I have retrofitted SYNC3 navigation into my 2015 Mustang with MFT. Got the parts from Naviupgrade (quite fast I might add, kudos to @Naviupgrade ) with programming. Used the SYNC3 APIM from my 2019 Expedition since I upgraded the SYNC3 APIM and ACM to get the extended XM channels. Got it all installed and programmed. All works well except for navigation. I get the dreaded navigation fault error. APIM DTC shows GPS open circuit.
The links are there in the quoted F150Chief’s write up.
I use the top one all the time, have you looked at the APIM config to verify the GPS placement setting?
Original programming had it roof mount. I changed it to dash mount without resolution of problem.
Most remarks are to stay away from Amazon GPS antennas and i figured eBay would be similar so I was looking elsewhere. If you have a good experience with the top link, then I can give ot a try. Was kind of hoping for a smaller cable length as it only needs about 2 feet of cable to work.
Interesting development on my navigation fault GPS open circuit issue.
After disconnecting the battery for an hour, clearing DTCs, rebooting APIM through Forscan, and trying another GPS antenna all without resolution, I decided to rewrite the SBL, calibration, and strategy. After the unit rebooted and clearing out the DTCs once again, the navigation fault and GPS open circuit DTC all went away. Anybody with any thoughts?
Had you previously updated the firmware/calibration?
If you had it sounds like a version that was incompatible with either the APIM or other hardware in the vehicle.
As an example, some folks with 2016 Fusions have issues after doing an MFT to Sync3 mod with spinning compasses and wrong direction showing (eg dash shows SE when you’re going N) unless they put in a used 2017 GWM.
Its possible.
I’ve also wondered more than once when I did an upgrade (Sync 3 non-NAV APIM to NAV) where the series was newer if the APIM matched the VIN number in the AB against the expected antenna type. There have been a few cases where the GPS wouldn’t lock in or showed an error that wouldn’t clear, but then went live when I loaded in the factory AB and left the NAV disabled for the first master reset. Enabling the NAV after that then worked correctly and never blinked afterwards.
Having the APIM boot in the non-navigation state may clear out prevoiusly stored values and then turning on navigation may repopulate the required values with the current antenna.
Maybe my reflashing the SBL, strategy, and calibration cleared those values and when the APIM booted back up it added the values appropriate for the attached antenna.
I have had Windows not completely initialize a new piece of hardware added. Rebooting woukd not fix it. The fix was to do an inplace reinstall of Windows for it to reassess all connected hardware and initialize them appropriately.
I broke the first rule. If it aint broke, don’t fix it. So I got the other GPS antenna in and tried it and the open circuit DTC came back and Navigation Fault error came back. Tried what I did before which I thought fixed it and it did not fix it. Went back to the prevuously working GPS antenna and the fault persisted. Will continue to work on it.
Other issue is I am getting the wrong direction in the IPC compass. Will trybto upgrade the GWM. Anyone with a recommendation on part number?
If you turned off the GPSM or disconnected it, put it back. Some versions of the IPC’s for 2015 (early models) will rely on the old modules still in place for the IPC compass. It’s the same on 2015 F-150’s.
You should understand that the GPS system in the APIM has nothing to do with the APIM firmware, other than passing location info to the Sync app. This is a separate subsystem of the APIM module, just as the NAV and Sync systems are separate systems. They only interact, with Sync being the human interface.
Is the number pf satellites the number of satellites the APIM is using to get a GPS fix?
I ask that because both my retrofit Mustang and my Expedition APIM has empty number of satellites and No GPSFix when started up but both show over a dozen satellites on the satellite map and signal screen (with the signals all green) I have not driven around with the bezel diagnostic screen up to see if those numbers change. The Expedition APIM has no DTCs and no navigation fault error while the retrofit Mustang does.
I was thinking about changing the roof antenna to a combination GPS/XM roof antenna but having a hard time finding the part numbers. I found one that states GPS/FM with a splitter cable but not one with GPS/XM. Trying to find one so that I can use the painted cover of the current XM antenna on the car.
So i drove around in my Expedition with the bezel diagnostics up. The number of satellites remains empty and no GPS fix. Satellite location and signal screens with multiple satellites. See photos. Again no DTCs or navigation errors on the Expedition. Navigation works as expected.
See if you can run the Interrogator Tool on the Expedition. See if the rw/data partition is nearly full. The Sync s not displaying the GPS system data, the GPS seems t be working properly.
