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Home >> Lexus >> 2004 >> GX 470 >> Repair and Diagnosis >> Suspension >> Electronic Suspension >> Electronic Modulated Suspension & Rear Air Suspension System - Diagnosis >> DTC C1786/86: Height Control Switch Circuit >> Inspection Procedure

Inspection Procedure

HINT:

Start the inspection from step 1 when using the hand-held tester, and start from step 2 when not using the hand-held tester.

  1. READ VALUE OF HAND-HELD TESTER 
    1. Connect the hand-held tester to DLC3.
    2. Turn the ignition switch ON, and turn the hand-held tester main switch ON.
    3. Select the item "HEIGHT SW DOWN" or "HEIGHT SW UP" in the DATA LIST, and read its value displayed on the hand-held tester.
    4. Check that the value displayed on the hand-held tester changes by pressing the height control switch "UP" and "DOWN".

    Standard: Height control switch value changes. 

    1. OK: CHECK AND REPLACE SUSPENSION CONTROL ECU (See  ELECTRONIC CIRCUIT INSPECTION PROCEDURE  ) 
    2. NG: GO TO NEXT STEP. 
  2. INSPECT HEIGHT CONTROL SWITCH 
    1. Remove the suspension control switch connector.
    2. Check continuity between each terminal of the height control switch when the height control switch position is "UP", "OFF" and "DOWN".

      Standard: 

      Fig 1: Switch Specification
      G01421661Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      Fig 2: Inspecting Height Control Switch
      G01421662Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    HINT:

    When the height control switch is faulty, replace the suspension control switch.

    1. NG: REPLACE SUSPENSION CONTROL SWITCH 
    2. OK: GO TO NEXT STEP. 
  3. CHECK HARNESS AND CONNECTOR (HEIGHT CONTROL SWITCH - SUSPENSION CONTROL ECU) 
    1. Check for open and short circuit in the harness and the connector between the height control switch and the suspension control ECU (See ELECTRONIC CIRCUIT INSPECTION PROCEDURE ).
    1. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 
    2. OK: GO TO NEXT STEP. 

      CHECK AND REPLACE SUSPENSION CONTROL ECU (See  ELECTRONIC CIRCUIT INSPECTION PROCEDURE  )