Relay Controlled Power Mode: Notes
WARNING: This page is about a different car, the 2005 Pontiac Pursuit and 2005 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
The body control module (BCM) uses the discrete ignition switch inputs Off/Run/Crank, Accessory, and ignition 1, to distinguish the correct power mode. The ignition 1 circuit is also routed to the Run/Crank relay for relay controlled power feeds during the appropriate power mode. The BCM, after determining the desired power mode, will activate the appropriate relays for that power mode.