Diagnosis & Repair (Using Lexus Scan Tool)
WARNING: This page is about a different car, the 2003 Lexus SC 430, 2003 Lexus LS 430, 2003 Lexus IS 300, 2003 Lexus GS 430, and 2003 Lexus GS 300. However, it is still accessible from the selected car via links, so may be relevant.
- Connect Lexus scan tool to Data Link Connector (DLC) No. 3. See Fig 1. Turn scan tool on. Turn ignition on. Using scan tool, read STA signal with ignition on and then while cranking starter.
- With ignition on, STA signal should be off. With ignition switch in START position, STA signal should be on. If STA signal is not as specified, go to next step. If STA signal is as specified, no problem is indicated at this time. Diagnose by symptom. See SYMPTOMS in TROUBLE SHOOTING - NO CODES article.
- Check for open in wiring harness between ECM and starter relay. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Repair as necessary. If wiring is okay, replace ECM and retest.