2008 Lexus IS FFACTORY OEM SERVICE PROCEDURE

Inspection Procedure

NOTE: Since the power window control system has functions that use multiplex communication (BEAN), first confirm that there is no malfunction in the multiplex communication system by inspecting the multiplex communication functions in accordance with the How to Proceed with Troubleshooting procedure (See HOW TO PROCEED WITH TROUBLESHOOTING  ). Then, conduct the following inspection procedure.
  1. CHECK OPERATION FUNCTION AFTER ENGINE SWITCH IS TURNED OFF 
    1. Check the power window operation function after the engine switch is turned off

      Result 

      RESULT REFERENCE

      Result Proceed to
      45 seconds pass and the power windows can still operate A
      Driver side door or front passenger side door is opened within 45 seconds but power window can still operate B

    A: REPLACE MAIN BODY ECU RH (COWL SIDE JUNCTION BLOCK RH) 

    B: Go to next step 

  2. CHECK LIGHTING SYSTEM (DOOR COURTESY LIGHT) 
    1. Check that the driver and front passenger door courtesy lights operate normally.

      OK: Driver and front passenger door courtesy lights illuminate. 

    NG: GO TO LIGHTING SYSTEM (DOOR COURTESY SWITCH CIRCUIT)  (See DOOR COURTESY SWITCH CIRCUIT )

    OK: REPLACE MAIN BODY ECU RH (COWL SIDE JUNCTION BLOCK RH) 

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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