Battery Rundown Protection
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2000 GMC Yukon XL, 2000 GMC Yukon, 2000 GMC Sierra, 2000 Chevrolet Tahoe, and 2000 Chevrolet Suburban. However, it is still accessible from the selected car via links, so may be relevant.
BCM helps to prevent inadvertent battery rundown from situations such as courtesy lights left on. The BCM will turn off courtesy light circuit after ignition has been off for 40 minutes and no light request input has been received.