Circuit Description
WARNING: This page is about a different car, the 2003 Pontiac Aztek and 2003 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.
Moving the ignition switch to the START position sends a 12 V signal to the PCM Ignition Crank Sense. The PCM then grounds the control circuit, which travels through the Park Neutral Position switch, of the CRANK relay. When the CRANK relay is energized it allows voltage to the starter solenoid S terminal.