The engine compartment is a harsh environment on any vehicle. But in a high-performance German sport sedan like the BMW 3-series, it is even more so. And the incredible technology that these cars use to manage fuel delivery, timing, and ignition are often the components that break down most often. The heat, vibration, and moisture under the hood can be very damaging to the sensitive electronics that these systems use.
If you think of your car as a living, breathing being then it is fair to call the car’s engine the heart of the being. The engine has similar general functions to a human being’s heart as it gets the blood (fuel) pumping and the rest of the body parts (other automotive parts) moving! If the engine is the heart, then the engine control unit (ECU) found in many modern vehicles is the brain. If you want to understand the fundamentals of electronic fuel injection then you need to understand the concept that electronic fuel injection would be non-existent without the brain of the car.