SEAT BELT WARNING SYSTEM Rear Seat Belt Warning Light Malfunction

DESCRIPTION

The main body ECU (multiplex network body ECU) detects whether either rear door is open or closed based on the condition of the left and right courtesy light switches and then sends the rear door status signal to the combination meter assembly. The combination meter assembly detects the rear seat belt state. The rear seat belt warning lights on the air conditioning control assembly illuminate or turn off in accordance with the rear door state, vehicle speed and rear seat belt state.

WIRING DIAGRAM

B003YDFE03
B003YL4E01

CAUTION / NOTICE / HINT

Note


  • The seat belt warning system uses the CAN communication system. First, confirm that there are no malfunctions 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.

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 assembly (for RH) ON or OFF

      ON: Rear door RH open

      OFF: Rear door RH closed

      		 -
      RL Door Courtesy SW Rear door courtesy light switch assembly (for 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. CHECK REAR SEAT BELT WARNING


    1. B003Y6XC01
      *1 Rear Seat Belt Warning Light (Air Conditioning Control Assembly)
      *a LH
      *b Center
      *c RH

      Check the rear seat belt warning function.

      Result
      Result Proceed to
      The rear seat belt warning lights operate normally A
      The rear seat belt warning lights (all seats) do not operate normally B
      The rear seat belt warning light (RH) does not operate normally C
      The rear seat belt warning light (center) does not operate normally D
      The rear seat belt warning light (LH) does not operate normally E

    A

    USE SIMULATION METHOD TO CHECK Click here

    C

    READ VALUE USING GTS (REAR SEAT BELT BUCKLE SWITCH (FOR RH)) Click here

    D

    READ VALUE USING GTS (REAR SEAT BELT BUCKLE SWITCH (FOR CENTER)) Click here

    E

    READ VALUE USING GTS (REAR SEAT BELT BUCKLE SWITCH (FOR LH)) Click here

    B

  3. CHECK HARNESS AND CONNECTOR (IG POWER SUPPLY - AIR CONDITIONING CONTROL ASSEMBLY)


    1. Disconnect the K65 air conditioning control assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      K65-8 (IG+) - Body ground Power switch on (IG) 11 to 14 V
      K65-8 (IG+) - Body ground Power switch off Below 1 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING CONTROL ASSEMBLY - COMBINATION METER ASSEMBLY)


    1. Reconnect the K65 air conditioning control assembly connector.

    2. Disconnect the K3 combination meter assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      K3-35 (RLMT) - Body ground Power switch on (IG) 11 to 14 V
      K3-36 (RCMT) - Body ground Power switch on (IG) 11 to 14 V
      K3-37 (RRMT) - Body ground Power switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE AIR CONDITIONING CONTROL ASSEMBLY


    1. Temporarily replace the air conditioning control assembly with a new or known good one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  6. CHECK REAR SEAT BELT WARNING


    1. B003Y6XC01
      *1 Rear Seat Belt Warning Light (Air Conditioning Control Assembly)
      *a LH
      *b Center
      *c RH

      Check the rear seat belt warning function.

      Click here

      OK
      The rear seat belt warning lights (all seats) operate normally.
      Result
      Proceed to
      OK
      NG

    OK

    END (AIR CONDITIONING CONTROL ASSEMBLY WAS DEFECTIVE)

    NG

    REPLACE COMBINATION METER ASSEMBLY Click here

  7. 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
      2nd-Row Seatbelt Buckle (R) Rear RH seat belt buckle switch signal ON or OFF

      OFF: Rear RH seat belt fastened

      ON: Rear RH seat belt not fastened

      		 -

      Body Electrical > Combination Meter > Data List
      Tester Display
      2nd-Row Seatbelt Buckle (R)
      Result
      Result Proceed to
      ON or OFF does not appear on the GTS screen according to the rear seat belt condition A
      ON or OFF appears on the GTS screen according to the rear seat belt condition B

    B

    CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - AIR CONDITIONING CONTROL ASSEMBLY) Click here

    A

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


    1. Disconnect the K3 combination meter assembly connector.

    2. Disconnect the Q27 rear seat inner belt assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K3-12 (RRSB) - Q27-1 (RBR+) Always Below 1 Ω
      K3-12 (RRSB) - Body ground Always 10 kΩ or higher
      Q27-1 (RBR+) - Body ground Always 10 kΩ or higher
      Q27-2 (RBR-) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE REAR SEAT INNER BELT ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  9. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - AIR CONDITIONING CONTROL ASSEMBLY)


    1. Disconnect the K3 combination meter assembly connector.

    2. Disconnect the K65 air conditioning control assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K3-37 (RRMT) - K65-1 (RRID) Always Below 1 Ω
      K3-37 (RRMT) - Body ground Always 10 kΩ or higher
      K65-1 (RRID) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  10. REPLACE AIR CONDITIONING CONTROL ASSEMBLY


    1. Temporarily replace the air conditioning control assembly with a new or known good one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  11. CHECK REAR SEAT BELT WARNING


    1. B003Y6XC01
      *1 Rear Seat Belt Warning Light (Air Conditioning Control Assembly)
      *a LH
      *b Center
      *c RH

      Check the rear seat belt warning function.

