This is not the case, review the video above. All he did was disconnect the HS-CAN pins 53, 54 in the existing APIM connector (HS1-CAN), which in Sync 4 is not implemented. Also, from the FFClub thread referenced at the top of this thread: Ford moves to CAN FD, UCDS will be relevant. UCDS already supports SYNC4 (configuration)… I do not use UCDS so I can’t tell you how they did it, but I suspect the latest version should just work, not unlike FORScan.
An older GWM should work to boot the unit, but it will be missing the ethernet communications. This is probably a moot point unless you also have an IPMA, TCU, or other ethernet based unit on the bench also. Again, the HS-CAN pins 53, 54 in the existing APIM connector will need to be disconnected. The appropriate wake signals will need to be sent over CAN. This is for Sync 3 and should be similar for Sync 4, since you can get a Sync 4 unit to boot in a vehicle and connect via FORScan.
From above:
{{0x109},{0x00, 0x03, 0x01, 0x00, 0x00, 0x00, 0x00, 0x28}} // Accessory ON, Gear Park, Speed 0 - this needed or else the APIM will default to driving mode and will lock out many settings.
If the APIM does not get any message that indicates the ignition position, gear and speed it defaults to the “car is driving” mode and locks out some settings.
NOTE: There is a TSB published about the APIM/TCU/GWM Diagnostics and Repairs - 2021 Ford F-150.
NHTSA ID Number: 10184628
Manufacturer Communication Number: SSM 49379
Summary
Before attempting repairs for SYNC 4 system, Telematics Control Unit (TCU) or Gateway Module (GWM) concerns, dealers must complete workshop manual (WSM) diagnostics in section 415-00 for SYNC 4 or TCU concerns and 418-00 for GWM concerns. Do not attempt APIM, TCU or GWM reprogramming or replacement unless directed by a WSM pinpoint test. If the root cause of a concern is isolated to the APIM, TCU or GWM with all other possible causes ruled out, dealers must contact the Technical Assistance Center prior to performing repairs.
And this issue…
21-2097_f150_battery_discharge.pdf (636.9 KB)