Nothing on the steering wheel works, radio, volume, high beams, turn signals, cruise control, wiper sensor, message knob. It just stopped working one day. The dealer says they have never seen it before. Only have 60,000 miles on the car.
Lost power on steering wheel controls on 2005 Volvo S60
All of these items are controlled by the SWM, Steering Wheel Module. Try pulling the fuse for the SWM, see if that resets the module. Other than that, this needs to be looked at by a shop that has the proper equipment to communicate with the SWM and the skill to diagnose the problem. This is often the dealer, but there are Independent shops that can do this as well.
There is a computer under the dash, it runs all these things and apparently is covered under the emission warranty. Same thing happened to me, took about 12 hours for them to find it, installed new computer programmed it and voila, back to normal.