wiring harness between A/C-ECU
connector C-22 (terminal 9) and A/C control panel
connector C-123 (terminal 9).
• Check the AC control panel signal line and ground line for
open and short circuit.
Q: Is the wiring harness between A/C-ECU connector C-22
(terminal 9) and A/C control panel connector C-123
(terminal 9) in good condition?
YES : Go to Step 10.
NO : Repair the wiring harness.
TSB Revision
55-24
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 10. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the A/C control panel. Then go to Step 11.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
STEP 11. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the A/C-ECU.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
DTC B1003: Mode Dial SW Error <Vehicles without A/C>
Heater Control Panel Circuit
CPU
HEATER
CONTROL
PANEL
INTERFACE
CIRCUIT
HEATER
CONTROL MODULE
AC901566
TSB Revision
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-25
Connectors: C-53, C-138
C-53 (B)
C-138
AC708951CK
.
DTC SET CONDITION
DTC B1003 will be set when the heater control module cannot
receive the signal of mode selection knob.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• The heater control module, the heater control panel, or connector(s) or wiring between the two may be defective.
Past trouble
• If DTC B1003 is stored as a past trouble, carry out diagnosis with particular emphasis on wiring and connector(s)
between the heater control module and the heater control
panel. If the connectors and wiring are normal, and obviously the ECU is the cause of the trouble, replace the ECU.
If in doubt, do not replace the ECU.
.
TROUBLESHOOTING HINT
•
•
•
•
Malfunction of connector.
Malfunction of the harness.
Malfunction of the heater control panel.
Malfunction of the heater control module.
DIAGNOSIS
Required Special Tool:
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
TSB Revision
55-26
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Go to Step 3.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
STEP 3. Check heater control panel connector C-138 and
heater control module connector C-53 for loose, corroded
or damaged terminals, or terminals pushed back in the
connector.
Q: Are heater control panel connector C-138 and heater
control module connector C-53 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
TSB Revision
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-27
STEP 4. Check the wiring harness between heater control
module connector C-53 (terminal 9) and heater control
panel connector C-138 (terminal 9).
• Check the heater control panel signal line and ground line
for open and short circuit.
Q: Is the wiring harness between heater control module
connector C-53 (terminal 9) and heater control panel
connector C-138 (terminal 9) in good condition?
YES : Go to Step 5.
NO : Repair the wiring harness.
STEP 5. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the heater control panel. Then go to Step 6.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
STEP 6. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the heater control module.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
TSB Revision
55-28
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
DTC B1003: Mode Dial SW Error
A/C Control Panel Circuit
CPU
A/C
CONTROL
PANEL
INTERFACE
CIRCUIT
A/C-ECU
AC901388
Connectors: C-22, C-123
C-22 (B)
C-123
AC708951AJ
.
DTC SET CONDITION
DTC B1003 will be set when the A/C-ECU cannot receive the
signal of mode selection knob.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• The A/C-ECU, the A/C control panel, or connector(s) or wiring between the two may be defective.
Past trouble
• If DTC B1003 is stored as a past trouble, carry out diagnosis with particular emphasis on wiring and connector(s)
between the A/C-ECU and the A/C control panel. If the connectors and wiring are normal, and obviously the ECU is the
cause of the trouble, replace the ECU. If in doubt, do not
replace the ECU.
.
TSB Revision
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-29
TROUBLESHOOTING HINT
•
•
•
•
Malfunction of connector.
Malfunction of the harness.
Malfunction of the A/C control panel.
Malfunction of the A/C-ECU.
DIAGNOSIS
Required Special Tool:
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Go to Step 3.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
TSB Revision
55-30
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 3. Check A/C control panel connector C-123 and
A/C-ECU connector C-22 for loose, corroded or damaged
terminals, or terminals pushed back in the connector.
Q: Are A/C control panel connector C-123 and A/C-ECU
connector C-22 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
STEP 4. Check the wiring harness between A/C-ECU
connector C-22 (terminal 9) and A/C control panel
connector C-123 (terminal 9).
• Check the A/C control panel signal line and ground line for
open and short circuit.
Q: Is the wiring harness between A/C-ECU connector C-22
(terminal 9) and A/C control panel connector C-123
(terminal 9) in good condition?
YES : Go to Step 5.
NO : Repair the wiring harness.
STEP 5. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the A/C control panel. Then go to Step 6.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
STEP 6. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the A/C-ECU.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
TSB Revision
55-31
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
DTC B1018: Temperature Control Dial SW Error <Vehicles without A/C>
Heater Control Panel Circuit
CPU
HEATER
CONTROL
PANEL
INTERFACE
CIRCUIT
HEATER
CONTROL MODULE
AC901566
Connectors: C-53, C-138
C-53 (B)
C-138
AC708951CK
.
DTC SET CONDITION
DTC B1018 will be set when the heater control module cannot
receive the signal of temperature adjustment knob.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• The heater control module, the heater control panel, or connector(s) or wiring between the two may be defective.
Past trouble
• If DTC B1018 is stored as a past trouble, carry out diagnosis with particular emphasis on wiring and connector(s)
between the heater control module and the heater control
panel. If the connectors and wiring are normal, and obviously the ECU is the cause of the trouble, replace the ECU.
If in doubt, do not replace the ECU.
.
TSB Revision
55-32
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
TROUBLESHOOTING HINT
•
•
•
•
Malfunction of connector.
Malfunction of the harness.
Malfunction of the heater control panel.
Malfunction of the heater control module.
DIAGNOSIS
Required Special Tool:
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Go to Step 3.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
TSB Revision
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-33
STEP 3. Check heater control panel connector C-138 and
heater control module connector C-53 for loose, corroded
or damaged terminals, or terminals pushed back in the
connector.
Q: Are heater control panel connector C-138 and heater
control module connector C-53 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
STEP 4. Check the wiring harness between heater control
module connector C-53 (terminal 9) and heater control
panel connector C-138 (terminal 9).
• Check the heater control panel signal line and ground line
for open and short circuit.
Q: Is the wiring harness between heater control module
connector C-53 (terminal 9) and heater control panel
connector C-138 (terminal 9) in good condition?
YES : Go to Step 5.
NO : Repair the wiring harness.
STEP 5. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the heater control panel. Then go to Step 6.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
STEP 6. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the heater control module.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
TSB Revision
55-34
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
DTC B1018: Temperature Control Dial SW Error
A/C Control Panel Circuit
CPU
A/C
CONTROL
PANEL
INTERFACE
CIRCUIT
A/C-ECU
AC901388
Connectors: C-22, C-123
C-22 (B)
C-123
AC708951AJ
.
DTC SET CONDITION
DTC B1018 will be set when the A/C-ECU cannot receive the
signal of temperature adjustment knob.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• The A/C-ECU, the A/C control panel, or connector(s) or wiring between the two may be defective.
Past trouble
• If DTC B1018 is stored as a past trouble, carry out diagnosis with particular emphasis on wiring and connector(s)
between the A/C-ECU and the A/C control panel. If the connectors and wiring are normal, and obviously the ECU is the
cause of the trouble, replace the ECU. If in doubt, do not
replace the ECU.
.
TSB Revision
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-35
TROUBLESHOOTING HINT
•
•
•
•
Malfunction of connector.
Malfunction of the harness.
Malfunction of the A/C control panel.
Malfunction of the A/C-ECU.
DIAGNOSIS
Required Special Tool:
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Go to Step 3.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
TSB Revision
55-36
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 3. Check A/C control panel connector C-123 and
A/C-ECU connector C-22 for loose, corroded or damaged
terminals, or terminals pushed back in the connector.
Q: Are A/C control panel connector C-123 and A/C-ECU
connector C-22 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
STEP 4. Check the wiring harness between A/C-ECU
connector C-22 (terminal 9) and A/C control panel
connector C-123 (terminal 9).
• Check the A/C control panel signal line and ground line for
open and short circuit.
Q: Is the wiring harness between A/C-ECU connector C-22
(terminal 9) and A/C control panel connector C-123
(terminal 9) in good condition?
YES : Go to Step 5.
NO : Repair the wiring harness.
STEP 5. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the A/C control panel. Then go to Step 6.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
STEP 6. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the A/C-ECU.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
TSB Revision
55-37
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
DTC B1021: Fan Dial SW Error <Vehicles without A/C>
Heater Control Panel Circuit
CPU
HEATER
CONTROL
PANEL
INTERFACE
CIRCUIT
HEATER
CONTROL MODULE
AC901566
Connectors: C-53, C-138
C-53 (B)
C-138
AC708951CK
.
DTC SET CONDITION
DTC B1021 will be set when the heater control module cannot
receive the signal of blower knob.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• The heater control module, the heater control panel, or connector(s) or wiring between the two may be defective.
Past trouble
• If DTC B1021 is stored as a past trouble, carry out diagnosis with particular emphasis on wiring and connector(s)
between the heater control module and the heater control
panel. If the connectors and wiring are normal, and obviously the ECU is the cause of the trouble, replace the ECU.
If in doubt, do not replace the ECU.
.
TSB Revision
55-38
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
TROUBLESHOOTING HINT
•
•
•
•
Malfunction of connector.
Malfunction of the harness.
Malfunction of the heater control panel.
Malfunction of the heater control module.
DIAGNOSIS
Required Special Tool:
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Go to Step 3.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
TSB Revision
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-39
STEP 3. Check heater control panel connector C-138 and
heater control module connector C-53 for loose, corroded
or damaged terminals, or terminals pushed back in the
connector.
Q: Are heater control panel connector C-138 and heater
control module connector C-53 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
STEP 4. Check the wiring harness between heater control
module connector C-53 (terminal 9) and heater control
panel connector C-138 (terminal 9).
• Check the heater control panel signal line and ground line
for open and short circuit.
Q: Is the wiring harness between heater control module
connector C-53 (terminal 9) and heater control panel
connector C-138 (terminal 9) in good condition?
YES : Go to Step 5.
NO : Repair the wiring harness.
STEP 5. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the heater control panel. Then go to Step 6.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
STEP 6. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the heater control module.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
TSB Revision
55-40
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
DTC B1021: Fan Dial SW Error
A/C Control Panel Circuit
CPU
A/C
CONTROL
PANEL
INTERFACE
CIRCUIT
A/C-ECU
AC901388
Connectors: C-22, C-123
C-22 (B)
C-123
AC708951AJ
.
DTC SET CONDITION
DTC B1021 will be set when the A/C-ECU cannot receive the
signal of blower knob.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• The A/C-ECU, the A/C control panel, or connector(s) or wiring between the two may be defective.
Past trouble
• If DTC B1021 is stored as a past trouble, carry out diagnosis with particular emphasis on wiring and connector(s)
between the A/C-ECU and the A/C control panel. If the connectors and wiring are normal, and obviously the ECU is the
cause of the trouble, replace the ECU. If in doubt, do not
replace the ECU.
.
TSB Revision
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-41
TROUBLESHOOTING HINT
•
•
•
•
Malfunction of connector.
Malfunction of the harness.
Malfunction of the A/C control panel.
Malfunction of the A/C-ECU.
DIAGNOSIS
Required Special Tool:
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Go to Step 3.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
TSB Revision
55-42
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 3. Check A/C control panel connector C-123 and
A/C-ECU connector C-22 for loose, corroded or damaged
terminals, or terminals pushed back in the connector.
Q: Are A/C control panel connector C-123 and A/C-ECU
connector C-22 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
STEP 4. Check the wiring harness between A/C-ECU
connector C-22 (terminal 9) and A/C control panel
connector C-123 (terminal 9).
• Check the A/C control panel signal line and ground line for
open and short circuit.
Q: Is the wiring harness between A/C-ECU connector C-22
(terminal 9) and A/C control panel connector C-123
(terminal 9) in good condition?
YES : Go to Step 5.
NO : Repair the wiring harness.
STEP 5. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the A/C control panel. Then go to Step 6.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
STEP 6. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the A/C-ECU.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
TSB Revision
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-43
DTC B1031, B1032: Fin Thermo Sensor System <Vehicles without A/C>
Fin Thermo Sensor Circuit
FIN THERMO
SENSOR
HEATER
CONTROL
MODULE
AC901567
Connectors: C-52, C-113
C-52 (B)
C-113
AC708951CL
.
DTC SET CONDITION
• DTC B1031 is set if there is a short circuit in the fin thermo
sensor input circuit.
• DTC B1032 is set if there is a defective connector connection, or if there is an open circuit in the harness.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• The heater control module, the fin thermo sensor, or connector(s) or wiring between the two may be defective.
Past trouble
• If DTC B1031 or B1032 is stored as a past trouble, carry out
diagnosis with particular emphasis on wiring and connector(s) between the heater control module and the fin thermo
sensor. If the connectors and wiring are normal, and obviously the ECU is the cause of the trouble, replace the ECU.
If in doubt, do not replace the ECU.
.
TSB Revision
55-44
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
TROUBLESHOOTING HINT
•
•
•
•
Malfunction of connector.
Malfunction of the harness.
Malfunction of the fin thermo sensor.
Malfunction of the heater control module.
DIAGNOSIS
Required Special Tool:
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Go to Step 3.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
TSB Revision
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-45
STEP 3. Check fin thermo sensor connector C-113 and
heater control module connector C-52 for loose, corroded
or damaged terminals, or terminals pushed back in the
connector.
Q: Are fin thermo sensor connector C-113 and heater
control module connector C-52 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
STEP 4. Check the wiring harness between heater control
module connector C-52 (terminals 22 and 21) and fin
thermo sensor connector C-113 (terminals 1 and 2).
• Check the sensor signal line and ground line for open and
short circuit.
Q: Is the wiring harness between heater control module
connector C-52 (terminals 22 and 21) and fin thermo
sensor connector C-113 (terminals 1 and 2) in good
condition?
YES : Go to Step 5.
NO : Repair the wiring harness.
Resistance
(kΩ)
STEP 5. Check the fin thermo sensor.
Measure the resistance between connector terminals 1 and 2
under at least two different temperatures. The resistance values should generally match those in the graph.
NOTE: The temperature at the check should not exceed the
range in the graph.
25
20
15
10
5
0
-10 0 10 20 30 40
(14) (32) (50) (68) (86) (104)
Temperature ºC (ºF)
AC609399AB
Q: Is the fin thermo sensor in good condition?
YES : Replace the heater control module. Then go to Step
6.
NO : Replace the fin thermo sensor. Then go to Step 6.
STEP 6. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Connect scan tool MB991958 to the data link connector
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Return to Step 1.
NO : The procedure is complete.
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55-46
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
DTC B1031, B1032: Fin Thermo Sensor System
Fin Thermo Sensor Circuit
FIN THERMO
SENSOR
A/C-ECU
AC708602
Connectors: C-20, C-113
C-20 (B)
C-113
AC708951AK
.
DTC SET CONDITION
• DTC B1031 is set if there is a short circuit in the fin thermo
sensor input circuit.
• DTC B1032 is set if there is a defective connector connection, or if there is an open circuit in the harness.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• The A/C-ECU, the fin thermo sensor, or connector(s) or wiring between the two may be defective.
Past trouble
• If DTC B1031 or B1032 is stored as a past trouble, carry out
diagnosis with particular emphasis on wiring and connector(s) between the A/C-ECU and the fin thermo sensor. If
the connectors and wiring are normal, and obviously the
ECU is the cause of the trouble, replace the ECU. If in
doubt, do not replace the ECU.
.
TSB Revision
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-47
TROUBLESHOOTING HINT
•
•
•
•
Malfunction of connector.
Malfunction of the harness.
Malfunction of the fin thermo sensor.
Malfunction of the A/C-ECU.
DIAGNOSIS
Required Special Tool:
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Go to Step 3.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
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55-48
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 3. Check fin thermo sensor connector C-113 and
A/C-ECU connector C-20 for loose, corroded or damaged
terminals, or terminals pushed back in the connector.
Q: Are fin thermo sensor connector C-113 and A/C-ECU
connector C-20 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
STEP 4. Check the wiring harness between A/C-ECU
connector C-20 (terminals 22 and 21) and fin thermo
sensor connector C-113 (terminals 1 and 2).
• Check the sensor signal line and ground line for open and
short circuit.
Q: Is the wiring harness between A/C-ECU connector C-20
(terminals 22 and 21) and fin thermo sensor connector
C-113 (terminals 1 and 2) in good condition?
YES : Go to Step 5.
NO : Repair the wiring harness.
Resistance
(kΩ)
STEP 5. Check the fin thermo sensor.
Measure the resistance between connector terminals 1 and 2
under at least two different temperatures. The resistance values should generally match those in the graph.
NOTE: The temperature at the check should not exceed the
range in the graph.
25
20
15
10
5
0
-10 0 10 20 30 40
(14) (32) (50) (68) (86) (104)
Temperature ºC (ºF)
AC609399AB
Q: Is the fin thermo sensor in good condition?
YES : Replace the A/C-ECU. Then go to Step 6.
NO : Replace the fin thermo sensor. Then go to Step 6.
STEP 6. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Connect scan tool MB991958 to the data link connector
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Return to Step 1.
NO : The procedure is complete.
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55-49
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
DTC B1034, B1035: Ambient air temperature Sensor System
Ambient air Temperature Sensor Circuit
ETACS-ECU
ANALOG
INTERFACE
CIRCUIT
AMBIENT AIR
TEMPERATURE
SENSOR
AC805057
Connector: C-312
ETACS-ECU
Connector: A-49
A-49 (B)
AC708972AP
AC708949AE
.
DTC SET CONDITION
• DTC B1034 is set if there is a short circuit in the ambient air
temperature sensor input circuit.
• DTC B1035 is set if there is a defective connector connection, or if there is an open circuit in the harness.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• The A/C-ECU, the ambient air temperature sensor, or connector(s) or wiring between the two may be defective.
Past trouble
• If DTC B1034 or B1035 is stored as a past trouble, carry out
diagnosis with particular emphasis on wiring and connector(s) between the A/C-ECU and the ambient air temperature sensor. If the connectors and wiring are normal, and
obviously the ECU is the cause of the trouble, replace the
ECU. If in doubt, do not replace the ECU.
.
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55-50
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
TROUBLESHOOTING HINT
•
•
•
•
Malfunction of connector.
Malfunction of the harness.
Malfunction of the ambient air temperature sensor.
Malfunction of the A/C-ECU.
DIAGNOSIS
Required Special Tool:
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Go to Step 3.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-51
STEP 3. Check ambient air temperature sensor connector
A-49 and ETACS-ECU connector C-312 for loose, corroded
or damaged terminals, or terminals pushed back in the
connector.
Q: Are ambient air temperature sensor connector A-49 and
ETACS-ECU connector C-312 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
STEP 4. Check the wiring harness between ambient air
temperature sensor connector A-49 (terminals 2 and 1) and
ETACS-ECU connector C-312 (terminals 7 and 14).
• Check the sensor signal line and ground line for open and
short circuit.
Q: Is the wiring harness between ambient air temperature
sensor connector A-49 (terminals 2 and 1) and
ETACS-ECU connector C-312 (terminals 7 and 14) in
good condition?
YES : Go to Step 5.
NO : Repair the wiring harness.
STEP 5. Check the ambient air temperature sensor.
Measure the resistance between connector terminals 1 and 2
under at least two different temperatures. The resistance values should generally match those in the graph.
NOTE: The temperature at the check should not exceed the
range in the graph.
Resistance
(kΩ) 10
8
6
4
2
0
-10
10
0
(50)
(14) (32)
Temperature ºC (ºF)
20
(68)
40
30
(86) (104)
AC209192 AB
Q: Is the ambient air temperature sensor in good
condition?
YES : Replace the A/C-ECU. Then go to Step 6.
NO : Replace the ambient air temperature sensor. Then go
to Step 6.
STEP 6. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Connect scan tool MB991958 to the data link connector
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Return to Step 1.
NO : The procedure is complete.
