My X308 4.0l gets the normal fault lights, gearbox fault, Trac not available, ASC not available, fail safe engine mode, ONLY when driving in the city on a hot day (30 deg C plus).
I normally turn into a side street, turn the engine off and raise the bonnet.
30 min later, it's all cooled down and off I drive.
Thoughts???

 

Abs unit is getting hot and bad solder joints do not make any connection anymore. I'll bet you'll have faultcode about pump motor in abs module.

 

There are many postings that indicate how this can be repaired. it may be wise to do
a search, and check what is involved.