Originally Posted by B&DCalgary

The same thing would happen on my Passat whenever I disconnected power. The reason was due to the anti-theft radio. It's designed not to work again if it's disconnected from the power, unless you have a code number to punch in that's unique to the radio. I'm guessing that might be the problem with yours, but you'll need to confirm that with the dealer. Call the service department and tell them the situation and they can probably help you.