JAGUAR XK8 - Stalling XK8

Q
I have a problem with my 2002 XK8. The car starts no problem, but when wanting to drive away I place my foot on the brake (not even starting to put it into gear) and the engine starts to stall and an audio bleeping is heard. If I leave my foot on the brake the car will stall, if I take my foot off of the brake the noise stops and the engine picks up, revs and runs as normal. I can put my foot back on the brake and it all happens again.
If I stop the engine and leave it for half an hour it usually starts and I can drive away, this has happened many times now, but on Friday the problem did not go away so I called the RAC, the mechanic attached his diagnostic scanner and found two codes - P1316 and P1111. After he detached his scanner the problem went away again.

A
This is a really strange one. P1316 indicates a misfire while P1111 merely confirms that a system check has been completed; the beeping on the other hand can warn that the door has been opened without first selecting Park. As to whether these are linked, we cannot say; all we can recommend is a thorough check over of the gearshift interlock and warning system (which incorporates a brake pedal switch) by a specialist with the necessary circuit diagrams.