SEAT HEATER SYSTEM Seat Heater for Front Left Seat does not Operate

DESCRIPTION

When the seat heater switch is operated, the air conditioning amplifier assembly receives the signal via CAN communication line. The air conditioning amplifier assembly receives the signal and operates the front seat heater.

WIRING DIAGRAM

Figure 1. for LHD:

B006FXNE22

Figure 2. for RHD:

B006FXNE23

CAUTION / NOTICE / HINT

Note


  • If the battery voltage is low, the seat heater system may not operate. When "High Power Consumption Partial Limit On AC/Heater Operation" is displayed on the multi-information display in the combination meter assembly, inspect the battery, referring to On-vehicle Inspection for the charging system.

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  • Inspect the fuses for circuits related to this system before performing the following procedure.

Tech Tips

If the battery voltage is low, the seat heater system may not operate. When "High Power Consumption Partial Limit On AC/Heater Operation" is not displayed on the multi-information display in the combination meter assembly, check the Data List item "Battery Control Count (Body ECU)".

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PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Body Electrical > Air Conditioner > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  2. CHECK FOR DTC


    1. Check for DTCs.

      Click here


      Body Electrical > Air Conditioner > Trouble Codes
      OK
      DTC B14C1 is not output.
      Result
      Proceed to
      OK
      NG

    NG

    GO TO DIAGNOSTIC TROUBLE CODE CHART Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (SEAT HEATER CONTROL SUB-ASSEMBLY LH - BATTERY)


    1. Disconnect the Q31 seat heater control sub-assembly LH connector.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      Q31-3 (IG) - Body ground Engine switch on (IG) 11 to 14 V
      Engine switch off Below 1 V
      Q31-1 (+B1) - Body ground Always 11 to 14 V
      Q31-8 (+B2) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. INSPECT SEPARATE TYPE FRONT SEAT CUSHION COVER LH


    1. Remove the separate type front seat cushion cover LH.

      Click here

    2. Inspect the separate type front seat cushion cover LH.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE SEPARATE TYPE FRONT SEAT CUSHION COVER LH Click here

    OK

  5. INSPECT SEPARATE TYPE FRONT SEATBACK COVER LH


    1. Remove the separate type front seatback cover LH.

      Click here

    2. Inspect the separate type front seatback cover LH.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE SEPARATE TYPE FRONT SEATBACK COVER LH Click here

    OK

  6. CHECK HARNESS AND CONNECTOR (SEPARATE TYPE FRONT SEAT CUSHION COVER LH - SEAT HEATER CONTROL SUB-ASSEMBLY LH AND BODY GROUND)


    1. Disconnect the Q36 separate type front seat cushion cover LH connector.

    2. Disconnect the Q31 seat heater control sub-assembly LH connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      Q36-6 - Q31-10 (E) Always Below 1 Ω
      Q36-6 or Q31-10 (E) - Other terminals and body ground Always 10 kΩ or higher
      Q36-1 - Q31-7 (Heater Output 1) Always Below 1 Ω
      Q36-1 or Q31-7 (Heater Output 1) - Other terminals and body ground Always 10 kΩ or higher
      Q36-3 - Q31-12 (Heater Output 2) Always Below 1 Ω
      Q36-3 or Q31-12 (Heater Output 2) - Other terminals and body ground Always 10 kΩ or higher
      Q36-2 - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. CHECK HARNESS AND CONNECTOR (SEPARATE TYPE FRONT SEAT CUSHION COVER LH - AIR CONDITIONING AMPLIFIER ASSEMBLY)


    1. Disconnect the Q36 separate type front seat cushion cover LH connector.

    2. Disconnect the G63 and G64 air conditioning amplifier assembly connectors.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      Q36-4 - G63-17 (TSL) Always Below 1 Ω
      Q36-4 or G63-17 (TSL) - Other terminals and body ground Always 10 kΩ or higher
      Q36-5 - G64-3 (SG-4) Always Below 1 Ω
      Q36-5 or G64-3 (SG-4) - Other terminals and body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. CHECK HARNESS AND CONNECTOR (SEAT HEATER CONTROL SUB-ASSEMBLY LH - AIR CONDITIONING AMPLIFIER ASSEMBLY)


    1. Disconnect the Q31 seat heater control sub-assembly LH connector.

    2. Disconnect the G63 air conditioning amplifier assembly connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      Q31-4 (PWM) - G63-15 (SHD+) Always Below 1 Ω
      Q31-4 (PWM) or G63-15 (SHD+) - Other terminals and body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. REPLACE SEAT HEATER CONTROL SUB-ASSEMBLY LH


    1. Temporarily replace the seat heater control sub-assembly LH with a new or known good one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  10. CHECK SEAT HEATER OPERATION


    1. Check the seat heater.

      Click here

      OK
      The seat heater operates normally.
      Result
      Proceed to
      OK
      NG

    OK

    END (SEAT HEATER CONTROL SUB-ASSEMBLY LH WAS DEFECTIVE)

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here