Code Reader will not connect for any codes. Radio/CD or Nav systems do not work.

When I start the engine, I have the error message as following : default charge battery. The car is 6 month old. After canceling the message, I have no more the battery signal lighting. The car is driving without problem. What can it be ?

Although weather strips on both rear-doors were changed two times at the dealer ,there is no change. Gum seals of lower-plate of rea doors do not fit to the under body.