2007 Lexus SC 430FACTORY OEM SERVICE PROCEDURE

Inspection Procedure

HINT:

  • If DTCs P0115, P0116, P0117, P0118 and P0125 are output simultaneously, an ECT sensor circuit may be open or shorted. Perform the TROUBLESHOOTING OF DTC P0115, P0117 OR P0118 FIRST .
  • Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
  1. CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P0125) 

    Result 

    RESULT CHART

    Display (DTC output) Proceed to
    P0125 A
    P0125 and other DTCs B

    HINT:

    If any other codes besides P0125 are output, perform the troubleshooting for those codes first.

    B: GO TO RELEVANT DTC CHART 

    A: Go to next step 

  2. INSPECT THERMOSTAT 
    1. Check the valve opening temperature of the thermostat.

      OK: 

      Valve opening temperature is 80 to 84°C (176 to 183°F) 

      HINT:

      Also check that the valve is completely closed below the opening temperature shown above.

    NG: REPLACE THERMOSTAT 

    OK: Go to next step 

  3. CHECK COOLING SYSTEM 
    1. Check for defects in the cooling system that might cause the system to be too cold, such as abnormal radiator fan operation or a modified cooling system.

    NG: REPAIR OR REPLACE COOLING SYSTEM 

    OK: REPLACE ENGINE COOLANT TEMPERATURE SENSOR 

Factory Service Tools

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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.