The PCM is the TCM; as well as the ECM. GM normally calls a module that controls both the engine and transmission functions a Powertrain control module. If there was a separate transmission control module, the PCM would be called an ECM and the separate transmission control module would be called the TCM.
Sometimes, they call it a PCM/TCM. Should I say someday in the future there will be a VCM (vehicle control module)?
