Having a problem with my 528e's speedometer flat lining. It prevents my brake lights from working when it does. I've noticed that when the car hits some bumps in the road the speedometer begins to work. Then another bump, and guess what? Back to zero. Where is the speed picked up? Is it the transmission? My last BMW was more mechanical than electrical and now I'm at a bit of a loss. Well if you might be of assistance it would be appreciated, greatly.
