Powertrain Control Module (PCM)

WARNING: This page is about a different car, the 2007 Pontiac G5 Pursuit, 2007 Pontiac G5, and 2007 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.

The powertrain control module (PCM) verifies that the password received from the theft deterrent module (TDM) via the serial data circuit is correct. The PCM can learn only one fuel continue password. If the fuel continue password is correct, the PCM enables the starting and fuel delivery systems.

The PCM disables the starting and fuel delivery systems if any of the following conditions occur:

The fuel continue password is incorrect.
The fuel disable password is sent by the TDM.
No passwords are received. There is no communication with the TDM.

On some vehicles, if the PCM is unable to communicate with the vehicle theft deterrent (VTD) system after the vehicle has started, the PCM will consider the VTD system to be malfunctioning. The PCM will enter a fail enable state and will command the security indicator to illuminate. When the PCM is in a fail enable state, the vehicle will NOT stall or stop running. If the PCM is in a fail enable state when the ignition is switched OFF, the PCM will remain fail enable until communications with the VTD system has been restored. When the PCM is in a fail enable state, the VTD system is NOT active and the vehicle will start. This feature is NOT available on all GM vehicle lines.