This is an answer which will be OK for a fair selection of cars and may help you.
The 'Engine Management Light' come on if the automatic monitoring system detects a malfunction in (usually) the powertrain components of the vehicle. If the fault has been fixed, then what you need to do to put the light out is:-
1 Disconnect the battery.
2 Reconnect the battery – this resets the engine management to its base onfiguration.
At this stage, if you start the car up the Light will still be on and will stay on until the monitoring system has completed a series of tests some of which depend upon the car being operated under various normal driving conditions. Typically this will take about 20 minutes of normal driving. If all the tests are within spec then the light will go out and you will be back on the road!
If the fault persists the you have a specific problem. You will either need to take it to a dealer who will be able to read the codes and fix the problem (lots of dosh outlay I suspect). If you are reasonably confident you could buy a code reader to find out the problem for yourself. Gendan are currently selling theirs for £39.95 free pp which covers all post 2001 petrol and post 2004 diesel cars. Note if you reset using a code reader you still have to go through the 20 minute drive process before you are “back in business”.
Shaun, March 2010
