SEAT WARMER SYSTEM DOES NOT OPERATE [SEAT WARMER SYSTEM (E)]

id0903m20221r2

Note

• When the seat warmer switch is turned on with the ignition switched ON (engine on), the seat warmer system operates.

Outline

Description

•  The seat warmer does not operate even though the seat warmer switch is operated.

Possible cause

•  Connector or terminal malfunction of the following parts:

―  Seat warmer control unit

―  Seat warmer unit

•  Short or open circuit to ground in the following wiring harnesses

―  Seat warmer control unit power supply circuit

―  Seat warmer unit signal circuit

•  Short or open circuit to power supply in the following wiring harness

―  Seat warmer unit ground circuit

•  Seat warmer unit malfunction

•  Seat warmer control unit malfunction

Diagnostic Procedure

Step

Inspection

Results

Action

1

VERIFY ALL SYSTEM DTCs

•  Perform the DTC inspection.
(See DTC INSPECTION.)

•  Are any DTCs displayed?

Yes

Repair the malfunctioning location according to the applicable DTC troubleshooting.

No

Go to the next step.

2

INSPECT SEAT WARMER CONTROL UNIT AND SEAT WARMER UNIT CONNECTORS FOR MALFUNCTION

•  Inspect the applicable connector and terminal.
(See CONNECTOR INSPECTION.)

•  Are the connector and terminal normal?

Yes

Go to the next step.

No

Repair or replace the malfunctioning location and perform the repair completion verification.

3

INSPECT SEAT WARMER CONTROL UNIT POWER SUPPLY CIRCUIT FOR SHORT TO GROUND AND OPEN CIRCUIT

•  Inspect the power supply circuit for a short to ground and open circuit.
(See CIRCUIT INSPECTION.)

•  Is the circuit normal?

Yes

Go to the next step.

No

Repair or replace the malfunctioning location and perform the repair completion verification.

4

INSPECT SEAT WARMER UNIT SIGNAL CIRCUIT FOR SHORT TO GROUND AND OPEN CIRCUIT

•  Inspect the signal circuit for a short to ground and open circuit.
(See CIRCUIT INSPECTION.)

•  Is the circuit normal?

Yes

Go to the next step.

No

Repair or replace the malfunctioning location and perform the repair completion verification.

5

INSPECT SEAT WARMER UNIT GROUND CIRCUIT FOR SHORT TO POWER SUPPLY AND OPEN CIRCUIT

•  Inspect the ground circuit for a short to power supply and open circuit.
(See CIRCUIT INSPECTION.)

•  Is the circuit normal?

Yes

Go to the next step.

No

Repair or replace the malfunctioning location and perform the repair completion verification.

6

INSPECT SEAT WARMER UNIT FOR MALFUNCTION

•  Inspect the applicable part.
(See SEAT WARMER UNIT INSPECTION [(E)].)

•  Is the part normal?

Yes

Go to the next step.

No

Repair or replace the malfunctioning location and perform the repair completion verification.

(See FRONT SEAT BACK TRIM REMOVAL/INSTALLATION [(E)].)

(See FRONT SEAT CUSHION TRIM REMOVAL/INSTALLATION [(E)].)

Repair completion verification

VERIFY THAT VEHICLE IS REPAIRED

•  Install/connect the part removed/disconnected during the troubleshooting procedure.

•  Has the malfunction symptom been eliminated?

Yes

Complete the symptom troubleshooting. (Explain contents of repair to customer)

No

Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error.

(See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].)

If the CAN communication is normal, perform the diagnosis from Step 1.

•  If the malfunction is not resolved, replace the seat warmer control unit.
(See SEAT WARMER CONTROL UNIT REMOVAL/INSTALLATION [(E)].)

Description	• The seat warmer does not operate even though the seat warmer switch is operated.
Possible cause	• Connector or terminal malfunction of the following parts: ― Seat warmer control unit ― Seat warmer unit • Short or open circuit to ground in the following wiring harnesses ― Seat warmer control unit power supply circuit ― Seat warmer unit signal circuit • Short or open circuit to power supply in the following wiring harness ― Seat warmer unit ground circuit • Seat warmer unit malfunction • Seat warmer control unit malfunction

Step	Inspection	Results	Action
1	VERIFY ALL SYSTEM DTCs • Perform the DTC inspection. (See DTC INSPECTION.) • Are any DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting.
1		No	Go to the next step.
2	INSPECT SEAT WARMER CONTROL UNIT AND SEAT WARMER UNIT CONNECTORS FOR MALFUNCTION • Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) • Are the connector and terminal normal?	Yes	Go to the next step.
2		No	Repair or replace the malfunctioning location and perform the repair completion verification.
3	INSPECT SEAT WARMER CONTROL UNIT POWER SUPPLY CIRCUIT FOR SHORT TO GROUND AND OPEN CIRCUIT • Inspect the power supply circuit for a short to ground and open circuit. (See CIRCUIT INSPECTION.) • Is the circuit normal?	Yes	Go to the next step.
3		No	Repair or replace the malfunctioning location and perform the repair completion verification.
4	INSPECT SEAT WARMER UNIT SIGNAL CIRCUIT FOR SHORT TO GROUND AND OPEN CIRCUIT • Inspect the signal circuit for a short to ground and open circuit. (See CIRCUIT INSPECTION.) • Is the circuit normal?	Yes	Go to the next step.
4		No	Repair or replace the malfunctioning location and perform the repair completion verification.
5	INSPECT SEAT WARMER UNIT GROUND CIRCUIT FOR SHORT TO POWER SUPPLY AND OPEN CIRCUIT • Inspect the ground circuit for a short to power supply and open circuit. (See CIRCUIT INSPECTION.) • Is the circuit normal?	Yes	Go to the next step.
5		No	Repair or replace the malfunctioning location and perform the repair completion verification.
6	INSPECT SEAT WARMER UNIT FOR MALFUNCTION • Inspect the applicable part. (See SEAT WARMER UNIT INSPECTION [(E)].) • Is the part normal?	Yes	Go to the next step.
6		No	Repair or replace the malfunctioning location and perform the repair completion verification. (See FRONT SEAT BACK TRIM REMOVAL/INSTALLATION [(E)].) (See FRONT SEAT CUSHION TRIM REMOVAL/INSTALLATION [(E)].)
Repair completion verification	VERIFY THAT VEHICLE IS REPAIRED • Install/connect the part removed/disconnected during the troubleshooting procedure. • Has the malfunction symptom been eliminated?	Yes	Complete the symptom troubleshooting. (Explain contents of repair to customer)
Repair completion verification		No	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].) If the CAN communication is normal, perform the diagnosis from Step 1. • If the malfunction is not resolved, replace the seat warmer control unit. (See SEAT WARMER CONTROL UNIT REMOVAL/INSTALLATION [(E)].)