Seat Heater System: Inspection

1. Inspect the seat heater switch continuity.
   CONTINUITY CHECK BETWEEN TERMINAL CHARTS
   
   

   Condition	Tester Connection	Specified Condition
   Constant	1 <=> 2 <=> 6 6 <=> 9 <=> 10 6 <=> 7	Continuity
   ON (Driver's Side Or Passenger's Side)	3 <=> 6	Continuity

   Fig 1: Identifying Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

2. Inspect seat heater switch indicator.
   1. Connect the positive (+) lead from the battery to terminal 7 and the negative (-) lead to terminal 6.
   2. Turn the driver's side and passenger's side heater switch ON and check that the each indicators light UP.

   If the operation is not as specified, replace the seat heater switch.

   Fig 2: Testing Seat Heater Switch Indicator

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Inspect the seat heater switch resistance.
   CONTINUITY CHECK BETWEEN TERMINAL CHARTS
   
   

   Tester Condition	Resistance
   1 <=> 6 6 <=> 10	Refer to illustration

If the resistance value is not as specified, replace the seat heater switch.

Fig 3: Testing Seat Heater Switch Varying Resistance

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Inspect the seat back heater assembly LH and RH continuity.
   CONTINUITY CHECK BETWEEN TERMINAL CHARTS
   
   

   Condition	Tester Connection	Specified Condition
   Constant	1 <=> 4	Continuity

   Fig 4: Identifying Front Seat Back Heater Assy Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If continuity is not as specified, replace the front seat back cover assembly.

1. Inspect the seat cushion heater assembly LH and RH continuity.
   CONTINUITY CHECK BETWEEN TERMINAL CHARTS
   
   

   Condition	Tester Connection	Specified Condition
   Constant	1 <=> 2	Continuity

   Fig 5: Identifying Front Seat Cushion Heater Assy Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   If continuity is not as specified, replace the front seat cushion cover assembly.

2. Inspect the seat cushion thermostat continuity.
   1. Disconnect the seat back heater from the seat cushion heater.
   2. Heat the thermostat with a light.
   3. Inspect the seat cushion heater continuity between terminals, as shown.
      Fig 6: Identifying Front Seat Cushion Heater Assy Terminals

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   CONTINUITY CHECK BETWEEN TERMINAL CHARTS
   
   

   Tester Connection	Condition	Specified Condition
   1 <=> 2	Seat heater temp. below 25 - 35°C(77 - 95°F)	Continuity
   	Seat heater temp. 25 - 35°C(77 - 95°F)	No continuity

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

1. Disconnect the 3 connectors.
2. Inspect the seat heater control.
   CONTINUITY CHECK BETWEEN TERMINAL CHARTS
   
   

   Tester Condition	Connection	Specified Condition
   1 <=> Body ground	Constant	Continuity
   1 <=> 2 1 <=> 3	Seat heater switch OFF	Continuity
   1 <=> 2 1 <=> 3	Seat heater switch ON	10 - 14 V
   4 <=> Body ground	Constant	10 - 14 V

If the value is not as specified, replace the seat heater control.

Fig 7: Identifying Seat Heater Control Sub-Assembly Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002