A few weeks ago I posted on here looking for advice regarding an issue with my 2001 XKR.
Out of the blue the airbag warning light came on - flash code 16.
At the same time the TRAC not available and ASC not available messages came on but not the red or yellow warning lights.
Other strange things included the indicator buzzer going very fast, windows intermittently not working. The car went into "limp home mode".
There were no engine trouble codes I could read with my Ultragauge. If I turned the ignition off and restarted all was well for a few minutes and then all the issues returned.
A new battery did not fix it.
Anyway, to cut a long story short a local auto electric shop diagnosed that the alternator was overcharging producing multiple faults mainly in the body processor. Apparently various modules shut down when faced with an overcharge. The "clincher" of an overcharging alternator if you don't have a voltmeter is that the green LCD information display/odometer flashes - slowly going dim then normal.
Just had a new alternator fitted and MOT and all issues are gone. Passed the MOT and driving very nicely.

I hope this post may be of assistance to others as I'd not come across this info anywhere and I doubt I'm the only one to have an overcharging alternator.