LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2010 >> LS 460L RWD >> Repair and Diagnosis >> Suspension >> Electronic Suspension >> Air Suspension (Diagnostic Codes & Circuit Tests) >> Air Suspension System >> DTC C1751: Compressor Relay Coil Malfunction >> Procedure

DTC C1751: Compressor Relay Coil Malfunction: Procedure

  1. CLEAR DTC 
    1. Clear the DTC. Refer to DTC CHECK / CLEAR .

    NEXT: Go to next step 

  2. CHECK MOTOR RELAY OPERATION (ACTIVE TEST) 
    1. Turn the engine switch off.
    2. Connect the Techstream to the DLC3.
    3. Turn the engine switch on (IG) and the Techstream on.
    4. Enter the following menus: Chassis / Air suspension / Active Test.
    5. Check the operation sound of the height control solenoid valve when the solenoid is turned on through the Active Test.
      AIR SUSPENSION

      Tester Display Test Part Control Range Diagnostic Note
      Motor Relay Suspension control relay ON or OFF Operation of solenoid (clicking sound) can be heard

      OK

      Operation of solenoid (clicking sound) can be heard

    NG → See step   4 

    OK: Go to next step 

  3. RECONFIRM DTC 
    1. Perform a road test.
    2. Check for DTC. Refer to DTC CHECK / CLEAR .
      RESULT

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

    B → See step   6 

    A: Go to next step 

  4. INSPECT SUSPENSION CONTROL RELAY (AIR SUS) 
    1. Turn the engine switch off.
    2. Remove the suspension control relay from the engine room No. 1 relay block.
      Fig 1: Identifying Suspension Control Relay Circuit Diagram
      GTY110843Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      3 - 5 When battery voltage is not applied to terminal 1 and 2 10 kΩ or higher
      When battery voltage is applied to terminal 1 and 2 Below 1 Ω

    NG → REPLACE SUSPENSION CONTROL RELAY 

    OK: Go to next step 

  5. CHECK HARNESS AND CONNECTOR (SUSPENSION CONTROL RELAY - ECU AND BODY GROUND) 
    1. Disconnect the L88 ECU connector.
    2. Remove the suspension control relay from the engine room No. 1 relay block.
      Fig 2: Checking Harness And Connector (Suspension Control Relay - ECU And Body Ground)
      GTY289389Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      L88-6 (RC) - Relay block suspension control relay terminal 1 Always Below 1 Ω
      L88-6 (RC) or Relay block suspension control relay terminal 1 - Body ground Always 10 kΩ or higher
      Relay block suspension control relay terminal 2 - Body ground Always Below 1 Ω

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   7 

  6. USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING 
  7. REPLACE SUSPENSION CONTROL ECU. Refer to  REMOVAL 
scientia non olet · About LEMON Manuals