SEAT WARMER SYSTEM OPERATES CONSTANTLY [SEAT WARMER SYSTEM]


id0903m2970900


Front Seat Warmer

Description
The front seat warmer warms the seat even though the front seat warmer switch is turned off.
Possible Causes
•  Front seat warmer switch 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*1/F*2 and front climate control unit terminal 1X

*1  :Without seat ventilation system
*2  :With seat ventilation system

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 3.
2
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*1/F*2 (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*1/F*2 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.
3
VERIFY IF MALFUNCTION CAUSE IS CORRECTED
•  Reconnect all the disconnected connectors.
•  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.

*1  :Without seat ventilation system
*2  :With seat ventilation system

Second-row Seat Warmer


Bench seat type

Description
The second-row seat warmer warms the seat even though the second-row seat warmer switch is turned off.
Possible Causes
•  Second-row seat warmer switch malfunction
•  Second-row seat warmer unit malfunction
•  Short to power supply in wiring harness between the following terminals:
―  Second-row seat warmer 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 3.
2
DETERMINE IF MALFUNCTION CAUSE IS SECOND-ROW SEAT WARMER 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 J (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.
3
VERIFY IF MALFUNCTION CAUSE IS CORRECTED
•  Reconnect all the disconnected connectors.
•  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.


Separate seat type

Description
The second-row seat warmer warms the seat even though the second-row seat warmer switch is turned off.
Possible Causes
•  Second-row seat warmer switch malfunction
•  Second-row seat warmer unit malfunction
•  Short to power supply in wiring harness between the following terminals:
―  Second-row seat warmer unit terminal J and second-row seat heater switch terminal C

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 3.
2
DETERMINE IF MALFUNCTION CAUSE IS SECOND-ROW SEAT WARMER 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 J (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 second-row seat heater switch terminal C
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.
3
VERIFY IF MALFUNCTION CAUSE IS CORRECTED
•  Reconnect all the disconnected connectors.
•  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.