2008 Lexus IS FFACTORY OEM SERVICE PROCEDURE

How To Proceed With Troubleshooting

HINT

  • Use the following procedure to troubleshoot the defogger system
  • * Use the Techstream
  1. VEHICLE BROUGHT TO WORKSHOP 
  2. INSPECT BATTERY VOLTAGE 

    Standard Voltage: 11 to 14 V 

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

  3. PROBLEM SYMPTOMS TABLE 

    Result 

    RESULT REFERENCE

    Result Proceed to
    Fault is not listed in problem symptoms table A
    Fault is listed in problem symptoms table B

    B:  GO TO STEP   5

    A: Go to next step 

  4. OVERALL ANALYSIS AND TROUBLESHOOTING* 
    1. Terminals of ECU (See TERMINALS OF ECU  ).
    2. Data List/Active Test (See DATA LIST / ACTIVE TEST  ).
    3. On-vehicle inspection (See ON-VEHICLE INSPECTION  ).
  5. REPAIR OR REPLACE 
  6. CONFIRMATION TEST 

    NEXT: END 

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.

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