Focus II Engine System Fault

[hajo]

Hello,

I've got a Focus II, 2007, 1.6 Petrol Auto. It's recently picked up an intermittent fault - occasionally when I try to start the car the dash lights up, it says "Engine System Fault", and nothing else - engine doesn't turn over. If I wait a bit and try it again, it starts. One time it has also come up with "Engine System Fault" while I was driving and went into limp home mode - that time I took it to a dealer that was close by who kept it for a week but couldn't reproduce the fault.

The dealer reckons it might be the Instrument Cluster Module which they'd charge £500 to replace, but they can't be sure unless they can reproduce the fault. Problem is, at the moment it only happens once a week, usually when the local garages are shut :) 

Does anyone know what this fault might be, and can anyone recommend someone near Windsor who might be able to fix it? Also, if I got a cheapo code reader myself to plug in when it happens, is it possible I might get a useful code out of it myself?

Thanks,

hajo