AIR SUSPENSION SYSTEM, Diagnostic DTC:C1731, C1732, C1733, C1734

DTC Code DTC Name
C1731 FR Damping Force Control Actuator Circuit
C1732 FL Damping Force Control Actuator Circuit
C1733 RR Damping Force Control Actuator Circuit
C1734 RL Damping Force Control Actuator Circuit

DESCRIPTION

The absorber control actuator switches the damping force depending on the suspension control ECU signals.

DTC Code DTC Detection Condition Trouble Area
C1731

Either condition is met:


  • An actuator open-circuit signal is detected for at least 1 second when the actuator operates.

  • An actuator short-circuit signal is consecutively detected 8 times when the actuator operates.

  • Harness or connector

  • Front absorber control actuator RH

  • Suspension control ECU
C1732

Either condition is met:


  • An actuator open-circuit signal is detected for at least 1 second when the actuator operates.

  • An actuator short-circuit signal is consecutively detected 8 times when the actuator operates.

  • Harness or connector

  • Front absorber control actuator LH

  • Suspension control ECU
C1733

Either condition is met:


  • An actuator open-circuit signal is detected for at least 1 second when the actuator operates.

  • An actuator short-circuit signal is consecutively detected 8 times when the actuator operates.

  • Harness or connector

  • Rear absorber control actuator RH (Rear shock absorber assembly)

  • Suspension control ECU
C1734

Either condition is met:


  • An actuator open-circuit signal is detected for at least 1 second when the actuator operates.

  • An actuator short-circuit signal is consecutively detected 8 times when the actuator operates.

  • Harness or connector

  • Rear absorber control actuator LH (Rear shock absorber assembly)

  • Suspension control ECU

WIRING DIAGRAM

B001GJXE08

CAUTION / NOTICE / HINT

Note

When replacing the suspension control ECU, perform registration Click here.

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS (DAMPER STEP)


    1. Turn the ignition switch off.

    2. Connect the GTS to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the GTS on.

    5. Enter the following menus: Chassis / Air suspension / Active Test.

      Air Suspension
      Tester Display Test Part Control Range Diagnostic Note
      Damper Step FR Changes damper step (Front RH) 1 to 17 step The shock absorber hardens as the damper step increases.
      Damper Step FL Changes damper step (Front LH) 1 to 17 step The shock absorber hardens as the damper step increases.
      Damper Step RR Changes damper step (Rear RH) 1 to 17 step The shock absorber hardens as the damper step increases.
      Damper Step RL Changes damper step (Rear LH) 1 to 17 step The shock absorber hardens as the damper step increases.
      OK
      The absorber control actuator operates.

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  2. INSPECT ABSORBER CONTROL ACTUATOR


    1. Turn the ignition switch off.

    2. Check the front absorber control actuator RH (when DTC C1731 is output).


      1. Disconnect the A56 actuator connector.

      2. B001CP6E12
        Text in Illustration
        *a

        Component without harness connected

        (Front Absorber Control Actuator RH)

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        1 (FAR+) - 2 (FAR-) Always 6.4 to 7.2 Ω
        3 (FBR+) - 4 (FBR-) Always 6.4 to 7.2 Ω

    3. Check the front absorber control actuator LH (when DTC C1732 is output).


      1. Disconnect the A57 actuator connector.

      2. B001CP6E13
        Text in Illustration
        *a

        Component without harness connected

        (Front Absorber Control Actuator LH)

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        1 (FAL+) - 2 (FAL-) Always 6.4 to 7.2 Ω
        3 (FBL+) - 4 (FBL-) Always 6.4 to 7.2 Ω

    4. Check the rear absorber control actuator RH (when DTC C1733 is output).


      1. Disconnect the S1 actuator connector.

      2. B001DKKE11
        Text in Illustration
        *a

        Component without harness connected

        (Rear Absorber Control Actuator RH)

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        1 (RAR-) - 2 (RAR+) Always 6.4 to 7.2 Ω
        3 (RBR-) - 4 (RBR+) Always 6.4 to 7.2 Ω

    5. Check the rear absorber control actuator LH (when DTC C1734 is output).


      1. Disconnect the S4 actuator connector.

      2. B001DKKE12
        Text in Illustration
        *a

        Component without harness connected

        (Rear Absorber Control Actuator LH)

