Thanks all for the replies.
I am transporting the vehicle back home (5 hours away) and will then investigate further. The workshop that looked at the car are prediicting a dead ecu because there is no response from the obd2 port at all.
Just because it is a distributor/rotor ignition system it still ...

Hi, I was away on a journey when my 850 stopped. First lost power and ran rough for a few moments then stopped and would not start again.
Roadside assistance found that it had fuel delivery but no spark. Checked coil and said it was likely faulty.
Towed to Volvo mechanic and reports that the coil ...