Please help strange electrics problems on my E53

[pg747]

Hi guys and Girls, I'm new to the forum just wondering if you could assist with the gremlins in my X5.
I own an E53 3.0d 2005 estoril blue a truely lovely car but.......
Have had a number of issues all at the same time:
Self levelling inact message comes on but car is level
Heated seats not working
Ac not working
Central locking from key opens but doesn't close
One touch driver window not working

All the above seem to happen all at once. Before this started and would go away after a couple of days. However for the last couple of weeks the problem has persisted. Any ideas or pointers?
Much appreciated.