In a Buick car, the Powertrain Control Module (PCM) is a crucial electronic component that controls and manages the powertrain system. The engine, transmission, and emissions control are just a few of the systems that the PCM is in charge of tracking and managing.

The ideal fuel and air mixture for the engine, as well as the ideal timing for ignition and gearshifting, are all determined by the PCM using data from various sensors distributed throughout the vehicle. To make sure the car is running safely and effectively, the PCM also communicates with other systems, such as the traction control and anti-lock braking systems, in the vehicle.

The PCM can identify and determine the cause of a system failure or glitch in the vehicle.