      Click here

      OK
      The rear seat belt warning light (RH) operates normally.
      Result
      Proceed to
      OK
      NG

    OK

    END (AIR CONDITIONING CONTROL ASSEMBLY WAS DEFECTIVE)

    NG

    REPLACE COMBINATION METER ASSEMBLY Click here

  12. READ VALUE USING GTS (REAR SEAT BELT BUCKLE SWITCH (FOR CENTER))


    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
      2nd-Row Seatbelt Buckle (C) Rear center seat belt buckle switch signal ON or OFF

      OFF: Rear center seat belt fastened

      ON: Rear center seat belt not fastened

      		 -

      Body Electrical > Combination Meter > Data List
      Tester Display
      2nd-Row Seatbelt Buckle (C)
      Result
      Result Proceed to
      ON or OFF does not appear on the GTS screen according to the rear seat belt condition A
      ON or OFF appears on the GTS screen according to the rear seat belt condition B

    B

    CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - AIR CONDITIONING CONTROL ASSEMBLY) Click here

    A

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


    1. Disconnect the K3 combination meter assembly connector.

    2. Disconnect the Q27 rear seat inner belt assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K3-13 (RCSB) - Q27-4 (CBR+) Always Below 1 Ω
      K3-13 (RCSB) - Body ground Always 10 kΩ or higher
      Q27-4 (CBR+) - Body ground Always 10 kΩ or higher
      Q27-5 (CBR-) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE REAR SEAT INNER BELT ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  14. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - AIR CONDITIONING CONTROL ASSEMBLY)


    1. Disconnect the K3 combination meter assembly connector.

    2. Disconnect the K65 air conditioning control assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K3-36 (RCMT) - K65-2 (RCID) Always Below 1 Ω
      K3-36 (RCMT) - Body ground Always 10 kΩ or higher
      K65-2 (RCID) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  15. REPLACE AIR CONDITIONING CONTROL ASSEMBLY


    1. Temporarily replace the air conditioning control assembly with a new or known good one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  16. CHECK REAR SEAT BELT WARNING


    1. B003Y6XC01
      *1 Rear Seat Belt Warning Light (Air Conditioning Control Assembly)
      *a LH
      *b Center
      *c RH

      Check the rear seat belt warning function.

      Click here

      OK
      The rear seat belt warning light (center) operates normally.
      Result
      Proceed to
      OK
      NG

    OK

    END (AIR CONDITIONING CONTROL ASSEMBLY WAS DEFECTIVE)

    NG

    REPLACE COMBINATION METER ASSEMBLY Click here

  17. READ VALUE USING GTS (REAR SEAT BELT BUCKLE SWITCH (FOR LH))


    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
      2nd-Row Seatbelt Buckle (L) Rear LH seat belt buckle switch signal ON or OFF

      OFF: Rear LH seat belt fastened

      ON: Rear LH seat belt not fastened

      		 -

      Body Electrical > Combination Meter > Data List
      Tester Display
      2nd-Row Seatbelt Buckle (L)
      Result
      Result Proceed to
      ON or OFF does not appear on the GTS screen according to the rear seat belt condition (for Fixed Seat Type) A
      ON or OFF does not appear on the GTS screen according to the rear seat belt condition (for Fold Down Seat Type) B
      ON or OFF appears on the GTS screen according to the rear seat belt condition C

    B

    CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - REAR NO. 1 SEAT INNER BELT ASSEMBLY LH - BODY GROUND) Click here

    C

    CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - AIR CONDITIONING CONTROL ASSEMBLY) Click here

    A

  18. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - REAR SEAT INNER WITH CENTER BELT ASSEMBLY LH - BODY GROUND)


    1. Disconnect the K3 combination meter assembly connector.

    2. Disconnect the Q25 rear seat inner with center belt assembly LH connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K3-14 (RLSB) - Q25-1 (LBR+) Always Below 1 Ω
      K3-14 (RLSB) - Body ground Always 10 kΩ or higher
      Q25-1 (LBR+) - Body ground Always 10 kΩ or higher
      Q25-2 (LBR-) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE REAR SEAT INNER WITH CENTER BELT ASSEMBLY LH Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  19. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - REAR NO. 1 SEAT INNER BELT ASSEMBLY LH - BODY GROUND)


    1. Disconnect the K3 combination meter assembly connector.

    2. Disconnect the Q25 rear No. 1 seat inner belt assembly LH connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K3-14 (RLSB) - Q25-1 (LBR+) Always Below 1 Ω
      K3-14 (RLSB) - Body ground Always 10 kΩ or higher
      Q25-1 (LBR+) - Body ground Always 10 kΩ or higher
      Q25-2 (LBR-) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE REAR NO. 1 SEAT INNER BELT ASSEMBLY LH Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  20. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - AIR CONDITIONING CONTROL ASSEMBLY)


    1. Disconnect the K3 combination meter assembly connector.

    2. Disconnect the K65 air conditioning control assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K3-35 (RLMT) - K65-3 (RLID) Always Below 1 Ω
      K3-35 (RLMT) - Body ground Always 10 kΩ or higher
      K65-3 (RLID) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  21. REPLACE AIR CONDITIONING CONTROL ASSEMBLY


    1. Temporarily replace the air conditioning control assembly with a new or known good one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  22. CHECK REAR SEAT BELT WARNING


    1. B003Y6XC01
      *1 Rear Seat Belt Warning Light (Air Conditioning Control Assembly)
      *a LH
      *b Center
      *c RH

      Check the rear seat belt warning function.

      Click here

      OK
      The rear seat belt warning light (LH) operates normally.
      Result
      Proceed to
      OK
      NG

    OK

    END (AIR CONDITIONING CONTROL ASSEMBLY WAS DEFECTIVE)

    NG

    REPLACE COMBINATION METER ASSEMBLY Click here