2008 Lexus IS 350FACTORY OEM SERVICE PROCEDURE

How To Proceed With Troubleshooting

WARNING: This page is about a different car, the 2008 Lexus IS F. However, it is still accessible from the selected car via links, so may be relevant.

HINT

  • Use this procedure to troubleshoot the multiplex communication system
  • *. Use the Techstream
  1. VEHICLE BROUGHT TO WORKSHOP 
  2. CHECK FOR DTC* 
    1. Check for DTCs and note any codes that are output (See DTC CHECK / CLEAR  ).
    2. Clear the DTC.
    3. Recheck for DTCs Try to prompt the DTC by simulating the original activity that the DTC suggests

      Result 

      DTC RESULT REFERENCE

      Result Proceed to
      DTC does not reoccur A
      DTC reoccurs B

    B: GO TO DTC CHART  (See DIAGNOSTIC TROUBLE CODE CHART  )

    A: Go to Next Step 

  3. OVERALL ANALYSIS AND TROUBLESHOOTING 
    1. Terminals of ECU (See TERMINALS OF ECU  )
  4. REPAIR OR REPLACE 
  5. 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.