Not sure how much you know about the Squib Ring, also known as a Clock Spring, but it carries the electical signals from the steering wheel controls and also for firing the air bag. I've not taken one apart but I guess from the name, Clock Spring, the cable is wound in a spiral inside the cassette so that it can wound/unwound as you turn the steering wheel.
Mine was not a permanent fault but came back after a couple of days so I suspect that there was an intermittent connection or broken wire somewhere.
If some of the steering wheel controls e.g. Cruise Control, Horn, Volume etc don't work then this could point to the Squib Ring. Some also report it being mechanically noisey as you turn the steering wheel.
There are some videos on Youtube on how to replace it but I didn't fancy getting hit in the face with the Air Bag if I did it wrong.
