FRONT POWER SEAT CONTROL SYSTEM, Diagnostic DTC:B2654

DTC Code DTC Name
B2654 Headrest Sensor Malfunction

DESCRIPTION

When the position control ECU assembly does not receive a sensor signal despite upward or downward movement of the seat head rest by power seat motor operation, this DTC is stored.

DTC No. Detection Item DTC Detection Condition Trouble Area
B2654 Headrest Sensor Malfunction The upward and downward lock detection position of the sensor is the same.

  • Position control ECU assembly LH

  • Position control ECU assembly RH

  • Front seat headrest assembly LH (headrest motor)

  • Front seat headrest assembly RH (headrest motor)

  • Harness or connector

WIRING DIAGRAM


  1. for Driver Seat

    Figure 1. for LHD:

    B004CGAE48

    Figure 2. for RHD:

    B004CGAE49

  2. for Front Passenger Seat

    Figure 3. for LHD:

    B004CGAE50

    Figure 4. for RHD:

    B004CGAE51

CAUTION / NOTICE / HINT

Note

Initializing the position control ECU assembly will clear the seat position memory.

Tech Tips


  • Make sure to initialize the position control ECU assembly after replacing the seat assembly or any related parts (including removal and installation).

  • Before initializing the seat ECU, make sure that the D/C CUT fuse is normal.

  • When any of the following conditions are met, the seat position Information in the position control ECU assembly will be cleared.


    • The power switch is turned off with any of the seat switches being operated and the D/C CUT fuse removed.

    • The power switch is turned off within 1 second of any of the seat switches being operated with the D/C CUT fuse removed.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Body Electrical > Driver Seat > Clear DTCs
      Body Electrical > Passenger Seat > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  2. CHECK FOR DTC


    1. Check for DTCs.

      Click here


      Body Electrical > Driver Seat > Trouble Codes
      Body Electrical > Passenger Seat > Trouble Codes
      OK
      DTC B2654 is not output.
      Result
      Result Proceed to
      DTC B2654 is not output A
      DTC B2654 output from "Driver Seat" B
      DTC B2654 output from "Front Passenger Seat" C

    A

    USE SIMULATION METHOD TO CHECK Click here

    C

    PERFORM ACTIVE TEST USING GTS (HEADREST OPERATION) Click here

    B

  3. PERFORM ACTIVE TEST USING GTS (HEADREST OPERATION)


    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 / Driver Seat / Active Test.

    5. Perform the Active Test according to the display on the GTS.


      Body Electrical > Driver Seat > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      Headrest Operation Headrest operation OFF/Down/Up -

      Body Electrical > Driver Seat > Active Test
      Tester Display
      Headrest Operation
      OK
      Motor operates normally.
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT FRONT SEAT HEADREST ASSEMBLY (HEADREST MOTOR) Click here

    OK

  4. CHECK POSITION CONTROL ECU ASSEMBLY (HEADRST MOTOR CIRCUIT)


    1. B004BIXC05
      *a

      Front view of wire harness connector

      (to Front Seat Headrest Assembly LH (Headrest Motor))

      for LHD:


      1. Disconnect the front seat headrest assembly LH (headrest motor) connector.

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

        Standard Voltage
        Tester Connection Switch Condition Specified Condition
        y5-2 - y5-3 Headrest switch on 4.8 to 5.1 V
    2. B004BIXC07
      *a

      Front view of wire harness connector

      (to Front Seat Headrest Assembly RH (Headrest Motor))

      for RHD:


      1. Disconnect the front seat headrest assembly RH (headrest motor) connector.

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

        Standard Voltage
        Tester Connection Switch Condition Specified Condition
        x5-2 - x5-3 Headrest switch on 4.8 to 5.1 V
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE FRONT SEAT HEADREST ASSEMBLY Click here

    NG

  5. CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU ASSEMBLY - FRONT SEAT HEADREST ASSEMBLY (HEADREST MOTOR))


    1. for LHD:


      1. Disconnect the w12 position control ECU assembly LH connector.

      2. Disconnect the y5 front seat headrest assembly LH (headrest motor) connector.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        w12-24 (SSRH) - y5-2 Always Below 1 Ω
        w12-24 (SSRH) or y5-2 - Other terminals and body ground Always 10 kΩ or higher
        w12-12 (SENG) - y5-3 Always Below 1 Ω

    2. for RHD:


      1. Disconnect the v12 position control ECU assembly RH connector.

      2. Disconnect the x5 front seat headrest assembly RH (headrest motor) connector.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        v12-24 (SSRH) - x5-2 Always Below 1 Ω
        v12-24 (SSRH) or x5-2 - Other terminals and body ground Always 10 kΩ or higher
        v12-12 (SENG) - x5-3 Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE POSITION CONTROL ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  6. INSPECT FRONT SEAT HEADREST ASSEMBLY (HEADREST MOTOR)


    1. Remove the front seat headrest assembly.

      Click here

    2. Inspect the front seat headrest assembly (headrest motor).

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE FRONT SEAT HEADREST ASSEMBLY Click here

