This may seem a really dumb question to lots of knowledgeable car people but this was the first question that highlighted how little I'd moved on from the cars I owned that used a coil and old fashioned distributor. To be honest the cars, post ignition coil, have been so reliable I haven't needed to know until one broke down and had to be repaired at some cost.
The answer is they now have electronic management systems and things called coil packs. In other words they have a coil per spark plug or perhaps coil per two spark plugs and probably other arrangements I'm unaware of. Anyway, the important thing is they are still ignition coils but packaged differently and directly wired to the engine management system which takes away the need for a distributor. A sensor now detects the rotation of the engine and the electronic management system uses this to time the trigger for the spark.
This same evolution has been mirrored by the replacement of the carburettor with fuel injection. This is electronically controlled by the management system which switches the fuel on and off at just the right time and length as dictated by the throttle position, combustion efficiency etc.
In other words the engine management system is now a sophisticated computer, collecting data from a variety of sensors all over the engine and making decisions on the measurements. But when a sensor fails or the computer thinks the readings aren't quite right is when the dreaded dashboard management information light (MIL) comes on.
And that's my position at the moment. Can I work out what it means? First I need to communicate with the engine management computer but fortunately after some research it's not as difficult or mind boggling as it first would appear.
