I had my z110bt in my truck for a few months. Did the bypass and everything was good. Got a 09 cobalt ss so I installed it in there since I will be driving it everyday. The car doesn't have bose, so it needed the os311 interface. I have everything hooked up except the vss wire (having trouble trying to locate it in the car). Now, the head unit comes on and says a message about a problem with the parking brake wire not being connected properly. This message has never come up before and now it won't play dvd's while moving. Why would it do this all of sudden? I read that there was an uodate for this problem...but don't understand why it just now comes up? Is it from the new onstar interface?

I'm thinking I should just try the update and see what happens.

Thanks for the help!

Why would it do this all of sudden?

Because you uninstalled the unit and likely shook the relocated wire loose from its connection. This is almost always the problem so go back and check your connections. Also run the update just to verify or eliminate it as the problem.