2003 Lexus LS 430FACTORY OEM SERVICE PROCEDURE

Trouble Shooting

WARNING: This page is about a different car, the 2002 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.

Trouble shooting of the power window system MUST begin with the multiplex communication system. See MULTIPLEX CONTROL SYSTEMS - AVALON article under COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT. If the multiplex communication system is functioning properly and no diagnostic trouble codes are stored, the body control system must be interrogated next to determine if the power window system fault is at the body control ECU level, driver door ECU level, front passenger door ECU level or power window component level. See BODY CONTROL SYSTEMS - AVALON article under COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT.

If body control ECU, driver door ECU and front passenger door ECU trouble shooting does not address particular power window system problem, diagnose by symptom. See SYMPTOM INDEXΒ  under SYSTEM TESTS.

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:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.

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