    OK

  7. CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU ASSEMBLY - FRONT SEAT HEADREST ASSEMBLY (HEADREST MOTOR))


    1. for LHD:


      1. Disconnect the w10 and w11 position control ECU assembly LH connectors.

      2. Disconnect the y5 front seat headrest assembly LH (headrest motor) connector.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        w10-4 (H+) - y5-1 Always Below 1 Ω
        w10-4 (H+) or y5-1 - Other terminals and body ground Always 10 kΩ or higher
        w11-2 (H-) - y5-4 Always Below 1 Ω
        w11-2 (H-) or y5-4 - Other terminals and body ground Always 10 kΩ or higher

    2. for RHD:


      1. Disconnect the v10 and v11 position control ECU assembly RH connectors.

      2. Disconnect the x5 front seat headrest assembly RH (headrest motor) connector.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        v10-4 (H+) - x5-1 Always Below 1 Ω
        v10-4 (H+) or x5-1 - Other terminals and body ground Always 10 kΩ or higher
        v11-2 (H-) - x5-4 Always Below 1 Ω
        v11-2 (H-) or x5-4 - Other terminals and body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE POSITION CONTROL ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  8. PERFORM ACTIVE TEST USING GTS (HEADREST OPERATION)


    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 / Passenger Seat / Active Test.

    5. Perform the Active Test according to the display on the GTS.


      Body Electrical > Passenger Seat > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      Headrest Operation Headrest operation OFF/Down/Up -

      Body Electrical > Passenger Seat > Active Test
      Tester Display
      Headrest Operation
      OK
      Motor operates normally.
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT FRONT SEAT HEADREST ASSEMBLY (HEADREST MOTOR) Click here

    OK

  9. CHECK POSITION CONTROL ECU ASSEMBLY (HEADREST MOTOR CIRCUIT)


    1. B004BIXC06
      *a

      Front view of wire harness connector

      (to Front Seat Headrest Assembly RH (Headrest Motor))

      for LHD:


      1. Disconnect the front seat headrest assembly RH (headrest motor) connector.

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

        Standard Voltage
        Tester Connection Switch Condition Specified Condition
        x5-2 - x5-3 Headrest switch on 4.8 to 5.1 V
    2. B004BIXC08
      *a

      Front view of wire harness connector

      (to Front Seat Headrest Assembly LH (Headrest Motor))

      for RHD:


      1. Disconnect the front seat headrest assembly LH (headrest motor) connector.

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

        Standard Voltage
        Tester Connection Switch Condition Specified Condition
        y5-2 - y5-3 Headrest switch on 4.8 to 5.1 V
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE FRONT SEAT HEADREST ASSEMBLY Click here

    NG

  10. CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU ASSEMBLY - FRONT SEAT HEADREST ASSEMBLY (HEADREST MOTOR))


    1. for LHD:


      1. Disconnect the v12 position control ECU assembly RH connector.

      2. Disconnect the x5 front seat headrest assembly RH (headrest motor) connector.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        v12-24 (SSRH) - x5-2 Always Below 1 Ω
        v12-24 (SSRH) or x5-2 - Other terminals and body ground Always 10 kΩ or higher
        v12-12 (SENG) - x5-3 Always Below 1 Ω

    2. for RHD:


      1. Disconnect the w12 position control ECU assembly LH connector.

      2. Disconnect the y5 front seat headrest assembly LH (headrest motor) connector.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        w12-24 (SSRH) - y5-2 Always Below 1 Ω
        w12-24 (SSRH) or y5-2 - Other terminals and body ground Always 10 kΩ or higher
        w12-12 (SENG) - y5-3 Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE POSITION CONTROL ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  11. INSPECT FRONT SEAT HEADREST ASSEMBLY (HEADREST MOTOR)


    1. Remove the front seat headrest assembly.

      Click here

    2. Inspect the front seat headrest assembly (headrest motor).

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE FRONT SEAT HEADREST ASSEMBLY Click here

    OK

  12. CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU ASSEMBLY - FRONT SEAT HEADREST ASSEMBLY (HEADREST MOTOR))


    1. for LHD:


      1. Disconnect the v10 and v11 position control ECU assembly RH connectors.

      2. Disconnect the x5 front seat headrest assembly RH (headrest motor) connector.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        v10-4 (H+) - x5-1 Always Below 1 Ω
        v10-4 (H+) or x5-1 - Other terminals and body ground Always 10 kΩ or higher
        v11-2 (H-) - x5-4 Always Below 1 Ω
        v11-2 (H-) or x5-4 - Other terminals and body ground Always 10 kΩ or higher

    2. for RHD:


      1. Disconnect the w10 and w11 position control ECU assembly LH connectors.

      2. Disconnect the y5 front seat headrest assembly LH (headrest motor) connector.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        w10-4 (H+) - y5-1 Always Below 1 Ω
        w10-4 (H+) or y5-1 - Other terminals and body ground Always 10 kΩ or higher
        w11-2 (H-) - y5-4 Always Below 1 Ω
        w11-2 (H-) or y5-4 - Other terminals and body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE POSITION CONTROL ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR