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. INSPECT FUSE (RADIO NO. 2, P-IG, AM1, TV) 
    1. Remove the RADIO NO. 2 and P-IG fuses from the passenger side junction block.
    2. Remove the AM1 fuse from the driver side junction block.
    3. Measure the resistance of the fuses.

      Standard resistance: 

      Below 1 Ω 

    NG: REPLACE FUSE 

    OK: Go to next step 

  2. INSPECT RELAY (Marking: ACC, IG1) 
    1. Remove the ACC and IG1 relay from the passenger side junction block.
      Fig 1: Identifying ACC And IG1 Relay Terminals
      G05293359Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance of the relays.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      3 - 5 Below 1 Ω
      3 - 5 10 kΩ or higher (when battery voltage is applied to terminals 1 and 2)

    NG: REPLACE RELAY 

    OK: Go to next step 

  3. CHECK WIRE HARNESS (INSTRUMENT CLUSTER FINISH PANEL CENTER - BATTERY AND BODY GROUND) 
    1. Disconnect the M5 panel connector.
      Fig 2: Identifying M5 Panel Connector Terminals
      G05293360Courtesy 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 Connector Specified Condition
      M5-11 (GND) - Body ground Below 1 Ω

      Standard voltage 

      TESTER CONNECTOR SPECIFIED CONDITION CHART

      Tester Connector Condition Specified Condition
      M5-10 (+B1) - Body ground Always 10 to 14 V
      M5-20 (ACC) - Body ground Ignition switch ACC 10 to 14 V
      M5-19 (IG) - Body ground Ignition switch ON 10 to 14 V

    NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

    OK: Go to next step 

  4. INSPECT INSTRUMENT CLUSTER FINISH PANEL CENTER 
    1. Remove the instrument cluster finish panel center.
      Fig 3: Identifying Instrument Cluster Finish Panel Center Connector Terminals
      G05293361Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance of the panel.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      M5-10 (+B1) - A-12 (+B1) Below 1 Ω
      M5-20 (ACC) - A-11 (ACC) Below 1 Ω
      M5-19 (IG) - A-10 (IG) Below 1 Ω
      M5-11 (GND) - A-3 (GND1) 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 OR DIAGNOSTIC TROUBLE CODE CHART 

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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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