What does it mean?
The engine control module (ECM) is just one of many computer systems in your car. Some of them are dedicated to some pretty basic things, like power windows. The ECM and other drivetrain and powertrain computers are what keep your engine and transmission running smoothly, such as the transmission control module (TCM), transfer case control module (TCCM), electronic throttle control system (ETCS), and anti-lock braking system (ABS), to name a few.
The ECM is pretty much like the computer on which you’re reading this article, whether it be a laptop, desktop, tablet, even smartphone, but with a couple of differences. A car ECM is a dedicated machine, specifically designed for a single vehicle application. The hardware portion consists of microprocessors and memory chips, which monitor inputs to constantly actuate outputs.
The software, similarly, is also very specific, perhaps applicable to a specific model, engine, transmission, and body style. Usually, the software is installed at the factory, though modern ECM’s may be programmable at the dealership, using a factory scan tool. The ECM constantly monitors itself and other controllers on the network. If it encounters an internal fault, such as memory loss or corruption, it will set a diagnostic trouble code (DTC) in memory.
One common fault is DTC P0607 – Control Module Performance.