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55-52
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
DTC B1079: Refrigerant Leaks
A/C Pressure Sensor Circuit
A/C PRESSURE
SENSOR
JOINT
CONNECTOR (2)
A/C-ECU
AC804914
Connector: A-53
Connectors: C-102, C-131
C-102 (B)
A-53 (B)
C-131
AC708948AF
Connector: C-22
C-22 (B)
AC708951AL
TSB Revision
AC708950AQ
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-53
.
DTC SET CONDITION
DTC B1079 will be set when the A/C pressure sensor detects
the refrigerant pressure of specified level or less.
NOTE: When DTC B1079 is set, the A/C indicator of A/C control panel flashes.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• The refrigerant amount is not at the specified level, or the
wiring harness or connector between the A/C-ECU and A/C
pressure sensor, and the A/C-ECU itself or A/C pressure
sensor itself may have failed.
Past trouble
• If DTC B1079 is stored as a past trouble, carry out diagnosis with particular emphasis on wiring and connector(s)
between the A/C-ECU and the A/C pressure sensor. If the
connectors and wiring are normal, and obviously the ECU is
the cause of the trouble, replace the ECU. If in doubt, do not
replace the ECU.
.
TROUBLESHOOTING HINT
•
•
•
•
Malfunction of connector.
Malfunction of the harness.
Malfunction of the A/C pressure sensor.
Malfunction of the A/C-ECU.
DIAGNOSIS
Required Special Tool:
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
TSB Revision
55-54
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Go to Step 3.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
STEP 3. Check A/C pressure sensor connector A-53 and
A/C-ECU connector C-22 for loose, corroded or damaged
terminals, or terminals pushed back in the connector.
Q: Are air A/C pressure sensor connector A-53 and
A/C-ECU connector C-22 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-55
STEP 4. Check the wiring harness between A/C-ECU
connector C-22 (terminals 20, 16 and 19) and A/C pressure
sensor connector A-53 (terminals 3, 2 and 1).
NOTE: Also check intermediate connector C-131 and joint connector C-102 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector
C-131 and joint connector C-102 is damaged, repair or replace
the connector as described in GROUP 00E, Harness Connector Inspection P.00E-2.
• Check the sensor signal line and ground line for open and
short circuit.
Q: Is the wiring harness between A/C-ECU connector C-22
(terminals 20, 16 and 19) and A/C pressure sensor
connector A-53 (terminals 3, 2 and 1) in good condition?
YES : Go to Step 5.
NO : Repair the wiring harness.
STEP 5. Check the A/C pressure sensor operation.
(1) Assemble a gauge manifold on the high pressure service
valve.
(2) Disconnect the A/C pressure sensor connector and connect
special tool test harness MB991658 as shown in the
illustration.
(3) Turn ON the engine and then turn ON the A/C switch.
A/C pressure sensor
AC609413AB
A/C
pressure
sensor
side
Harness side
MB991658
AC307368AC
(4) At this time, check to see that the voltage of A/C pressure
sensor terminal No. 2 reflects the specifications of the
figure.
NOTE: The allowance shall be defined as ±5%.
Output voltage
(V)
5
4
3
Q: Is the A/C pressure sensor operating properly?
YES : Go to Step 6.
NO : Replace the A/C pressure sensor. Then go to Step 7.
2
1
0
1 (145) 2 (290) 3 (435)
Refrigerant pressure MPa (psi)
AC208297AG
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55-56
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 6. Check the refrigerant level.
Use the refrigerant recovery station to remove all of the refrigerant, and then calculate the amount of the refrigerant and
charge it.
Q: Is the refrigerant level correct?
YES : Go to Step 7.
NO : Correct the refrigerant level (Refer to On-vehicle
Service P.55-165). Then go to Step 7.
STEP 7. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Connect scan tool MB991958 to the data link connector
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Return to Step 1.
NO : The procedure is complete.
DTC B2214: Control Panel Failure <Vehicles without A/C>
Heater Control Panel Circuit
CPU
HEATER
CONTROL
PANEL
INTERFACE
CIRCUIT
HEATER
CONTROL MODULE
AC901566
TSB Revision
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-57
Connectors: C-53, C-138
C-53 (B)
C-138
AC708951CK
.
DTC SET CONDITION
DTC B2214 will be set when the heater control module detects
the heater control panel abnormality.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• The heater control module, the heater control panel, or connector(s) or wiring between the two may be defective.
Past trouble
• If DTC B2214 is stored as a past trouble, carry out diagnosis with particular emphasis on wiring and connector(s)
between the heater control module and the heater control
panel. If the connectors and wiring are normal, and obviously the ECU is the cause of the trouble, replace the ECU.
If in doubt, do not replace the ECU.
.
TROUBLESHOOTING HINT
•
•
•
•
Malfunction of connector.
Malfunction of the harness.
Malfunction of the heater control panel.
Malfunction of the heater control module.
DIAGNOSIS
Required Special Tool:
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
TSB Revision
55-58
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Go to Step 3.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
STEP 3. Check heater control panel connector C-138 and
heater control module connector C-53 for loose, corroded
or damaged terminals, or terminals pushed back in the
connector.
Q: Are heater control panel connector C-138 and heater
control module connector C-53 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
TSB Revision
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-59
STEP 4. Check the wiring harness between heater control
module connector C-53 (terminal 9) and heater control
panel connector C-138 (terminal 9).
• Check the heater control panel signal line and ground line
for open and short circuit.
Q: Is the wiring harness between heater control module
connector C-53 (terminal 9) and heater control panel
connector C-138 (terminal 9) in good condition?
YES : Go to Step 5.
NO : Repair the wiring harness.
STEP 5. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the heater control panel. Then go to Step 6.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
STEP 6. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the heater control module.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
TSB Revision
55-60
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
DTC B2214: Control Panel Failure
A/C Control Panel Circuit
CPU
A/C
CONTROL
PANEL
INTERFACE
CIRCUIT
A/C-ECU
AC901388
Connectors: C-22, C-123
C-22 (B)
C-123
AC708951AJ
.
DTC SET CONDITION
DTC B2214 will be set when the A/C-ECU detects the A/C control panel abnormality.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• The A/C-ECU, the A/C control panel, or connector(s) or wiring between the two may be defective.
Past trouble
• If DTC B2214 is stored as a past trouble, carry out diagnosis with particular emphasis on wiring and connector(s)
between the A/C-ECU and the A/C control panel. If the connectors and wiring are normal, and obviously the ECU is the
cause of the trouble, replace the ECU. If in doubt, do not
replace the ECU.
.
TSB Revision
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-61
TROUBLESHOOTING HINT
•
•
•
•
Malfunction of connector.
Malfunction of the harness.
Malfunction of the A/C control panel.
Malfunction of the A/C-ECU.
DIAGNOSIS
Required Special Tool:
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Go to Step 3.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
TSB Revision
55-62
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 3. Check A/C control panel connector C-123 and
A/C-ECU connector C-22 for loose, corroded or damaged
terminals, or terminals pushed back in the connector.
Q: Are A/C control panel connector C-123 and A/C-ECU
connector C-22 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
STEP 4. Check the wiring harness between A/C-ECU
connector C-22 (terminal 9) and A/C control panel
connector C-123 (terminal 9).
• Check the A/C control panel signal line and ground line for
open and short circuit.
Q: Is the wiring harness between A/C-ECU connector C-22
(terminal 9) and A/C control panel connector C-123
(terminal 9) in good condition?
YES : Go to Step 5.
NO : Repair the wiring harness.
STEP 5. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the A/C control panel. Then go to Step 6.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
STEP 6. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the A/C-ECU.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
TSB Revision
55-63
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
DTC B223B: Control Panel Improperly Assembled <Vehicles without A/C>
A/C Control Panel Circuit
CPU
A/C
CONTROL
PANEL
INTERFACE
CIRCUIT
A/C-ECU
AC901527
Connectors: C-53, C-138
C-53 (B)
C-138
AC708951CK
.
DTC SET CONDITION
DTC B223B will be set when the heater control panel sends an
abnormal data, the heater control panel for RHD is improperly
assembled, or the ETACS-ECU sends incorrect vehicle information (information for RHD is sent).
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• The heater control module, the heater control panel, or connector(s) or wiring between the two may be defective.
Past trouble
• If DTC B223B is stored as a past trouble, carry out diagnosis with particular emphasis on wiring and connector(s)
between the heater control module and the heater control
panel. If the connectors and wiring are normal, and obviously the ECU is the cause of the trouble, replace the ECU.
If in doubt, do not replace the ECU.
.
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55-64
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
TROUBLESHOOTING HINT
•
•
•
•
Malfunction of connector.
Malfunction of the harness.
Malfunction of the heater control panel.
Malfunction of the heater control module.
DIAGNOSIS
Required Special Tool:
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Go to Step 3.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-65
STEP 3. Check heater control panel connector C-138 and
heater control module connector C-53 for loose, corroded
or damaged terminals, or terminals pushed back in the
connector.
Q: Are heater control panel connector C-138 and heater
control module connector C-53 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
STEP 4. Check the wiring harness between heater control
module connector C-53 (terminal 9) and heater control
panel connector C-138 (terminal 9).
• Check the heater control panel signal line and ground line
for open and short circuit.
Q: Is the wiring harness between heater control module
connector C-53 (terminal 9) and heater control panel
connector C-138 (terminal 9) in good condition?
YES : Go to Step 5.
NO : Repair the wiring harness.
STEP 5. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the heater control panel. Then go to Step 6.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
STEP 6. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the heater control module.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
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55-66
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
DTC B223B: Control Panel Improperly Assembled
A/C Control Panel Circuit
CPU
A/C
CONTROL
PANEL
INTERFACE
CIRCUIT
A/C-ECU
AC901388
Connectors: C-22, C-123
C-22 (B)
C-123
AC708951AJ
.
DTC SET CONDITION
DTC B223B will be set when the A/C control panel sends an
abnormal data, the A/C control panel for RHD is improperly
assembled, or the ETACS-ECU sends incorrect vehicle information (information for RHD is sent).
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• The A/C-ECU, the A/C control panel, or connector(s) or wiring between the two may be defective.
Past trouble
• If DTC B223B is stored as a past trouble, carry out diagnosis with particular emphasis on wiring and connector(s)
between the A/C-ECU and the A/C control panel. If the connectors and wiring are normal, and obviously the ECU is the
cause of the trouble, replace the ECU. If in doubt, do not
replace the ECU.
.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-67
TROUBLESHOOTING HINT
•
•
•
•
Malfunction of connector.
Malfunction of the harness.
Malfunction of the A/C control panel.
Malfunction of the A/C-ECU.
DIAGNOSIS
Required Special Tool:
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Go to Step 3.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 3. Check A/C control panel connector C-123 and
A/C-ECU connector C-22 for loose, corroded or damaged
terminals, or terminals pushed back in the connector.
Q: Are A/C control panel connector C-123 and A/C-ECU
connector C-22 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
STEP 4. Check the wiring harness between A/C-ECU
connector C-22 (terminal 9) and A/C control panel
connector C-123 (terminal 9).
• Check the AC control panel signal line and ground line for
open and short circuit.
Q: Is the wiring harness between A/C-ECU connector C-22
(terminal 9) and A/C control panel connector C-123
(terminal 9) in good condition?
YES : Go to Step 5.
NO : Repair the wiring harness.
STEP 5. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the A/C control panel. Then go to Step 6.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
STEP 6. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the A/C-ECU.
NO : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-69
DTC U1415: Coding Not Completed
CAUTION
If DTC U1415 is set in the A/C-ECU, diagnose the
CAN main bus line.
CAUTION
Whenever the ECU is replaced, ensure that the
communication circuit is normal.
.
TROUBLE JUDGMENT
The A/C-ECU receives the vehicle information signals from the ETACS-ECU via the CAN bus lines. If
incorrect global coding data is received or coding
data cannot be received with the ignition switch
turned ON when the coding confirmation is completed, diagnostic trouble code U1415 is stored.
.
TROUBLESHOOTING HINTS
• Malfunction of the ETACS-ECU
• Malfunction of the A/C-ECU
• Damaged harness wires and connectors
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: V.C.I.
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 2. Using scan tool MB991958 read the ETACS-ECU
diagnostic trouble code.
Check whether an ETACS DTC.
(1) Turn the ignition switch to the "ON" position.
(2) Check for the DTC related to the ETACS-ECU.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Diagnose the ETACS-ECU (Refer to GROUP 54A,
Diagnostic Trouble Code P.54A-646 ).
NO : Go to Step 3.
STEP 3. Using scan tool MB991958, check for any
diagnostic trouble code.
Check if a DTC, which relates to CAN communication-linked
systems below, is set.
• WCM <vehicles with WCM>
B2204: Coding data unmatched
• KOS <vehicles with KOS>
B2204: Coding data unmatched
(1) Turn the ignition switch to the "ON" position.
(2) Check for a DTC related to the relevant system.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Go to Step 5.
NO : Go to Step 4.
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the ETACS-ECU. On completion, check that
the DTC is not reset.
NO : A poor connection, open circuit or other intermittent
malfunction is present in the lines between the
ETACS-ECU and the A/C-ECU (Refer to GROUP
00E, Harness Connector Inspection P.00E-2).
STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the A/C-ECU. On completion, check that the
DTC is not reset.
NO : A poor connection, open circuit or other intermittent
malfunction is present in the lines between the
ETACS-ECU and the A/C-ECU (Refer to GROUP
00E, Harness Connector Inspection P.00E-2).
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-71
DTC U0019: Bus Off (CAN1)
.
CAUTION
If DTC U0019is set in the A/C-ECU, diagnose the
CAN main bus line.
CAUTION
Whenever the ECU is replaced, ensure that the
communication circuit is normal.
TECHNICAL DESCRIPTION (COMMENT)
The wiring harness wire or connectors may have
loose, corroded, or damage terminals, or terminals
pushed back in the connector, or the A/C-ECU may
be defective.
.
TROUBLESHOOTING HINTS
.
TROUBLE JUDGMENT
DTC U0019 will be stored when the A/C-ECU ceases
CAN communication (bus off) and then resumes the
communication when the ignition switch is turned to
the "LOCK" (OFF) position.
• Defective connector(s) or wiring harness
• Malfunction of the A/C-ECU
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: V.C.I.
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 2. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Connect scan tool MB991958 to the data link connector
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the A/C-ECU. On completion, check that the
DTC is not reset.
NO : There is an intermittent malfunction such as poor
engaged connector(s) or open circuit (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points −How to Cope with Intermittent
Malfunctions P.00-15.)
DTC U0141: ETACS-ECU Time-out
CAUTION
If DTC U0141 is set in the A/C-ECU, diagnose the
CAN main bus line.
CAUTION
Whenever the ECU is replaced, ensure that the
communication circuit is normal.
.
TROUBLE JUDGMENT
The A/C-ECU receives air conditioning operation-related signals from the ETACS-ECU via the
CAN bus lines. If the ECU cannot receive any of the
air conditioning control-related signals from the
ETACS-ECU, the diagnostic trouble code U0141 is
stored.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• Connector(s) or wiring harness in the CAN bus
lines between the ETACS-ECU and the
A/C-ECU, the power supply system to the
ETACS-ECU, the ETACS-ECU itself, or the
A/C-ECU may be defective.
Past trouble
• If DTC U0141 is stored as a past trouble, carry
out diagnosis with particular emphasis on wiring
and connector(s) in the CAN bus line between
the A/C-ECU and the ETACS-ECU, and the
power supply system to the ETACS-ECU. If the
connectors and wiring are normal, and obviously
the ECU is the cause of the trouble, replace the
ECU. If in doubt, do not replace the ECU.
NOTE: For a past trouble, you cannot find it by
the scan tool CAN bus diagnostics even if there is
a failure in CAN bus lines. In this case, refer to
GROUP 00, How to Use Troubleshooting/Inspection Service Points −How to Cope with Intermittent Malfunctions P.00-15) and check the CAN
bus lines. You can narrow down the possible
cause of the trouble by referring to the DTC,
which is set regarding the CAN communication-linked ECUs (Refer to GROUP 54C, Explanation about the scan too CAN bus diagnostics
P.54C-15).
.
TROUBLESHOOTING HINTS
• Malfunction of the A/C-ECU
• Malfunction of the ETACS-ECU
• Damaged harness wires and connectors
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-73
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: V.C.I.
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Using scan tool MB991958 read the ETACS-ECU
diagnostic trouble code.
Check whether an ETACS-ECU DTCs are set or not.
(1) Turn the ignition switch to the "ON" position.
(2) Check for ETACS-ECU DTCs.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Diagnose the ETACS-ECU (Refer to GROUP 54A,
Diagnostic Trouble Code P.54A-646).
NO : Go to Step 3.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 3. Using scan tool MB991958, check for any
diagnostic trouble code.
Check if a DTC, which relates to CAN communication-linked
systems below, is set.
• Combination meter
DTC indicating a time-out error related to the engine or
automatic transaxle control system
(1) Turn the ignition switch to the "ON" position.
(2) Check for a DTC related to the relevant system.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Go to Step 4.
NO : Go to Step 5.
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the ETACS-ECU. On completion, check that
the DTC is not reset.
NO : There is an intermittent malfunction such as poor
engaged connector(s) or open circuit (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points −How to Cope with Intermittent
Malfunctions P.00-15.)
STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the A/C-ECU. On completion, check that the
DTC is not reset.
NO : There is an intermittent malfunction such as poor
engaged connector(s) or open circuit (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points −How to Cope with Intermittent
Malfunctions P.00-15.)
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-75
DTC U0151: SRS-ECU Time-out
CAUTION
If DTC U0151 is set in the A/C-ECU, diagnose the
CAN main bus line.
CAUTION
Whenever the ECU is replaced, ensure that the
communication circuit is normal.
.
TROUBLE JUDGMENT
The A/C-ECU receives air conditioning operation-related signals from the SRS-ECU via the CAN
bus lines. If any of the air conditioning control-related
signals from the SRS-ECU cannot be received, the
diagnostic trouble code U0151 is stored.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• Connector(s) or wiring harness in the CAN bus
lines between the SRS-ECU and the A/C-ECU,
the power supply system to the SRS-ECU, the
SRS-ECU itself, or the A/C-ECU may be defective.
Past trouble
• If DTC U0151 is stored as a past trouble, carry
out diagnosis with particular emphasis on wiring
and connector(s) in the CAN bus line between
the A/C-ECU and the SRS-ECU, and the power
supply system to the SRS-ECU. If the connectors
and wiring are normal, and obviously the ECU is
the cause of the trouble, replace the ECU. If in
doubt, do not replace the ECU.
NOTE: For a past trouble, you cannot find it by
the scan tool CAN bus diagnostics even if there is
a failure in CAN bus lines. In this case, refer to
GROUP 00, How to Use Troubleshooting/Inspection Service Points −How to Cope with Intermittent Malfunctions P.00-15) and check the CAN
bus lines. You can narrow down the possible
cause of the trouble by referring to the DTC,
which is set regarding the CAN communication-linked ECUs (Refer to GROUP 54C, Explanation about the scan too CAN bus diagnostics
P.54C-15).
.
TROUBLESHOOTING HINTS
• Malfunction of the SRS-ECU
• Malfunction of the A/C-ECU
• Damaged harness wires and connectors
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: V.C.I.
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Using scan tool MB991958 read the SRS-ECU
diagnostic trouble code.
Check whether an SRS-ECU DTCs are set or not.
(1) Turn the ignition switch to the "ON" position.
(2) Check for SRS-ECU DTCs.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Diagnose the SRS-ECU (Refer to GROUP 52B,
Diagnostic Trouble Code P.52B-30).
NO : Go to Step 3.
STEP 3. Using scan tool MB991958, check for any
diagnostic trouble code.
Check if a DTC, which relates to CAN communication-linked
systems below, is set.
• ETACS-ECU
DTC indicating a time-out error related to the SRS-ECU
system
(1) Turn the ignition switch to the "ON" position.
(2) Check for a DTC related to the relevant system.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Go to Step 4.
