Jaguar X350 XJ8 2004

[davidkitching]

I have a Jag x350 and has an intermittent fault when you open drivers door if millage doesn't show on dash the car does not power up when you put key in ignition. When turning the key the only warning is the air bag logo that stays on for 30 secs or so nothing else. The battery is fully charged, the lights, horn central locking all work. I can leave the car for a few days then when open door and millage shows all works ok. This has happened several times over last few months and I can't work out the problem. I took it for MOT to garage last week drove there ok but this fault appeared again and garage could not start to MOT. Any ideas please. AA has been out to look at it but had no ideas said I need a specialist.!!
David