I just installed a Z110BT in my 04 Avalanche, everything is good except that the navigation is showing that my truck is facing the other direction.
The arrow is spot on as far as location goes, but its just reversed. Anyone have this problem before? Any help is appreciated.
Thanks.
I guess you just need to drive backwards 
Sorry, couldn't resist....
Do you have the Violet/White (REVERSE GEAR SIGNAL INPUT) wire connected? From the installation manual, " Unless connected, the sensor may not detect your vehicle traveling forward/backward properly". Although mine is not connected, I am not having this problem.
If yours is connected, it is possible you don't have it connected to the right circuit (always on or high when going forward).
Next check the polarity. Go to Home/Navi Settings/Connection Status. Make sure that when the gear is shifted into "Forward", the 'Back Signal" value is "Low".
To correct it, I think you go to Home/System Settings/System Settings/Back Camera/Camera and change the polarity.
It must have to do with the unit incorrectly thinking you are going in reverse. These are the things that come to mind.