NO : Go to Step 5.
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STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the SRS-ECU. On completion, check that
the DTC is not reset.
NO : There is an intermittent malfunction such as poor
engaged connector(s) or open circuit (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points −How to Cope with Intermittent
Malfunctions P.00-15.)
STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the A/C-ECU. On completion, check that the
DTC is not reset.
NO : There is an intermittent malfunction such as poor
engaged connector(s) or open circuit (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points −How to Cope with Intermittent
Malfunctions P.00-15.)
DTC U0154: Occupant classification ECU time-out
CAUTION
If DTC U0154 is set in the A/C-ECU, diagnose the
CAN main bus line.
CAUTION
Whenever the ECU is replaced, ensure that the
communication circuit is normal.
.
TROUBLE JUDGMENT
The A/C-ECU receives air conditioning operation-related signals from the SRS-ECU via the CAN
bus lines. If any of the air conditioning control-related
signals from the SRS-ECU cannot be received, the
diagnostic trouble code U0154 is stored.
.
TSB Revision
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• Connector(s) or wiring harness in the CAN bus
lines between the SRS-ECU and the A/C-ECU,
the power supply system to the SRS-ECU, the
SRS-ECU itself, or the A/C-ECU may be defective.
Past trouble
• If DTC U0151 is stored as a past trouble, carry
out diagnosis with particular emphasis on wiring
and connector(s) in the CAN bus line between
the A/C-ECU and the SRS-ECU, and the power
supply system to the SRS-ECU. If the connectors
and wiring are normal, and obviously the ECU is
the cause of the trouble, replace the ECU. If in
doubt, do not replace the ECU.
55-78
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
NOTE: For a past trouble, you cannot find it by
the scan tool CAN bus diagnostics even if there is
a failure in CAN bus lines. In this case, refer to
GROUP 00, How to Use Troubleshooting/Inspection Service Points −How to Cope with Intermittent Malfunctions P.00-15) and check the CAN
bus lines. You can narrow down the possible
cause of the trouble by referring to the DTC,
which is set regarding the CAN communication-linked ECUs (Refer to GROUP 54C, Explanation about the scan too CAN bus diagnostics
P.54C-15).
.
TROUBLESHOOTING HINTS
• Malfunction of the SRS-ECU
• Malfunction of the A/C-ECU
• Damaged harness wires and connectors
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: V.C.I.
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-79
STEP 2. Using scan tool MB991958 read the SRS-ECU
diagnostic trouble code.
Check whether an SRS-ECU DTCs are set or not.
(1) Turn the ignition switch to the "ON" position.
(2) Check for SRS-ECU DTCs.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Diagnose the SRS-ECU (Refer to GROUP 52B,
Diagnostic Trouble Code P.52B-316).
NO : Go to Step 3.
STEP 3. Using scan tool MB991958, check for any
diagnostic trouble code.
Check if a DTC, which relates to CAN communication-linked
systems below, is set.
• ETACS-ECU
DTC indicating a time-out error related to the SRS-ECU
system
(1) Turn the ignition switch to the "ON" position.
(2) Check for a DTC related to the relevant system.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Go to Step 4.
NO : Go to Step 5.
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the SRS-ECU. On completion, check that
the DTC is not reset.
NO : There is an intermittent malfunction such as poor
engaged connector(s) or open circuit (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points −How to Cope with Intermittent
Malfunctions P.00-15.)
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55-80
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the A/C-ECU. On completion, check that the
DTC is not reset.
NO : There is an intermittent malfunction such as poor
engaged connector(s) or open circuit (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points −How to Cope with Intermittent
Malfunctions P.00-15.)
DTC U0155: Combination meter Time-out
CAUTION
If DTC U0155 is set in the A/C-ECU, diagnose the
CAN main bus line.
CAUTION
Whenever the ECU is replaced, ensure that the
communication circuit is normal.
.
TROUBLE JUDGMENT
The A/C-ECU receives the air conditioning control-related signals from the combination meter via
the CAN bus lines. If any of the air conditioning control-related signals from the combination meter cannot be received, the diagnostic trouble code U0155 is
stored.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• Connector(s) or wiring harness in the CAN bus
lines between the combination meter and the
A/C-ECU, the power supply system to the combination meter, the combination meter itself, or the
A/C-ECU may be defective.
Past trouble
• If DTC U0155 is stored as a past trouble, carry
out diagnosis with particular emphasis on wiring
and connector(s) in the CAN bus line between
the A/C-ECU and the combination meter, and the
power supply system to the combination meter. If
the connectors and wiring are normal, and obviously the ECU is the cause of the trouble, replace
the ECU. If in doubt, do not replace the ECU.
NOTE: For a past trouble, you cannot find it by
the scan tool CAN bus diagnostics even if there is
a failure in CAN bus lines. In this case, refer to
GROUP 00, How to Use Troubleshooting/Inspection Service Points −How to Cope with Intermittent Malfunctions P.00-15) and check the CAN
bus lines. You can narrow down the possible
cause of the trouble by referring to the DTC,
which is set regarding the CAN communication-linked ECUs (Refer to GROUP 54C, Explanation about the scan too CAN bus diagnostics
P.54C-9).
.
TROUBLESHOOTING HINTS
• Malfunction of the combination meter
• Malfunction of the A/C-ECU
• Damaged harness wires and connectors
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: V.C.I.
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-81
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Using scan tool MB991958 read the combination
meter diagnostic trouble code.
Check whether a combination meter DTCs are set or not.
(1) Turn the ignition switch to the "ON" position.
(2) Check for combination meter DTCs.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Diagnose the combination meter (Refer to GROUP
54A, Diagnostic Trouble Code P.54A-32).
NO : Go to Step 3.
STEP 3. Using scan tool MB991958, check for any
diagnostic trouble code.
Check if a DTC, which relates to CAN communication-linked
systems below, is set.
• ETACS-ECU
DTC indicating a time-out error related to the combination
meter system
(1) Turn the ignition switch to the "ON" position.
(2) Check for a DTC related to the relevant system.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Go to Step 4.
NO : Go to Step 5.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the combination meter. On completion,
check that the DTC is not reset.
NO : There is an intermittent malfunction such as poor
engaged connector(s) or open circuit (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points −How to Cope with Intermittent
Malfunctions P.00-15.)
STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the A/C-ECU. On completion, check that the
DTC is not reset.
NO : There is an intermittent malfunction such as poor
engaged connector(s) or open circuit (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points −How to Cope with Intermittent
Malfunctions P.00-15.)
DTC U0168: WCM Time-out
CAUTION
If DTC U0168 is set in the A/C-ECU, diagnose the
CAN main bus line.
CAUTION
Whenever the ECU is replaced, ensure that the
communication circuit is normal.
.
TROUBLE JUDGMENT
The A/C-ECU receives the air conditioning control-related signals from the WCM-ECU via the CAN
bus lines. If any of the air conditioning control-related
signals from the WCM-ECU cannot be received,
diagnostic trouble code U0168 is stored.
.
TSB Revision
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• Connector(s) or wiring harness in the CAN bus
lines between the WCM-ECU and the A/C-ECU,
the power supply system to the WCM-ECU, the
WCM-ECU itself, or the A/C-ECU may be defective.
Past trouble
• If DTC U0168 is stored as a past trouble, carry
out diagnosis with particular emphasis on wiring
and connector(s) in the CAN bus line between
the A/C-ECU and the WCM-ECU, and the power
supply system to the WCM-ECU. If the connectors and wiring are normal, and obviously the
ECU is the cause of the trouble, replace the ECU.
If in doubt, do not replace the ECU.
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
NOTE: For a past trouble, you cannot find it by
the scan tool CAN bus diagnostics even if there is
a failure in CAN bus lines. In this case, refer to
GROUP 00, How to Use Troubleshooting/Inspection Service Points −How to Cope with Intermittent Malfunctions P.00-15) and check the CAN
bus lines. You can narrow down the possible
55-83
cause of the trouble by referring to the DTC,
which is set regarding the CAN communication-linked ECUs (Refer to GROUP 54C, Explanation about the scan too CAN bus diagnostics
P.54C-9).
.
TROUBLESHOOTING HINTS
• Malfunction of the WCM-ECU
• Malfunction of the A/C-ECU
• Damaged harness wires and connectors
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: V.C.I.
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 2. Using scan tool MB991958 read the WCM-ECU
diagnostic trouble code.
Check whether an WCM-ECU DTCs are set or not.
(1) Turn the ignition switch to the "ON" position.
(2) Check for WCM-ECU DTCs.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Go to Step 3.
NO : Diagnose the WCM-ECU (Refer to GROUP 42C,
Diagnostic Trouble Code P.42C-14).
STEP 3. Using scan tool MB991958, check for any
diagnostic trouble code.
Check if a DTC, which relates to CAN communication-linked
systems below, is set.
• ETACS-ECU
DTC indicating a time-out error related to the WCM-ECU
system
(1) Turn the ignition switch to the "ON" position.
(2) Check for a DTC related to the relevant system.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Go to Step 4.
NO : Go to Step 5.
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the WCM-ECU. On completion, check that
the DTC is not reset.
NO : There is an intermittent malfunction such as poor
engaged connector(s) or open circuit (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points −How to Cope with Intermittent
Malfunctions P.00-15.)
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AUTO A/C DIAGNOSIS
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STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the A/C-ECU. On completion, check that the
DTC is not reset.
NO : There is an intermittent malfunction such as poor
engaged connector(s) or open circuit (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points −How to Cope with Intermittent
Malfunctions P.00-15.)
DTC U0184: Audio Time-out
CAUTION
If DTC U0184 is set in the A/C-ECU, diagnose the
CAN main bus line.
CAUTION
Whenever the ECU is replaced, ensure that the
communication circuit is normal.
.
TROUBLE JUDGMENT
The A/C-ECU receives air conditioning operation-related signals from the audio via the CAN bus
lines. If any of the air conditioning control-related signals from the audio cannot be received, the diagnostic trouble code U0184 is stored.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• Connector(s) or wiring harness in the CAN bus
lines between the Audio and the A/C-ECU, the
power supply system to the Audio, the Audio
itself, or the A/C-ECU may be defective.
Past trouble
• If DTC U0184 is stored as a past trouble, carry
out diagnosis with particular emphasis on wiring
and connector(s) in the CAN bus line between
the A/C-ECU and the Audio, and the power supply system to the Audio. If the connectors and
wiring are normal, and obviously the ECU is the
cause of the trouble, replace the ECU. If in doubt,
do not replace the ECU.
NOTE: For a past trouble, you cannot find it by
the scan tool CAN bus diagnostics even if there is
a failure in CAN bus lines. In this case, refer to
GROUP 00, How to Use Troubleshooting/Inspection Service Points −How to Cope with Intermittent Malfunctions P.00-15) and check the CAN
bus lines. You can narrow down the possible
cause of the trouble by referring to the DTC,
which is set regarding the CAN communication-linked ECUs (Refer to GROUP 54C, Explanation about the scan too CAN bus diagnostics
P.54C-9).
.
TROUBLESHOOTING HINTS
• Malfunction of the Audio
• Malfunction of the A/C-ECU
• Damaged harness wires and connectors
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: V.C.I.
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
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55-86
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Using scan tool MB991958 read the Audio
diagnostic trouble code.
Check whether an audio DTCs are set or not.
(1) Turn the ignition switch to the "ON" position.
(2) Check for Audio DTCs.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Diagnose the Audio (Refer to GROUP 54A,
Diagnostic Trouble Code P.54A-322).
NO : Go to Step 3.
STEP 3. Using scan tool MB991958, check for any
diagnostic trouble code.
Check if a DTC, which relates to CAN communication-linked
systems below, is set.
• ETACS-ECU
DTC indicating a time-out error related to the Audio system
(1) Turn the ignition switch to the "ON" position.
(2) Check for a DTC related to the relevant system.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Go to Step 4.
NO : Go to Step 5.
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AUTO A/C DIAGNOSIS
55-87
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the Audio. On completion, check that the
DTC is not reset.
NO : There is an intermittent malfunction such as poor
engaged connector(s) or open circuit (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points −How to Cope with Intermittent
Malfunctions P.00-15.)
STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the A/C-ECU. On completion, check that the
DTC is not reset.
NO : There is an intermittent malfunction such as poor
engaged connector(s) or open circuit (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points −How to Cope with Intermittent
Malfunctions P.00-15.)
DTC U0195: Satellite radio tuner timeout
CAUTION
If DTC U0195 is set in the A/C-ECU, diagnose the
CAN main bus line.
CAUTION
Whenever the ECU is replaced, ensure that the
communication circuit is normal.
.
TROUBLE JUDGMENT
The A/C-ECU receives air conditioning operation-related signals from the satellite radio via the
CAN bus lines. If any of the air conditioning control-related signals from the satellite radio cannot be
received, the diagnostic trouble code U0195 is
stored.
.
TSB Revision
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• Connector(s) or wiring harness in the CAN bus
lines between the Satellite Radio and the
A/C-ECU, the power supply system to the Satellite Radio, the Satellite Radio itself, or the
A/C-ECU may be defective.
Past trouble
• If DTC U0195 is stored as a past trouble, carry
out diagnosis with particular emphasis on wiring
and connector(s) in the CAN bus line between
the A/C-ECU and the Satellite Radio, and the
power supply system to the Satellite Radio. If the
connectors and wiring are normal, and obviously
the ECU is the cause of the trouble, replace the
ECU. If in doubt, do not replace the ECU.
55-88
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
NOTE: For a past trouble, you cannot find it by
the scan tool CAN bus diagnostics even if there is
a failure in CAN bus lines. In this case, refer to
GROUP 00, How to Use Troubleshooting/Inspection Service Points −How to Cope with Intermittent Malfunctions P.00-15) and check the CAN
bus lines. You can narrow down the possible
cause of the trouble by referring to the DTC,
which is set regarding the CAN communication-linked ECUs (Refer to GROUP 54C, Explanation about the scan too CAN bus diagnostics
P.54C-9).
.
TROUBLESHOOTING HINTS
• Malfunction of the Satellite Radio
• Malfunction of the A/C-ECU
• Damaged harness wires and connectors
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: V.C.I.
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
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STEP 2. Using scan tool MB991958 read the Satellite Radio
diagnostic trouble code.
Check whether an satellite radio DTCs are set or not.
(1) Turn the ignition switch to the "ON" position.
(2) Check for Satellite Radio DTCs.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Diagnose the Satellite Radio (Refer to GROUP 54A,
Diagnostic Trouble Code).
NO : Go to Step 3.
STEP 3. Using scan tool MB991958, check for any
diagnostic trouble code.
Check if a DTC, which relates to CAN communication-linked
systems below, is set.
• ETACS-ECU
DTC indicating a time-out error related to the Satellite Radio
system
(1) Turn the ignition switch to the "ON" position.
(2) Check for a DTC related to the relevant system.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Go to Step 4.
NO : Go to Step 5.
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the Satellite Radio. On completion, check
that the DTC is not reset.
NO : There is an intermittent malfunction such as poor
engaged connector(s) or open circuit (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points −How to Cope with Intermittent
Malfunctions P.00-15.)
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HEATER, AIR CONDITIONING AND VENTILATION
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STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the A/C-ECU. On completion, check that the
DTC is not reset.
NO : There is an intermittent malfunction such as poor
engaged connector(s) or open circuit (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points −How to Cope with Intermittent
Malfunctions P.00-15.)
DTC U0197: Hands Free Module Time-out
CAUTION
If DTC U0197 is set in the A/C-ECU, diagnose the
CAN main bus line.
CAUTION
Whenever the ECU is replaced, ensure that the
communication circuit is normal.
.
TROUBLE JUDGMENT
The A/C-ECU receives the air conditioning control-related signals from the hands-free module via
the CAN bus lines. If any of the air conditioning control-related signals from the hands free module cannot be received, the diagnostic trouble code U0197 is
stored.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• Connector(s) or wiring harness in the CAN bus
lines between the hands free module and the
A/C-ECU, the power supply system to the hands
free module, the hands free module itself, or the
A/C-ECU may be defective.
Past trouble
• If DTC U0151 is stored as a past trouble, carry
out diagnosis with particular emphasis on wiring
and connector(s) in the CAN bus line between
the A/C-ECU and the hands free module, and the
power supply system to the hands free module. If
the connectors and wiring are normal, and obviously the ECU is the cause of the trouble, replace
the ECU. If in doubt, do not replace the ECU.
NOTE: For a past trouble, you cannot find it by
the scan tool CAN bus diagnostics even if there is
a failure in CAN bus lines. In this case, refer to
GROUP 00, How to Use Troubleshooting/Inspection Service Points −How to Cope with Intermittent Malfunctions P.00-15) and check the CAN
bus lines. You can narrow down the possible
cause of the trouble by referring to the DTC,
which is set regarding the CAN communication-linked ECUs (Refer to GROUP 54C, Explanation about the scan too CAN bus diagnostics
P.54C-9).
.
TROUBLESHOOTING HINTS
• Malfunction of the hands free module
• Malfunction of the A/C-ECU
• Damaged harness wires and connectors
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-91
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: V.C.I.
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Using scan tool MB991958 read the hands free
module diagnostic trouble code.
Check whether an hands free module DTCs are set or not.
(1) Turn the ignition switch to the "ON" position.
(2) Check for hands free module DTCs.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Diagnose the hands free module (Refer to GROUP
54A, Diagnostic Trouble Code).
NO : Go to Step 3.
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55-92
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 3. Using scan tool MB991958, check for any
diagnostic trouble code.
Check if a DTC, which relates to CAN communication-linked
systems below, is set.
• ETACS-ECU
DTC indicating a time-out error related to the hands free
module system
(1) Turn the ignition switch to the "ON" position.
(2) Check for a DTC related to the relevant system.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Go to Step 4.
NO : Go to Step 5.
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the SRS-ECU. On completion, check that
the DTC is not reset.
NO : There is an intermittent malfunction such as poor
engaged connector(s) or open circuit (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points −How to Cope with Intermittent
Malfunctions P.00-15.)
STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the A/C-ECU. On completion, check that the
DTC is not reset.
NO : There is an intermittent malfunction such as poor
engaged connector(s) or open circuit (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points −How to Cope with Intermittent
Malfunctions P.00-15.)
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-93
DTC U0245: Audio visual navigation unit CAN time-out
CAUTION
If DTC U0245 is set in the A/C-ECU, diagnose the
CAN main bus line.
CAUTION
Whenever the ECU is replaced, ensure that the
communication circuit is normal.
.
TROUBLE JUDGMENT
The A/C-ECU receives the air conditioning control-related signals from the hands-free module via
the CAN bus lines. If any of the air conditioning control-related signals from the audio visual navigation
unit cannot be received, the diagnostic trouble code
U0245 is stored.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
• Connector(s) or wiring harness in the CAN bus
lines between the audio visual navigation unit
and the A/C-ECU, the power supply system to
the audio visual navigation unit, the audio visual
navigation unit itself, or the A/C-ECU may be
defective.
Past trouble
• If DTC U0245 is stored as a past trouble, carry
out diagnosis with particular emphasis on wiring
and connector(s) in the CAN bus line between
the A/C-ECU and the audio visual navigation unit,
and the power supply system to the audio visual
navigation unit. If the connectors and wiring are
normal, and obviously the ECU is the cause of
the trouble, replace the ECU. If in doubt, do not
replace the ECU.
NOTE: For a past trouble, you cannot find it by
the scan tool CAN bus diagnostics even if there is
a failure in CAN bus lines. In this case, refer to
GROUP 00, How to Use Troubleshooting/Inspection Service Points −How to Cope with Intermittent Malfunctions P.00-15) and check the CAN
bus lines. You can narrow down the possible
cause of the trouble by referring to the DTC,
which is set regarding the CAN communication-linked ECUs (Refer to GROUP 54C, Explanation about the scan too CAN bus diagnostics
P.54C-9).
.