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        1 (RAL-) - 2 (RAL+) Always 6.4 to 7.2 Ω
        3 (RBL-) - 4 (RBL+) Always 6.4 to 7.2 Ω
        Result
        Result Proceed to
        OK A
        NG (Front absorber control actuator RH) B
        NG (Front absorber control actuator LH) C
        NG (Rear absorber control actuator RH) D
        NG (Rear absorber control actuator LH) E

    B

    REPLACE FRONT ABSORBER CONTROL ACTUATOR RH Click here

    C

    REPLACE FRONT ABSORBER CONTROL ACTUATOR LH Click here

    D

    REPLACE REAR SHOCK ABSORBER ASSEMBLY RH Click here

    E

    REPLACE REAR SHOCK ABSORBER ASSEMBLY LH Click here

    A

  3. CHECK HARNESS AND CONNECTOR (ABSORBER CONTROL ACTUATOR - SUSPENSION CONTROL ECU)


    1. Check the front side absorber control actuator.


      1. Disconnect the A56 and/or A57 front absorber control actuator connector.

      2. Disconnect the A14 suspension control ECU connector.

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

        Standard Resistance
        for Front RH (for DTC C1731)
        Tester Connection Condition Specified Condition
        A56-1 (FAR+) - A14-7 (FAR+) Always Below 1 Ω
        A56-2 (FAR-) - A14-8 (FAR-) Always Below 1 Ω
        A56-3 (FBR+) - A14-1 (FBR+) Always Below 1 Ω
        A56-4 (FBR-) - A14-2 (FBR-) Always Below 1 Ω
        A56-1 (FAR+) - Body ground Always 10 kΩ or higher
        A56-2 (FAR-) - Body ground Always 10 kΩ or higher
        A56-3 (FBR+) - Body ground Always 10 kΩ or higher
        A56-4 (FBR-) - Body ground Always 10 kΩ or higher
        for Front LH (for DTC C1732)
        Tester Connection Condition Specified Condition
        A57-1 (FAL+) - A14-3 (FAL+) Always Below 1 Ω
        A57-2 (FAL-) - A14-5 (FAL-) Always Below 1 Ω
        A57-3 (FBL+) - A14-6 (FBL+) Always Below 1 Ω
        A57-4 (FBL-) - A14-4 (FBL-) Always Below 1 Ω
        A57-1 (FAL+) - Body ground Always 10 kΩ or higher
        A57-2 (FAL-) - Body ground Always 10 kΩ or higher
        A57-3 (FBL+) - Body ground Always 10 kΩ or higher
        A57-4 (FBL-) - Body ground Always 10 kΩ or higher

    2. Check the rear side absorber control actuator.


      1. Disconnect the S1 and/or S4 rear absorber control actuator connector.

      2. Disconnect the R19 suspension control ECU connector.

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

        Standard Resistance
        for Rear RH (for DTC C1733)
        Tester Connection Condition Specified Condition
        S1-1 (RAR-) - R19-2 (RAR-) Always Below 1 Ω
        S1-2 (RAR+) - R19-1 (RAR+) Always Below 1 Ω
        S1-3 (RBR-) - R19-4 (RBR-) Always Below 1 Ω
        S1-4 (RBR+) - R19-3 (RBR+) Always Below 1 Ω
        S1-1 (RAR-) - Body ground Always 10 kΩ or higher
        S1-2 (RAR+) - Body ground Always 10 kΩ or higher
        S1-3 (RBR-) - Body ground Always 10 kΩ or higher
        S1-4 (RBR+) - Body ground Always 10 kΩ or higher
        for Rear LH (for DTC C1734)
        Tester Connection Condition Specified Condition
        S4-1 (RAL-) - R19-6 (RAL-) Always Below 1 Ω
        S4-2 (RAL+) - R19-5 (RAL+) Always Below 1 Ω
        S4-3 (RBL-) - R19-8 (RBL-) Always Below 1 Ω
        S4-4 (RBL+) - R19-7 (RBL+) Always Below 1 Ω
        S4-1 (RAL-) - Body ground Always 10 kΩ or higher
        S4-2 (RAL+) - Body ground Always 10 kΩ or higher
        S4-3 (RBL-) - Body ground Always 10 kΩ or higher
        S4-4 (RBL+) - Body ground Always 10 kΩ or higher

    OK

    REPLACE SUSPENSION CONTROL ECU Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR