ADAPTIVE VARIABLE SUSPENSION SYSTEM, Diagnostic DTC:C1789

DTC Code DTC Name
C1789 Vehicle Identification Malfunction

DESCRIPTION


DTC No. Detection Item DTC Detection Condition Trouble Area Warning Indicate Note
C1789 Vehicle Identification Malfunction

Either condition is met:


  • The vehicle identification information is not stored.

  • Vehicle identification information that is different from the stored information has been received 3 times.

  • The stop and start system setting availability stored value is not stored.*2

  • After determining that the vehicle is not equipped with a stop and start system, the absorber control ECU receives information indicating that the vehicle is equipped with a stop and start system.*2

  • CAN communication system

  • Vehicle identification information

  • ECM

  • Steering sensor

  • VGRS ECU (Front steering control ECU)*1

  • Engine stop and start ECU*2

  • Absorber control ECU

 Does not come on

  • *1: w/ VGRS System

  • *2: w/ Stop and start system

CAUTION / NOTICE / HINT

Note


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

  • If DTC C1781 (Suspension Control ECU Malfunction) is output at the same time, perform troubleshooting for C1781 first.

    Click here

  • If DTC C1782 (Power Source Voltage Malfunction) is output at the same time, perform troubleshooting for C1782 first.

    Click here

  • Before replacing the absorber control ECU, perform all of the following again: 1) symptom simulation; 2) DTC inspection; and 3) GTS inspection (ECU Data List or Active Test Click here). If no malfunctions are found in other areas, replace the absorber control ECU.

  • w/ Stop and Start System:

    Before replacing the engine stop and start ECU, refer to Registration.

    Click here

  • When the absorber control ECU is replaced, switch to test mode and check that all test mode DTCs are cleared when their respective deletion conditions are met.

    Click here

PROCEDURE


  1. CHECK FOR DTC (CAN COMMUNICATION SYSTEM)


    1. Check for DTCs.

      Click here


      Chassis > Air suspension > Trouble Codes
      Result
      Result Proceed to
      CAN DTC is not output A
      CAN DTC is output B

    B

    GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) Click here

    A

  2. CHECK VEHICLE IDENTIFICATION INFORMATION STATUS


    1. Check that vehicle identification information has been stored.

      Click here

      Result
      Result Proceed to
      Information stored (w/ Stop and start system) A
      Information stored (w/o Stop and start system) B
      Information not stored C

    B

    GO TO STEP 4 Click here

    C

    PERFORM VEHICLE IDENTIFICATION INFORMATION REGISTRATION Click here

    A

  3. READ VALUE USING GTS (STOP AND START LEARNING STATUS (w/ Stop and start system))


    1. Turn the engine switch off.

    2. Connect the GTS to the DLC3.

    3. Turn the engine switch on (IG).

    4. Turn the GTS on.

    5. Enter the following menus: Chassis / Air suspension / Data List.


      Chassis > Air suspension > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Stop and Start Learning Status Learning status of stop and start setting availability after vehicle identification information registration is performed Unset, OFF or ON ON

      • w/ Stop and start system

      • When "Unset", DTC C1789 is output.

      Chassis > Air suspension > Data List
      Tester Display
      Stop and Start Learning Status
      OK
      The normal condition value is displayed on the GTS.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE ABSORBER CONTROL ECU Click here

    OK

  4. CHECK RELATED PART


    1. If the DTC was output as a result of the replacement of a related part, replace the part with one that has a correct part number.

      Related Part ECM
      Steering sensor

      w/ VGRS system:

      VGRS ECU (Front steering control ECU)

      w/ Stop and start system:

      Engine stop and start ECU

      Note

      When removing a related part to check it, be sure to follow the appropriate procedures and precautions.


      • Refer to the following procedures to remove the ECM.

        - 2GR-FSE

        Click here

        - 8AR-FTS

        Click here

      • Refer to the following procedures to remove the steering sensor.

        Click here

      • Refer to the following procedures to remove the VGRS ECU (front steering control ECU).

        Click here

      • Refer to the following procedures to remove the engine stop and start ECU.

        Click here

      Tech Tips

      If parts have not been replaced and DTC C1789 is output, there may be an internal malfunction in the absorber control ECU. Therefore, replace the absorber control ECU.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  5. CHECK FOR DTC


    1. Clear the DTCs.

      Click here


      Chassis > Air suspension > Clear DTCs

    2. Turn the engine switch off.

    3. Check if DTC C1789 is output.

      Click here


      Chassis > Air suspension > Trouble Codes
      OK
      DTC C1789 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END

    NG

    REPLACE ABSORBER CONTROL ECU Click here