KEY REMINDER WARNING SYSTEM Key Reminder Buzzer does not Sound

DTC Code DTC Name
Key Reminder Buzzer does not Sound

DESCRIPTION

The key reminder warning buzzer sounds when the driver door is opened while the ignition switch is off or ACC. The key reminder warning buzzer is activated when the main body ECU (multiplex network body ECU) sends an unlock warning switch signal and driver door courtesy light switch signal to the combination meter assembly via CAN communication.

WIRING DIAGRAM

  1. for LHD

    B281179E15

  2. for RHD

    B319944E03

CAUTION / NOTICE / HINT

Note:

  • The key reminder warning system uses the CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting. Troubleshoot the key reminder warning system after confirming that the communication systems are functioning properly.

    Click hereClick here

  • When replacing the main body ECU (multiplex network body ECU), make sure to replace it with a new one.

PROCEDURE

  1. CHECK COMBINATION METER ASSEMBLY (SEAT BELT WARNING BUZZER OPERATION)

    1. Check seat belt warning system operation.

      Click here

      Tip:

      The key reminder warning system sounds the buzzer built into the combination meter assembly as a key reminder warning. This buzzer is also used for the seat belt warning system. Therefore, check the operation of the combination meter buzzer by checking if the buzzer sounds to inform that the seat belt is not fastened.

    Result

    Proceed to

    Combination meter buzzer sounds

    Combination meter buzzer not sounds
    Combination meter buzzer not sounds

    GO TO SEAT BELT WARNING SYSTEM

    Click here

    Combination meter buzzer sounds

  2. READ VALUE USING GTS (FR Door Courtesy SW, FL Door Courtesy SW)

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    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

      FR Door Courtesy SW

      Front door courtesy light switch RH signal

      ON or OFF

      ON: Front door RH open

      OFF: Front door RH closed

      *1

      FL Door Courtesy SW

      Front door courtesy light switch LH signal

      ON or OFF

      ON: Front door LH open

      OFF: Front door LH closed

      *2

      • *1: for RHD

      • *2: for LHD

      Body Electrical > Main Body > Data List

      Tester Display

      FR Door Courtesy SW

      FL Door Courtesy SW

      OK

      The GTS indicates ON or OFF according to the driver door condition shown in the table.

    Result

    Proceed to

    OK

    NG
    NG

    INSPECT FRONT DOOR COURTESY LIGHT SWITCH ASSEMBLY (for Driver Door)Click here

    OK

  3. READ VALUE USING GTS (Key Unlock Warning SW)

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    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

      Key Unlock Warning SW

      Unlock warning switch signal

      ON or OFF

      ON: Key in ignition key cylinder

      OFF: No key in ignition key cylinder

      -

      Body Electrical > Main Body > Data List

      Tester Display

      Key Unlock Warning SW

      OK

      The GTS indicates ON or OFF according to whether the key is in the ignition key cylinder.

    Result

    Proceed to

    OK

    NG
    NG

    INSPECT UNLOCK WARNING SWITCH ASSEMBLYClick here

    OK

  4. CHECK MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

    1. Temporarily replace the main body ECU (multiplex network body ECU) with a new one.

    2. Check the key reminder buzzer operation.

      Click here

    Result

    Proceed to

    Key reminder buzzer sounds

    Key reminder buzzer not sounds
    Key reminder buzzer sounds

    END (MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU] WAS DEFECTIVE)

    Key reminder buzzer not sounds

    GO TO METER / GAUGE SYSTEM

    Click hereClick here

  5. INSPECT UNLOCK WARNING SWITCH ASSEMBLY

    1. Remove the unlock warning switch assembly.

      Click here

    2. Inspect the unlock warning switch assembly.

      Click here

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE UNLOCK WARNING SWITCH ASSEMBLY

    Click here

    OK

  6. CHECK HARNESS AND CONNECTOR (UNLOCK WARNING SWITCH ASSEMBLY - MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU])

    1. Disconnect the G7 unlock warning switch assembly connector.

    2. Disconnect the G78 main body ECU (multiplex network body ECU) connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      G7-1 - G78-17 (KSW)

      Always

      Below 1 Ω

      G7-2 - Body ground

      Always

      Below 1 Ω

      G7-1 - Body ground

      Always

      10 kΩ or higher

      G78-17 (KSW) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. CHECK MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

    1. Temporarily replace the main body ECU (multiplex network body ECU) with a new one.

    2. Check the key reminder buzzer operation.

      Click here

    Result

    Proceed to

    Key reminder buzzer sounds

    Key reminder buzzer not sounds
    Key reminder buzzer sounds

    END (MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU] WAS DEFECTIVE)

    Key reminder buzzer not sounds

    GO TO METER / GAUGE SYSTEM

    Click hereClick here

  8. INSPECT FRONT DOOR COURTESY LIGHT SWITCH ASSEMBLY (for Driver Door)

    1. Remove the front door courtesy light switch assembly (for driver door).

      Click here

    2. Inspect the front door courtesy light switch assembly (for driver door).

      Click here

    Result

    Proceed to

    OK (for LHD)

    OK (for RHD)

    NG
    OK (for RHD)

    CHECK HARNESS AND CONNECTOR (FRONT DOOR COURTESY LIGHT SWITCH ASSEMBLY RH - MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU])Click here

    NG

    REPLACE FRONT DOOR COURTESY LIGHT SWITCH ASSEMBLY (for Driver Door)

    Click here

    OK (for LHD)

  9. CHECK HARNESS AND CONNECTOR (FRONT DOOR COURTESY LIGHT SWITCH ASSEMBLY LH - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

    1. Disconnect the N6 front door courtesy light switch assembly LH connector.

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

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      N6-1 - 3E-40

      Always

      Below 1 Ω

      N6-1 - Body ground

      Always

      10 kΩ or higher

      3E-40 - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  10. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

    1. Remove the instrument panel junction block assembly.

      Click here

      B281983C16

      *a

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

      -

      -

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      3E-40 - A-2 (FLCY)

      Always

      Below 1 Ω

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

    Click here

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

    Click here

  11. CHECK HARNESS AND CONNECTOR (FRONT DOOR COURTESY LIGHT SWITCH ASSEMBLY RH - MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU])

    1. Disconnect the M4 front door courtesy light switch assembly RH connector.

    2. Disconnect the G78 main body ECU (multiplex network body ECU) connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      M4-1 - G78-19 (FRCY)

      Always

      Below 1 Ω

      M4-1 - Body ground

      Always

      10 kΩ or higher

      G78-19 (FRCY) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

    Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR