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Seat Heater System: Inspection

  1. INSPECT FUSE 
    1. Remove the D S/HTR fuse from the driver side J/B.
    2. Remove the P S/HTR fuse from the passenger side J/B.
    3. Remove the RR S/HTR fuse from the luggage room J/B.
    4. Remove the P-IG fuse from the passenger side J/B.
    5. Measure the resistance.

      Standard: Below 1 Ω 

    If the result is not as specified, replace the fuse.

  2. INSPECT RELAY (Marking: D-IG1, P-IG1, L-IG1) 
    1. Remove the D-IG1 relay from the driver side J/B.
    2. Remove the P-IG1 relay from the passenger side J/B.
    3. Remove the L-IG1 relay from the luggage room J/B.
    4. Measure the resistance.

      Standard: 

      TESTER CONDITION SPECIFICATION

      Tester Condition Specified Condition
      3 - 5 10 kΩ or higher
      3 - 5 Below 1 Ω (when battery voltage is applied to terminals 1 and 2)

      If the result is not as specified, replace the relay.

      Fig 1: Inspecting Fuse
      G03525350Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. INSPECT FRONT SEAT HEATER SWITCH 
    1. Driver's side:

      Measure the resistance between the terminals when the switch is operated.

      Standard: 

      SWITCH CONDITION SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      12 (THL) - 14 (IG) Switch ON (LH) (Min. to Max.) 5.6 kΩ to 3.3 kΩ

      HINT:

      As the dial is being turned, the resistance changes gradually.

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

    2. Passenger's side:

      Measure the resistance between the terminals when the switch is operated.

      Standard: 

      SWITCH CONDITION SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      14 (IG) - 16 (THR) Switch ON (RH) (Min. to Max.) 5.6 kΩ to 3.3 kΩ

      HINT:

      As the dial is being turned, the resistance changes gradually. If the result is not as specified, replace the switch.

      Fig 2: Inspecting Front Seat Heater Switch
      G03525351Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. INSPECT REAR SEAT HEATER SWITCH 
    1. Turn the ignition switch to the ON position.
    2. Measure the voltage of the wire harness side connector.

      Standard: 

      SWITCH CONDITION SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      S62-2(HIL) - Body ground Switch ON (Switch L) 10 to 14 V
      S62-5(HIR)- Body ground Switch ON (Switch R) 10 to 14 V

      If the result is not as specified, replace the switch assy.

      Fig 3: Inspecting Rear Seat Heater Switch
      G03525352Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  5. CHECK WIRE HARNESS (FRONT) 
    1. Disconnect the T7 switch, S40 and S41 seat heater connectors.
    2. Measure the voltage of the wire harness side connector.

      Standard: 

      SWITCH CONDITION SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      T7-14 (IG) - Body ground Ignition switch OFF --> ON Below 1 V --> 10 to 14 V
      S36-1 - Body ground Ignition switch OFF --> ON Below 1 V --> 10 to 14 V
      S37-1 - Body ground Ignition switch OFF --> ON Below 1 V --> 10 to 14 V
    3. Measure the resistance of the wire harness side connectors.

      Standard: 

      SWITCH CONDITION SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      T7-12 (THL) - S36-2 (TH) Constant Below 1 Ω
      T7-16 (THR) - S37-2 (TH) Constant Below 1 Ω
      T7-6(E) - Body ground Constant Below 1 Ω
      S40-3 - Body ground Constant Below 1 Ω
      S41-3 - Body ground Constant Below 1 Ω

      If the voltage and resistance measurements are not as specified but the other suspected areas listed in the (see PROBLEM SYMPTOMS TABLE ) are operating normally, repair or replace the wire harness and connector.

      Fig 4: Checking Wire Harness (Front)
      G03525353Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  6. CHECK WIRE HARNESS (REAR) 
    1. Disconnect the S64 switch, S44 and S45 seat heater connectors.
    2. Measure the resistance of the wire harness side connector.

      Standard: 

      SWITCH CONDITION SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      S62-2 (HIL) - S40-1 Constant Below 1 Ω
      S62-5 (HIR) - S41-1 Constant Below 1 Ω
      S62-11 (E) - Body ground Constant Below 1 Ω
      S40-4 - Body ground Constant Below 1 Ω
      S41-4 - Body ground Constant Below 1 Ω

      If the voltage and resistance measurements are not as specified but the other suspected areas listed in the (see PROBLEM SYMPTOMS TABLE ) are operating normally, repair or replace the wire harness and connector.

      Fig 5: Checking Wire Harness (Rear)
      G03525354Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  7. INSPECT LUGGAGE ROOM J/B ECU 
    1. Disconnect the L13 luggage room J/B ECU connector.
    2. Measure the voltage and resistance of the wire harness side connector.

      Standard: 

      SWITCH CONDITION SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      L14-8 (IG) - Body ground Ignition switch OFF --> ON Below 1 V --> 10 to 14V
      L14-14 (P-GND) - Body ground Constant Below 1 Ω

      If the result is not as specified, there may be a malfunction on the wire harness side.

      Fig 6: Inspecting Luggage Room J/B ECU
      G03525355Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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