Check The Harness Circuit (Rear)

CHECK POWER SUPPLY CIRCUIT .
1. Disconnect the harness connector of the rear seat heater control module.
2. Measure the voltage between harness connector terminal and chassis ground.
  Connector and terminal
  
  (R83) No. 14 (+) - Chassis ground (-):
  
  Is the voltage 10 V or more?
  
  Yes : Go to 2 .
  
  No : Repair or replace the harness.
CHECK POWER SUPPLY CIRCUIT .
1. Turn the ignition switch to ON.
2. Measure the voltage between harness connector terminal and chassis ground.
  Connector and terminal
  
  (R83) No. 5 (+) - Chassis ground (-):
  
  Is the voltage 10 V or more?
  
  Yes : Go to 3 .
  
  No : Repair or replace the harness.
CHECK GROUND CIRCUIT .
Measure the resistance between harness connector terminal and chassis ground.

Connector and terminal

(R83) No. 7 - Chassis ground:

Is the resistance less than 10 Ω?

Yes : Go to 4 .

No : Repair the harness.
CHECK HARNESS .
Measure the resistance between rear seat heater control module and rear seat heater switch terminal.

Connector and terminal

(R84) No. 14 - (R34) No. 8:

(R84) No. 16 - (R34) No. 7:

(R84) No. 6 - (R34) No. 6:

(R84) No. 4 - (R33) No. 8:

(R84) No. 2 - (R33) No. 7:

(R84) No. 8 - (R33) No. 6:

Is the resistance less than 10 Ω?

Yes : Check the rear seat heater unit. Ref. to SEATS>SEAT HEATER SYSTEM>INSPECTION>SEAT HEATER UNIT (REAR) .

No : Repair the harness.