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

DESCRIPTION

When the driver side seat belt is not fastened and the power switch is on (IG), the driver side seat belt warning light on the combination meter assembly blinks to inform the driver. The main body ECU (multiplex network body ECU) detects the driver side seat belt condition and sends a signal to the combination meter assembly via CAN communication.

WIRING DIAGRAM

A003TKLE01

INSPECTION PROCEDURE

Note

The seat belt warning system uses the CAN communication system. First, confirm that there is no malfunction in the communication system by checking communication function of the CAN communication system. Refer to the How to Proceed with Troubleshooting procedure Click here.

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the intelligent tester on.

    4. Enter the following menus: Body / Main Body / Data List.

    5. Read the Data List according to the display on the intelligent tester.

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

      OFF: Driver side seat belt fastened

      ON: Driver side seat belt not fastened

      		 -
      OK
      ON or OFF appears on the tester screen according to the driver seat belt condition.

    NG

    INSPECT FRONT SEAT INNER BELT ASSEMBLY (FOR DRIVER SIDE) Click here

    OK

  2. PERFORM ACTIVE TEST USING INTELLIGENT TESTER


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the intelligent tester on.

    4. Enter the following menus: Body / Combination Meter /Active Test.

    5. Perform the Active Test according to the display on the intelligent tester.

      Combination Meter (Combination Meter Assembly)
      Tester Display Test Part Control Range Diagnostic Note
      Driver Side Seat Belt Driver side seat belt warning light OFF or ON -
      OK
      The driver side seat belt warning light on the combination meter assembly operates normally.

    NG

    REPLACE COMBINATION METER ASSEMBLY Click here

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

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


    1. A003RISE01
      Text in Illustration
      *1 for LHD
      *2 for RHD
      *a

      Component without harness connected

      (Front Seat Inner Belt Assembly (for Driver Side))

      Remove the front seat inner belt assembly (for driver side) Click here.

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      L22-1 - L22-2 Driver side seat belt unfastened Below 1 Ω
      L22-1 - L22-2 Driver side seat belt fastened 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      M10-1 - M10-2 Driver side seat belt unfastened Below 1 Ω
      M10-1 - M10-2 Driver side seat belt fastened 10 kΩ or higher

    NG

    REPLACE FRONT SEAT INNER BELT ASSEMBLY (FOR DRIVER SIDE) Click here

    OK

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


    1. Disconnect the 2D instrument panel junction block assembly connector.*1

    2. Disconnect the 2B instrument panel junction block assembly connector.*2

    3. Disconnect the L22 front seat inner belt assembly (for driver side) connector.*1

    4. Disconnect the M10 front seat inner belt assembly (for driver side) connector.*2


      • *1: for LHD

      • *2: for RHD

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      2D-27 (DBKL) - L22-1 Always Below 1 Ω
      L22-2 - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      2B-14 (DBKL) - M10-1 Always Below 1 Ω
      M10-2 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


    1. Remove the instrument panel junction block assembly.

    2. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

      A003S0WE01

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

      Tech Tips

      This inspection is to check the wire harness in the instrument panel junction block assembly that connects the wire harness to the built-in main body ECU (multiplex network body ECU).

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      MB-18 (DBKL) - 2D-27 (DBKL) Always Below 1 Ω
      2D-27 (DBKL) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      MB-18 (DBKL) - 2B-14 (DBKL) Always Below 1 Ω
      2B-14 (DBKL) - Body ground Always 10 kΩ or higher
      Text in Illustration
      *a

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

    OK

  6. CHECK HARNESS AND CONNECTOR (FRONT SEAT INNER BELT ASSEMBLY - BODY GROUND)


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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      L22-2 - Body ground Always Below 1 Ω
      for RHD
      Tester Connection Condition Specified Condition
      M10-2 - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)