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

DESCRIPTION

When the driver side seat belt is not fastened with the power switch 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

A01J8UWE01

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 seat belt buckle switch signal/ON or OFF

      ON: Driver seat belt fastened

      OFF: Driver seat belt not fastened

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

    NG

    INSPECT FRONT SEAT INNER BELT ASSEMBLY (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 seat belt warning light OFF or ON Confirm that the vehicle is stopped with the engine idling.
      OK
      The driver side seat belt warning light on the combination meter assembly operates normally.

    NG

    REPLACE NO. 5 METER CIRCUIT PLATE Click here

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

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


    1. A01JC87E03
      Text in Illustration
      *1

      Component without harness connected

      (Front Seat Inner Belt Assembly (Driver Side))
      *2 for LHD
      *3 for RHD

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition

      R5-3 (+) - R5-2 (E)*1

      S22-3 (+) - S22-2 (E)*2

      		 Driver side seat belt unfastened Below 1 Ω

      R5-3 (+) - R5-2 (E)*1

      S22-3 (+) - S22-2 (E)*2

      		 Driver side seat belt fastened 10 kΩ or higher

      • *1: for LHD

      • *2: for RHD


    NG

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

    OK

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


    1. A01JBHVE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Instrument Panel Junction Block Assembly)
      *2

      Front view of wire harness connector

      (to Front Seat Inner Belt Assembly (Driver Side))
      *3 for LHD
      *4 for RHD

      Disconnect the 2B connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition

      2B-14 (DBKL) - R5-3 (+)*1

      2B-14 (DBKL) - S22-3 (+)*2

      		 Always Below 1 Ω
      2B-14 (DBKL) - Body ground Always 10 kΩ or higher

      R5-2 (E) - Body ground*1

      S22-2 (E) - Body ground*2

      		 Always Below 1 Ω

      • *1: for LHD

      • *2: for RHD


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


    1. Remove the instrument panel junction block assembly Click here.

      A01J9FHE01

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

    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
      Tester Connection Condition Specified Condition
      A-18 (DBKL) - 2B-14 (DBKL) Always Below 1 Ω
      2B-14 (DBKL) - Body ground Always 10 kΩ or higher
      Text in Illustration
      *1

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

      		 *2

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

  6. REPLACE NO. 5 METER CIRCUIT PLATE


    1. Replace the No. 5 meter circuit plate Click here.


    NEXT

  7. CHECK DRIVER SIDE SEAT BELT WARNING LIGHT


    1. Check the driver side seat belt warning light Click here.

      OK
      The driver side seat belt warning light operates normally.

    NG

    REPLACE NO. 2 METER CIRCUIT PLATE Click here

    OK

    END (NO. 5 METER CIRCUIT PLATE WAS DEFECTIVE)

  8. REPLACE NO. 2 METER CIRCUIT PLATE


    1. Replace the No. 2 meter circuit plate Click here.


    NEXT

  9. CHECK DRIVER SIDE SEAT BELT WARNING LIGHT


    1. Check the driver side seat belt warning light Click here.

      OK
      The driver side seat belt warning light operates normally.

    NG

    REPLACE NO. 3 METER CIRCUIT PLATE Click here

    OK

    END (NO. 2 METER CIRCUIT PLATE WAS DEFECTIVE)