2008 Lexus GS 450hFACTORY OEM SERVICE PROCEDURE

How To Proceed With Troubleshooting

HINT:

*: Use the Techstream.

  1. VEHICLE BROUGHT TO WORKSHOP 
  2. INSPECT BATTERY VOLTAGE 

    Standard voltage: 

    11 to 14 V 

    HINT:

    If the voltage is below 11V, recharge or replace the battery before proceeding.

  3. INSPECT COMMUNICATION FUNCTION OF CAN COMMUNICATION SYSTEM* 
    1. Using the Techstream, inspect the CAN communication function to ensure there are no malfunctions in the communication system.

      Result 

      RESULT REFERENCE

      Result Proceed to
      No DTCs output A
      DTCs output B

    B: PROCEED TO  CAN COMMUNICATION SYSTEM 

    A: Go to next step 

  4. INSPECT COMMUNICATION FUNCTION OF MULTIPLEX COMMUNICATION SYSTEM* 
    1. Using the Techstream, inspect the multiplex communication function to ensure there are no malfunctions in the communication system.

      Result 

      RESULT REFERENCE

      Result Proceed to
      No DTCs output A
      DTCs output B

      HINT:

      The skid control ECU sends the signals of each warning light to the gateway ECU via CAN communication, and the gateway ECU sends the signals to the combination meter via the multiplex communication system (BEAN).

    B: PROCEED TO  MULTIPLEX COMMUNICATION SYSTEM 

    A: Go to next step 

  5. CHECK DTC AND FREEZE FRAME DATA* 
  6. CLEAR DTC AND FREEZE FRAME DATA* 
  7. PROBLEM SYMPTOM CONFIRMATION 
  8. DTC CHECK AND CLEAR* 
  9. PROBLEM SYMPTOM CONFIRMATION 

    Result 

    RESULT REFERENCE

    Result Proceed to
    Symptom does not occur A
    Symptom occurs B

    B:  GO TO STEP  11

    A: Go to next step 

  10. SYMPTOM SIMULATION 
  11. CHECK FOR DTC (OTHER THAN CAN AND MULTIPLEX COMMUNICATION SYSTEM DTC)* 

    Result 

    RESULT REFERENCE

    Result Proceed to
    No DTCs output A
    DTCs output B

    B:  GO TO STEP  13

    A: Go to next step 

  12. PROBLEM SYMPTOMS TABLE 

    NEXT:  GO TO STEP  14

  13. DTC CHART 
  14. CIRCUIT INSPECTION* 
  15. IDENTIFICATION OF PROBLEM 
  16. REPAIR OR REPLACE 
  17. CONFIRMATION TEST* 

    NEXT: 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.

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