Circuit Description
WARNING: This page is about a different car, the 2003 Pontiac Montana, 2003 Oldsmobile Silhouette, and 2003 Chevrolet Venture. However, it is still accessible from the selected car via links, so may be relevant.
The theft deterrent control module produces the theft deterrent fuel and starter enable signal when ignition is ON and the proper transponder key value is detected. The powertrain control module (PCM) monitors the fuel and starter enable signal during crank. If the proper signal is present on the Class 2 Serial Data Circuit, the PCM enables the fuel delivery and starter operation in order to allow the engine to start. If the PCM detects an incorrect password, vehicle theft deterrent (VTD) system failure or attempted vehicle theft, DTC P1631 is set. The engine will not start or crank as long as the condition is present.