SEAT BELT WARNING SYSTEM(w/ Occupant Classification System) Rear Seat Belt Warning Light Malfunction

DESCRIPTION

The main body ECU (multiplex network body ECU) detects whether either the rear doors are open or closed based on the courtesy light switch condition and then sends the rear door status signal to the combination meter assembly. The combination meter assembly detects rear seat belt state. The rear seat belt warning light on the telltale light assembly illuminates, blinks or turns off in accordance with the rear door state, vehicle speed and rear seat belt state.

WIRING DIAGRAM

Figure 1. w/o Rear Power Seat:

B004T1UE01

Figure 2. w/ Rear Power Seat:

B004TNXE01

CAUTION / NOTICE / HINT

Note


  • The seat belt warning system uses the CAN communication system. First, confirm that there is no malfunction in the CAN communication system. Refer to the How to Proceed with Troubleshooting procedure.

    Click here

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

  • If the main body ECU (multiplex network body ECU) is replaced, refer to the Service Bulletin.

  • When replacing the combination meter assembly, always replace it with a new one. If a combination meter assembly which was installed to another vehicle is used, the information stored in it will not match the information from the vehicle and a DTC may be stored.

PROCEDURE


  1. READ VALUE USING GTS (REAR DOOR COURTESY LIGHT SWITCH)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

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

    5. Read the Data List according to the display on the GTS.


      Body Electrical > Main Body > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      RR Door Courtesy SW Rear door courtesy light switch RH ON or OFF

      ON: Rear door RH open

      OFF: Rear door RH closed

      		 -
      RL Door Courtesy SW Rear door courtesy light switch LH ON or OFF

      ON: Rear door LH open

      OFF: Rear door LH closed

      		 -

      Body Electrical > Main Body > Data List
      Tester Display
      RR Door Courtesy SW
      RL Door Courtesy SW
      OK
      The GTS display changes correctly in response to the rear door condition.
      Result
      Proceed to
      OK
      NG

    NG

    GO TO LIGHTING SYSTEM Click here

    OK

  2. READ VALUE USING GTS (REAR SEAT BELT BUCKLE SWITCH (FOR RH))


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Combination Meter / Data List.

    5. Read the Data List according to the display on the GTS.


      Body Electrical > Combination Meter > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Rear Right Seat Buckle / Occupant Detection Warning Switch Rear seat inner with center belt RH buckle signal ON or OFF

      ON: Rear RH seat belt not fastened

      OFF: Rear RH seat belt fastened

      		 -
      Rear Left Seat Buckle / Occupant Detection Warning Switch Rear seat inner with center belt LH (for LH) buckle signal ON or OFF

      ON: Rear LH seat belt (for LH) not fastened

      OFF: Rear LH seat belt (for LH) fastened

      		 -
      Rear Center Seat Buckle / Occupant Detection Warning Switch Rear seat inner with center belt LH (for center) buckle signal ON or OFF

      ON: Rear LH seat belt (for center) not fastened

      OFF: Rear LH seat belt (for center) fastened

      		 -

      Body Electrical > Combination Meter > Data List
      Tester Display
      Rear Right Seat Buckle / Occupant Detection Warning Switch
      Rear Left Seat Buckle / Occupant Detection Warning Switch
      Rear Center Seat Buckle / Occupant Detection Warning Switch
      OK
      The GTS display changes according to rear seat buckle switch condition.
      Result
      Proceed to
      OK
      NG (w/o Rear Power Seat)
      NG (w/ Rear Power Seat)

    NG (w/o Rear Power Seat)

    INSPECT REAR SEAT INNER BELT ASSEMBLY Click here

    NG (w/ Rear Power Seat)

    INSPECT REAR SEAT INNER BELT ASSEMBLY Click here

    OK

  3. INSPECT TELLTALE LIGHT ASSEMBLY


    1. Remove the telltale light assembly.

      Click here

    2. Inspect the telltale light assembly.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE TELLTALE LIGHT ASSEMBLY Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (TELLTALE LIGHT ASSEMBLY - BATTERY)


    1. Disconnect the G34 combination meter assembly.

    2. Disconnect the G31 telltale light assembly connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G31-5 (IG+) - Body ground Power switch off → Power switch on (IG) Below 1 V → 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (TELLTALE LIGHT ASSEMBLY - COMBINATION METER ASSEMBLY)


