Circuit/System Verification

Ignition ON, verify that no ignition, starter relay, brake pedal position sensor, 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 Push Button Ignition Switch parameter. Place the ignition switch in the crank position, the parameter should display Active.
- If not the specified value, refer to Power Mode Mismatch .
Transmission range selector in park, verify the scan tool Transmission Control Module (TCM) Internal Mode Switch parameter displays Park.
- If the TCM Internal Mode Switch parameter does not indicate Park, refer to Transmission Internal Mode Switch Logic .
Transmission range selector in park or neutral attempt to start the vehicle. The crank relay should click and the engine should begin cranking.