Automatic Transaxle Shift Lock Control
WARNING: This page is about a different car, the 2002 Pontiac Sunfire, 2002 Chevrolet Cavalier, 2001 Pontiac Sunfire, and 2001 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
Body Control Module (BCM) controls shift lock function by supplying system ground. Shift lock is released when ignition is on and brake is applied. See appropriate DIAGNOSIS article in AUTOMATIC TRANSMISSIONS.