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

id0903m2971000

Type A

Description

•  The temperature of the seat warmer cannot be adjusted (temperature level cannot be switched).

•  The seat warmer temperature continues to rise.

Possible Causes

•  Seat warmer switch malfunction

•  Thermistor (built into 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 J and indicator unit terminal D

Diagnostic Procedure

Step	Inspection		Action
1	DETERMINE IF MALFUNCTION CAUSE IS SEAT WARMER SWITCH • Inspect the indicator unit. (See INDICATOR UNIT INSPECTION.) • Is the indicator unit normal?	Yes	Go to the next step.
1		No	Replace the indicator unit. (See INDICATOR UNIT REMOVAL/INSTALLATION.)
2	VERIFY IF MALFUNCTION CAUSE IS SEAT WARMER UNIT • Switch the ignition OFF. • Inspect the thermistor built into the seat warmer unit. (See FRONT SEAT WARMER UNIT INSPECTION.) • Is the seat warmer unit normal?	Yes	Go to the next step.
2		No	Replace the 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. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Disconnect the front seat warmer control unit connector. • Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Switch the ignition ON (engine off or on). • Measure the voltage at front 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. ― Front seat warmer control unit terminal J 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.
3		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 seat warmer switch to turn on the seat warmer system. • Does the seat warmer system operate normally?	Yes	Troubleshooting completed. (Explain the contents of the servicing to the customer.)
4		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

Diagnostic Procedure

Step	Inspection		Action
1	DETERMINE IF MALFUNCTION CAUSE IS SEAT WARMER SWITCH • Inspect the indicator unit. (See INDICATOR UNIT INSPECTION.) • Is the indicator unit normal?	Yes	Go to the next step.
1		No	Replace the indicator unit. (See INDICATOR UNIT REMOVAL/INSTALLATION.)
2	VERIFY IF MALFUNCTION CAUSE IS SEAT WARMER UNIT • Switch the ignition OFF. • Inspect the thermistor built into the seat warmer unit. (See FRONT SEAT WARMER UNIT INSPECTION.) • Is the seat warmer unit normal?	Yes	Go to the next step.
2		No	Replace the 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. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Disconnect the front seat warmer control unit connector. • Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Switch the ignition ON (engine off or on). • Measure the voltage at front seat warmer control unit terminal F (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 F 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.
3		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 seat warmer switch to turn on the seat warmer system. • Does the seat warmer system operate normally?	Yes	Troubleshooting completed. (Explain the contents of the servicing to the customer.)
4		No	Verify the malfunction symptom in the symptom troubleshooting chart and perform the other applicable malfunction diagnosis. (See SYMPTOM TROUBLESHOOTING [SEAT WARMER SYSTEM].)

Description	• The temperature of the seat warmer cannot be adjusted (temperature level cannot be switched). • The seat warmer temperature continues to rise.
Possible Causes	• Seat warmer switch malfunction • Thermistor (built into 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 J and indicator unit terminal D