2008 Lexus SC 430FACTORY OEM SERVICE PROCEDURE

Inspection Procedure

  1. CHECK FOR EXHAUST GAS LEAK 
    1. Allow the engine to idle.
    2. Check for an exhaust gas leak around the HO2S.

    OK: 

    No leak from the HO2S. 

    NG: REPAIR LEAK 

    OK: Go to next step 

  2. CHECK HEATED OXYGEN SENSOR 
    Fig 1: Fuel-Trim And Rear HO2S Voltage Pattern
    G04967990Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Warm up the engine.
    2. Allow the engine to idle.
    3. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
    4. Check the O2S B1 S2 (O2S B2 S2) values when the Control the Injection Volume for A/F Sensor is -12.5% (Lean fuel-trim).
    5. Check the O2S B1 S2 (O2S B2 S2) values when the Control the Injection Volume for A/F Sensor is 25% (Rich fuel-trim).

    Standard 

    PROBLEM SYMPTOM CHART

    Control the Injection Volume for A/F Sensor O2S B1 S2 (O2S B2 S2)
    -12.5% Less than 0.2 V
    25% More than 0.8 V

    NG: REPLACE HEATED OXYGEN SENSOR 

    OK: Go to next step 

  3. CHECK DTC 
    1. Clear DTC.
    2. Turn the ignition switch OFF.
    3. Disconnect the cable from the negative battery terminal and wait for 1 minute.
    4. Connect the cable to the negative battery terminal.
    5. Start the engine.
      Fig 2: Engine Coolant Temperature Drive Pattern
      G04967991Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    6. Perform the drive pattern.
      1. Warm up the engine.
      2. Accelerate the vehicle until 80 km/h (50 mph) and stop the vehicle.
      3. Drive the vehicle by 60 to 80 km/h (35 to 50 mph) for 5 minutes or more.
    7. Check DTC.

    OK: 

    P0606 is not present. 

    NG: REPLACE ECM 

    OK: CHECK FOR INTERMITTENT PROBLEMS 

Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready ToolsCompare Repair QuoteQuote Shield Pro

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.