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: Whether you need a replacement ECU or repairs for your existing module, Flagship One, Inc has the solutions you need. Visit our website today to learn more about our services and how we can help you keep ...