Parking assist
 

I have a 2005 4.4 e53 with parking assist. When I bought it the parking assist would start beeping faster the closer I got to an object. Recently I had to replace the battery. It was dead for over a week. now the parking assist is not working. The button lights up when you press it but it's not working.

Any ideas?

The irony? The radio stations kept the memory as well as all of the remote and seat & mirror memory.