Diagnosis & Repair (Using Lexus Scan Tester)
- Remove instrument panel fuse cover. Connect Lexus scan tester to Data Link Connector (DLC) No. 3. See Figure. Turn scan tester on. Turn ignition on. Using scan tester, 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 as specified, no problem is indicated at this time. Diagnose by symptom. See TROUBLE SHOOTING - NO CODES article. If STA signal is not as specified, go to next step.
- Check for open in wiring harness between ECM and starter relay. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair as necessary. If wiring is okay, replace ECM and retest.