Circuit/System Verification

WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.

Ignition ON, verify that no starter relay, theft deterrent, or automatic transmission DTCs are set that would cause the ECM to disable engine starting.
- If DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .
Ignition ON, observe the scan tool BCM Starter Switch parameter. Place ignition switch in the crank position, the parameter should display ON.
- If not the specified value, refer to Power Mode Mismatch .
Transmission range selector in park, verify the scan tool ECM PNP Switch and TCM IMS parameters display Park/Neutral.
- If the TCM IMS parameter does not indicate Park/Neutral, refer to Transmission Internal Mode Switch Logic
- If the ECM Park/Neutral parameter does not indicate Park/Neutral, refer to ECM Park Switch Circuit Malfunction in Circuit/System Testing .
Transmission range selector in park or neutral, attempt to start the vehicle. The crank relay should click and the engine should begin cranking.
- If the crank relay does not click or the engine does not crank, refer to Crank Relay Circuit Malfunction in Circuit/System Testing .