TROUBLESHOOTING HINTS
• Malfunction of the audio visual navigation unit
• Malfunction of the A/C-ECU
• Damaged harness wires and connectors
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: V.C.I.
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
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55-94
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C,
Diagnosis P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Using scan tool MB991958 read the audio visual
navigation unit diagnostic trouble code.
Check whether an audio visual navigation unit DTCs are set or
not.
(1) Turn the ignition switch to the "ON" position.
(2) Check for audio visual navigation unit DTCs.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Diagnose the audio visual navigation unit (Refer to
GROUP 54A, Diagnostic Trouble Code ).
NO : Go to Step 3.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-95
STEP 3. Using scan tool MB991958, check for any
diagnostic trouble code.
Check if a DTC, which relates to CAN communication-linked
systems below, is set.
• ETACS-ECU
DTC indicating a time-out error related to the audio visual
navigation unit system
(1) Turn the ignition switch to the "ON" position.
(2) Check for a DTC related to the relevant system.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Go to Step 4.
NO : Go to Step 5.
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the audio visual navigation unit. On
completion, check that the DTC is not reset.
NO : There is an intermittent malfunction such as poor
engaged connector(s) or open circuit (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points −How to Cope with Intermittent
Malfunctions P.00-15.)
STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the A/C-ECU. On completion, check that the
DTC is not reset.
NO : There is an intermittent malfunction such as poor
engaged connector(s) or open circuit (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points −How to Cope with Intermittent
Malfunctions P.00-15.)
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55-96
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
SYMPTOM CHART <Vehicles without A/C>
M1552009900774
CAUTION
During diagnosis, a DTC code associated with
other system may be set when the ignition switch
is turned on with connector(s) disconnected. On
completion, confirm all systems for DTC code(s).
If DTC code(s) are set, erase them all.
Symptom
Inspection
procedure
Reference
page
Malfunction of the A/C power supply system. <Vehicles without A/C>
1
P.55-97
Blower fan and motor do not turn. <Vehicles without A/C>
2
P.55-101
Blower air amount cannot be changed. <Vehicles without A/C>
3
P.55-106
Outside/inside air changeover is not possible. <Vehicles without A/C>
4
P.55-109
A/C outlet air temperature does not increase. <Vehicles without A/C>
5
P.55-112
Air outlet vent cannot be changed. <Vehicles without A/C>
6
P.55-114
Blower motor power supply system. <Vehicles without A/C>
7
P.55-117
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-97
SYMPTOM PROCEDURES <VEHICLES WITHOUT A/C>
INSPECTION PROCEDURE 1: Malfunction of the heater control unit Power Supply System. <Vehicles
without A/C>
Heater Control Unit Power Supply Circuit
FUSIBLE
LINK 36
IGNITION
SWITCH (IG1)
FUSIBLE
LINK 34
RELAYBOX
ENGINE
COMPARTMENT
ETACS
-ECU
IG1
RELAY
HEATER CONTROL
MODULE
POWER
SUPPLY
POWER
SUPPLY
AC901575
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55-98
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
Connector: C-53
Connector: C-317
Junction block
C-53 (B)
AC708972AB
AC708951CM
.
TECHNICAL DESCRIPTION (COMMENT)
The heater control module power system may be defective if
the air conditioning, defogger, and outside/inside air selection
damper motor all do not operate normally.
.
TROUBLESHOOTING HINTS
• Malfunction of the heater control module
• Damaged harness wires or connectors
DIAGNOSIS
Required Special Tool:
• MB991223: Test Harness Set
STEP 1. Check heater control module connector C-53 for
loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Is heater control module connector C-53 in good
condition?
YES : Go to Step 2.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2. Check
that the A/C works normally.
STEP 2. Measure the voltage at heater control module
connector C-53.
(1) Disconnect heater control module connector C-53 and
measure the voltage at the harness side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 15 and ground.
• The measured value should be approximately 12 volts
(battery positive voltage).
Connector C-53
(Harness side)
Q: Is the measured voltage approximately 12 volts?
YES : Go to Step 5.
NO : Go to Step 3.
AC608254 ER
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-99
STEP 3. Check ETACS-ECU connector C-317 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is ETACS-ECU connector C-317 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2. Check
that the A/C works normally.
STEP 4. Check the wiring harness between heater control
module connector C-53 (terminal 15) and ETACS-ECU
connector C-317 (terminal 5).
• Check the heater control module power supply line for open
circuit.
Q: Is the wiring harness between heater control module
connector C-53 (terminal 15) and ETACS-ECU connector
C-317 (terminal 5) in good condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
NO : Repair the wiring harness. Check that the A/C works
normally.
STEP 5. Measure the voltage at heater control module
connector C-53.
(1) Disconnect heater control module connector C-53 and
measure the voltage at the harness side.
(2) Measure the voltage between terminal 13 and ground.
• The measured value should be approximately 12 volts
(battery positive voltage).
Connector C-53
(Harness side)
Q: Is the measured voltage approximately 12 V?
YES : Go to Step 7.
NO : Go to Step 6.
AC608254 ES
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55-100
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 6. Check the wiring harness between heater control
module connector C-53 (terminal 13) and the fusible link
(36).
NOTE: Also check ETACS-ECU connectors C-307 and C-317
for loose, corroded, or damaged terminals, or terminals pushed
back in the connector. If ETACS-ECU connectors C-307 and
C-317 is damaged, repair or replace the connector as
described in GROUP 00E, Harness Connector Inspection
P.00E-2.
• Check the heater control module power supply line for open
circuit.
Q: Is the wiring harness between heater control module
connector C-53 (terminal 13) and the fusible link (36) in
good condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
NO : Repair the wiring harness. Check that the A/C works
normally.
STEP 7. Measure the resistance at heater control module
connector C-53.
(1) Disconnect heater control module connector C-53, and
measure at the wiring harness side.
(2) Measure the resistance between terminal 14 and ground.
• The measured value should be 2 ohms or less.
Connector C-53
(Harness side)
Q: Does the measured resistance value correspond with
this range?
YES : Replace the heater control module, and check that
the A/C works normally.
NO : Go to Step 8.
AC608255 DA
STEP 8. Check the wiring harness between heater control
module connector C-53 (terminal 14) and the ground.
• Check the heater control module ground line for open circuit.
Q: Is the wiring harness between heater control module
connector C-53 (terminal 14) and ground in good
condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
NO : Repair the wiring harness. Check that the A/C works
normally.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-101
INSPECTION PROCEDURE 2: Blower fan and motor do not turn. <Vehicles without A/C>
Blower Motor Circuit
FUSIBLE
LINK 37
ETACSECU
BLOWER
RELAY
BLOWER
MOTOR
POWER
TRANSISTOR
HEATER
CONTROL
MODULE
AC901584
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55-102
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
Connectors: C-53, C-115, C-119
C-53 (B)
C-119
C-115
AC708951CN
.
CIRCUIT OPERATION
If the blower motor does not operate, the blower relay system is
suspected.
.
TROUBLESHOOTING HINTS
•
•
•
•
Malfunction of the power transistor
Malfunction of the blower motor
Malfunction of the heater control module
Damaged harness wires or connectors
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
STEP 1. Check blower motor connector C-115 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is blower motor connector C-115 in good condition?
YES : Go to Step 2.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.The
blower motor should operate normally.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-103
STEP 2. Measure the voltage at blower motor connector
C-115.
(1) Disconnect blower motor connector C-115, and measure
the voltage at the wiring harness side.
(2) Turn the ignition switch to the "ON" position.
(3) Turn the blower switch to the "Maximum air volume"
position.
(4) Measure the voltage between terminal 1 and ground.
• The measured value should be approximately 12 volts
(battery positive voltage).
Connector C-115
(Harness side)
Q: Is the measured voltage approximately 12 volts?
YES : Go to Step 3.
NO : Refer to Inspection procedure 9, "Blower motor power
supply system P.55-117."
AC608254 CO
STEP 3. Check blower motor connector C-115 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is blower motor connector C-115 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.The
blower motor should operate normally.
STEP 4. Check the blower fan and motor operation.
Check that the motor turns when applying battery power
between the connector terminals. Also check to see that there
is no abnormal sound emitted from the motor at this time.
Q: Is there any abnormal noise?
YES : Go to Step 5.
NO : Replace the blower relay. The blower motor should
operate normally.
AC611918AC
STEP 5. Check heater control module connector C-53 for
loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Is heater control module connector C-53 in good
condition?
YES : Go to Step 6.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.The
blower motor should operate normally.
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55-104
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 6. Check the wiring harness between heater control
module connector C-53 (terminal 1) and blower motor
connector C-115 (terminal 2).
• Check the heater control module signal line for open and
short circuit.
Q: Is the wiring harness between heater control module
connector C-53 (terminal 1) and blower motor connector
C-115 (terminal 2) in good condition?
YES : Go to Step 7.
NO : Repair the wiring harness. The blower motor should
operate normally.
STEP 7. Check power transistor connector C-119 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is power transistor connector C-119 in good condition?
YES : Go to Step 8.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.The
blower motor should operate normally.
STEP 8. Measure the resistance at power transistor
connector C-119.
(1) Disconnect power transistor connector C-119, and measure
the resistance at the wiring harness side.
(2) Measure the resistance value between terminal 1 and
ground.
OK: The measured value should be 2 ohms or less
Connector C-119
(Harness side)
Q: Does the measured resistance value correspond with
this range?
YES : Go to Step 10.
NO : Go to Step 9.
AC608255 BS
STEP 9. Check the wiring harness between power
transistor connector C-119 (terminal 1) and ground.
• Check the power transistor ground line for open circuit.
Q: Is the wiring harness between power transistor
connector C-119 (terminal 1) and ground in good
condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
NO : Repair the wiring harness. The blower motor should
operate normally.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-105
STEP 10. Check the wiring harness between heater control
module connector C-53 (terminals 1 and 2) and power
transistor connector C-119 (terminals 2 and 4).
• Check the heater control module signal line for open and
short circuit.
Q: Is the wiring harness between heater control module
connector C-53 (terminals 1 and 2) and power transistor
connector C-119 (terminals 2 and 4) in good condition?
YES : Go to Step 11.
NO : Repair the wiring harness. The blower motor should
operate normally.
STEP 11. Replace the power transistor and check the
trouble symptom again
Check the trouble symptom again.
Q: Is the check result satisfactory?
YES : The procedure is complete.
NO : Replace the heater control module.
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55-106
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
INSPECTION PROCEDURE 3: Blower air amount cannot be changed. <Vehicles without A/C>
Blower Motor Circuit
FUSIBLE
LINK 37
ETACSECU
BLOWER
RELAY
BLOWER
MOTOR
POWER
TRANSISTOR
HEATER
CONTROL
MODULE
AC901584
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-107
Connectors: C-53, C-119
C-53 (B)
C-119
AC708951CO
.
CIRCUIT OPERATION
If the blower motor speed cannot be changed, the power transistor circuit is suspected.
.
TROUBLESHOOTING HINTS
• Malfunction of the power transistor
• Malfunction of the heater control module
• Damaged harness wires or connectors
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
STEP 1. Check power transistor connector C-119 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is power transistor connector C-119 in good condition?
YES : Go to Step 2.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.The
blower motor should operate normally.
STEP 2. Measure the resistance at power transistor
connector C-119.
(1) Disconnect power transistor connector C-119, and measure
the resistance at the wiring harness side.
(2) Measure the resistance value between terminal 1 and
ground.
OK: The measured value should be 2 ohms or less
Q: Does the measured resistance value correspond with
this range?
YES : Go to Step 4.
NO : Go to Step 3.
Connector C-119
(Harness side)
AC608255 BT
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55-108
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 3. Check the wiring harness between power
transistor connector C-119 (terminal 1) and ground.
• Check the power transistor ground line for open circuit.
Q: Is the wiring harness between power transistor
connector C-119 (terminal 1) and ground in good
condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
NO : Repair the wiring harness. The blower motor should
operate normally.
STEP 4. Check heater control module connector C-53 for
loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Is heater control module connector C-53 in good
condition?
YES : Go to Step 5.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.The
blower motor should operate normally.
STEP 5. Check the wiring harness between heater control
module connector C-53 (terminals 1 and 2) and power
transistor connector C-119 (terminals 2 and 4).
• Check the heater control module signal line for open and
short circuit.
Q: Is the wiring harness between heater control module
connector C-53 (terminals 1 and 2) and power transistor
connector C-119 (terminals 2 and 4) in good condition?
YES : Go to Step 6.
NO : Repair the wiring harness. The blower motor should
operate normally.
STEP 6. Replace the power transistor and check the
trouble symptom again
Check the trouble symptom again.
Q: Is the check result satisfactory?
YES : The procedure is complete.
NO : Replace the heater control module.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-109
INSPECTION PROCEDURE 4: Outside/inside air changeover is not possible <Vehicles without A/C>
Outside/Inside Damper Control Motor Circuit
HEATER
CONTROL
MODULE
OUTSIDE/INSIDE AIR
SELECTION DAMPER
CONTROL MOTOR
AC901585
Connectors: C-52, C-111
C-111
C-52 (B)
AC708951CP
.
CIRCUIT OPERATION
If the outside/inside air selection damper control motor does not
operate normally, the outside/inside air selection damper control motor system may be defective.
.
TROUBLESHOOTING HINTS
• Malfunction of the outside/inside air selection damper control motor
• Malfunction of the heater control module
• Damaged harness wires or connectors
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55-110
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: V.C.I.
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, check for diagnostic
trouble code.
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
Check if an heater control module DTC is set.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the DTC set?
YES : Refer to DIAGNOSTIC TROUBLE CODE CHART
P.55-10.
NO : Go to Step 2.
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Check outside/inside air selection damper control
motor connector C-111 and heater control module
connector C-52 for loose, corroded or damaged terminals,
or terminals pushed back in the connector.
Q: Are outside/inside air selection damper control motor
connector C-111 and heater control module connector
C-52 in good condition?
YES : Go to Step 3.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2. Check
that the A/C works normally.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-111
STEP 3. Check the wiring harness between heater control
module connector C-52 (terminal 26, 25, 27, 24 and 29) and
outside/inside air selection damper control motor
connector C-111 (terminals 2, 5, 4. 1 and 3).
• Check the heater control module signal line for open and
short circuit.
Q: Are the wiring harness between heater control module
connector C-52 (terminal 26, 25, 27, 24 and 29) and
outside/inside air selection damper control motor
connector C-111 (terminals 2, 5, 4. 1 and 3) in good
condition?
YES : Go to Step 4.
NO : Repair the wiring harness. Check that the A/C works
normally.
STEP 4. Replace the outside/inside air selection damper
control motor and check the trouble symptom again
Check the trouble symptom again.
Q: Is the check result satisfactory?
YES : The procedure is complete.
NO : Replace the heater control module.
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55-112
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
INSPECTION PROCEDURE 5: A/C outlet air temperature does not increase <Vehicles without A/C>
Air Mixing Damper Control Motor Circuit
HEATER
CONTROL
MODULE
AIR MIXING
DAMPER CONTROL
MOTOR
AC901599
Connectors: C-52, C-114
C-52 (B)
C-114
AC708951CQ
.
CIRCUIT OPERATION
If the air outlet temperature cannot be adjusted, the air mixing
damper control motor circuit may be failed.
.
TROUBLESHOOTING HINTS
• Malfunction of the air mixing damper control motor
• Malfunction of the heater control module
• Damaged harness wires or connectors
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-113
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: V.C.I.
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, check for diagnostic
trouble code.
Check if an heater control module DTC is set.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the DTC set?
YES : Refer to DIAGNOSTIC TROUBLE CODE CHART
P.55-96.
NO : Go to Step 2.
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Check air mixing damper control motor connector
C-114 and heater control module connector C-52 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Are air mixing damper control motor connector C-114
and heater control module connector C-52 in good
condition?
YES : Go to Step 3.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2. Check
that the A/C works normally.
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55-114
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 3. Check the wiring harness between heater control
module connector C-52 (terminal 29, 35, 36, 34 and 28) and
air mixing damper control motor connector C-114
(terminals 3, 2, 5. 4 and 1).
• Check the heater control module signal line for open and
short circuit.
Q: Are the wiring harness between heater control module
connector C-52 (terminal 29, 35, 36, 34 and 28) and air
mixing damper control motor connector C-114
(terminals 3, 2, 5. 4 and 1) in good condition?
YES : Go to Step 4.
NO : Repair the wiring harness. Check that the A/C works
normally.
STEP 4. Replace the air mixing damper control motor and
check the trouble symptom again
Check the trouble symptom again.
Q: Is the check result satisfactory?
YES : The procedure is complete.
NO : Replace the heater control module.
INSPECTION PROCEDURE 6: Air outlet vent cannot be changed. <Vehicles without A/C>
Mode Selection Damper Control Motor Circuit
HEATER
CONTROL
MODULE
MODE SELECTION
DAMPER CONTROL
MOTOR
AC901600
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-115
Connectors: C-52, C-112
C-52 (B)
C-112
AC708951CR
.
CIRCUIT OPERATION
If the air outlet cannot be switched, the mode selection damper
control motor circuit may be failed.
.
TROUBLESHOOTING HINTS
• Malfunction of the mode selection damper control motor
• Malfunction of the heater control module
• Damaged harness wires or connectors
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: V.C.I.
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, check for diagnostic
trouble code.
Check if an heater control module DTC is set.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the DTC set?
YES : Refer to DIAGNOSTIC TROUBLE CODE CHART
P.55-10.
NO : Go to Step 2.
MB991910
MB991824
MB991827
AC608435 AB
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55-116
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 2. Check mode selection damper control motor
connector C-112 and heater control module connector
C-52 for loose, corroded or damaged terminals, or
terminals pushed back in the connector.
Q: Are mode selection damper control motor connector
C-112 and heater control module connector C-52 in
good condition?
YES : Go to Step 3.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2. Check
that the A/C works normally.
STEP 3. Check the wiring harness between heater control
module connector C-52 (terminal 29, 31, 32, 30 and 33) and
mode selection damper control motor connector C-112
(terminals 3, 2, 5, 4 and 1).
• Check the heater control module signal line for open and
short circuit.
Q: Are the wiring harness between heater control module
connector C-52 (terminal 29, 31, 32, 30 and 33) and
mode selection damper control motor connector C-112
(terminals 3, 2, 5, 4 and 1) in good condition?
YES : Go to Step 4.
NO : Repair the wiring harness. Check that the A/C works
normally.
STEP 4. Replace the mode selection damper control motor
and check the trouble symptom again
Check the trouble symptom again.
Q: Is the check result satisfactory?
YES : The procedure is complete.
NO : Replace the heater control module.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-117
INSPECTION PROCEDURE 7: Blower motor power supply system. <Vehicles without A/C>
Blower Motor Circuit
FUSIBLE
LINK 37
ETACSECU
BLOWER
RELAY
BLOWER
MOTOR
POWER
TRANSISTOR
HEATER
CONTROL
MODULE
AC901604
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55-118
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
Connector: C-115
Connectors: C-303, C-309, C-315
ETACS-ECU
C-303
C-315
C-309 (B)
AC708972AT
AC708951AU
.
TECHNICAL DESCRIPTION (COMMENT)
If the voltage is not supplied to the blower motor, the blower
relay system may be failed.
.
TROUBLESHOOTING HINTS
• Malfunction of the ETACS-ECU
• Malfunction of the blower relay
• Damaged harness wires or connectors
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
STEP 1. Check blower relay connector C-303 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is blower relay connector C-303 in good condition?
YES : Go to Step 2.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
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55-119
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 2. Check the blower relay continuity.
Follow the table below to check the blower relay for continuity.
Blower relay
1
2
3
4
AC605627
4
3
1
2
Battery voltage
Tester connection Specified
condition
Not applied
3 −4
• Connect
3 −4
terminal 1 to the
positive battery
terminal
• Connect
terminal 2 to the
negative battery
terminal
Open circuit
Less than 2 ohms
Q: Is the blower relay in good condition?
