DS5 fault codes F303 and FD86

[FGB]

I have a 2017 DS5 2.0 diesel.
Recently the dash lit up like a Christmas tree with umpteen failures ESP, ASR, handbrake auto-release and others I have probably forgotten.
After a quick stop and a bite for lunch to recover composure these faults all vanished to be replaced by the engine management light. The car
drove fine and the following day this too cleared. In the following 2 weeks there have been no further faults.
I visited my local trusted garage today. 33 faults were originally reported, after clearing them two remain:

F303 Secure configuration fault
FD86 Choice of architecture not defined

They say, whatever these mean, I'll need to go to a DS main dealer to find what is wrong. Be easier breaking into the Tower of London than getting
an appointment at a franchised DS dealer in Scotland, and probably cheaper.

Should I worry?

[GiveMeABreak]

Those faults sound like they relate to the BSI. The FD86 fault would seem to suggest that the electronic architecture has not been defined (ECO or FULL) and the other F303 on is a non-specific BSI fault. F303 may indicate that the BSI or another ECU has gone into Secure mode (locked) or similar.

So I can only assume these have happened if somebody has connected some diagnostic kit up to the car and changed something intentionally or not to the BSI.

Until the problem is rectified, as the BSI is the main computer in the vehicle that talks and controls to a greater degree all the other ECUs. you may very well start seeing multiple electric failures or system warnings, so be very wary of this.

Your only recourse at this point is to get it to a DS dealer and get them to hook it up to Diagbox in online mode to check the faults and see what is wrong. I wouldn't waste your time going elsewhere as these types of faults will generally need to be checked in dealer-connected mode to their servers to resolve.

[FGB]

Thanks Marc. I've had the car for 4 years and got it from a main dealer and have had no electronic issues in that time.

I'll make efforts to arrange a trip to a DS dealer. Will report back when I get an answer.

Fraser