2008 Lexus SC 430FACTORY OEM SERVICE PROCEDURE

Inspection Procedure

WARNING: This page is about a different car, the 2007 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK WIRE HARNESS (INSTRUMENT CLUSTER FINISH PANEL CENTER - BATTERY AND BODY GROUND) 
    1. Disconnect the M5 panel connector.
      Fig 1: Identifying M5 Panel Connector Terminals
      G05293355Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance and voltage of the wire harness side connector.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      M5-11 (GND1) - Body ground Below 1 Ω

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Condition Specified Condition
      M5-10 (+B1)*Body ground Always 10 to 14 V
      M5-12 (ST1) - Body ground Ignition switch OFF OV
      M5-12 (ST1) - Body ground Ignition switch START 10 to 14 V
      M5-20 (ACC) - Body ground Ignition switch OFF OV
      M5-20 (ACC) - Body ground Ignition switch ACC 10 to 14 V

    NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

    OK: Go to next step 

  2. CHECK WIRE HARNESS (NAVIGATION ECU - STEREO COMPONENT AMPLIFIER AND BODY GROUND) 
    1. Disconnect the M6 panel connector.
    2. Disconnect the A8 A/C connector.
      Fig 2: Identifying A8 A/C Connector Terminals
      G05293356Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance of the wire harness connectors.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      M5-3 (OPEN) - A8-14 (EMOP) Below 1 Ω
      MS-13 (TILT) - A8-4 (EMTI) Below 1 Ω
      M5-4 (RE1) - A10-2 (SW1) Below 1 Ω
      M5-14 (RE2) - A10-7 (SW2) Below 1 Ω
      M5-3 (OPEN) - Body ground 10 kΩ or higher
      M5-13 (TILT) - Body ground 10 kΩ or higher
      M5-3 (RE1) - Body ground 10 kΩ or higher
      M5-13 (RE2) - Body ground 10 kΩ or higher

    NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

    OK: Go to next step 

  3. INSPECT INSTRUMENT CLUSTER FINISH PANEL SUB-ASSEMBLY CENTER 
    1. Remove the instrument cluster finish panel center.
      Fig 3: Identifying Instrument Cluster Finish Panel Center Connector Terminals
      G05293357Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance of the panel.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      M5-3 (OPEN) - C-8 (OPEN/CLOSE) Below 1 Ω
      M5-13 (TILT) - C-7 (TILT) Below 1 Ω
      M5-4 (RE1) - C-3 (OPEN) Below 1 Ω
      M5-14 (RE2) - C-2 (CLOSE) Below 1 Ω
      M5-12 (ST1) - C-5 (ST1) Below 1 Ω
      M5-20 (ACC) - C-6 (ACC) Below 1 Ω
      M5-11 (GND1) - C-9 (GND1) Below 1 Ω
      M5-10 (+B1) - C-10 (+B1) Below 1 Ω

    NG: REPAIR OR REPLACE INSTRUMENT CLUSTER FINISH PANEL SUB-ASSEMBLY CENTER 

    OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE 

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Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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