Oh great hive mind, i seek your advice!
I've retrofitted sat nav to my 2014 Fiesta Mk7.5 Titanium, replacing the 4.3" sync display screen (FCDIM) with the 5" one - did this at the end of october and fitted a reversing camera too. I've also swapped my APIM/Bluetooth module for a newer one that supports the track/artist names over bluetooth. Everything has been working absolutely fine until new years day, where the display has started to randomly reboot itself. After a couple of minutes of being on (regardless of car moving/not moving, engine running/not running) and functioning perfectly it flashes, goes to black. Most of the time it then reboots and goes back to the start screen with the blue rectangles on it (sleep screen), and occasionally just stays off until you press the power button on the controls.
A friend of mine has suggested that the canbus wires that activate whether the screen should be on/off are shorting, but then I'd assume that i wouldn't turn off when locked or come on with ignition in the first place?
Plugged in forscan, the codes I get is the same in the Audio Control Module (ACM), Instrument Panel Cluster (IPC) and Accessory Protocol Interface Module (APIM). They all read "U0257 - Lost Communication With Front Controls / Display Interface Module". If the screen is black (completely off not just sleeping) it is present at time of request and if the screen is on then it's a previously recorded dtc that will clear until the problem happens again.
I've ran self tests on all the connected modules (ACM, APIM, FCDIM) and the FCDIM gives the error "Code: B119E - FM Reception; Additional Fault Symptom: - No Signal ". I'm pretty confident therefore that the problem is limited to just the screen module as when the screen reboots itself, the radio station will keep playing, until the screen has come back on and then the ACM then has to work out what the screen is now saying (usually the same radio station as before it rebooted).
I've tried pulling the various fuses all at the same time to get resets, doing resets by the menu options on the screen itself and have performed module resets via forscan and the problem persists.
At the same time as all of this, the FCDIM/screen now tells me that my SD card for the maps is faulty with the error that you usually get when you take out the SD card. No amount of turning off ignition putting the card back in has solved this. I've even taken the screen out, disassembled it down to the circuit boards to see if there were any obviously burnt out chips or capacitors and there was not.
Has anyone else had an electrical gremlin like this before? Should I try just replacing the screen with another or get some extra help? If it is beyond me - does anyone have any reputable automotive electricians that would fix this kind of thing? I'm expecting ford dealers not to touch it purely because "the car didn't come with that screen", and they'll probably just go on a costly part replacing spree too.