LEMON Manuals: Even more car manuals for everyone
Home >> Toyota >> 2021 >> Mirai Limited >> Repair and Diagnosis >> Accessories & Equipment >> Seats >> Seat Heater System - Diagnostic Codes & Symptom Tests >> Seat Heater System >> Seat Heater for Front Right Seat does not Operate [11/2020 - 12/2022] >> Procedure

Seat Heater for Front Right Seat does not Operate [11/2020 - 12/2022]: Procedure

  1. PERFORM ACTIVE TEST USING GTS (SEAT HEATER) 
    1. Perform the Active Test according to the display on the GTS.

      Body Electrical > Air Conditioner > Active Test 

      Tester Display Measurement Item Control Range Diagnostic Note
      Front Right Seat Heater Front right seat heater operation OFF/ON -

      Body Electrical > Air Conditioner > Active Test 

      Tester Display
      Front Right Seat Heater

      OK

      Front passenger side seat heater operates normally.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  3

    Result: 

    OK 

    See step  2

  2. CHECK SEAT HEATER OPERATION 
    1. Check the seat heater operation.

      Refer to OPERATION CHECK [11/2020 - ]

      OK

      The seat heater operates normally.

      Result

      Result Proceed to
      Does not operate normally with operation of either the multi-display or seat heater switch A
      Does not operate normally with operation of the multi-display B
      Does not operate normally with operation of the seat heater switch C

    Result: 

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [11/2020 - ] 

    Result: 

    GO TO TOYOTA MULTI OPERATION TOUCH SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [11/2020 - 12/2022] 

    Result: 

    REPLACE AIR CONDITIONING CONTROL ASSEMBLY. Refer to  REMOVAL [11/2020 - 11/2021]  , or refer to  REMOVAL [11/2021 - 12/2022] 

  3. CHECK HARNESS AND CONNECTOR (SEAT HEATER CONTROL SUB-ASSEMBLY RH - BATTERY) 
    1. Disconnect the L14 seat heater control sub-assembly RH connector.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      L14-1 (+B1) - Body ground Ignition switch ON 11 to 14 V
      L14-1 (+B1) - Body ground Ignition switch off Below 1 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  4

  4. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - SEAT HEATER CONTROL SUB-ASSEMBLY RH) 
    1. Disconnect the D79 air conditioning amplifier assembly connector.
    2. Disconnect the L14 seat heater control sub-assembly RH connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      D79-14 (SM1R) - L14-5 (SWR) Always Below 1 Ω
      D79-14 (SM1R) or L14-5 (SWR) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  5

  5. CHECK HARNESS AND CONNECTOR (FRONT SEAT CUSHION HEATER ASSEMBLY RH - SEAT HEATER CONTROL SUB-ASSEMBLY RH AND BODY GROUND) 
    1. Disconnect the L10 front seat cushion heater assembly RH connector.
    2. Disconnect the L14 seat heater control sub-assembly RH connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      L10-6 - L14-10 (E) Always Below 1 Ω
      L10-6 or L14-10 (E) - Body ground Always 10 kΩ or higher
      L10-1 - L14-7 (HTR1) Always Below 1 Ω
      L10-1 or L14-7 (HTR1) - Body ground Always 10 kΩ or higher
      L10-2 - Body ground Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  6

  6. INSPECT FRONT SEAT CUSHION HEATER ASSEMBLY RH 

    Refer to INSPECTION [11/2020 - ]

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    REPLACE FRONT SEAT CUSHION HEATER ASSEMBLY RH. Refer to  REMOVAL [11/2020 - 11/2021]  , or refer to  REMOVAL [11/2021 - 12/2022] 

    Result: 

    OK 

    See step  7

  7. INSPECT FRONT SEATBACK HEATER ASSEMBLY RH 

    Refer to INSPECTION [11/2020 - ]

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    REPLACE FRONT SEATBACK HEATER ASSEMBLY RH. Refer to  REMOVAL [11/2020 - 11/2021]  , or refer to  REMOVAL [11/2021 - 12/2022] 

    Result: 

    OK 

    See step  8

  8. REPLACE SEAT HEATER CONTROL SUB-ASSEMBLY RH 
    1. Replace the seat heater control sub-assembly RH with a new or known good one.

      Refer to REMOVAL [11/2020 - 11/2021] , or refer to REMOVAL [11/2021 - 12/2022]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  9

  9. CHECK FRONT SEAT HEATER OPERATION 
    1. Check the side seat heater operation.

      Refer to OPERATION CHECK [11/2020 - ]

      OK

      Front seat heater operates normally.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

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

    Result: 

    NG 

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [11/2020 - ]