YES : Go to Step 3.
NO : Replace the rear window defogger relay.
AC609984AB
STEP 3. Measure the voltage at blower relay connector
C-303.
(1) Disconnect blower relay connector C-303, and measure the
voltage at the junction block side.
(2) Measure the voltage between terminals 1 and ground.
• The measured value should be approximately 12 volts
(battery positive voltage).
Connector C-303
(Junction block side)
AC608254 AW
(3) Measure the voltage between terminals 4 and ground.
• The measured value should be approximately 12 volts
(battery positive voltage).
Connector C-303
(Junction block side)
Q: Is the measured voltage approximately 12 volts?
YES : Go to Step 5.
NO : Go to Step 4.
AC608254 AX
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 4. Check the wiring harness between blower relay
connector C-303 (terminals 1 and 4) and the fusible link
(37).
NOTE: Also check ETACS-ECU connector C-309 for loose,
corroded, or damaged terminals, or terminals pushed back in
the connector. If ETACS-ECU connector C-309 is damaged,
repair or replace the connector as described in GROUP 00E,
Harness Connector Inspection P.00E-2.
• Check the blower relay power supply line for open circuit.
Q: Is the wiring harness between blower relay connector
C-303 (terminals 1 and 4) and the fusible link (37) in
good condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
NO : Repair or replace the wiring harness. Refer to
GROUP 00E, Harness Connector Inspection
P.00E-2.
STEP 5. Check blower relay connector C-115 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is blower relay connector C-115 in good condition?
YES : Go to Step 6.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
STEP 6. Check the wiring harness between blower relay
connector C-303 (terminal 3) and blower motor connector
C-115 (terminal 1).
NOTE: Also check ETACS-ECU connector C-315 for loose,
corroded, or damaged terminals, or terminals pushed back in
the connector. If ETACS-ECU connector C-315 is damaged,
repair or replace the connector as described in GROUP 00E,
Harness Connector Inspection P.00E-2.
• Check the blower motor power supply line for open circuit.
Q: Is the wiring harness between blower relay connector
C-303 (terminal 3) and blower motor connector C-115
(terminal 1) in good condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
NO : Repair or replace the wiring harness. Refer to
GROUP 00E, Harness Connector Inspection
P.00E-2.
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55-121
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
SYMPTOM CHART
M1552009900729
CAUTION
During diagnosis, a DTC code associated with
other system may be set when the ignition switch
is turned on with connector(s) disconnected. On
completion, confirm all systems for DTC code(s).
If DTC code(s) are set, erase them all.
Symptom
Inspection
procedure
Reference
page
When the A/C is operation, temperature inside the passenger
compartment does not decrease (Cool air is not emitted).
1
P.55-121
Malfunction of the A/C-ECU power supply system.
2
P.55-124
The compressor does not work.
3
P.55-128
Blower fan and motor do not turn.
4
P.55-135
Blower air amount cannot be changed.
5
P.55-140
Outside/inside air changeover is not possible.
6
P.55-143
A/C outlet air temperature does not increase.
7
P.55-146
Air outlet vent cannot be changed.
8
P.55-148
Blower motor power supply system.
9
P.55-151
SYMPTOM PROCEDURES
INSPECTION PROCEDURE 1: When the A/C is Operation, Temperature Inside the Passenger
Compartment does not Decrease (Cool Air is not Emitted).
.
.
TECHNICAL DESCRIPTION (COMMENT)
TROUBLESHOOTING HINTS
The blower system or the compressor system may
be defective if there is no cool air coming from the
vents.
• Malfunction of blower motor
• Malfunction of A/C-ECU
• Malfunction of A/C compressor
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55-122
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
DIAGNOSIS
STEP 1. Using scan tool MB991958, read the diagnostic
trouble code.
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
Check if an A/C-ECU DTC is set.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the DTC set?
YES : Refer to Diagnostic Trouble Code Chart P.55-10.
NO : Go to Step 2.
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Check that the blower motor operation when the
blower knob is moved to the "Maximum air volume"
position.
(1) Turn the ignition switch to the "ON" position.
(2) Turn the blower knob to the "Maximum air volume" position
Q: Does the blower motor operate when the blower knob is
moved to the "Maximum air volume" position?
YES : Go to Step 3.
NO : Refer to Inspection procedure 4 "Blower fan and
motor do not turn P.55-101."
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-123
STEP 3. Check the rear window defogger and
outside/inside air selection damper control motor
operation.
(1) Turn the ignition switch to the "ON" position.
(2) Check the engine running.
(3) Check the operations of rear window defogger and
outside/inside air selection damper control motor.
Q: Do the rear window defogger and outside/inside air
selection damper control motor work normally?
YES : Refer to Inspection procedure 3 "The A/C compressor
does not Work P.55-128."
NO : Refer to Inspection procedure 2, "Malfunction of the
A/C-ECU power supply system P.55-124."
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55-124
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
INSPECTION PROCEDURE 2: Malfunction of the A/C-ECU Power Supply System.
A/C-ECU Power Supply Circuit
FUSIBLE
LINK 36
IGNITION
SWITCH (IG1)
FUSIBLE
LINK 34
RELAY BOX
(ENGINE
COMPARTMENT)
ETACS
-ECU
IG1
RELAY
A/C-ECU
POWER
SUPPLY
POWER
SUPPLY
AC708617
Connector: C-22
Connector: C-317
Junction block
C-22 (B)
AC708951AO
.
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AC708972AB
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-125
TECHNICAL DESCRIPTION (COMMENT)
The A/C-ECU power system may be defective if the air conditioning, defogger, and outside/inside air selection damper
motor all do not operate normally.
.
TROUBLESHOOTING HINTS
• Malfunction of the A/C-ECU
• Damaged harness wires or connectors
DIAGNOSIS
Required Special Tool:
• MB991223: Test Harness Set
STEP 1. Check A/C-ECU connector C-22 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is A/C-ECU connector C-22 in good condition?
YES : Go to Step 2.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2. Check
that the A/C works normally.
STEP 2. Measure the voltage at A/C-ECU connector C-22.
(1) Disconnect A/C-ECU connector C-22 and measure the
voltage at the harness side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 15 and ground.
• The measured value should be approximately 12 volts
(battery positive voltage).
Connector C-22
(Harness side)
Q: Is the measured voltage approximately 12 volts?
YES : Go to Step 5.
NO : Go to Step 3.
AC608254 CJ
STEP 3. Check ETACS-ECU connector C-317 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is ETACS-ECU connector C-317 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2. Check
that the A/C works normally.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 4. Check the wiring harness between A/C-ECU
connector C-22 (terminal 15) and ETACS-ECU connector
C-317 (terminal 5).
• Check the A/C-ECU power supply line for open circuit.
Q: Is the wiring harness between A/C-ECU connector C-22
(terminal 15) and ETACS-ECU connector C-317 (terminal
5) in good condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
NO : Repair the wiring harness. Check that the A/C works
normally.
STEP 5. Measure the voltage at A/C-ECU connector C-22.
(1) Disconnect A/C-ECU connector C-22 and measure the
voltage at the harness side.
(2) Measure the voltage between terminal 13 and ground.
• The measured value should be approximately 12 volts
(battery positive voltage).
Connector C-22
(Harness side)
Q: Is the measured voltage approximately 12 V?
YES : Go to Step 7.
NO : Go to Step 6.
AC608254 CK
STEP 6. Check the wiring harness between A/C-ECU
connector C-22 (terminal 13) and the fusible link (36).
NOTE: Also check ETACS-ECU connectors C-307 and C-317
for loose, corroded, or damaged terminals, or terminals pushed
back in the connector. If ETACS-ECU connectors C-307 and
C-317 is damaged, repair or replace the connector as
described in GROUP 00E, Harness Connector Inspection
P.00E-2.
• Check the A/C-ECU power supply line for open circuit.
Q: Is the wiring harness between A/C-ECU connector C-22
(terminal 13) and the FUSIBLE LINK (36) in good
condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
NO : Repair the wiring harness. Check that the A/C works
normally.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-127
STEP 7. Measure the resistance at A/C-ECU connector
C-22.
(1) Disconnect A/C-ECU connector C-22, and measure at the
wiring harness side.
(2) Measure the resistance between terminal 14 and ground.
• The measured value should be 2 ohms or less.
Connector C-22
(Harness side)
Q: Does the measured resistance value correspond with
this range?
YES : Replace the A/C-ECU, and check that the A/C works
normally.
NO : Go to Step 8.
AC608255 BR
STEP 8. Check the wiring harness between A/C-ECU
connector C-22 (terminal 14) and the ground.
• Check the A/C-ECU ground line for open circuit.
Q: Is the wiring harness between A/C-ECU connector C-22
(terminal 14) and ground in good condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
NO : Repair the wiring harness. Check that the A/C works
normally.
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55-128
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
INSPECTION PROCEDURE 3: The Compressor does not Work.
A/C Compressor Assembly Circuit
FUSIBLE
LINK 36
RELAY
BOX
A/C
COMPRESSOR
CLUTCH RELAY
ENGINE CONTROL MODULE
A/C
REFRIGERANT
TEMPERATURE
SWITCH
A/C
COMPRESSOR
ASSEMBLY
A/C
COMPRESSOR
CLUTCH
AC708618
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
Connector: A-17X
55-129
Connector: B-110
C-110 (GR)
AC709111AB
AC709136 AB
Connector: B-10
C-10 (GR)
AC709137AB
.
FUNCTION
Compressor that recovers the refrigerant, which evaporated in
the evaporator and became a high-temperature and high-pressure gas, and turns it into liquid again.
.
PROBABLE CAUSES
• Insufficient refrigerant
• Malfunction of connector.
• Malfunction of the harness (A/C compressor circuit is
open/shorted to ground)
• Malfunction of the A/C pressure sensor.
• Malfunction of the A/C compressor.
• Malfunction of the A/C compressor clutch relay.
• Malfunction of the A/C-ECU.
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
• MB991658: Test Harness Set
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: V.C.I.
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
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55-130
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line.
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus lines (Refer to GROUP 54C,
precautions on how to repair the CAN bus lines
P.54C-15).
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Using scan tool MB991958, read the diagnostic
trouble code.
Check if an A/C-ECU DTC is set.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Refer to Diagnostic Trouble Code Chart P.55-10.
NO : Go to Step 3.
STEP 3. Check A/C compressor assembly connector B-110
for loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Is A/C compressor assembly connector B-110 in good
condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-131
STEP 4. Check the A/C compressor clutch operation.
Connect the compressor connector terminal to the battery positive (+) terminal and ground the battery’s negative (-) terminal
to the compressor unit. At that time, the A/C compressor clutch
should make a definite operating sound.
Q: Can the sound (click) of the A/C compressor clutch
operation be heard?
YES : Go to Step 5.
NO : Replace the compressor magnet clutch.
AC506471
STEP 5. Check A/C compressor clutch relay connector
A-17X for loose, corroded or damaged terminals, or
terminals pushed back in the connector.
Q: Is A/C compressor clutch relay connector A-17X in good
condition?
YES : Go to Step 6.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
STEP 6. Check the A/C compressor clutch relay continuity.
Follow the table below to check the A/C compressor clutch
relay for continuity.
AC605626
A/C compressor clutch relay
1
2
3
4
4
3
2
1
Battery voltage
Tester connection Specified
condition
Not applied
3 −4
• Connect
3 −4
terminal 2 to the
positive battery
terminal
• Connect
terminal 1 to the
negative battery
terminal
Open circuit
Less than 2 ohms
Q: Is the A/C compressor clutch relay in good condition?
YES : Go to Step 7.
NO : Replace the A/C compressor clutch relay.
AC609971AB
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AUTO A/C DIAGNOSIS
STEP 7. Check engine control module connector B-10 for
loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Is engine control module connector B-10 in good
condition?
YES : Go to Step 8.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
STEP 8. Measure the voltage at A/C compressor assembly
connector B-10.
(1) Disconnect A/C compressor assembly connector B-10 and
measure the voltage at the wiring harness side.
(2) Disconnect engine control module connector B-10 and
ground harness side terminal No.102.
(3) Turn the ignition switch to the "ON" position.
(4) A/C compressor assembly connector B-110 terminal 1 and
ground.
• The measured value should be approximately 12 volts
(battery positive voltage).
Connector B-110
(Harness side)
Q: Is the measured voltage approximately 12 volts?
YES : Go to Step 13.
NO : Go to Step 9.
AC608254 CM
STEP 9. Measure the voltage at A/C compressor clutch
relay connector A-17X.
(1) Disconnect A/C compressor connector A-17X and measure
the voltage at the relay box side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 4 and ground.
• The measured value should be approximately 12 volts
(battery positive voltage).
(4) Measure the voltage between terminal 2 and ground.
• The measured value should be approximately 12 volts
(battery positive voltage).
Connector A-17X
(Harness side)
Q: Is the measured voltage approximately 12 volts?
YES : Go to Step 11.
NO : Go to Step 10.
AC608254 CN
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STEP 10. Check the wiring harness between A/C
compressor clutch relay connector A-17X (terminals 2 and
4) and the fusible link (36).
• Check the A/C compressor clutch relay power supply line
for open circuit.
Q: Is the wiring harness between A/C compressor clutch
relay connector A-17X (terminals 2 and 4) and the
fusible link (36) in good condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
NO : Repair the wiring harness. Check that the A/C works
normally.
STEP 11. Check the wiring harness between A/C
compressor clutch relay connector A-17X (terminal 3) and
A/C compressor assembly connector B-110 (terminal 1).
• Check the A/C compressor assembly power supply line for
open circuit.
Q: Is the wiring harness between A/C compressor clutch
relay connector A-17X (terminal 3) and A/C compressor
assembly connector B-110 (terminal 1) in good
condition?
YES : Go to Step 12.
NO : Repair the wiring harness. Check that the A/C works
normally.
STEP 12. Check the wiring harness between engine
control module connector B-10 (terminal 102) and A/C
compressor clutch relay connector A-17X (terminal 1).
• Check the powertrain control module signal line for open
and short circuit.
Q: Is the wiring harness between engine control module
connector B-10 (terminal 102) and A/C compressor
clutch relay connector A-17X (terminal 1) in good
condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
NO : Repair the wiring harness. Check that the A/C works
normally.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 13. Check the refrigerant temperature switch.
CAUTION
Do not heat more than necessary.
(1) Dip the metal part of the cooling temperature switch into
engine oil and increase the oil temperature using a gas
burner or similar.
Thermometer
Engine oil
AC100787AG
125˚C
(257˚F)
155˚C
(311˚F)
(2) When the oil temperature reaches the standard value,
check that resistance is supplied between the terminals.
Standard value:
Less than 2Ω
No continuity
OIL TEMPERATURE
Item
Temperature
Less than 2 ohms
Slightly below 125° C (257° F)
No continuity
155° C (311° F) or more
NOTE: When the oil temperature is 155° C (311° F) or more
and there is no continuity, the resistance will not be 2Ω or
lower until the oil temperature reduces to 125° C (257° F) or
less.
AC100810AV
Q: Is the refrigerant temperature switch operating
properly?
YES : Go to Step 14.
NO : Replace the refrigerant temperature switch. Check
that the A/C works normally.
STEP 14. Replace the A/C-ECU.
Q: Does the A/C operate normally?
YES : No action is necessary and testing is complete.
NO : Replace the engine control module. Check that the
A/C works normally.
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INSPECTION PROCEDURE 4: Blower Fan and Motor do not Turn.
Blower Motor Circuit
FUSIBLE
LINK 37
ETACSECU
BLOWER
RELAY
BLOWER
MOTOR
POWER
TRANSISTER
A/C-ECU
AC708621
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
Connectors: C-22, C-115, C-119
C-22 (B)
C-119
C-115
AC708951AP
.
CIRCUIT OPERATION
If the blower motor does not operate, the blower relay system is
suspected.
.
TROUBLESHOOTING HINTS
•
•
•
•
Malfunction of the power transistor
Malfunction of the blower motor
Malfunction of the A/C-ECU
Damaged harness wires or connectors
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
STEP 1. Check blower motor connector C-115 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is blower motor connector C-115 in good condition?
YES : Go to Step 2.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.The
blower motor should operate normally.
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STEP 2. Measure the voltage at blower motor connector
C-115.
(1) Disconnect blower motor connector C-115, and measure
the voltage at the wiring harness side.
(2) Turn the ignition switch to the "ON" position.
(3) Turn the blower switch to the "Maximum air volume"
position.
(4) Measure the voltage between terminal 1 and ground.
• The measured value should be approximately 12 volts
(battery positive voltage).
Connector C-115
(Harness side)
Q: Is the measured voltage approximately 12 volts?
YES : Go to Step 3.
NO : Refer to Inspection procedure 9, "Blower motor power
supply system P.55-151."
AC608254 CO
STEP 3. Check blower motor connector C-115 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is blower motor connector C-115 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.The
blower motor should operate normally.
STEP 4. Check the blower fan and motor operation.
Check that the motor turns when applying battery power
between the connector terminals. Also check to see that there
is no abnormal sound emitted from the motor at this time..
Q: Is there any abnormal noise?
YES : Go to Step 5.
NO : Replace the blower relay. The blower motor should
operate normally.
AC611918AC
STEP 5. Check A/C-ECU connector C-22 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is A/C-ECU connector C-22 in good condition?
YES : Go to Step 6.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.The
blower motor should operate normally.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 6. Check the wiring harness between A/C-ECU
connector C-22 (terminal 1) and blower motor connector
C-115 (terminal 2).
• Check the A/C-ECU signal line for open and short circuit.
Q: Is the wiring harness between A/C-ECU connector C-22
(terminal 1) and blower motor connector C-115 (terminal
2) in good condition?
YES : Go to Step 7.
NO : Repair the wiring harness. The blower motor should
operate normally.
STEP 7. Check power transistor connector C-119 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is power transistor connector C-119 in good condition?
YES : Go to Step 8.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.The
blower motor should operate normally.
STEP 8. Measure the resistance at power transistor
connector C-119.
(1) Disconnect power transistor connector C-119, and measure
the resistance at the wiring harness side.
(2) Measure the resistance value between terminal 1 and
ground.
OK: The measured value should be 2 ohms or less
Connector C-119
(Harness side)
Q: Does the measured resistance value correspond with
this range?
YES : Go to Step 10.
NO : Go to Step 9.
AC608255 BS
STEP 9. Check the wiring harness between power
transistor connector C-119 (terminal 1) and ground.
• Check the power transistor ground line for open circuit.
Q: Is the wiring harness between power transistor
connector C-119 (terminal 1) and ground in good
condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
NO : Repair the wiring harness. The blower motor should
operate normally.
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AUTO A/C DIAGNOSIS
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STEP 10. Check the wiring harness between A/C-ECU
connector C-22 (terminals 1 and 2) and power transitor
connector C-119 (terminals 2 and 4).
• Check the A/C-ECU signal line for open and short circuit.
Q: Is the wiring harness between A/C-ECU connector C-22
(terminals 1 and 2) and power transistor connector
C-119 (terminals 2 and 4) in good condition?
YES : Go to Step 11.
NO : Repair the wiring harness. The blower motor should
operate normally.
STEP 11. Replace the power transistor and check the
trouble symptom again
Check the trouble symptom again.
Q: Is the check result satisfactory?
YES : The procedure is complete.
NO : Replace the A/C-ECU.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
INSPECTION PROCEDURE 5: Blower Air Amount cannot be Changed.
Blower Motor Circuit
FUSIBLE
LINK 37
ETACSECU
BLOWER
RELAY
BLOWER
MOTOR
POWER
TRANSISTER
A/C-ECU
AC708621
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-141
Connectors: C-22, C-119
C-22 (B)
C-119
AC708951AQ
.
CIRCUIT OPERATION
If the blower motor speed cannot be changed, the power transistor circuit is suspected.
.
