The cd/radio does not work, but the steering wheel controls still work
|Car||Citroen Xsara Picasso|
Probably a duff set , pull and bench test to confirm .
My Merc R300 used to do this occasionally, radio would work but controls on it wouldn't do anything, the steering wheel controls still worked though.
It used to sort itself out after being switched off for a few hours, I've heard of problems like this with other cars where you need to hard reset the system, sometimes disconnecting the battery.
Not hit the on/off button by mistake ?