Some background. I did a SYNC3 retrofit to my 2015 Mustang from MFT. I was having horrible luck finding an aftermarket GPS antenna that would not give me the dreaded GPS Open Circuit error in my SYNC3 retrofit. Bought a total of 4 different GPS antennas which all gave me the same error.
So what I diecided to try was to buy a splitter from Ford - part number LC3Z-10E928-A to see if that would solve my issue.
I plugged the splitter between the APIM and GPS antenna, and low and behold, the error went away.
I then tested the 3 other GPS antennas I bought that gave me the same error, and none of them gave me the error anymore as long as that splitter was plugged between the APIM and GPS antenna.
Just thought that may be helpful for others if they experience that problem when they do their retrofit upgrades in the future.
I did see the article and bought the two recommended GPS antennas in that article and used it as a referencefor the others I bought. The others I bought were the eightwood GPS from Amazon, one from @NaviUpgrade, and one from Pasternack. All of them gave me the same GPS open circuit error which all resolved when placing the splitter between them and the APIM. So I actually tested 5 GPS antennas not 4.
It’s interesting that the Eightwood and the other 2 antennas in the article show an open indication, as both of these are 50 ohm terminated units. I have tested all 3 of these connected directly to my APIM’s and they do not indicate an open circuit and terminate properly at 50 ohms. I would be suspicious of the connector on the APIM itself, especially the later version APIM’s which use the plastic shell. Those need to seat rather snugly.
Maybe. I do not know. When connected, the FAKRA connector is flush to APIM and a devil to get back off for all the GPS antennas tested.
The connector on the APIM is metal. No plastic shell.
Any suggestions on how to test the antennas. I guess testing for 50 ohm termination would use a multimeter with a probe on each part of the FAKRA connector. What would be the acceptable tolerance for it?
I understand that error is caused by a grounding issue with aftermarket antennas. Thats why the OEM antenna’s do not do it. The OEM ones ground out through the connection to the car body wear as the aftermarket ones do not.
I can see that but then why does the intervening splitter solve the issue? It does not have a grounding point other than the FAKRA connector.
My thought is that the electricronics inside the splitter provides the termination that the APIM is looking for. I think I doan experiment and disconnect the GPS from the splitter and see what error I get if any.
Disconnecting that causes a siriusxm antenna fault. The siriusxm FAKRA connector is mustard colored. So somewhere between the blue FAKRA connector and mustard FAKRA connector must be a splitter. It looks like the wire loom behind the radio wity the mustard FAKRA connector goes toward the driver side and the wire loom with the blue FAKRA connector is hard to tell. Anyone have an idea where the splitter is located?
I tried to hook my splitter between the blue FAKRA connector and my radio but it still does not see any satellites.
I am going to replace my current siriusxm antenna with this one HR3Z10E893ACPTM which looks to have both GPS and siriusxm capabilities and try my splitter again.
It is a little confusing that blue FAKRA connector in the center console. I don’t think it has anything to do with GPS. I think that it is a direct connection to the (nonGPS) siriusxm antenna
So I got the HR3Z10E893ACPTM antenna in today and temporarily connected to the system in place of the original antenna. My splitter was connected to the mustatd FAKRA connector that was connected originally to the radio. (Had to modify the blue FAKRA connector on the splitter a little to accomplish this.) The other ends of the splitter were connected to the appropriate connectors on the radio and APIM.
The GPS signals were picked up well with the siriusxm signals kind of picked up. Could not keep the signal acquired because the antenna was inside the car.
Next nice day I will remove the old siriusxm antenna off the car, tranfer the color matched cap from the old antenna to the new, and install the new antenna. I also bought a new splitter HC3Z10E928A that has a mustard FAKRA connector that will connect to the mustard FAKRA connector that originally went to the radio and will replace the current one I am using that has the modified blue FAKRA connector. Will then test the system to make all signals are good.
If all is good, then this antenna and splitter combination can be a solution for the GPS open circuit error for those who are doing a Mustang MFT/SYNC2 upgrade. It is surprisingly easy to replace the antenna. Much easier than taking the dash apart to upgrade the APIM.
