I have a Daimler super 8 2007 and have exactly the same issue. The engine light has been plaguing me for about a year on and off and finally now I have been dealing with David Marks - He really knows his stuff.
He is a little baffled at present but I am sure he will get to the root of the problem soon.
He has thus far dealt with a number of the earth points which were suspected to be the problem - Sadly not so. On my second visit he will deal with the remaining earth points plus I have asked him to have the car given the teraclean treatment, The car has been driven very short distances over its 8 year life and I suspect the engine and exhausts need a good clear out which could be responsible for the engine light popping up.
I will know more y next week.
I have a second issue which is particularly odd in that from time to time the car has a senior moment and all the warning lights and wording come on at once ending by the car saying the park brake is not functioning. Whilst driving the lights stay on and the speedo goes off as well as the temp gauge drops off whilst the red light coms on.
Also the air con goes off and he radio etc fails. This has also been put down to a dodgy earth point by david Marks.
Time will tell.