The heart of a modern car is the computerised engine management system, commonly known as a "black box".
Using powerful silicon chips - with greater computing power than many desk top office machines - the "black box" is connected to sensors measuring many of the cars parameters every few milli-seconds.
It digests the information and optimises functions as diverse as the fuel/air proportions of the combustion mix, the strength and timing of the ignition charge, the efficiency of the air conditioning system, the speed of the wipers and the operation of such safety features as ABS, Traction Control and the Airbags.
Like electronic ignition it is extremely reliable but, as the modern brain of car, if it fails you go nowhere.
Article © Graham Benge 2007