For anyone still listening/watching…update:
Just brought the old girl home from the dealers, they’ve given up.
They resynced the ems to everything else so it would start and get me home.
Did an experiment when I got home, turned the key back on after switching engine off, then with a trickle charger connected to the battery, left it for around 40 minutes, after which time it would normally not start, turned the key and away it went.
Whether or not I’ve got closer to fixing the issue remains to be seen, but possibly a constant supply of power to somewhere is not happening like it should be…? Will consult wiring diagrams and go fishing.
