ACTIVE HEIGHT CONTROL SUSPENSION, Diagnostic DTC:C1764, C1765

DTC Code DTC Name
C1764 Abnormal Leveling Valve Oil Pressure
C1765 Abnormal Accumulator Valve Oil Pressure

DESCRIPTION

The solenoid valve is located in the No. 1 height control valve. When the vehicle height is adjusted, the fluid line is opened or closed according to the signal from the suspension control ECU. If the height control pump and motor activates when the fluid line is closed due to the solenoid valve malfunctioning, the solenoid valve being stuck, or foreign matter clogging the fluid line, fluid pressure increases abnormally. When this problem with the fluid pressure is detected, DTC C1764 and/or DTC C1765 is stored.

DTC Code Detection Condition Trouble Area
C1764

When the height control pump and motor activates and the fluid pressure is 18.5 MPa (188.6 kgf/cm2, 2683 psi) or more for 0.3 seconds.

  • No. 1 height control valve (Each solenoid valve is stuck)

  • Clog in the fluid line

  • Suspension control ECU
C1765

When the height control pump and motor activates and the fluid pressure is 18.5 MPa (188.6 kgf/cm2, 2683 psi) or more for 0.3 seconds.

  • No. 1 height control valve (Each solenoid valve is stuck)

  • Clog in the fluid line

  • Suspension control ECU

INSPECTION PROCEDURE

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 (EACH LEVELING VALVE AND ACCUMULATOR VALVE)


    1. Connect the intelligent tester to the DLC3.

    2. Start the engine and turn the tester on.

    3. Select the Active Test mode on the intelligent tester.

    4. Check the operation sound of the solenoid or vibration of the leveling valve solenoid and accumulator valve solenoid when operating the solenoid with the intelligent tester.

      AHC
      Tester Display Test Part Control Range Diagnostic Note
      Front Right Height Solenoid Front height control solenoid valve RH ON or OFF Operation of solenoid can be heard.
      Front Left Height Solenoid Front height control solenoid valve LH ON or OFF Operation of solenoid can be heard.
      Rear Right Height Solenoid Rear height control solenoid valve RH ON or OFF Operation of solenoid can be heard.
      Rear Left Height Solenoid Rear height control solenoid valve LH ON or OFF Operation of solenoid can be heard.
      Accumulator Valve Accumulator solenoid valve ON or OFF Operation of solenoid can be heard.
      OK
      The operation sound of the solenoid should be heard or the vibration of the leveling valve solenoid or accumulator valve solenoid should be felt.

    NG

    REPLACE NO. 1 HEIGHT CONTROL VALVE Click here

    OK

  2. CHECK FLUID LINE


    1. Check if the fluid line is clogged.

      Tech Tips


      • Check if the fluid line that connects the height control pump and motor and No. 1 height control valve is clogged. If it is not clogged, there probably is foreign matter clogging the interior of the No. 1 height control valve.

      • Follow the removal and installation procedures for each part, as all parts need to be removed.


    NG

    REPAIR OR REPLACE CLOGGED PARTS

    OK

    REPLACE SUSPENSION CONTROL ECU Click here