I have the exact same problem with mine. Sometimes the nav will work perfect and other times it will be off in a field somewhere in outer Mongolia. The compass will be read wrong the red light on the mirror, the clock will lock up. Oh yes and the dreaded" Vehicle Phone Requires Service" Contact dealer warning. My daughter had the same problem with her Durango The dealer replaced the complete unit under warranty and it was happy ever after. My rig is out of Bumper/bumper to replace it would be costly. When I need navigation I use my phone it is more reliable.