Hi, my x type has a wobbly every now and again. It will work fine on fob lock/unlock for a few weeks. Then for no apparent reason will not lock with fob have to use key.....not a great hardship. If locked using key it wont unlock with fob and have to use key then the alarm will go off until key is put in ignition. I've run a diagnostic check on it. Flight navigator has been activated at some point, checked inertia switch and car runs fine? Any ideas? I have changed batteries in fobs and reprogrammed them.

This is the most peculiar, have you consulted a Jaguar dealer about this?

I was hoping I could sort it myself :(

Could it possibly be that your car batteriy is low from time to time if you are not out in it daily?