So I did my upgrade today and everything went well except whenever the APIM does a full reboot I get a nav fault error, I click close and the error goes away and Nav works fine. As long as the APIM doesn’t do a full reboot the error doesn’t come back. I bought this GPS antenna. I’ve read that it could be caused by a bad Antenna. I’ve tried to reseat the connector multiple times. The DTC was GPS Antenna: Circuit Open. My APIM has a 2018 manufacture date.
I’ve updated to the latest Sync 3.4 and Factory reset the APIM but that did not fix it either. Is this normal? If not where can I buy a proven good Antenna?
Since this is a retrofit than it’s a 99% chance it is the antenna. Most on the internet are cheap and ultimately have issues.
You can go to a 17-20 Fusion Antenna and then add the splitter behind the glove box that gives you the Nav plug. Going the OEM route for the Nav is the best way to go if you’re not afraid of a little project.