ACTIVE HEIGHT CONTROL SUSPENSION, Diagnostic DTC:C1731, C1732, C1733, C1734

DTC Code DTC Name
C1731 Front Damping Force Control Actuator RH Circuit Malfunction
C1732 Front Damping Force Control Actuator LH Circuit Malfunction
C1733 Rear Damping Force Control Actuator RH Circuit Malfunction
C1734 Rear Damping Force Control Actuator LH Circuit Malfunction

DESCRIPTION

The ECU sends a signal to the damping force control actuator to drive the rotary valve of the shock absorber changing the shock absorber damping force.

The actuator is driven electromagnetically by a step motor so that it can accurately follow the driving conditions that change frequently.

DTC Code Detection Condition Trouble Area
C1731

When either of the following is detected:


  • 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 shock absorber control valve RH (Front damping force control actuator RH)

  • Suspension control ECU
C1732

When either of the following is detected:


  • 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 shock absorber control valve LH (Front damping force control actuator LH)

  • Suspension control ECU
C1733

When either of the following is detected:


  • 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 shock absorber control valve RH (Rear damping force control actuator RH)

  • Suspension control ECU
C1734

When either of the following is detected:


  • 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 shock absorber control valve LH (Rear damping force control actuator LH)

  • Suspension control ECU

WIRING DIAGRAM

B001WJTE02

CAUTION / NOTICE / HINT

Note


  • Before performing troubleshooting, inspect the connectors of related circuits.

  • If the suspension control ECU or height control sensor is replaced, the vehicle height offset calibration must be performed Click here.

PROCEDURE


  1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (DAMPER STEP)


    1. According to the display on the intelligent tester, perform the Active Test.

    2. Check if the damping force control actuator operates in accordance with the Active Test.

      AHC
      Tester Display Test Part Control Range Diagnostic Note
      Damper Step FR Changes front damper RH step

      min.: 1 step

      max.: 16 step

      		 The Damper Step item of the Data List changes to the step selected in the Active Test.
      Damper Step FL Changes front damper LH step

      min.: 1 step

      max.: 16 step

      		 The Damper Step item of the Data List changes to the step selected in the Active Test.
      Damper Step RR Changes rear damper RH step

      min.: 1 step

      max.: 16 step

      		 The Damper Step item of the Data List changes to the step selected in the Active Test.
      Damper Step RL Changes rear damper LH step

      min.: 1 step

      max.: 16 step

      		 The Damper Step item of the Data List changes to the step selected in the Active Test.
      OK
      The damping force control actuator operates.

    NG

    CHECK HARNESS AND CONNECTOR (DAMPING FORCE CONTROL ACTUATOR - SUSPENSION CONTROL ECU) Click here

    OK

  2. RECONFIRM DTC OUTPUT


    1. Clear the DTCs Click here.

    2. Perform a road test.

    3. Check for DTCs.

      Result
      Result Proceed to
      DTC is output A
      DTC is not output B

    B

    USE SIMULATION METHOD TO CHECK Click here

    A

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


    1. Check the front side damping force control actuator.


      1. Disconnect the N9 and/or N11 actuator connector.

      2. Disconnect the K36 ECU connector.

        B001YQVE02

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

        Standard Resistance
        for RH (C1731)
        Tester Connection Condition Specified Condition
        K36-5 (FAR-) - N9-4 (FAR-) Always Below 1 Ω
        K36-5 (FAR-) - Body ground Always 10 kΩ or higher
        K36-6 (FAR+) - N9-1 (FAR+) Always Below 1 Ω
        K36-6 (FAR+) - Body ground Always 10 kΩ or higher
        K36-17 (FBR-) - N9-3 (FBR-) Always Below 1 Ω
        K36-17 (FBR-) - Body ground Always 10 kΩ or higher
        K36-18 (FBR+) - N9-5 (FBR+) Always Below 1 Ω
        K36-18 (FBR+) - Body ground Always 10 kΩ or higher
        N9-2 (E FR) - Body ground Always Below 1 Ω
        for LH (C1732)
        Tester Connection Condition Specified Condition
        K36-2 (FBL+) - N11-5 (FBL+) Always Below 1 Ω
        K36-2 (FBL+) - Body ground Always 10 kΩ or higher
        K36-3 (FAL-) - N11-4 (FAL-) Always Below 1 Ω
        K36-3 (FAL-) - Body ground Always 10 kΩ or higher
        K36-4 (FAL+) - N11-1 (FAL+) Always Below 1 Ω
        K36-4 (FAL+) - Body ground Always 10 kΩ or higher
        K36-12 (FBL-) - N11-3 (FBL-) Always Below 1 Ω
        K36-12 (FBL-) - Body ground Always 10 kΩ or higher
        N11-2 (E FL) - Body ground Always Below 1 Ω

