What is a car PCM module in the UK?

A PCM (Powertrain Control Module) is the engine control unit that manages your vehicle's performance. In UK cars like the Vauxhall Corsa or Ford Focus, the PCM processes sensor data to control fuel injection, ignition timing, air/fuel mixture, and emissions systems while monitoring for faults. The PCM performs two key functions: 1) Engine Management - It calculates optimal fuel delivery, ignition timing, and air intake (including electronic throttle control) based on temperature, load, and knock sensor readings. 2) Diagnostics - UK models store fault codes (like OBD-II codes) and illuminate the MIL (Malfunction Indicator Lamp) when issues are detected, helping technicians at garages like Kwik Fit identify problems during MOT tests. Modern British-market vehicles like the MINI Electric still use PCM technology, though in EVs it manages battery and motor systems instead of combustion processes.