Some of the biggest advances in automotive technology in the past 10 years have come in the area of safety. Spurred by improvements in microprocessor speed, miniaturization, and software development, the automobile continues to evolve. In addition to telemetric based services like OnStar, digital satellite radio and in-car e-mail, recent advances in braking technology have led to shorter stopping distances and increased control while driving in inclement conditions. All these developments have been possible because a certain device, the ECU, was integrated into the automobiles.
An Electronic Control Unit or ECU (also known as an "engine management system") is an electronic device, basically a computer, in an internal combustion engine that reads several sensors in the engine and uses the information to control the fuel injection and ignition systems of the engine. This approach allows an engine's operation to be controlled in great detail, allowing greater fuel efficiency, better power and responsiveness, and much lower pollution levels than earlier generations of engines. Because the ECU is dealing with actual measured engine performance from millisecond to millisecond, it can compensate for many variables that traditional systems cannot.
Modern ECUs use a microprocessor which can process the inputs from the engine sensors in real time. An electronic control unit comprises both hardware and software. The hardware consists of electronic components on a printed circuit board (PCB). The main component on this circuit board is a micro-controller chip (CPU). The software is stored in the microcontroller or other similar chips on the PCB, typically in Flash-Memory or EPROM's so that the CPU can be re-programmed by uploading updated code. This is also referred to as an electronic' Engine Management System (EMS).
Sophisticated management systems receive inputs from other sources apart from the engine hence controlling other