SEAT BELT WARNING SYSTEM Driver Side Seat Belt Warning Light does not Operate

DESCRIPTION

When the ignition switch is turned to ON, the main body ECU (multiplex network body ECU) transmits front seat inner belt LH*1 (or RH*2) state signals to the combination meter through the CAN. If the driver seat belt is not fastened, the combination meter blinks the front seat belt warning light. If the seat belt is fastened, the warning light goes off.


WIRING DIAGRAM

A004G42E02

CAUTION / NOTICE / HINT

Note

Since the seat belt warning system has functions that use CAN communication, first confirm that there is no malfunction in the communication system by inspecting the CAN communication functions in accordance with How to Proceed with Troubleshooting. Then conduct the following troubleshooting procedure.

Initialization is necessary when the main body ECU is replaced Click here.

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS (DRIVER SIDE SEAT BELT WARNING LIGHT)


    1. Select the Active Test, use the GTS to generate a control command, and then check that the driver side seat belt warning light turns on/off Click here.

      Combination Meter
      Item Test Part Control Range Diagnostic Note
      Driver Side Seat Belt Driver side seat belt warning light OFF or ON Confirm that the vehicle is stopped and the engine is idling.
      OK
      Driver side seat belt warning light condition can be switched by Active Test.

    NG

    REPLACE COMBINATION METER ASSEMBLY Click here

    OK

  2. READ VALUE USING GTS (DRIVER SIDE SEAT BELT BUCKLE SWITCH)


    1. Check the Data List for proper functioning of the driver side seat belt buckle switch Click here.

      Main Body
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      D Seat Buckle SW Driver side seat belt buckle signal / OFF or ON

      OFF: Driver side seat belt unfastened

      ON: Driver side seat belt fastened

      		 -
      OK
      The display is as specified in the normal condition column.

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  3. INSPECT FRONT SEAT INNER BELT ASSEMBLY (FOR DRIVER SIDE)


    1. Remove the front seat inner belt assembly (Driver Side) Click here.

    2. Inspect the front seat inner belt assembly (Driver Side) Click here.


    NG

    REPLACE FRONT SEAT INNER BELT ASSEMBLY Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (FRONT SEAT INNER BELT - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) AND BODY GROUND)


    1. Disconnect the K8*2 or K9*1 front seat inner belt assembly connector.


      • *1: for LHD

      • *2: for RHD

    2. Disconnect the 3D instrument panel junction block assembly connector.

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

      Standard Resistance (for LHD)
      Tester Connection Condition Specified Condition
      3D-34 - K9-3 Always Below 1 Ω
      K9-2 - Body ground Always Below 1 Ω
      3D-34 - Body ground Always 10 kΩ or higher
      Standard Resistance (for RHD)
      Tester Connection Condition Specified Condition
      3D-34 - K8-3 Always Below 1 Ω
      K8-2 - Body ground Always Below 1 Ω
      3D-34 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)


    1. Replace the main body ECU Click here.


    NEXT

  6. READ VALUE USING GTS (DRIVER SIDE SEAT BELT BUCKLE SWITCH)


    1. Check the Data List for proper functioning of the driver side seat belt buckle switch Click here.

      Main Body
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      D Seat Buckle SW Driver side seat belt buckle signal / OFF or ON

      OFF: Driver side seat belt unfastened

      ON: Driver side seat belt fastened

      		 -
      OK
      The display is as specified in the normal condition column.

    OK

    END (MAIN BODY ECU WAS DEFECTIVE)

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here