The most common acronyms you'll find when dealing with the engine management system are the following:

ECM: Engine Control Module
PCM: Powertrain Control Module
VCM: Vehicle Control Module
TCM: Transmission Control Module

Initially we called our product PCM Suite. This was fine but GM is moving more toward the VCM terminology for future vehicles and thus we decided we should go with VCM right off the bat to avoid confusion later on down the road.

VCM is just the newer computer unit that you'll find controlling your vehicles functionality. Our product still works without hitch on the PCM equipped vehicles that you'll typically find between 1997 and 2003.