PCM Not communicating with BCM/Various other modules

[rpowlette]

Hi all,

I recently carried out a firmware update on a 2024 Mustang Mach-E using FORScan. The update itself completed without any errors and appeared to go through smoothly.

Once the vehicle came back online, however, the instrument cluster lit up with multiple warnings. This isn’t unusual for me after updates done through FDRS, so initially I wasn’t too concerned. Unfortunately, this time the vehicle displayed “Stop Safely Now”, along with a large number of faults.

I power-cycled the vehicle several times, but the issue remained. I then attempted to perform a PCM relearn, it said completed sucessful but it dont think it did due to parameters not being found. I also tried clearing the DTCs with a diagnostic scanner, which made no difference.

At that point, I reverted the PCM back to the original factory firmware, but the symptoms were unchanged. I also reloaded the factory As-Built data, again with no improvement.

When scanning the vehicle now:

There are multiple PCM fault codes, mostly loss of communication

Logs mention something along the lines of “initial startup unconfigured”

The vehicle will not start

The PCM is still detected in FORScan and can be programmed, so it does not appear to be fully bricked

I’ve since:

Locked the vehicle multiple times to force sleep cycles

Started a 12V battery disconnect to see if that helps

At the moment, the vehicle is back on factory firmware but still in the same state.

Has anyone experienced something similar on a Mach-E, particularly after programming via FORScan rather than FDRS?
Any guidance on recovery steps or missing configuration routines would be greatly appreciated.

Thanks in advance.

[boosted_diesel]

You need to restore the software.
Software updates should only be done when they are necessary due to the risks of bricking your car.
They shouldn't be done for the hell of it.