Monitored Loads
WARNING: This page is about a different car, the 2000 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
The BCM can detect if certain electrical loads have been left on to minimize the possibility of battery rundown. When BCM detects that ignition has been turned off, BCM immediately checks status of load monitor input. If BCM detects that a load is present (ground on circuit No. 640), BCM will turn on load monitor relay for 15 minutes. If BCM detects load is still present after 15 minutes, BCM will turn off relay, removing battery voltage from loads. If a switch transition is detected by BCM, BCM will turn on relay again for another 15-minute period.