Check Power Supply And Ground Circuit (Front)

1. Disconnect the harness connector of seat heater switch.
2. Turn the ignition switch to ON.
3. Measure the voltage between harness connector terminal and chassis ground.

   Connector & terminal 

   Driver's seat: (R42) No. 4 (+) - Chassis ground (-):

   Passenger's seat: (R45) No. 4 (+) - Chassis ground (-):

Is the voltage 12 V or more?

• Yes: Go to 2  .
• No: Check the harness between the seat heater switch and fuse.

Measure the resistance between harness connector terminal and chassis ground.

Connector & terminal 

Driver's seat: (R42) No. 6 - Chassis ground:

Passenger's seat: (R45) No. 6 - Chassis ground:

Is the resistance less than 10 Ω?

• Yes: Go to 3  .
• No: Repair the harness.

Measure the resistance between seat heater switch terminals.

Connector & terminal 

Driver's seat: (R42) No. 4 - (R42) No. 6:

Passenger's seat: (R45) No. 4 - (R45) No. 6:

Is the resistance less than 10 Ω?

• Yes: The power supply and ground circuit are OK.
• No: Replace the seat heater switch. Ref. to SEATS>Seat Heater System>REMOVAL>SEAT HEATER SWITCH - FRONT .