an ECU is like the brain of the vehicle it takes information in from all differrent sensors around the car and then fixes any problems. for example
wheel speed sensor; makes a small amount of power, that is sent to the ecu, the more power the fasted ur traveling, the ecu then tells the speedo on the dash that ur doing X amount of speed, this all happens in spit seconds so its much faster than u can think!
jezza, March 2010
