LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2004 >> GX 470 >> Repair and Diagnosis >> Suspension >> Electronic Suspension >> Electronic Modulated Suspension & Rear Air Suspension System - Diagnosis >> DTC C1751/51: Continuous Electric Current To Height Control Compressor >> Inspection Procedure

Inspection Procedure

  1. INSPECT HEIGHT CONTROL COMPRESSOR CIRCUIT (See  DTC C1742/42 HEIGHT CONTROL COMPRESSOR CIRCUIT  ) 
  2. INSPECT AIR LEAKAGE (See  SUSPENSION CONTROL SYSTEM  ) 
    1. NG: REPAIR OR REPLACE AIR TUBE 
    2. OK: GO TO NEXT STEP. 
  3. INSPECT HEIGHT CONTROL SOLENOID VALVE OR EXHAUST SOLENOID VALVE 

    When using hand-held tester: 

    1. Connect the hand-held tester to DLC3.
    2. Turn the ignition switch ON, and push the hand-held tester main switch ON.
    3. Select the item "LEVEL SOL REAR", "GATE SOL REAR", "LOW PRS TNK SOL" in the ACTIVE TEST, and operate it with the hand-held tester.

      HINT:

      The exhaust solenoid valve cannot be tested in ACTIVE TEST.

    4. Check whether the solenoid makes sound.
    5. Check whether the height control solenoid valve has a continuity (will vibrate).

    Standard: The solenoid makes sound, the height control solenoid valve has a continuity (will vibrate). 

    When not using hand-held tester: 

    1. Disconnect the valve connector.
    2. Check the operating sound of the valves when battery positive voltage is applied to the terminals as shown below.
      Fig 1: Solenoid Valve Specification
      G01421621Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      Fig 2: Inspecting Height Control Solenoid Valve Or Exhaust Solenoid Valve
      G01421622Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard: It make an operating sound (click). 

    HINT:

    • When a malfunction is found in the gate solenoid valve, the leveling valve or the tank solenoid valve, replace the height control reservoir assy.
    • When a malfunction is found in the exhaust solenoid valve, replace the height control compressor assy.
    1. NG: REPLACE HEIGHT CONTROL RESERVOIR ASSY 
    2. NG: REPLACE HEIGHT CONTROL COMPRESSOR ASSY 
    3. OK: GO TO NEXT STEP. 
  4. INSPECT HEIGHT CONTROL SENSOR LINK SUB-ASSY 
    1. Inspect and adjust the height control sensor link sub-assy (See SUSPENSION CONTROL SYSTEM ).
  5. RECONFIRM DTC 
    1. Clear the DTC and repeat the procedure to re-check it ( PRE-CHECK ).

    HINT:

    If the DTC C1751/51 is still output, proceed to the next step.

  6. CHECK AND REPAIR OR REPLACE PARTS OF MALFUNCTION CAUSES 
    1. Air tube is clogged (See SUSPENSION CONTROL SYSTEM )
    2. Compressor is faulty (See REPLACEMENT )
    3. Relief valve is faulty (See REPLACEMENT )
    4. Height control sensor sub-assy rear is faulty (See REPLACEMENT )
    5. Foreign material entered in the height control solenoid valve (gate solenoid valve) and the exhaust solenoid valve
    6. Suspension control ECU malfunctions (See TERMINALS OF ECU )