Hello Norman,
I have a feeling that possibly this isn’t going to answer your question, but…..
Straight from the school of eliminating simple things first - with a vast array of equipment on such cars, the battery gets a hammering, and it’s quite common for systems to stop operating/ throw up warnings, as the monitoring of many aspects of the battery’s efficiency shows up some deficiency in its performance. 3 and a half years old batteries giving issues? Again not uncommon.
Unlikely association?? Personally, I would want to eliminate before throwing anymore handfuls of £100s at it.
I must say Norman, your post makes me appreciate even more, the advantages, and almost worry-free motoring enjoyed in a long association with the good old Morris 1000. All you needed was a key - or someone else’s key! - and off you went, without any concern about warning lights and systems not working. Not a diagnostic port in sight, no hint of ADAS - you just had to keep your eyes open, and respect the rule of the road that dictated the occasional wandering sheep took precedence. Life was far less complex, and almost no worries about what ‘toy’ was going to stop working today!
Kind regards,
Gareth.