Seat Heater System: Inspection

Inspect seat heater switch continuity :

Fig 1: Identifying Seat Heater Switch Positions & Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 2: Seat Heater Switch Specifications Chart
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If the continuity is not as specified, replace the switch.
Inspect seat heater indicator light operation :
1. Connect the positive (+) lead from the battery to terminal 3 and the negative (-) lead to terminal 2.
  
  Fig 3: Identifying Seat Heater Light & Connector Terminals
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Push the seat heater switch right or left side and check that the indicator light lights up.
  If the operation is not as specified, replace the switch.
Inspect seat heater switch circuit :
Disconnect the switch connector and inspect the connector on the wire harness side.

Fig 4: Identifying Seat Heater Switch Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 5: Seat Heater Switch Specifications Chart
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If the circuit is not as specified, inspect the circuits connected to other parts.
Inspect seat cushion heater continuity :
1. Heat the thermostats with a light.
2. Inspect the seat cushion heater continuity between the terminals.
  
  Fig 6: Identifying Seat Cushion Heater Cushion Thermostat & Terminals
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 7: Seat Cushion Heater Switch Specifications Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  If the continuity is not as specified, replace the seat cushion heater.
Inspect seat back heater continuity :
Inspect the seat back heater continuity between the terminals.

Fig 8: Identifying Seat Back Heater Cushion Thermostat & Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 9: Seat Back Heater Switch Specifications Chart
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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