Bingo We also have a 56 Zetec but 2.0 TDI and this has been going on for some time but with no resolution. Ours was under warranty when it first occured but as with yours this has now run out. We have a service booked for next week and are waiting to see what response we get this time. This has now gone to far and we have had nothing but problems since buying this car. We have had the alarm going off with out any warning then the wipers just started and we could not stop them. Now the keys only unlock the car when they want to and then the engine will not start. We have low milage on ours as well and it is not used on a daily basis but this should not have any effect on the running of a car.