Luxury class car use between 70 to 100 microprocessor electronic control units a.k.a. ECUs which are located all over the body of the car. Even low-end cars feature as many as 30 to 50 ECUs.
ECUs started to work their way into cars in 1977. General Motors was the first to use them in the Oldsmobile Toronado. Back then, the ECU had a single purpose -- it controlled the timing of the electronic spark. Next came a trip computer for the Cadillac Seville in 1978 which displayed the speed of the vehicle, amount of fuel used, trip, and engine info. This processor also served as a test of whether these devices could control multiple functions including port fuel injection, electronic spark timing, and cruise control.
By 1981 GM cars were using microprocessors to control the engine. Not surprisingly, other automakers started to jump onto the new technology bandwagon.
As a result of all this, the car’s warranty costs have been affected and it has become much more difficult to repair a car. On many occasions, insurance companies have found that it is more cost effective to just call a vehicle involved in an accident a total loss because it would cost too much to fix it.
And what does the future hold? It is said that off-site technicians will be able to download data as well as analyze the vehicle and upload software corrections.