What makes this computer different trom your home PC is how it gets input. On your PC you provide input through the keyboard or mouse. On the car’s ECM, it receives input through multiple sensors located throughout the car. These sensors monitor almost every function of the car including; temperature, speed, luel mixture, timing, spark, braking, and much more.
The ECM monitors these sensors and then makes adjustments to the vehicle to optimize performance. This scenario is played out hundreds of times every second; input, analysis, output, and then input, analysis, etc.
Subjected to constant vibration, grease, dirt, flying debris, not to mention extreme heat, the ECM has to overcome an unlriendly environment to perform. That is why it is so important to have it serviced at regular intervals.