SEAT WARMER SYSTEM OPERATES CONSTANTLY [SEAT WARMER SYSTEM]

id0903m2970900

Front seat side (Type A)

Description

The seat warmer warms the seat even though the 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 J and indicator unit terminal D

Diagnostic Procedure

Step	Inspection		Action
1	DETERMINE IF MALFUNCTION CAUSE IS FRONT 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	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.
2		No	Replace the front seat warmer control unit, then go to the next step. (See FRONT SEAT WARMER CONTROL UNIT REMOVAL/INSTALLATION.)
3	VERIFY IF MALFUNCTION CAUSE IS CORRECTED • Reconnect all the disconnected connectors. • 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.)
3		No	Verify the malfunction symptom in the symptom troubleshooting chart and perform the other applicable malfunction diagnosis. (See SYMPTOM TROUBLESHOOTING [SEAT WARMER SYSTEM].)

Front seat side (Type B)

With seat ventilation system

Description

The seat warmer warms the seat even though the seat warmer switch is turned off.

Possible Causes

•  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 F and front climate control unit terminal 1X

Diagnostic Procedure

Step	Inspection		Action
1	DETERMINE IF MALFUNCTION CAUSE IS SEAT WARMER SWITCH • Inspect the front climate control unit. (See FRONT CLIMATE CONTROL UNIT INSPECTION.) • Is the front climate control unit normal?	Yes	Go to the next step.
1		No	Replace the front climate control unit. (See FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.)
2	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 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.
2		No	Replace the front seat warmer control unit, then go to the next step. (See FRONT SEAT WARMER CONTROL UNIT REMOVAL/INSTALLATION.)
3	VERIFY IF MALFUNCTION CAUSE IS CORRECTED • Reconnect all the disconnected connectors. • 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.)
3		No	Verify the malfunction symptom in the symptom troubleshooting chart and perform the other applicable malfunction diagnosis. (See SYMPTOM TROUBLESHOOTING [SEAT WARMER SYSTEM].)

Without seat ventilation system

Diagnostic Procedure

Step	Inspection		Action
1	DETERMINE IF MALFUNCTION CAUSE IS FRONT SEAT WARMER SWITCH • Inspect the front climate control unit. (See FRONT CLIMATE CONTROL UNIT INSPECTION.) • Is the front climate control unit normal?	Yes	Go to the next step.
1		No	Replace the front climate control unit. (See FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.)
2	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 front climate control 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.
2		No	Replace the front seat warmer control unit, then go to the next step. (See FRONT SEAT WARMER CONTROL UNIT REMOVAL/INSTALLATION.)
3	VERIFY IF MALFUNCTION CAUSE IS CORRECTED • Reconnect all the disconnected connectors. • 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.)
3		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 side

Description

The seat warmer warms the seat even though the seat warmer switch is turned off.

Possible Causes

•  Second-row seat warmer switch 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 C

Diagnostic Procedure

Step

Inspection

Action

1

DETERMINE IF MALFUNCTION CAUSE IS SECOND-ROW SEAT WARMER SWITCH

•  Inspect the rear climate control unit.
(See REAR CLIMATE CONTROL UNIT INSPECTION.)

•  Is the rear climate control unit normal?

Yes

Go to the next step.

No

Replace the rear climate control unit.

(See REAR CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.)

2

DETERMINE IF MALFUNCTION CAUSE IS SECOND-ROW SEAT WARMER CONTROL UNIT

•  Disconnect the negative battery terminal.
(See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.)

•  Disconnect the second-row 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 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 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.

(See SECOND-ROW SEAT WARMER CONTROL UNIT REMOVAL/INSTALLATION.)

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.

(See SYMPTOM TROUBLESHOOTING [SEAT WARMER SYSTEM].)

Description	The seat warmer warms the seat even though the 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 J and indicator unit terminal D

Step	Inspection		Action
1	DETERMINE IF MALFUNCTION CAUSE IS SECOND-ROW SEAT WARMER SWITCH • Inspect the rear climate control unit. (See REAR CLIMATE CONTROL UNIT INSPECTION.) • Is the rear climate control unit normal?	Yes	Go to the next step.
1		No	Replace the rear climate control unit. (See REAR CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.)
2	DETERMINE IF MALFUNCTION CAUSE IS SECOND-ROW SEAT WARMER CONTROL UNIT • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Disconnect the second-row 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 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 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.
2		No	Replace the second-row seat warmer control unit, then go to the next step. (See SECOND-ROW SEAT WARMER CONTROL UNIT REMOVAL/INSTALLATION.)
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.)
3		No	Verify the malfunction symptom in the symptom troubleshooting chart and perform the other applicable malfunction diagnosis. (See SYMPTOM TROUBLESHOOTING [SEAT WARMER SYSTEM].)