TROUBLESHOOTING HINTS
• Malfunction of the power transistor
• Malfunction of the A/C-ECU
• Damaged harness wires or connectors
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
STEP 1. Check power transistor connector C-119 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is power transistor connector C-119 in good condition?
YES : Go to Step 2.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.The
blower motor should operate normally.
STEP 2. Measure the resistance at power transistor
connector C-119.
(1) Disconnect power transistor connector C-119, and measure
the resistance at the wiring harness side.
(2) Measure the resistance value between terminal 1 and
ground.
OK: The measured value should be 2 ohms or less
Q: Does the measured resistance value correspond with
this range?
YES : Go to Step 4.
NO : Go to Step 3.
Connector C-119
(Harness side)
AC608255 BT
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 3. Check the wiring harness between power
transistor connector C-119 (terminal 1) and ground.
• Check the power transistor ground line for open circuit.
Q: Is the wiring harness between power transistor
connector C-119 (terminal 1) and ground in good
condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
NO : Repair the wiring harness. The blower motor should
operate normally.
STEP 4. Check A/C-ECU connector C-22 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is A/C-ECU connector C-22 in good condition?
YES : Go to Step 5.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.The
blower motor should operate normally.
STEP 5. Check the wiring harness between A/C-ECU
connector C-22 (terminals 1 and 2) and power transistor
connector C-119 (terminals 2 and 4).
• Check the A/C-ECU signal line for open and short circuit.
Q: Is the wiring harness between A/C-ECU connector C-22
(terminals 1 and 2) and power transistor connector
C-119 (terminals 2 and 4) in good condition?
YES : Go to Step 6.
NO : Repair the wiring harness. The blower motor should
operate normally.
STEP 6. Replace the power transistor and check the
trouble symptom again
Check the trouble symptom again.
Q: Is the check result satisfactory?
YES : The procedure is complete.
NO : Replace the A/C-ECU.
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55-143
INSPECTION PROCEDURE 6: Outside/Inside Air Changeover is not possible.
Outside/Inside Damper Control Motor Circuit
A/C-ECU
OUTSIDE/INSIDE AIR
SELECTION DAMPER
CONTROL MOTOR
AC708622
Connectors: C-20, C-111
C-111
C-20 (B)
AC708951AR
.
CIRCUIT OPERATION
If the outside/inside air selection damper control motor does not
operate normally, the outside/inside air selection damper control motor system may be defective.
.
TROUBLESHOOTING HINTS
• Malfunction of the outside/inside air selection damper control motor
• Malfunction of the A/C-ECU
• Damaged harness wires or connectors
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55-144
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: V.C.I.
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, check for diagnostic
trouble code.
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
Check if an A/C-ECU DTC is set.
(1) Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55-7."
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the DTC set?
YES : Refer to DIAGNOSTIC TROUBLE CODE CHART
P.55-10.
NO : Go to Step 2.
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Check outside/inside air selection damper control
motor connector C-111 and A/C-ECU connector C-20 for
loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Are outside/inside air selection damper control motor
connector C-111 and A/C-ECU connector C-20 in good
condition?
YES : Go to Step 3.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2. Check
that the A/C works normally.
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AUTO A/C DIAGNOSIS
55-145
STEP 3. Check the wiring harness between A/C-ECU
connector C-20 (terminal 26, 25, 27, 24 and 29) and
outside/inside air selection damper control motor
connector C-111 (terminals 2, 5, 4. 1 and 3).
• Check the A/C-ECU signal line for open and short circuit.
Q: Are the wiring harness between A/C-ECU connector
C-20 (terminal 26, 25, 27, 24 and 29) and outside/inside
air selection damper control motor connector C-111
(terminals 2, 5, 4. 1 and 3) in good condition?
YES : Go to Step 4.
NO : Repair the wiring harness. Check that the A/C works
normally.
STEP 4. Replace the outside/inside air selection damper
control motor and check the trouble symptom again
Check the trouble symptom again.
Q: Is the check result satisfactory?
YES : The procedure is complete.
NO : Replace the A/C-ECU.
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55-146
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
INSPECTION PROCEDURE 7: A/C Outlet Air Temperature does not Increase
Air Mixing Damper Control Motor Circuit
A/C-ECU
AIR MIXING
DAMPER CONTROL
MOTOR
AC708623
Connectors: C-20, C-114
C-20 (B)
C-114
AC708951AS
.
CIRCUIT OPERATION
If the air outlet temperature cannot be adjusted, the air mixing
damper control motor circuit may be failed.
.
TROUBLESHOOTING HINTS
• Malfunction of the air mixing damper control motor
• Malfunction of the A/C-ECU
• Damaged harness wires or connectors
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55-147
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: V.C.I.
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, check for diagnostic
trouble code.
Check if an A/C-ECU DTC is set.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the DTC set?
YES : Refer to DIAGNOSTIC TROUBLE CODE CHART
P.55-121.
NO : Go to Step 2.
MB991910
MB991824
MB991827
AC608435 AB
STEP 2. Check air mixing damper control motor connector
C-114 and A/C-ECU connector C-20 for loose, corroded or
damaged terminals, or terminals pushed back in the
connector.
Q: Are air mixing damper control motor connector C-114
and A/C-ECU connector C-20 in good condition?
YES : Go to Step 3.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2. Check
that the A/C works normally.
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 3. Check the wiring harness between A/C-ECU
connector C-20 (terminal 29, 35, 36, 34 and 28) and air
mixing damper control motor connector C-114 (terminals
3, 2, 5. 4 and 1).
• Check the A/C-ECU signal line for open and short circuit.
Q: Are the wiring harness between A/C-ECU connector
C-20 (terminal 29, 35, 36, 34 and 28) and air mixing
damper control motor connector C-114 (terminals 3, 2,
5. 4 and 1) in good condition?
YES : Go to Step 4.
NO : Repair the wiring harness. Check that the A/C works
normally.
STEP 4. Replace the air mixing damper control motor and
check the trouble symptom again
Check the trouble symptom again.
Q: Is the check result satisfactory?
YES : The procedure is complete.
NO : Replace the A/C-ECU.
INSPECTION PROCEDURE 8: Air Outlet Vent cannot be Changed.
Mode Selection Damper Control Motor Circuit
A/C-ECU
MODE SELECTION
DAMPER CONTROL
MOTOR
AC708624
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
55-149
Connectors: C-20, C-112
C-20 (B)
C-112
AC708951AT
.
CIRCUIT OPERATION
If the air outlet cannot be switched, the mode selection damper
control motor circuit may be failed.
.
TROUBLESHOOTING HINTS
• Malfunction of the mode selection damper control motor
• Malfunction of the A/C-ECU
• Damaged harness wires or connectors
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: V.C.I.
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, check for diagnostic
trouble code.
Check if an A/C-ECU DTC is set.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Data link connector
Q: Is the DTC set?
YES : Refer to DIAGNOSTIC TROUBLE CODE CHART
P.55-10.
NO : Go to Step 2.
MB991910
MB991824
MB991827
AC608435 AB
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HEATER, AIR CONDITIONING AND VENTILATION
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STEP 2. Check mode selection damper control motor
connector C-112 and A/C-ECU connector C-20 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Are mode selection damper control motor connector
C-112 and A/C-ECU connector C-20 in good condition?
YES : Go to Step 3.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2. Check
that the A/C works normally.
STEP 3. Check the wiring harness between A/C-ECU
connector C-20 (terminal 29, 31, 32, 30 and 33) and mode
selection damper control motor connector C-112
(terminals 3, 2, 5, 4 and 1).
• Check the AC-ECU signal line for open and short circuit.
Q: Are the wiring harness between A/C-ECU connector
C-20 (terminal 29, 31, 32, 30 and 33) and mode selection
damper control motor connector C-112 (terminals 3, 2,
5, 4 and 1) in good condition?
YES : Go to Step 4.
NO : Repair the wiring harness. Check that the A/C works
normally.
STEP 4. Replace the mode selection damper control motor
and check the trouble symptom again
Check the trouble symptom again.
Q: Is the check result satisfactory?
YES : The procedure is complete.
NO : Replace the A/C-ECU.
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HEATER, AIR CONDITIONING AND VENTILATION
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55-151
INSPECTION PROCEDURE 9: Blower Motor power supply system.
Blower Motor Circuit
FUSIBLE
LINK 37
ETACSECU
BLOWER
RELAY
BLOWER
MOTOR
POWER
TRANSISTER
A/C-ECU
AC708621
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HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
Connector: C-115
Connectors: C-303, C-309, C-315
ETACS-ECU
C-303
C-315
C-309 (B)
AC708972AT
AC708951AU
.
TECHNICAL DESCRIPTION (COMMENT)
If the voltage is not supplied to the blower motor, the blower
relay system may be failed.
.
TROUBLESHOOTING HINTS
• Malfunction of the ETACS-ECU
• Malfunction of the blower relay
• Damaged harness wires or connectors
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
STEP 1. Check blower relay connector C-303 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is blower relay connector C-303 in good condition?
YES : Go to Step 2.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
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HEATER, AIR CONDITIONING AND VENTILATION
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STEP 2. Check the blower relay continuity.
Follow the table below to check the blower relay for continuity.
Blower relay
1
2
3
4
AC605627
4
3
1
2
Battery voltage
Tester connection Specified
condition
Not applied
3 −4
• Connect
3 −4
terminal 1 to the
positive battery
terminal
• Connect
terminal 2 to the
negative battery
terminal
Open circuit
Less than 2 ohms
Q: Is the blower relay in good condition?
YES : Go to Step 3.
NO : Replace the rear window defogger relay.
AC609984AB
STEP 3. Measure the voltage at blower relay connector
C-303.
(1) Disconnect blower relay connector C-303, and measure the
voltage at the junction block side.
(2) Measure the voltage between terminals 1 and ground.
• The measured value should be approximately 12 volts
(battery positive voltage).
Connector C-303
(Junction block side)
AC608254 AW
(3) Measure the voltage between terminals 4 and ground.
• The measured value should be approximately 12 volts
(battery positive voltage).
Connector C-303
(Junction block side)
Q: Is the measured voltage approximately 12 volts?
YES : Go to Step 5.
NO : Go to Step 4.
AC608254 AX
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55-154
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
STEP 4. Check the wiring harness between blower relay
connector C-303 (terminals 1 and 4) and the fusible link
(37).
NOTE: Also check ETACS-ECU connector C-309 for loose,
corroded, or damaged terminals, or terminals pushed back in
the connector. If ETACS-ECU connector C-309 is damaged,
repair or replace the connector as described in GROUP 00E,
Harness Connector Inspection P.00E-2.
• Check the blower relay power supply line for open circuit.
Q: Is the wiring harness between blower relay connector
C-303 (terminals 1 and 4) and the fusible link (37) in
good condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
NO : Repair or replace the wiring harness. Refer to
GROUP 00E, Harness Connector Inspection
P.00E-2.
STEP 5. Check blower relay connector C-115 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is blower relay connector C-115 in good condition?
YES : Go to Step 6.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.
STEP 6. Check the wiring harness between blower relay
connector C-303 (terminal 3) and blower motor connector
C-115 (terminal 1).
NOTE: Also check ETACS-ECU connector C-315 for loose,
corroded, or damaged terminals, or terminals pushed back in
the connector. If ETACS-ECU connector C-315 is damaged,
repair or replace the connector as described in GROUP 00E,
Harness Connector Inspection P.00E-2.
• Check the blower motor power supply line for open circuit.
Q: Is the wiring harness between blower relay connector
C-303 (terminal 3) and blower motor connector C-115
(terminal 1) in good condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points −How to
Cope with Intermittent Malfunctions P.00-15.
NO : Repair or replace the wiring harness. Refer to
GROUP 00E, Harness Connector Inspection
P.00E-2.
TSB Revision
55-155
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
DATA LIST REFERENCE TABLE
M1554005100846
Scan tool display
Item
No.
Inspection status
The display content
under normal
condition
Engine speed
17
−
Displays correct engine
speed.
Ambient temperature sensor
19
−
Ambient temperature is
the same as scan tool
displayed temperature
Air thermo sensor
20
−
Evaporator outlet
temperature is the same
as scan tool displayed
temperature.
Interior temperature sensor
21
−
Interior temperature is
the same as scan tool
displayed temperature
Temperature setting
23
ETC sensor
24
−
Engine coolant
temperature is the same
as scan tool displayed
temperature.
Vehicle speed
26
−
Displays vehicle speed.
Compressor ON
ON
Compressor OFF
OFF
Air conditioning switch ON
ON
Air conditioning switch OFF
OFF
A/C Compressor drive request 27
Air conditioning switch
28
Displays air conditioning
set temperature.
Refrigerant leak
29
−
Normal
Idle up request
34
−
Displays idle-up request
signal.
Rear heater SW light*
35
−
−
PTC heater 1*
36
−
−
PTC heater 2*
37
−
−
PTC heater 3*
38
−
−
In/out select damp poten
(target)
45
−
Displays outside/inside
air selection damper
target position.
In/out select damp
potentiometer
46
−
Displays outside/inside
air selection damper
position.
Air outlet c/o potentiometer
55
−
Displays air outlet
changeover damper
position.
Air outlet c/o potentio. (Target) 56
−
Displays air outlet
changeover damper
target position.
TSB Revision
55-156
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
Scan tool display
Item
No.
Inspection status
The display content
under normal
condition
Low pressure judgment
57
−
Normal
Rear defogger switch
60
Rear window defogger switch ON
ON
Rear window defogger switch OFF
OFF
Pressure sensor
61
−
Displays refrigerant
pressure.
Air mix potentiometer
63
−
Displays the air mix
damper position.
Photo sensor
67
−
Displays sunload.
Front blower fan
68
−
Displays blower motor
condition.
Front blower fan (Target)
69
−
Displays blower motor
target value.
Refrigerant pressure
73
−
Displays refrigerant
pressure status.
Condenser fan
74
−
Displays condenser fan
running condition.
Temp. set dial position
76
−
Displays the set
temperature output
value on the control
panel.
A/C Panel type
77
−
Dial/Auto/RHD
Fan set dial position
78
−
Displays the air volume
output value on the
control panel.
Air outlet c/o set dial position
79
−
Displays output value to
the air outlet
changeover dial on the
control panel.
Fan set dial operation flag
80
−
ON when the air volume
adjusting dial is
operated
A/C SW operation flag
81
−
ON when the air
conditioning switch is
operated
Temp. set dial operation flag
82
−
ON when the air
conditioning switch is
operated
Defogger flag
83
−
ON when the air outlet
changeover dial is set to
the DEF position.
In/out air c/o SW operation
flag
84
−
ON when the inside
air/outside air
changeover switch is
operated
TSB Revision
55-157
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
Scan tool display
Item
No.
Inspection status
The display content
under normal
condition
Rear defogger SW operation
flag
87
−
ON when the rear
window switch is
operated
Rear defogger SW light
88
−
Displays rear window
switch indicator status.
A/C SW light
89
−
Displays air conditioning
switch indicator status.
In/out air c/o SW light
90
−
Displays the status of
the inside air/outside air
changeover switch
indicator.
A/C Compressor drive flag
91
−
ON when the
compressor is activated.
Wiper operation flag
92
−
ON when the wiper is
operated.
Ignition position information
93
−
Ignition switch position
status
Power source voltage
94
−
Displays power supply
voltage.
IOD fuse equipment flag
95
−
IOD fuse status
A/T lock up open request
96
−
Displays A/T lock open
request signal.
System operation time
100
−
−
Compressor use times
101
−
−
Rear defogger use times
102
−
−
In/out air c/o poten drive time
103
−
−
Air outlet c/o poten drive time
104
−
−
Air mix potentiometer drive
time
105
−
−
Hot state time (Interior TEMP.) 106
−
−
Cold state time (Interior
TEMP.)
107
−
−
Hot state time (Ambient
TEMP.)
108
−
−
Cold state time (Ambient
TEMP.)
109
−
−
Maximum ambient
temperature
110
−
−
Minimum ambient temperature 111
−
−
Maximum Engine coolant
TEMP.
112
−
−
Engine high speed time
113
−
−
TSB Revision
55-158
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
Scan tool display
Item
No.
Inspection status
The display content
under normal
condition
Maximum Engine speed
114
−
−
High pressure drive time
115
−
−
High pressure cut times
116
−
−
Maximum pressure (kPa)
117
−
−
A/C use rate
118
−
−
Compressor operation rate
119
−
−
Eco operation rate
120
−
−
Recirc use rate
121
−
−
A/C operation times
122
−
−
In/out air c/o operation times
123
−
−
Mode dial operation times
124
−
−
Blower fan dial operation
times
125
−
−
TEMP. set dial operation times 126
−
−
FACE mode use rate
127
−
−
B/L mode use rate
128
−
−
FOOT mode use rate
129
−
−
D/F mode use rate
130
−
−
DEF mode use rate
131
−
−
Fan OFF use rate
132
−
−
Fan 1-2step use rate
133
−
−
Fan 3-4step use rate
134
−
−
Fan 5-6step use rate
135
−
−
Fan 7-8step use rate
136
−
−
Temp 1-7 step use rate
137
−
−
Temp 8-10step use rate
138
−
−
Temp 11-13 step use rate
139
−
−
Temp 17-19step use rate
140
−
−
Temp 20-22step use rate
141
−
−
Temp 23-29step use rate
142
−
−
PTC heater1 use times
143
−
−
PTC heater2 use times
144
−
−
PTC heater3 use times
145
−
−
Fan LO driving time
146
−
−
Fan M1 driving time
147
−
−
Fan M2 driving time
148
−
−
TSB Revision
55-159
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
Scan tool display
Item
No.
Inspection status
The display content
under normal
condition
Fan HI driving time
149
−
−
Rear PTC heater counter
150
−
−
NOTE: * shows that it is displayed but not used.
ACTUATOR TEST
M1554005201062
Item No.
Check item
Driven content
2
idle up request*1
Idle-up request signal
5
In/out select damper
The moving position of outside/inside air
selection damper motor
6
Air mix damper motor
The moving position of air mix damper
motor
7
Front blower fan
The amount of blower motor rotation
8
Air outlet c/o damper
Air outlet changeover damper motor
moving position
10
Condenser fan*1
The amount of condenser fan rotation
11
Air conditioning switch*1
A/C switch selection position
12
Rear defogger switch*1
Rear window defogger switch selection
position
13
A/T lock up open request*2
A/T lock open request signal
NOTE: .
• *1: When the engine is not running these function
do not work.
TSB Revision
•
*2
shows that it is displayed but not used.
55-160
HEATER, AIR CONDITIONING AND VENTILATION
AUTO A/C DIAGNOSIS
CHECK AT A/C-ECU TERMINAL
M1552010302329
C-22
C-20
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 2223 24 25 26 27 28
29 30 31 32 33 34 35 36
AC210339 AG
Terminal
No.
Check item
Check condition
1
Power transistor (DRAIN)
Air volume control dial: Maximum air 0 to 2 V
volume
2
Power transistor (GATE)
Air volume control dial: Maximum air Battery positive voltage
volume
3 −8
−
−
−
9
A/C control panel (input)
−
−
10
A/C control panel (input)
−
−
11, 12
−
−
−
13
Battery power supply
Always
Battery positive voltage
14
Ground
Always
1 V or less
15
IG1 power supply
Ignition switch: IG1
Battery positive voltage
16
A/C pressure sensor input
Refer to P.55-164.
Refer to P.55-164.
17
Interior temperature sensor
Sensor probe temperature: 25° C
(77° F) (4.0 kΩ)
2.1 to 2.7 V
18
−
−
−
19
Sensor ground
Always
1 V or less
20
A/C pressure sensor power
supply
Ignition switch: IG2
5V
21
Air thermo sensor ground
Always
1 V or less
22
Air thermo sensor
Sensor probe temperature: 25° C
(77° F) (4.0 kΩ)
2.1 to 2.7 V
23
−
−
−
24
Motor for air outside/inside
air circulation switching
damper
−
−
25
Motor for air outside/inside
air circulation switching
damper
−
−
26
Motor for air outside/inside
air circulation switching
damper
−
−
27
Motor for air outside/inside
air circulation switching
damper
−
−
TSB Revision
Normal condition
HEATER, AIR CONDITIONING AND VENTILATION
SPECIAL TOOLS
55-161
Terminal
No.
