Circuit/System Description
WARNING: This page is about a different car, the 2009 Pontiac Torrent and 2009 Chevrolet Equinox. However, it is still accessible from the selected car via links, so may be relevant.
The body control module (BCM) monitors the vehicle system voltage on 2 circuits: the BCM B+ circuit terminal 3 X3, which is fed through the BCM fuse, and the high resolution B+ circuit terminal 10 X4, which is fed through the RVC fuse. The BCM monitors the system voltage to ensure that the voltage stays within the proper range. Damage to components, and incorrect data may occur when the voltage is out of range. The BCM monitors the system voltage over an extended length of time. If the BCM detects the system voltage is outside an expected range, or if the two BCM battery sense circuits differ, DTC B1517 will set.