I recently added a oem nav system to my 08 silverado, i purchased the system on ebay, i installed it and the antenna, had it unlocked at the dealership, everything works, but the system will not give you step by step directions when you enter a address. It only tells you where to start and when you reach your destination, but no turns in between, and also it has a compass screen on the right side and map on the left, I can not get compass screen off. Please help, thanks