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 (RADIO RECEIVER - AUDIO DOOR CONTROL SWITCH) 
    1. Disconnect the R1 receiver connector.
      Fig 1: Identifying R1 Receiver Connector Terminals
      G05293092Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the A25 switch connector.
    3. Measure the resistance of the wire harness side connectors.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      R1-2 (DOS1) - A25-8 Below 1 Ω
      R1-2 (DOS1) - Body ground 10 kΩ or higher

    NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

    OK: Go to next step 

  2. CHECK WIRE HARNESS (AUDIO DOOR CONTROL SWITCH - BATTERY AND BODY GROUND) 
    1. Disconnect A25 connector.
      Fig 2: Identifying A25 Connector Terminals
      G05293093Courtesy 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
      A25-6 (GND) - Body ground Below 1 Ω

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Condition Specified Condition
      A25-10 (+B) - Body ground Always 10 to 14 V
      A25-4 (ACC) - Body ground Ignition switch ACC 10 to 14 V

    NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

    OK: Go to next step 

  3. REPLACE INSTRUMENT CLUSTER FINISH PANEL SUB-ASSEMBLY LOWER CENTER (AUDIO DOOR CONTROL SWITCH) 
    1. After replacing the instrument cluster finish panel lower center (audio door control switch), check that the audio door can be opened and closed by using the audio door control switch.

      OK: 

      Audio door can be opened and closed with switch. 

    NG: REPLACE RADIO RECEIVER ASSEMBLY 

    OK: END 

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When to See a Mechanic

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.