est What is an ECU, PCM, and ECM? Electronic Control Unit (ECU), Powertrain Control Module (PCM), and Engine Control Module (ECM are all terms used interchangeably to refer to the computer system that controls various aspects of your vehicle’s performance. Here’s a breakdown of each component: The ECU, or Engine Control Unit, is responsible for controlling various engine functions, such as ignition timing, fuel delivery, and emissions systems. It plays a crucial role in optimizing engine performance and improving fuel efficiency. Seek Professional Help: If you are unable to diagnose or fix the problem on your own, it is best …