Seat Heater System: Inspection

Fig 1: Identifying Seat Heater Switch

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 2: Identifying Seat Heater Switch Continuity Chart

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If the continuity is not as specified, replace the switch.

1. Connect the positive (+) lead from the battery to terminal 4 and the negative (-) lead to terminal 6.
2. Push the left and right seat heater HI and LO switches. Check if the indicator lights illuminate.
   Fig 3: Identifying Seat Heater Indicator Light Operation

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   If operation is not as specified, replace the switch and inspect the circuits connected to other parts.

1. Heat the thermostat with a light.
2. Check the seat heater continuity between terminals.
   Fig 4: Inspecting Seat Heater Cushion

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   SEAT HEATER CUSHION CONTINUITY
   
   

   Tester Connection	Condition	Specified Condition
   A3 - B2	Constant	Continuity
   A1 - A2	Seat heater temperature below 25°C (77°F)	Continuity
   A2 - B1	Seat heater temperature below 25°C (77°F)	Continuity
   A1 - A2	Seat heater temperature above 45°C (113°F)	No continuity
   A2 - B1	Seat heater temperature above 45°C (113°F)	No continuity

   If the continuity is not as specified, replace the seat cushion pad.

Check the seat heater continuity between the terminals, as shown in IDENTIFYING SEAT BACK CONTINUITY .

Fig 5: Identifying Seat Back

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If the continuity is not as specified, replace the seat back pad.