Spoke to soon

I suppose I tempted fate, by posting a reply on a topic a couple of weeks ago about Ex-Addison Lee ownership.
I mentioned that I've had no major problems and am happy with the car.
Well it happened - Car broke down and had to be brought home on the back of AA Flat Bed Recovery Truck.

It's in the Garage at the moment but was wondering if anyone has any ideas?
It'll start and run smooth for 20 seconds but then just cuts out. It beeps to tell me there's a warning message but no message is displayed

Also - does the Central Locking Alarm have it's own battery, because they had to take the battery off to charge (I'd flattened it trying to get the car going) and when they locked it up, the alarm was sounding for about half an hour?