    2. Check the rear side damping force control actuator.


      1. Disconnect the N6 and/or N8 actuator connector.

      2. Disconnect the K35 ECU connector.

        B001Z68E02

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

        Standard Resistance
        for RH (C1733)
        Tester Connection Condition Specified Condition
        K35-4 (RBR-) - N6-3 (RBR-) Always Below 1 Ω
        K35-4 (RBR-) - Body ground Always 10 kΩ or higher
        K35-5 (RAR+) - N6-1 (RAR+) Always Below 1 Ω
        K35-5 (RAR+) - Body ground Always 10 kΩ or higher
        K35-13 (RBR+) - N6-5 (RBR+) Always Below 1 Ω
        K35-13 (RBR+) - Body ground Always 10 kΩ or higher
        K35-14 (RAR-) - N6-4 (RAR-) Always Below 1 Ω
        K35-14 (RAR-) - Body ground Always 10 kΩ or higher
        N6-2 (E RR) - Body ground Always Below 1 Ω
        for LH (C1734)
        Tester Connection Condition Specified Condition
        K35-2 (RAL-) - N8-4 (RAL-) Always Below 1 Ω
        K35-2 (RAL-) - Body ground Always 10 kΩ or higher
        K35-3 (RAL+) - N8-1 (RAL+) Always Below 1 Ω
        K35-3 (RAL+) - Body ground Always 10 kΩ or higher
        K35-7 (RBL-) - N8-3 (RBL-) Always Below 1 Ω
        K35-7 (RBL-) - Body ground Always 10 kΩ or higher
        K35-8 (RBL+) - N8-5 (RBL+) Always Below 1 Ω
        K35-8 (RBL+) - Body ground Always 10 kΩ or higher
        N8-2 (E RL) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. INSPECT DAMPING FORCE CONTROL ACTUATOR


    1. Check the front side damping force control actuator.


      1. Connect the N9 and/or N11 front absorber control actuator connector.

      2. Disconnect the K36 ECU connector.

        B00207HE01

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

        Standard Resistance
        for RH (C1731)
        Tester Connection Condition Specified Condition
        K36-5 (FAR-) - Body ground Always 12.0 to 13.6 Ω
        K36-6 (FAR+) - Body ground Always 12.0 to 13.6 Ω
        K36-17 (FBR-) - Body ground Always 12.0 to 13.6 Ω
        K36-18 (FBR+) - Body ground Always 12.0 to 13.6 Ω
        for LH (C1732)
        Tester Connection Condition Specified Condition
        K36-2 (FBL+) - Body ground Always 12.0 to 13.6 Ω
        K36-3 (FAL-) - Body ground Always 12.0 to 13.6 Ω
        K36-4 (FAL+) - Body ground Always 12.0 to 13.6 Ω
        K36-12 (FBL-) - Body ground Always 12.0 to 13.6 Ω

    2. Check the rear side damping force control actuator.


      1. Connect the N6 and/or N8 rear absorber control actuator connector.

      2. Disconnect the K35 ECU connector.

        B001Z3PE02

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

        Standard Resistance
        for RH (C1733)
        Tester Connection Condition Specified Condition
        K35-4 (RBR-) - Body ground Always 12.0 to 13.6 Ω
        K35-5 (RAR+) - Body ground Always 12.0 to 13.6 Ω
        K35-13 (RBR+) - Body ground Always 12.0 to 13.6 Ω
        K35-14 (RAR-) - Body ground Always 12.0 to 13.6 Ω
        for LH (C1734)
        Tester Connection Condition Specified Condition
        K35-2 (RAL-) - Body ground Always 12.0 to 13.6 Ω
        K35-3 (RAL+) - Body ground Always 12.0 to 13.6 Ω
        K35-7 (RBL-) - Body ground Always 12.0 to 13.6 Ω
        K35-8 (RBL+) - Body ground Always 12.0 to 13.6 Ω
      Result
      Result Proceed to
      OK A
      Front damping force control actuator RH malfunction B
      Front damping force control actuator LH malfunction C
      Rear damping force control actuator RH malfunction D
      Rear damping force control actuator LH malfunction E

    A

    REPLACE SUSPENSION CONTROL ECU Click here

    B

    REPLACE FRONT SHOCK ABSORBER CONTROL VALVE RH Click here

    C

    REPLACE FRONT SHOCK ABSORBER CONTROL VALVE LH Click here

    D

    REPLACE REAR SHOCK ABSORBER CONTROL VALVE RH Click here

    E

    REPLACE REAR SHOCK ABSORBER CONTROL VALVE LH Click here