But you can easily read the on-board diagnostics yourself to identify the problem which is, assuming the car is running nicely, most likely a coolant temperature sensor wire connection problem or something like that. You have to find the little black OBD box in the engine bay, insert the pin in position 2 and press the button for between 1 and 3 seconds, if I recall the sequence correctly. Note the flash pattern and report back, or refer to a Bentley for the answer. I just went through a couple of check engine, coolant sensor but a little clean up and reconnecting and teh light has not re-appeared in weeks.