Diagnosis & Repair (Using Lexus Scan Tool)

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 TESTS W/O CODES article.
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.

Fig 1: Identifying Data Link Connector (DLC) No. 3. Location