    1. Disconnect the G34 combination meter assembly.

    2. Disconnect the G31 telltale light assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G34-24 (RLMT) - G31-8 (RLID) Always Below 1 Ω
      G34-28 (RRMT) - G31-10 (RRID) Always Below 1 Ω
      G34-27 (RCMT) - G31-9 (RCID) Always Below 1 Ω
      G34-24 (RLMT) or G31-8 (RLID) - Body ground Always 10 kΩ or higher
      G34-28 (RRMT) or G31-10 (RRID) - Body ground Always 10 kΩ or higher
      G34-27 (RCMT) or G31-9 (RCID) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK COMBINATION METER ASSEMBLY


    1. Replace the combination meter assembly with a new one.

      Click here

    2. Check that the seat belt warning light operates normally.

      OK
      Seat belt warning light operates normally.
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    END (COMBINATION METER ASSEMBLY WAS DEFECTIVE)

  7. INSPECT REAR SEAT INNER BELT ASSEMBLY


    1. Remove the rear seat inner belt assembly.

      Click here

    2. Inspect the rear seat inner belt assembly.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE REAR SEAT INNER BELT ASSEMBLY Click here

    OK

  8. CHECK HARNESS AND CONNECTOR (REAR SEAT INNER BELT ASSEMBLY - COMBINATION METER ASSEMBLY AND BODY GROUND)


    1. Disconnect the L91 rear seat inner with center belt assembly RH.

    2. Disconnect the L92 rear seat inner belt assembly LH.

    3. Disconnect the G34 combination meter assembly.

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

      Standard Resistance
      RH
      Tester Connection Condition Specified Condition
      G34-12 (RRSB) - L91-4 (RBR+) Always Below 1 Ω
      L91-3 (RBR-) - Body ground Always Below 1 Ω
      G34-12 (RRSB) or L91-4 (RBR+) - Body ground Always 10 kΩ or higher
      Center
      Tester Connection Condition Specified Condition
      G34-13 (RCSB) - L91-7 (CBR+) Always Below 1 Ω
      L91-6 (CBR-) - Body ground Always Below 1 Ω
      G34-13 (RCSB) or L91-7 (CBR+) - Body ground Always 10 kΩ or higher
      LH
      Tester Connection Condition Specified Condition
      G34-14 (RLSB) - L92-5 (LBR+) Always Below 1 Ω
      L92-4 (LBR-) - Body ground Always Below 1 Ω
      G34-14 (RLSB) or L92-5 (LBR+) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  9. INSPECT REAR SEAT INNER BELT ASSEMBLY


    1. Remove the rear seat inner belt assembly.

      Click here

    2. Inspect the rear seat inner belt assembly.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE REAR SEAT INNER BELT ASSEMBLY Click here

    OK

  10. CHECK HARNESS AND CONNECTOR (REAR SEAT INNER BELT ASSEMBLY - COMBINATION METER ASSEMBLY AND BODY GROUND)


    1. Disconnect the R24 rear seat inner belt assembly RH.

    2. Disconnect the L154 rear center seat lap type belt assembly RH.

    3. Disconnect the R49 rear seat inner belt assembly LH.

    4. Disconnect the G34 combination meter assembly.

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

      Standard Resistance
      RH
      Tester Connection Condition Specified Condition
      G34-12 (RRSB) - R24-5 Always Below 1 Ω
      R24-3 - Body ground Always Below 1 Ω
      G34-12 (RRSB) or R24-5 - Body ground Always 10 kΩ or higher
      Center
      Tester Connection Condition Specified Condition
      G34-13 (RCSB) - L154-2 (CBR+) Always Below 1 Ω
      L154-1 (CBR-) - Body ground Always Below 1 Ω
      G34-13 (RCSB) or L154-2 (CBR+) - Body ground Always 10 kΩ or higher
      LH
      Tester Connection Condition Specified Condition
      G34-14 (RLSB) - R49-5 Always Below 1 Ω
      R49-3 - Body ground Always Below 1 Ω
      G34-14 (RLSB) or R49-5 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR