TEMPERATURE FOR SEAT WARMER SYSTEM CANNOT BE ADJUSTED [SEAT WARMER SYSTEM]

id0903m2971000

Caution
•  Vehicle specifications differ depending on the vehicle identification number (VIN).
?  Type A VIN:
JM0 TC2WLA*# 100001—300000
JM0 TC4WLA*# 100001—300000
JMZ TB5WYA*# 100001—600000
JMZ TB6WYA*# 100001—600000
JMZ TBEWYA*# 100001—600000
JMZ TBFWYA*# 100001—600000
JM7 TC2WLA*# 100001—300000
JM7 TC4WLA*# 100001—300000
JM5 TCAWY**# 100001—300000
JM6 TC2WLA*# 100001—300000
JM6 TC4WLA*# 100001—300000
?  Type B VIN:
JM0 TC2WLA*# 300001—400000
JM0 TC4WLA*# 300001—400000
JMZ TB5WYA*# 600001—700000
JMZ TB6WYA*# 600001—700000
JMZ TBEWYA*# 600001—700000
JMZ TBFWYA*# 600001—700000
JM7 TC2WLA*# 300001—400000
JM7 TC4WLA*# 300001—400000
JM5 TCAWY**# 300001—400000
JM6 TC2WLA*# 300001—400000
JM6 TC4WLA*# 300001—400000
?  Type C VIN:
JM0 TC2WLA*# 400001—
JM0 TC4WLA*# 400001—
JMZ TB5WYA*# 700001—
JMZ TB6WYA*# 700001—
JMZ TBEWYA*# 700001—
JMZ TBFWYA*# 700001—
JM7 TC2WLA*# 400001—
JM7 TC4WLA*# 400001—
JM5 TCAWY**# 400001—
JM6 TC2WLA*# 400001—
JM6 TC4WLA*# 400001—

Front Seat Warmer


Type A VIN:

Description
•  The temperature of the front seat warmer cannot be adjusted (temperature level cannot be switched).
•  The front seat warmer temperature continues to rise.
Possible Causes
•  Front seat warmer switch malfunction
•  Thermistor (built into front seat warmer unit) malfunction
•  Front seat warmer control unit malfunction
•  Short to power supply in wiring harness between the following terminals:
?  Front seat warmer control unit terminal I and indicator unit terminal D

Diagnostic procedure

Step

Inspection

Action
1
DETERMINE IF MALFUNCTION CAUSE IS FRONT SEAT WARMER SWITCH
•  Inspect the indicator unit.
•  Is the indicator unit normal?
Yes
Go to the next step.
No
Replace the indicator unit, then go to Step 4.
(See INDICATOR UNIT REMOVAL/INSTALLATION.)
2
VERIFY IF MALFUNCTION CAUSE IS FRONT SEAT WARMER UNIT
•  Switch the ignition OFF.
•  Inspect the thermistor built into the front seat warmer unit.
•  Is the front seat warmer unit normal?
Yes
Go to the next step.
No
Replace the front seat warmer unit (front seat cushion pad or front seat back pad) which has a malfunction, then go to Step 4.
(See FRONT SEAT CUSHION TRIM REMOVAL/INSTALLATION.)
(See FRONT SEAT BACK TRIM REMOVAL/INSTALLATION.)
3
DETERMINE IF MALFUNCTION CAUSE IS FRONT SEAT WARMER CONTROL UNIT
•  Disconnect the negative battery terminal.
•  Disconnect the front seat warmer control unit connector.
•  Connect the negative battery terminal.
•  Switch the ignition ON (engine off or on).
•  Measure the voltage at front seat warmer control unit terminal I (vehicle wiring harness side).
•  Is the voltage 1.0 V or more?
Yes
•  Refer to the wiring diagram and verify if there is a common connector between the following terminals.
?  Front seat warmer control unit terminal I and indicator unit terminal D
If there is a common connector:
•  Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short to power supply to determine the malfunctioning location.
•  Repair or replace the wiring harness which is shorted to the power supply.
If there is no common connector:
•  Repair or replace the wiring harness which is shorted to the power supply.
•  Go to the next step.
No
Replace the front seat warmer control unit, then go to the next step.
(See FRONT SEAT WARMER CONTROL UNIT REMOVAL/INSTALLATION.)
4
VERIFY IF MALFUNCTION CAUSE IS CORRECTED
•  Switch the ignition ON (engine off or on).
•  Operate the front seat warmer switch to turn on the front seat warmer system.
•  Does the front seat warmer system operate normally?
Yes
Troubleshooting completed. (Explain the contents of the servicing to the customer.)
No
Verify the malfunction symptom in the symptom troubleshooting chart and perform the other applicable malfunction diagnosis.
(See SYMPTOM TROUBLESHOOTING [SEAT WARMER SYSTEM].)


Type B,C VIN:

Description
•  The temperature of the front seat warmer cannot be adjusted (temperature level cannot be switched).
•  The front seat warmer temperature continues to rise.
Possible Causes
•  Front seat warmer switch malfunction
•  Thermistor (built into front seat warmer unit) malfunction
•  Front seat warmer control unit malfunction
•  Short to power supply in wiring harness between the following terminals:
?  Front seat warmer control unit terminal I and front climate control unit terminal 1X

Diagnostic procedure

Step

Inspection

Action
1
DETERMINE IF MALFUNCTION CAUSE IS FRONT SEAT WARMER SWITCH
•  Inspect the front climate control unit.
•  Is the front climate control unit normal?
Yes
Go to the next step.
No
Replace the front climate control unit, then go to Step 4.
(See FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.)
2
VERIFY IF MALFUNCTION CAUSE IS FRONT SEAT WARMER UNIT
•  Switch the ignition OFF.
•  Inspect the thermistor built into the front seat warmer unit.
•  Is the front seat warmer unit normal?
Yes
Go to the next step.
No
Replace the front seat warmer unit (front seat cushion pad or front seat back pad) which has a malfunction, then go to Step 4.
(See FRONT SEAT CUSHION TRIM REMOVAL/INSTALLATION.)
(See FRONT SEAT BACK TRIM REMOVAL/INSTALLATION.)
3
DETERMINE IF MALFUNCTION CAUSE IS FRONT SEAT WARMER CONTROL UNIT
•  Disconnect the negative battery terminal.
•  Disconnect the front seat warmer control unit connector.
•  Connect the negative battery terminal.
•  Switch the ignition ON (engine off or on).
•  Measure the voltage at front seat warmer control unit terminal I (vehicle wiring harness side).
•  Is the voltage 1.0 V or more?
Yes
•  Refer to the wiring diagram and verify if there is a common connector between the following terminals.
?  Front seat warmer control unit terminal I and front climate control unit terminal 1X
If there is a common connector:
•  Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short to power supply to determine the malfunctioning location.
•  Repair or replace the wiring harness which is shorted to the power supply.
If there is no common connector:
•  Repair or replace the wiring harness which is shorted to the power supply.
•  Go to the next step.
No
Replace the front seat warmer control unit, then go to the next step.
(See FRONT SEAT WARMER CONTROL UNIT REMOVAL/INSTALLATION.)
4
VERIFY IF MALFUNCTION CAUSE IS CORRECTED
•  Switch the ignition ON (engine off or on).
•  Operate the front seat warmer switch to turn on the front seat warmer system.
•  Does the front seat warmer system operate normally?
Yes
Troubleshooting completed. (Explain the contents of the servicing to the customer.)
No
Verify the malfunction symptom in the symptom troubleshooting chart and perform the other applicable malfunction diagnosis.
(See SYMPTOM TROUBLESHOOTING [SEAT WARMER SYSTEM].)


Second-row Seat Warmer

Description
•  The temperature of the second-row seat warmer cannot be adjusted (temperature level cannot be switched).
•  The second-row seat warmer temperature continues to rise.
Possible Causes
•  Second-row seat warmer switch malfunction
•  Thermistor (built into second-row seat warmer unit) malfunction
•  Second-row seat warmer control unit malfunction
•  Short to power supply in wiring harness between the following terminals:
?  Second-row seat warmer control unit terminal J and rear climate control unit terminal T

Diagnostic procedure

Step

Inspection

Action
1
DETERMINE IF MALFUNCTION CAUSE IS SECOND-ROW SEAT WARMER SWITCH
•  Inspect the rear climate control unit.
•  Is the rear climate control unit normal?
Yes
Go to the next step.
No
Replace the rear climate control unit, then go to Step 4.
(See REAR CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.)
2
VERIFY IF MALFUNCTION CAUSE IS SECOND-ROW SEAT WARMER UNIT
•  Switch the ignition OFF.
•  Inspect the thermistor built into the second-row seat warmer unit.
•  Is the second-row seat warmer unit normal?
Yes
Go to the next step.
No
Replace the second-row seat warmer unit (second-row seat) which has a malfunction, then go to Step 4.
(See SECOND-ROW SEAT REMOVAL/INSTALLATION.)
3
DETERMINE IF MALFUNCTION CAUSE IS SECOND-ROW SEAT WARMER CONTROL UNIT
•  Disconnect the negative battery terminal.
•  Disconnect the second-row seat warmer control unit connector.
•  Connect the negative battery terminal.
•  Switch the ignition ON (engine off or on).
•  Measure the voltage at second-row seat warmer control unit terminal I (vehicle wiring harness side).
•  Is the voltage 1.0 V or more?
Yes
•  Refer to the wiring diagram and verify if there is a common connector between the following terminals.
?  Second-row seat warmer control unit terminal J and rear climate control unit terminal T
If there is a common connector:
•  Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short to power supply to determine the malfunctioning location.
•  Repair or replace the wiring harness which is shorted to the power supply.
If there is no common connector:
•  Repair or replace the wiring harness which is shorted to the power supply.
•  Go to the next step.
No
Replace the second-row seat warmer control unit, then go to the next step.
(See SECOND-ROW SEAT REMOVAL/INSTALLATION.)
4
VERIFY IF MALFUNCTION CAUSE IS CORRECTED
•  Switch the ignition ON (engine off or on).
•  Operate the second-row seat warmer switch to turn on the second-row seat warmer system.
•  Does the second-row seat warmer system operate normally?
Yes
Troubleshooting completed. (Explain the contents of the servicing to the customer.)
No
Verify the malfunction symptom in the symptom troubleshooting chart and perform the other applicable malfunction diagnosis.
(See SYMPTOM TROUBLESHOOTING [SEAT WARMER SYSTEM].)