Doors Do Not Automatically Lock When All Doors Are Closed &
WARNING: This page is about a different car, the 1994 Cadillac Fleetwood. However, it is still accessible from the selected car via links, so may be relevant.
Transmission Is Shifted Out Of Park With Ignition In Run
1) Turn ignition switch to RUN position. Shift transmission into Park. Backprobe test light between Remote Control Door Lock Receiver/Theft Deterrent Module (RCDLR/TDM) terminal C16 (Light Green wire) and ground.
2) If test light does not light, repair open circuit in Light Green wire. If wire is okay, replace transmission position switch. If test light lights, shift transmission to Drive. Connect test light between RCDLR/TDM connector C16 (Light Green wire) and ground.
3) If test light does not light, replace RCDLR/TDM. If test light lights, repair short to voltage in Light Green wire. If wire is okay, replace transmission position switch.