Starter Signal Circuit Test: GS300
Remove ECM hood and cover, and locate ECM. See COMPONENT LOCATIONS . Using DVOM, backprobe ECM 28-pin connector E5 terminal No. 2 (Black wire). See Fig 1. Check for voltage with ignition in START position. If voltage is 6 volts or more, ECM is okay. If voltage is less than 6 volts, check for open in wiring harness or connectors between ECM and starter relay. Repair as necessary. If wiring harness and connectors are okay, replace ECM.