AIR SUSPENSION SYSTEM, Diagnostic DTC:C1761

DTC Code DTC Name
C1761 Continuous Electric Current to Height Control Compressor Motor

DESCRIPTION

The signal from the suspension control ECU operates the suspension control relay and the height control compressor motor starts. The height control compressor motor operates until the targeted vehicle height is reached. Then the height control sensor sends the signal to the suspension control ECU. Then, the suspension control ECU stops the height control compressor motor.

DTC No. Detection Condition Trouble Area
C1761 While suspension control relay is ON, vehicle height does not reach target for 3 minutes or more

  • Air leakage from the air tube or valves

  • Suspension control relay

  • Height control compressor

  • No. 1 height control valve

  • No. 2 height control valve

  • Suspension control ECU

INSPECTION PROCEDURE

Note


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

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

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

  • The system may output DTC C1761 even when the system is normal if one of the following occurs: 1) the vehicle is full of passengers and the luggage compartment is full; 2) the vehicle is being driven or is stopped on an irregular surface; or 3) the air ducts are frozen.

  • When refilling the air, when a current is applied to the height control compressor for 3 minutes or more, DTC C1761 may be output.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTC Click here.


    NEXT

  2. INSPECT FOR AIR LEAK


    1. Check for air leak Click here.

      OK
      No leaks.

    NG

    REPAIR OR REPLACE AIR TUBE

    OK

  3. INSPECT IF NO. 1 HEIGHT CONTROL VALVE IS STUCK


    1. Remove the No. 1 height control valve Click here.

    2. A01H05LE43

      Check the No. 1 height control valve (valve RH).


      1. Apply 12 V battery voltage to the control valve and check the operation of the valve RH.

        OK
        Measurement Condition Specified Condition

        12 V battery positive (+) → Terminal 1 (RH+)

        12 V battery negative (-) → Terminal 2 (E)

        		 It make an operating sound
    3. A01H05LE44

      Check the No. 1 height control valve (valve LH).


      1. Apply 12 V battery voltage to the control valve and check the operation of the valve LH.

        OK
        Measurement Condition Specified Condition

        12 V battery positive (+) → Terminal 3 (LH+)

        12 V battery negative (-) → Terminal 2 (E)

        		 It make an operating sound

    NG

    REPLACE NO. 1 HEIGHT CONTROL VALVE Click here

    OK

  4. INSPECT IF NO. 2 HEIGHT CONTROL VALVE IS STUCK


    1. Remove the No. 2 height control valve Click here.

    2. A01H05LE45

      Check the No. 2 height control valve (valve RH).


      1. Apply 12 V battery voltage to the control valve and check the operation of the valve RH.

        OK
        Measurement Condition Specified Condition

        12 V battery positive (+) → Terminal 1 (+RH)

        12 V battery negative (-) → Terminal 2 (E)

        		 It make an operating sound
    3. A01H05LE46

      Check the No. 2 height control valve (valve LH).


      1. Apply 12 V battery voltage to the control valve and check the operation of the valve LH.

        OK
        Measurement Condition Specified Condition

        12 V battery positive (+) → Terminal 3 (+LH)

        12 V battery negative (-) → Terminal 2 (E)

        		 It make an operating sound

    NG

    REPLACE NO. 2 HEIGHT CONTROL VALVE Click here

    OK

  5. INSPECT IF HEIGHT CONTROL COMPRESSOR IS STUCK


    1. Remove the height control compressor Click here.

    2. A01H0JTE02

      Inspect if the exhaust valve is stuck.


      1. Apply 12 V battery voltage to the exhaust valve and check the operation of the valve.

        OK
        Measurement Condition Specified Condition

        12 V battery positive (+) → Terminal 1

        12 V battery negative (-) → Terminal 2

        		 It should make an operating sound (click)
    3. A01GXVJE04

      Inspect if the compressor is stuck.


      1. Apply 12 V battery voltage to the compressor motor and check the operation of the motor.

        OK
        Measurement Condition Specified Condition

        12 V battery positive (+) → Terminal 1 (B)

        12 V battery negative (-) → Terminal 2 (E)

        		 Motor operates

        Note


        • Do not allow the motor to operate for approximately 60 seconds or more.

        • If the compressor is shorted, locked, or has a similar type of malfunction, a large amount of current will be flowing. Therefore, if the motor does not operate, immediately stop this inspection.


    NG

    REPLACE HEIGHT CONTROL COMPRESSOR Click here

    OK

  6. INSPECT SUSPENSION CONTROL RELAY (AIR SUS)


    1. Turn the power switch OFF.

    2. A01GXC2E11

      Remove the suspension control relay from the engine room No. 5 relay block.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      3 - 5 When 12 V battery voltage is not applied to terminal 1 and 2 10 kΩ or higher
      When 12 V battery voltage is applied to terminal 1 and 2 Below 1 Ω
      Result
      Result Proceed to
      NG A
      OK (for LHD) B
      OK (for RHD) C

    B

    REPLACE SUSPENSION CONTROL ECU Click here

    C

    REPLACE SUSPENSION CONTROL ECU Click here

    A

    REPLACE SUSPENSION CONTROL RELAY