Illumination Of Rear Seat Heater Switch Does Not Illuminate

CHECK ADAPTER HARNESS .
1. Remove the seat heater switch. Ref. to EXTERIOR/INTERIOR TRIM>CONSOLE BOX>DISASSEMBLY>CONSOLE REAR .
2. Check the continuity between the adapter harness connectors.
Connector & terminal

LH side:

(C3) No. 7 - (C34) No. 5:

(C3) No. 8 - (C34) No. 3:

RH side:

(C3) No. 7 - (C33) No. 5:

(C3) No. 8 - (C33) No. 3:

Is there continuity between the terminals?

Yes: Go to 2.

No: If no continuity exists, replace the adapter harness.
CHECK SEAT HEATER SWITCH UNIT .
Apply battery voltage between seat heater switch terminals, and perform the inspection.

CAUTION: When applying battery voltage, do not mix up the positive (+) side and the negative (?) side. Incorrect polarity connection may cause LED damage inside the switch.

Connector & terminal

LH side:

No. 5 (+) - No. 3 (?):

RH side:

No. 5 (+) - No. 3 (?):

Courtesy of SUBARU OF AMERICA, INC.

Do the illuminations come on?

Yes: Go to 3.

No: If the indicator does not illuminate, replace the seat heater switch with a new part. Ref. to SEATS>SEAT HEATER SYSTEM>REMOVAL>REAR SEAT HEATER SWITCH .
CHECK POWER SUPPLY CIRCUIT .
1. Turn the ignition switch to ON.
2. Set the lighting switch to the switch 1 (TAIL) or switch 2 (HEAD).
3. Measure the voltage between harness connector terminal and chassis ground.
Connector & terminal

(R58) No. 2 (+) - Chassis ground (?):

(R58) No. 4 (+) - Chassis ground (?):

Is the voltage 10 V or more?

Yes: Go to 8.

No: Go to 4.
CHECK HARNESS .
1. Turn the ignition switch to OFF.
2. Disconnect the connector of body integrated unit.
3. Measure the resistance between terminals of the seat heater switch and the body integrated unit.
Connector & terminal

(R58) No. 7 - (B71) No. 11:

Is the resistance less than 10 Ω?

Yes: Go to 5.

No: Repair or replace the harness.
CHECK INPUT OF BODY INTEGRATED UNIT .
1. Turn the ignition switch to ON.
2. Using Subaru Select Monitor, display [Lighting I Switch Input] in [Data Monitor] of [Body Control].
3. Set the lighting switch to the switch 1 (TAIL) position and remove your hand.
Does the indication change between [OFF] ←→ [ON] according to the switch operation?

Yes: Replace the body integrated unit. Ref. to BODY CONTROL/COMMUNICATION SYSTEM>BODY INTEGRATED UNIT .

No: Go to 6.
CHECK LIGHTING SWITCH .
1. Turn the ignition switch to OFF.
2. Check the lighting switch. Ref. to LIGHTING SYSTEM>COMBINATION SWITCH (LIGHT)>INSPECTION>LIGHTING SWITCH .
Is the lighting switch OK?

Yes: Go to 7.

No: Replace the lighting switch. Ref. to LIGHTING SYSTEM>COMBINATION SWITCH (LIGHT) .
CHECK HARNESS .
1. Disconnect the connectors of body integrated unit and combination switch (light).
2. Measure the resistance between terminals of the body integrated unit and the combination switch (light).
Connector & terminal

For U4 and U5

(i83) No. 20 - (i131) No. 19:

(i82) No. 35 - (i131) No. 18:

Except for U4 and U5

(i83) No. 20 - (i131) No. 18:

(i82) No. 35 - (i131) No. 19:

Is the resistance less than 10 Ω?

Yes: Replace the body integrated unit. Ref. to BODY CONTROL/COMMUNICATION SYSTEM>BODY INTEGRATED UNIT .

No: Repair or replace the harness.
CHECK HARNESS .
1. Turn the ignition switch to OFF.
2. Disconnect the connector of combination meter.
3. Measure the resistance between terminals of the seat heater switch and the combination meter.
Connector & terminal

(R58) No. 8 - (i97) No. 34:

Is the resistance less than 10 Ω?

Yes: Go to 9.

No: Repair or replace the harness.
CHECK HARNESS .
Measure the resistance between the combination meter and the chassis ground.

Connector & terminal

(i97) No. 40 - Chassis ground:

Is the resistance less than 10 Ω?

Yes: Replace the combination meter. Ref. to INSTRUMENTATION/DRIVER INFO>COMBINATION METER .

No: Repair or replace the harness.