Check item
Check condition
Normal condition
28
Air mix damper motor
−
−
29
Motor power supply
−
−
30
Air outlet changeover
damper motor
−
−
31
Air outlet changeover
damper motor
−
−
32
Air outlet changeover
damper motor
−
−
33
Air outlet changeover
damper motor
−
−
34
Air mix damper motor
−
−
35
Air mix damper motor
−
−
36
Air mix damper motor
−
−
SPECIAL TOOLS
Tool
Tool number
and name
Supersession
M1552000600806
Application
MB991367
MB991367-01
Special spanner
Armature mounting nut of
compressor removal and
installation
MB991386 Pin
Armature mounting nut of
compressor removal and
installation
B991367
MIT217213
MB991658
Tool not available
Test harness set
MB991658
TSB Revision
Inspection of throttle position
sensor
55-162
HEATER, AIR CONDITIONING AND VENTILATION
SPECIAL TOOLS
Tool
a
b
Tool number
and name
Supersession
Application
MB991223
a. MB991219
b. MB991220
c. MB991221
d. MB991222
Harness set
a. Check harness
b. LED harness
c. LED harness
adapter
d. Probe
Continuity check and voltage
measurement at harness wire or
connector
a. For checking connector pin
contact pressure
b. For checking power supply
circuit
c. For checking power supply
circuit
d. For connecting a locally
sourced tester
MB992006
Extra fine probe
General service tool
Making voltage and resistance
measurement during
troubleshooting
c
d
DO NOT USE
MB991223BA
MB992006
TSB Revision
HEATER, AIR CONDITIONING AND VENTILATION
SPECIAL TOOLS
Tool
a
MB991824
b
MB991827
c
MB991910
d
DO NOT USE
MB991911
e
DO NOT USE
MB991914
f
MB991825
g
MB991826
MB991958
Tool number
and name
Supersession
MB991958
a. MB991824
b. MB991827
c. MB991910
d. MB991911
e. MB991914
f. MB991825
g. MB991826
M.U.T.-III
sub-assembly
a. Vehicle
communicatio
n interface
(V.C.I.)
b. M.U.T.-III
USB cable
c. M.U.T.-III
main harness
A (Vehicles
with CAN
communicatio
n system)
d. M.U.T.-III
main harness
B (Vehicles
without CAN
communicatio
n system)
e. M.U.T.-III
main harness
C (for
Chrysler only)
f. M.U.T.-III
measurement
adapter
g. M.U.T.-III
trigger
harness
MB991824-KIT
NOTE: G: MB991826
M.U.T.-III Trigger
Harness is not
necessary when
pushing V.C.I.
ENTER key.
TSB Revision
55-163
Application
CAUTION
M.U.T.-III main harness A
(MB991910) should be used.
M.U.T.-III main harness B and
C should not be used for this
vehicle.
DTC, data list and actuator test
check.
55-164
HEATER, AIR CONDITIONING AND VENTILATION
ON-VEHICLE SERVICE
ON-VEHICLE SERVICE
REFRIGERANT LEVEL TEST
M1552008400594
Use the refrigerant recovery station to remove all of the refrigerant, and then calculate the amount of the refrigerant and
charge it.
A/C COMPRESSOR CLUTCH TEST
M1552019900128
1. Disconnect the A/C compressor clutch connector to the A/C
compressor clutch.
2. Connect positive battery voltage directly to the connector for
the A/C compressor clutch.
3. Supply a ground to the A/C compressor assembly.
4. If the A/C compressor clutch is normal, there will be a "click."
If the pulley and armature do not make contact ("no click"),
there is a malfunction.
AC506471
SIMPLE INSPECTION OF THE A/C PRESSURE
SENSOR
M1552014700464
1. Assemble a gauge manifold on the high pressure service
valve.
2. Disconnect the A/C pressure sensor connector and connect
special tool test harness MB991658 as shown in the illustration.
3. Turn ON the engine and then turn ON the air conditioner
switch.
A/C pressure sensor
AC609413AB
A/C
pressure
sensor
side
Harness side
MB991658
AC307368AC
TSB Revision
HEATER, AIR CONDITIONING AND VENTILATION
ON-VEHICLE SERVICE
55-165
4. At this time, check to see that the voltage of A/C pressure
sensor terminal No. 2 reflects the specifications of the figure.
NOTE: The allowance shall be defined as ±5%.
Output voltage
(V)
5
4
3
2
1
0
1 (145) 2 (290) 3 (435)
Refrigerant pressure MPa (psi)
AC208297AG
COMPRESSOR DRIVE BELT ADJUSTMENT
M1552001001082
Refer to GROUP 11A, On-vehicle Service −Drive Belt tension
check and adjustment P.11A-7.
CHARGING
M1552001200663
Use the refrigerant recovery station to charge the refrigerant.
METHOD BY USING REFRIGERANT RECOVERY
AND RECYCLING UNIT
Using the refrigerant recovery and recycling unit, refill the
refrigerant.
NOTE: Refer to the Refrigerant Recovery and Recycling Unit’s
Instruction Manual for operation of the unit.
DISCHARGING SYSTEM
Use the refrigerant recovery unit to discharge refrigerant gas
from the system.
NOTE: Refer to the Refrigerant Recovery and Recycling Unit’s
Instruction Manual for operation of the unit.
REFILLING OF OIL IN THE A/C SYSTEM
Too little oil will provide inadequate compressor lubrication and
cause a compressor failure. Too much oil will increase discharge air temperature.
When a compressor is installed at the factory, it contains 140
cm3 (4.7 fl.oz) of refrigerant oil. While the A/C system is in
operation, the oil is carried through the entire system by the
refrigerant. Some of this oil will be trapped and retained in various parts of the system.
When the following system components are changed, it is necessary to add oil to the system to replace the oil being removed
with the component.
Compressor oil: SUN PAG 56
Quantity:
Evaporator: 60 cm3 (2.0 fl.oz)
Condenser: 15 cm3 (0.5 fl.oz)
Suction hose: 10 cm3 (0.3 fl.oz)
TSB Revision
55-166
HEATER, AIR CONDITIONING AND VENTILATION
ON-VEHICLE SERVICE
PERFORMANCE TEST
Low-pressure
valve
High-pressure
valve
Gauge manifold
Charging
hose (Red)
Charging
hose (Blue)
Adaptor
valve
(For
low-pressure)
A
Lowpressure
service
valve
Highpressure
service
valve
Sleeve
Adaptor
valve
(For highpressure)
AC609415AC
Thermometer
M1552001400957
The vehicles to be tested should be parked out of direct sunlight.
1. Close the high and low-pressure valve of the gauge
manifold.
2. Connect the charging hose (blue) to the low-pressure valve
and connect the charging hose (red) to the high-pressure
valve of the gauge manifold.
3. Install the quick joint (for low-pressure) to the charging hose
(blue), and connect the quick joint (for high-pressure) to the
charging hose (red).
CAUTION
• To connect the quick joint, press section A firmly
against the service valve until a click is heard.
• When connecting, run your hand along the hose while
pressing to ensure that there are no bends in the hose.
4. Connect the quick joint (for low-pressure) to the
low-pressure service valve and connect the quick joint (for
high-pressure) to the high-pressure service valve.
NOTE: The high-pressure service valve is on the A/C pipe
and the low-pressure service valve is on the suction hose.
5. Start the engine.
6. Set the A/C controls as follows:
• A/C switch: A/C −ON position
• Mode selection: FACE position
• Temperature control: MAXIMUM COOLING position
• Air selection: RECIRCULATION position
• Blower switch: Maximum air volume
7. Set the engine speed to the idle speed.
8. Engine should be warmed up with hood, doors and windows
opened.
9. Insert a thermometer in the center air outlet and operate the
engine for 20 minutes.
NOTE: If the A/C clutch cycles, take the reading before the
clutch disengages.
10.Note the discharge air temperature.
AC609414AB
TSB Revision
55-167
HEATER, AIR CONDITIONING AND VENTILATION
ON-VEHICLE SERVICE
PERFORMANCE TEMPERATURE CHART
Garage
ambient air
temperature
° C (° F)
20 (68)
25 (77)
30 (86)
35 (95)
Discharge air
temperature
° C (° F)
4.7 (40) −
17 (63)
10 (50) −23 15 (59) −28 20 (68) −33 26 (79) −38 31 (88) −44 36 (97) −49
(73)
(82)
(91)
(100)
(111)
(120)
Compressor
high pressure
kPa (psi)
934 (136) − 1068 (155) 1201 (174) 1335 (193) 1468 (213) 1602 (232) 1735 (252)
1700 (247) −1850
−2000
−2150
−2300
−2450
−2600
(268)
(290)
(312)
(334)
(355)
(377)
Compressor
low pressure
kPa (psi)
170 (24.7) − 215 (31.2) − 260 (37.7) − 305 (44.2) − 350 (50.8) − 395 (57.3) − 440 (63.8) −
359 (52.1) 406 (58.9) 452 (65.6) 499 (72.4) 545 (79.1) 592 (85.9) 638 (92.6)
REFRIGERANT LEAK REPAIR PROCEDURE
40 (104)
45 (113)
50 (122)
M1552001500448
LOST CHARGE
HANDLING TUBING AND FITTINGS
If the system has lost all charge due to a leak:
1. Evacuate the system. (Refer to P.55-165).
2. Charge the system with approximately 0.453 kg (1
pound) of refrigerant.
3. Check for leaks.
4. Discharge the system.
5. Repair leaks.
Kinks in the refrigerant tubing or sharp bends in the
refrigerant hose lines will greatly reduce the capacity
of the entire system. High pressures are produced in
the system when it is operating. Extreme care must
be exercised to make sure that all connections are
pressure tight. Dirt and moisture can enter the system when it is opened for repair or replacement of
lines or components. The following precautions must
be observed. The system must be completely discharged before opening any fitting of connection in
the refrigeration system. Open fittings with caution
even after the system has been discharged. If any
pressure is noticed as a fitting is loosened, allow
trapped pressure to bleed off very slowly.
Never attempt to rebend formed lines to fit. Use the
correct line for the installation you are servicing. A
good rule for the flexible hose lines is keep the radius
of all bends at least 10 times the diameter of the
hose.
Sharper bends will reduce the flow of refrigerant. The
flexible hose lines should be routed so that they are
at least 80 mm (3.1 inches) from the exhaust manifold. It is good practice to inspect all flexible hose
lines at least once a year to make sure they are in
good condition and properly routed.
On standard plumbing fittings with O-rings, these
O-rings are not reusable.
CAUTION
Replacement filter-drier units must be sealed
while in storage. The drier used in these units will
saturate water quickly upon exposure to the
atmosphere. When installing a drier, have all
tools and supplies ready for quick assembly to
avoid keeping the system open any longer than
necessary.
6. Replace receiver drier.
7. Evacuate and charge system.
LOW CHARGE
If the system has not lost all of its refrigerant charge;
locate and repair all leaks. If it is necessary to
increase the system pressure to find the leak
(because of an especially low charge) add refrigerant. If it is possible to repair the leak without discharging the refrigerant system, use the procedure
for correcting low refrigerant level.
TSB Revision
55-168
HEATER, AIR CONDITIONING AND VENTILATION
ON-VEHICLE SERVICE
COMPRESSOR NOISE CHECK
You must first know the conditions when the noise
occurs. These conditions are: weather, vehicle
speed, in gear or neutral, engine temperature or any
other special conditions.
Noises that develop during A/C operation can often
be misleading. For example: what sounds like a
failed front bearing or connecting rod, may be
caused by loose bolts, nuts, mounting brackets, or a
loose clutch assembly. Verify accessory drive belt
tension (power steering or generator).
Improper accessory drive belt tension can cause a
misleading noise when the compressor is engaged
and little or no noise when the compressor is disengaged.
Drive belts are speed-sensitive. That is, at different
engine speeds, and depending upon belt tension,
belts can develop unusual noises that are often mistaken for mechanical problems within the compressor.
ADJUSTMENT
M1552008700487
1. Select a quiet area for testing. Duplicate
conditions as much as possible. Switch the
compressor on and off several times to clearly
identify compressor noise. To duplicate high
ambient conditions (high head pressure), restrict
air flow through the condenser. Install a manifold
gauge set to make sure discharge pressure
doesn't exceed 2,070 kPa (300.2 psi).
2. Tighten all compressor mounting bolts, clutch
mounting bolt, and compressor drive belt. Check
to assure clutch coil is tight (no rotation or
wobble).
3. Check refrigerant hoses for rubbing or
interference that can cause unusual noises.
4. Check refrigerant charge (Refer to P.55-165).
5. Recheck compressor noise as in Step 1.
6. If noise still exists, loosen compressor mounting
bolts and retighten. Repeat Step 1.
7. If noise continues, replace compressor and repeat
from Step 1.
POWER RELAY CHECK
M1552008801249
A/C COMPRESSOR CLUTCH RELAY CONTINUITY
CHECK
AC605626
A/C compressor clutch relay
1
2
3
4
Battery voltage
Tester connection Specified
condition
Not applied
3 −4
• Connect
3 −4
terminal 2 to the
positive battery
terminal
• Connect
terminal 1 to the
negative battery
terminal
3
4
1
2
AC609971AB
TSB Revision
Open circuit
Less than 2 ohms
55-169
HEATER, AIR CONDITIONING AND VENTILATION
ON-VEHICLE SERVICE
BLOWER RELAY CONTINUITY CHECK
Blower relay
1
2
3
4
AC605627
Battery voltage
Tester connection Specified
condition
Not applied
3 −4
• Connect
3 −4
terminal 1 to the
positive battery
terminal
• Connect
terminal 2 to the
negative battery
terminal
Open circuit
Less than 2 ohms
4
3
1
2
AC609984AB
IDLE-UP OPERATION CHECK
M1552001601761
Before inspection and adjustment, set vehicle in the following
condition:
• Engine coolant temperature: 80 −90 ° C (176.0 −194.0 ° F)
• Lights, electric cooling fan and accessories: OFF
• Transaxle: Neutral ("N" or "P" position)
• Steering wheel: Straightforward
1. Check whether or not the idle speed is the standard value.
Refer to GROUP 11A, On-vehicle Service −Idle Speed
Check P.11A-12.
Standard value: 700 ± 100 r/min
2. Turn on the air conditioning switch and the blower speed
selection dial. Engine idling speed should be within the
standard value:
Standard value: 800 ± 100 r/min
NOTE: It is not necessary to make an adjustment, because
the idling speed is automatically adjusted by the ISC system. If, however, a deviation from the standard value occurs
for some reason, check the ISC system (Refer to GROUP
11A, On-vehicle Service −Idle Speed Check P.11A-12)
TSB Revision
55-170
HEATER, AIR CONDITIONING AND VENTILATION
ON-VEHICLE SERVICE
REPLACE THE CLEAN AIR FILTER
M1552020100289
1. Remove the glove box (Refer to GROUP 52A −glove box,
P.52A-7).
2. Loosen the two lugs as shown to replace the clean air filter.
3. Install the glove box.
AC611715AB
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HEATER, AIR CONDITIONING AND VENTILATION
HEATER CONTROL UNIT
55-171
HEATER CONTROL UNIT
REMOVAL AND INSTALLATION
M1554014700772
Pre-removal and Post-installation Operation
• Side cover, Instrument panel garnish, Upper panel
Removal and Installation (Refer to GROUP 52A, Instrument Panel P.52A-3).
• Floor console Removal and Installation (Refer to GROUP
52A, Floor console P.52A-10).
2
1
AC608191AB
1.
2.
Removal steps
Instrument panel center lower
(Refer to GROUP 52A, Instrument
panel center panel P.52A-8)
Heater control panel <Vehicles
without A/C> or A/C control panel
TSB Revision
55-172
HEATER, AIR CONDITIONING AND VENTILATION
HEATER UNIT AND BLOWER ASSEMBLY
HEATER UNIT AND BLOWER ASSEMBLY
REMOVAL AND INSTALLATION
M1552020800716
WARNING
• Before removing the steering wheel assembly and driver's air bag module/knee air bag
module, always refer to GROUP 52B − Service Precautions P.52B-24 and Air bag Module
and Clock Spring P.52B-413 or Knee Air bag Module P.52B-425.)
Pre-removal and Post-installation Operation
• Refrigerant draining and Refilling (Refer to Charging and
Discharging P.55-165).
• Engine coolant Draining and Refilling (Refer to GROUP
00, Engine coolant P.00-72).
• Steering Column Shaft Assembly Removal and Installation (Refer to GROUP 37, Steering Shaft P.37-33).
• Instrument Panel Removal and Installation (Refer to
GROUP 52A, Instrument Panel P.52A-3).
• Floor console Removal and Installation (Refer to GROUP
52A, Floor console P.52A-10).
-Pipe coupling
7.0 ± 3.0 N·m
62 ± 27 in-lb
3, 4
2
5
A/C compressor oil:
SUN PAG 56
11 ± 4 N·m
98 ± 35 in-lb
8
4.9 ± 0.9 N·m
43 ± 8 in-lb
1
N
5
3
20 ± 5 N·m
15 ± 3 ft-lb
4
23 ± 6 N·m
17 ± 4 ft-lb
11 ± 4 N·m
98 ± 35 in-lb
7
6
18 ± 7 N·m
13 ± 3 ft-lb
18 ± 7 N·m
13 ± 3 ft-lb
20 ± 5 N·m
15 ± 3 ft-lb
AC608202 AD
TSB Revision
HEATER, AIR CONDITIONING AND VENTILATION
HEATER UNIT AND BLOWER ASSEMBLY
1.
2.
3.
4.
<<A>>
<<A>>
Removal steps
Dash panel heat protector
Heater hose connection
Flexible suction hose connection
Liquid pipe B connection
<<B>>
5.
6.
7.
8.
55-173
Removal steps (Continued)
O-ring
Front deck crossmember
Drain hose
Heater unit
REMOVAL SERVICE POINTS
.
<<A>> SUCTION PIPE AND LIQUID PIPE DISCONNECTION
CAUTION
As the compressor oil and receiver are highly moisture
absorbent, use a non-porous material to plug the hose and
nipples.
To prevent the entry of dust or other foreign bodies, plug the
dismantled hose and the nipples of the expansion valves.
.
<<B>> HEATER UNIT AND DECK
CROSSMEMBER ASSEMBLY REMOVAL
Disconnect the following connectors to gain access to the front
deck crossmember.
Connector Connector name
number
C-132
C-131
C-130
C-133
C-128
C-129
C-42
C-41
AC708950BM
C-116
C-117
C-23
C-24
C-34
AC708951BZ
C-23
Instrument panel wiring harness and floor
wiring harness combination
C-24
Instrument panel wiring harness and floor
wiring harness combination
C-33
Instrument panel wiring harness and console
wiring harness combination
C-41
Instrument panel wiring harness and floor
wiring harness combination
C-42
Instrument panel wiring harness and floor
wiring harness combination
C-116
Instrument panel wiring harness and front door
wiring harness (RH) combination
C-117
Instrument panel wiring harness and front door
wiring harness (RH) combination
C-128
Instrument panel wiring harness and front door
wiring harness (LH) combination
C-129
Instrument panel wiring harness and front door
wiring harness (LH) combination
C-130
Instrument panel wiring harness and front
wiring harness combination
TSB Revision
55-174
HEATER, AIR CONDITIONING AND VENTILATION
HEATER UNIT AND BLOWER ASSEMBLY
Connector Connector name
number
C-131
Instrument panel wiring harness and front
wiring harness combination
C-132
Instrument panel wiring harness and front
wiring harness combination
C-133
Instrument panel wiring harness and roof wiring
harness combination
DISASSEMBLY AND REASSEMBLY
M1552020900638
1
3
32
23
2
12
10
9
27
28
13
29
30
16
5
25
17 N
27
24
8
11
26
7
6
14
19
4
18
21
31
15
33
22
20
AC608203AB
1.
