Yes, there is some conflicting information contained in this thread, but this is a ‘living document’ and meant for folks to ask questions and find answers. The thread has evolved and does contain information not readily available elsewhere.
However, to summarize the majority of the information, I would say this:
Vehicle Architecture: CGEA 1.3 is an almost direct installation as long as the wiring is complete. CGEA 1.2 is possible but takes a little more work with the asbuilt. C1CMA vehicles cannot run Sync 4 without some type of CAN emulator installed to enable the Sync 4 APIM to boot. (There may be some progress made on this that I am not aware of at this time, but that was the state several months ago in this very thread.)
Wiring: Most likely folks will be upgrading from Sync 3 to Sync 4, even if they own a previously Sync 2 vehicle, because these are the folks who like to tinker. The proper wiring is absolutely required to make Sync 4 boot in your vehicle. Here is the wiring for the APIM connector for Sync 1 thru 4. We know from experience in this thread that the HS1-CAN and MS-CAN wiring must be removed from the APIM connector to prevent issues in the vehicle and to enable Sync 4 to boot.
APIM Connector Versions.pdf (201.5 KB)
Hardware mounting: This is probably one of the most difficult hurdles to overcome in specific vehicles. Usually this will require a custom bracket to mount the Sync 4 APIM securely in the proper orientation. Any movement of the APIM relative to the vehicle will cause navigation errors and apparent ‘jumping’ on the display.
Sync 4 APIM Type: There are 2 types of Sync 4 APIM; one for the 8 and 10" displays and one for the 12" and larger displays. These APIM’s are not interchangeable. If you are retrofitting Sync 4 into a Sync 3 vehicle with an 8-10" screen, you will need the Sync 4 APIM for this screen size. It has not been shown to work otherwise at this time.
Programming: UCDS and FORScan can communicate with a Sync 4 APIM in an older vehicle. This is supported by FORScan for more vehicles as those models are retrofitted by customers. I cannot speak for UCDS as I do not use the program, but there are a few folks here that could answer those questions.
Asbuilt Info: There is a complete Sync 4 Asbuilt Database posted here on the site. Sync 4 APIM Database - CyanLabs
This database was made by @Livnitup over at F150Forum and F150Gen14.
Note: Your Sync 3 asbuilt is not compatible with Sync 4. You can use it a a reference for the Sync 4 settings, however.
In a nutshell, retrofitting Sync 4 into a CGEA 1.3 vehicle is rather straightforward, especially 2021-22 vehicles originally equipped with Sync 3. I have helped folks convert to Sync 4 with F150’s, Mavericks, Fusions, etc., and have found that the retrofits have several things in common:
Navigation will initially not function properly, WIFI will not be functional, FordPass will not work, and you will have no sound from the radio. All of this can be overcome by settings in the asbuilt, except for some cases of the WIFI not working. The WIFI issue is not really an issue however, since the vehicle will not get any kind of updates via OTA, so it’s really kind of useless.
Speaking of updates for Sync 4: OTA updates for a Sync 4 retrofit will (probably) never work. USB updates are possible, but only through a Ford service department (or someone with FDRS). Maps updates will not be possible for Sync 4 retrofits for some time. Since you cannot get a NAV subscription for a Sync 4 retrofit, you will not be able to enter destinations, etc., into the onboard NAV system hosted by Sync, therefore, I would suggest you save the money and install a NON-NAV Sync 4 APIM and use AA or CP for your navigation.
EDIT:
UCDS does support the Mustang MACH-E with Sync 4A, so reading and writing to Sync 4 is possible.