2.
Disassembly steps
KOS-ECU
Rear center duct
TSB Revision
3.
4.
Disassembly steps (Continued)
Front center duct
Foot duct
HEATER, AIR CONDITIONING AND VENTILATION
HEATER UNIT AND BLOWER ASSEMBLY
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
Disassembly steps (Continued)
Heater control module <Vehicles
without A/C> or A/C-ECU
Air mixing damper control motor
Mode selection damper control
motor
Mode lever
Outside/Inside air selection damper
control motor
Heater core cover
Heater core
Expansion valve cover
Upper case assembly
Evaporator
Fin thermo sensor
Expansion valve
O-ring
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
55-175
Disassembly steps (Continued)
Clean air filter cover
Clean air filter
Power transistor
Blower motor
Insulator
Air intake duct
Blower case upper
Outside/inside air selection damper
Blower case lower
Upper case
Mode selection damper (FOOT)
Mode selection damper (DEF)
Air mixing damper
Wiring harness
Aspirator
Lower case
INSPECTION
M1554011900409
.
FIN THERMO SENSOR CHECK
Resistance
(kΩ)
Measure the resistance between the sensor terminals under at
least two temperatures. The resistance values should meet the
values shown.
NOTE: The temperature should be within the shown range.
25
20
15
10
5
0
-10 0 10 20 30 40
(14) (32) (50) (68) (86) (104)
Temperature ºC (ºF)
AC609399AB
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55-176
HEATER, AIR CONDITIONING AND VENTILATION
MOTORS AND TRANSISTOR
MOTORS AND TRANSISTOR
REMOVAL AND INSTALLATION
M1551006900095
5
1
3
2
8
4
7
6
AC708788AC
•
1.
•
2.
3.
Power transistor removal steps
Bottom cover (passenger side)
(Refer to GROUP 52A −Glove box
P.52A-7).
Power transistor
Blower motor removal steps
Bottom cover (passenger side)
(Refer to GROUP 52A −Glove box
P.52A-7).
Hose
Blower motor
TSB Revision
•
<<A>>
<<A>>
•
4.
5.
<<A>>
6.
7.
8.
>>A<<
Air mixing damper control motor,
mode selection damper control
motor and outside/inside air
selection damper control motor
removal steps
Rear heater duct A (Refer to
P.55-189).
A/C-ECU (Refer to P.55-180).
Air mixing damper control motor
Mode selection damper control
motor
Clean air filter cover
Clean air filter
Outside/inside air selection damper
control motor
55-177
HEATER, AIR CONDITIONING AND VENTILATION
MOTORS AND TRANSISTOR
REMOVAL SERVICE POINT
.
<<A>> AIR MIXING DAMPER CONTROL MOTOR,
OUTSIDE/INSIDE AIR SELECTION DAMPER
MOTOR, MODE SELECTION DAMPER CONTROL
MOTOR REMOVAL
NOTE: A normal plate-type ratchet driver is recommended.
AC100628 AB
INSTALLATION SERVICE POINT
.
>>A<< OUTSIDE/INSIDE AIR SELECTION
DAMPER MOTOR INSTALLATION
From the hole where the clean air filter and blower motor are
removed, support the outside/inside air selection damper from
beneath, and then perform the alignment.
INSPECTION
M1551006300758
BLOWER MOTOR CHECK
Check that the motor turns when applying battery power
between the connector terminals. Also check to see that there
is no abnormal sound emitted from the motor at this time.
AC611918AC
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55-178
HEATER, AIR CONDITIONING AND VENTILATION
AMBIENT AIR TEMPERATURE SENSOR
AMBIENT AIR TEMPERATURE SENSOR
REMOVAL AND INSTALLATION
M1554017500108
•
1
Horn (low)
1.
Removal step
Headlight support panel cover
(Refer to GROUP 51, Front bumper
assembly P.51-3).
Ambient air temperature sensor
AC605673AI
INSPECTION
M1551006300769
.
AMBIENT AIR TEMPERATURE SENSOR CHECK
CAUTION
The ambient air temperature sensor should be checked
without removing it. If the sensor is removed, it is no
longer serviceable.
Measure the resistance between the sensor terminals under at
least two temperatures. The resistance values should meet the
values shown.
NOTE: The temperature should be within the shown range.
Resistance
(kΩ) 10
8
6
4
2
0
-10
10
0
(50)
(14) (32)
Temperature ºC (ºF)
20
(68)
40
30
(86) (104)
AC209192 AB
TSB Revision
HEATER, AIR CONDITIONING AND VENTILATION
INTERIOR TEMPERATURE SENSOR
55-179
INTERIOR TEMPERATURE SENSOR
REMOVAL AND INSTALLATION
M1554026400381
Cross-section A-A
Claw
1
AC704919
Instrument panel
1
2
A
A
AC709099AC
•
Interior temperature sensor
removal steps
Lower panel (Refer to GROUP 52A,
Instrument panel P.52A-3).
INSPECTION
1.
2.
Interior temperature sensor
removal steps (Continued)
Interior temperature sensor
Aspirator hose
M1552014303852
.
INTERIOR TEMPERATURE SENSOR CHECK
When the resistance between the sensor terminals is measured under two or more temperature conditions, the resistance should approximately satisfy the illustrated values.
NOTE: The temperature conditions when checking should not
exceed the range shown in the diagram.
Resistance
20
(kΩ)
15
10
5
0
-10
0
(14)
(32)
Temperature ºC (ºF)
10
(50)
20
(68)
30
(86)
40
(104)
AC609165AB
TSB Revision
55-180
HEATER, AIR CONDITIONING AND VENTILATION
A/C-ECU
A/C-ECU
REMOVAL AND INSTALLATION
M1554016600469
Pre-removal and Post-installation Operation
• Glove Box and Bottom Cover Assembly (passenger's
side) Removal and Installation (Refer to GROUP 52A −
Instrument Panel P.52A-3).
• Foot duct Removal and Installation (Refer to P.55-189).
heater control module
<Vehicles without A/C>
or A/C-ECU
TSB Revision
AC708793AG
55-181
HEATER, AIR CONDITIONING AND VENTILATION
COMPRESSOR ASSEMBLY AND TENSION PULLEY
COMPRESSOR ASSEMBLY AND TENSION PULLEY
REMOVAL AND INSTALLATION
M1552004100706
Pre-removal Operation
• Refrigerant Discharging (Refer to P.55-165).
• Engine room under cover front A (Refer to GROUP 51,
under cover P.51-15).
• Front Under Cover RH (Refer to GROUP 51, Under cover
P.51-15).
Post-installation Operation
• Drive Belt Tension Adjustment (Refer to GROUP 11A, On
vehicle service −Drive Belt P.11A-7).
• Refrigerant Charging (Refer to P.55-165).
• Engine room under cover front A (Refer to GROUP 51,
under cover P.51-15).
• Front Under Cover RH (Refer to GROUP 51, Under cover
P.51-15).
-Pipe coupling
1, 2
3
A/C compressor oil:
SUN PAG 56
25 ± 4 N·m
18 ± 3 ft-lb
3N
6
23 ± 6 N·m
17 ± 4 ft-lb
1
5
2
N
3
25 ± 4 N·m
18 ± 3 ft-lb
23 ± 6 N·m
17 ± 4 ft-lb
4
AC608280
<<A>>
<<A>>
1.
2.
3.
4.
Removal steps
Flexible discharge hose connection <<B>>
Flexible suction hose connection
O-ring
Drive belt
TSB Revision
>>A<<
5.
6.
Removal steps (Continued)
A/C compressor and clutch
assembly
A/C compressor bracket
55-182
HEATER, AIR CONDITIONING AND VENTILATION
COMPRESSOR ASSEMBLY AND TENSION PULLEY
REMOVAL SERVICE POINTS
.
<<A>> FLEXIBLE DISCHARGE HOSE AND FLEXIBLE SUCTION HOSE DISCONNECTION
CAUTION
As the compressor oil and receiver are highly moisture
absorbent, use a non-porous material to plug the hose and
nipples.
To prevent the entry of dust or other foreign bodies, plug the
dismantled hoses and compressor nipples.
.
<<B>> A/C COMPRESSOR AND CLUTCH
ASSEMBLY REMOVAL
Take care not to spill any compressor oil when removing the
compressor.
INSTALLATION SERVICE POINT
.
>>A<< A/C COMPRESSOR AND CLUTCH ASSEMBLY INSTALLATION
If a new compressor is installed, first adjust the amount of oil
according to the procedures described below, and then install
the compressor.
1. Measure the amount [X cm3 (X fl.oz) of oil within the
removed compressor.
2. Drain (from the new compressor) the amount of oil
calculated according to the following formula, and then
install the new compressor.
New compressor oil amount = 80cm3 (2.7 fl.oz)
80 cm3 −X cm3 = Y cm3 (2.7 fl.oz. −X fl.oz. = Y fl.oz)
NOTE: Y cm3 (Y fl.oz) indicates the amount of oil in the refrigerant line, the condenser, the evaporator, etc.
NOTE: When replacing the following parts at the same times as
the compressor, subtract the rated oil amount of each part from
Y cm3 (Y fl.oz) and discharge from the new compressor.
3. Tighten A/C compressor and clutch assembly mounting
bolts to the specified torque in the order of number shown in
the figure.
Tightening torque: 23 ± 6 N⋅ m
1
3
2
A/C compressor
and clutch assembly
AC506759 AE
TSB Revision
55-183
HEATER, AIR CONDITIONING AND VENTILATION
COMPRESSOR ASSEMBLY AND TENSION PULLEY
INSPECTION
M1552014303711
COMPRESSOR A/C COMPRESSOR CLUTCH
OPERATION CHECK
Connect the compressor connector terminal to the battery positive (+) terminal and ground the battery’s negative (-) terminal
to the compressor unit. At that time, the A/C compressor clutch
should make a definite operating sound.
AC506471
DISASSEMBLY AND ASSEMBLY
M1552004602291
1
3
2
9.8 ± 2.0 N·m
87± 17 in-lb
12
11
6
10
9
16 ± 1 N·m
11.8± 0.7 in-lb
N4
8
5
7
AC807970 AF
1.
2.
3.
<<A>>
>>E<<
>>D<<
>>C<<
•
4.
5.
6.
7.
Refrigerant temperature switch
disassembly steps
Bracket
Snap ring
Refrigerant temperature switch
A/C compressor clutch
disassembly
Air gap adjustment
Self-locking nut
Armature
Shim
Snap ring
TSB Revision
>>B<<
>>A<<
A/C compressor clutch
disassembly (Continued)
8. Rotor
9. Snap ring
10. Field core
11. A/C compressor
12. A/C compressor high pressure
relief valve.
Required Special Tools:
• MB991367: Special Spanner
• MB991386: Pin
55-184
HEATER, AIR CONDITIONING AND VENTILATION
COMPRESSOR ASSEMBLY AND TENSION PULLEY
DISASSEMBLY SERVICE POINT
.
<<A>> SELF-LOCKING NUT REMOVAL
MB991386
MB991367
AC507128AB
ASSEMBLY SERVICE POINTS
.
>>A<< A/C COMPRESSOR HIGH PRESSURE
RELIEF VALVE INSTALLATION
CAUTION
Be careful not to damage the O-ring when installing the
high-pressure relief valve.Apply the specified refrigerating
machine oil the high-pressure relief valve mounting hole
before installation
Check that O-ring is installed to the high-pressure relief and
use the adjust torque wrench to install the high-pressure relief
valve to the main body of the compressor.
.
>>B<< FIELD CORE ATTACHMENT
Line up the pin hole on the compressor unit with the field core
projection and attach.
Compressor
unit pin hole
Field core
projection
AC609150AB
.
>>C<< SNAP RING INSTALLATION
Snap ring
Rotor
Clutch coil
Using snap ring pliers, fit the snap ring so that the snap ring’s
tapered part is on the outside.
Tapered part
AC001412 AE
.
TSB Revision
HEATER, AIR CONDITIONING AND VENTILATION
COMPRESSOR ASSEMBLY AND TENSION PULLEY
55-185
>>D<< SELF-LOCKING NUT INSTALLATION
Using a special tool, as when removing the nut, secure the
armature and tighten the self-locking nut.
.
>>E<< AIR GAP ADJUSTMENT
Check whether or not the air gap of the clutch is within the standard value.
Standard value:
0.3 −0.5 mm (0.012 −0.020 inch)
NOTE: If there is a deviation of the air gap from the standard
value, make the necessary adjustment by adjusting the number
of shims.
Thickness
gauge
AC507127AC
INSPECTION
M1552014304792
COOLING TEMPERATURE SWITCH
CAUTION
Do not heat more than necessary.
1. Dip the metal part of the cooling temperature switch into
engine oil and increase the oil temperature using a gas
burner or similar.
Thermometer
Engine oil
AC100787AG
125˚C
(257˚F)
155˚C
(311˚F)
2. When the oil temperature reaches the standard value, check
that resistance is supplied between the terminals.
Standard value:
Less than 2Ω
No continuity
OIL TEMPERATURE
AC100810AV
Item
Temperature
Less than 2 ohms
Slightly below 125° C (257° F)
No continuity
155° C (311° F) or more
NOTE: When the oil temperature is 155° C (311° F) or more
and there is no continuity, the resistance will not be 2Ω or
lower until the oil temperature reduces to 125° C (257° F) or
less.
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55-186
HEATER, AIR CONDITIONING AND VENTILATION
CONDENSER ASSEMBLY
CONDENSER ASSEMBLY
REMOVAL AND INSTALLATION
M1552015401339
Pre-removal and Post-installation Operation
• Refrigerant Draining and Refilling (Refer to P.55-165).
• Headlight support upper panel Removal and Installation
(Refer to GROUP 42A, Loose panel P.42A-198).
-Pipe coupling
4.9 ± 0.9 N·m
43 ± 8 in-lb
2, 3
2
8
Radiator assembly
8N
A/C compressor oil:
SUN PAG 56
5
1
6
8N
4.9 ± 0.9 N·m
43 ± 8 in-lb
4
7
3
8N
9
AC901550AB
1.
<<A>>
<<A>>
2.
3.
4.
Removal steps
A/C pressure sensor connector
connection
Flexible discharge hose connection
Liquid pipe A connection
Condenser assembly
5.
6.
7.
8.
9.
Removal steps (Continued)
Clamp
Receiver
Joint
O-ring
Condenser
REMOVAL SERVICE POINT
.
<<A>> FLEXIBLE DISCHARGE HOSE AND LIQUID
PIPE A DISCONNECTION
CAUTION
As the compressor oil and receiver are highly moisture
absorbent, use a non-porous material to plug the hose and
nipples.
To prevent the entry of dust or other foreign bodies, plug the
dismantled hose and condenser assembly nipples.
TSB Revision
55-187
HEATER, AIR CONDITIONING AND VENTILATION
REFRIGERANT LINE
REFRIGERANT LINE
REMOVAL AND INSTALLATION
M1552006402516
Pre-removal and Post-installation Operation
Refrigerant Draining and Refilling (Refer to Charging and
Discharging P.55-165).
High-pressure
Side service valve
4.0 ± 2.0 N·m 7.0 ± 3.0 N·m
36 ± 17 in-lb 61 ± 26 in-lb
Low-pressure
Side service valve
1
3
8N
13 ± 1 N·m
115 ± 9 in-lb
4.9 ± 0.9 N·m
43 ± 8 in-lb
5
25 ± 4 N·m
18 ± 3 ft-lb
4.9 ± 0.9 N·m
43 ± 8 in·lb
8N
4
N
8
8N
2
7
-Pipe coupling
8 N 8 N
6
8N
3, 4, 5, 6, 7
4
8
A/C compressor oil: SUN PAG 56
AC901539 AC
<<A>>
<<A>>
<<A>>
1.
•
2.
8.
1.
3.
8.
1.
•
•
Expansion valve removal steps
<<A>>
Dash panel heat protector
Flexible suction hose and Liquid
pipe B connection
Expansion valve
O-ring
Flexible suction hose removal
steps
Dash panel heat protector
<<A>>
Flexible suction hose
O-ring
Liquid pipe B removal steps
Dash panel heat protector
Radiator condenser tank (Refer to
GROUP 14 −Radiator P.14-32)
Oil reservoir (Refer to GROUP 37 −
Power steering hose P.37-47)
TSB Revision
4.
8.
•
•
5.
8.
Liquid pipe B removal steps
Liquid pipe B
O-ring
Liquid pipe A removal steps
Radiator condenser tank (Refer to
GROUP 14 −Radiator P.14-32)
Headlight support upper panel
(Refer to GROUP 42A −Loose
panel P.42A-198)
Liquid pipe A
O-ring
55-188
HEATER, AIR CONDITIONING AND VENTILATION
REFRIGERANT LINE
•
•
•
<<A>>
<<A>>
6.
7.
8.
Flexible discharge hose and A/C
pressure sensor removal steps
Headlight support panel cover
(Refer to GROUP 51 −Front
bumper and radiator grille P.51-3)
Charge air cooler Intake pipe B
(Refer to GROUP 15 −Charge air
cooler P.15-12)
Engine room under cover front A
(Refer to GROUP 51 −under cover
P.51-15)
Flexible discharge hose
A/C pressure sensor
O-ring
REMOVAL SERVICE POINT
.
<<A>> HOSE/PIPE DISCONNECTION
CAUTION
As the compressor oil and receiver are highly moisture
absorbent, use a non-porous material to plug the hose and
nipples.
To prevent the entry of other foreign bodies, plug the condenser, compressor, and expansion valve nipples.
TSB Revision
55-189
HEATER, AIR CONDITIONING AND VENTILATION
DUCTS
DUCTS
REMOVAL AND INSTALLATION
M1553001001256
WARNING
For removal and installation of the passenger's side air bag module, always observe the service procedures described in GROUP 52B, Air Bag Module and Clock Spring P.52B-413.
4
3
1
2
5
9
7
8
6
8
AC709091AB
TSB Revision
55-190
HEATER, AIR CONDITIONING AND VENTILATION
VENTILATORS
•
1.
2.
3.
4.
•
5.
•
6.
Defroster nozzle and distribution
duct removal steps
Instrument panel (Refer to GROUP
52A P.52A-3).
Front center duct
Rear center duct
Ventilator air distribution duct &
Side defroster duct
Defroster nozzle
Foot duct and rear heater duct
removal steps
Instrument panel cover lower <MR>
(Refer to GROUP 52A, Instrument
panel lower panel P.52A-9).
Foot duct (driver’s side)
Glove box (Refer to GROUP 52A,
Glove box P.52A-7).
Foot duct (passenger’s side)
Foot duct and rear heater duct
removal steps
Floor console assembly (Refer to
GROUP 52A, Floor console
assembly P.52A-10).
Instrument panel under cover
(Refer to GROUP 52A, Instrument
center panel P.52A-8).
Rear heater duct A
Front seat assembly (Refer to
GROUP 52A, Front seat assembly
P.52A-21).
Glove box (Refer to GROUP 52A,
Glove box P.52A-7).
Front scuff plate, cowl side trim
(Refer to GROUP 52A, Trims
P.52A-12).
Floor carpet peeling
Rear heater duct B
Accelerator stopper (Refer to
GROUP 17, Accelerator cable and
pedal P.17-8).
Foot duct
•
•
7.
•
•
•
•
8.
•
9.
REMOVAL AND INSTALLATION
VENTILATORS
M1553001600675
Section A-A
Claw
Rear ventilation duct
Rear ventilation duct
A
A
Note
: Claw positions
AC705024AD
•
1.
Removal steps
Rear bumper assembly (Refer to
GROUP 51, P.51-6).
Rear ventilation duct
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