R2FU

...but all belts are intact. Any clues as to likely cause or simple checks I can do?

MarkD

most likely the belt sensor failed

http://www.pcarworkshop.com/index.ph...an_Belt_Sensor

R2FU

Thanks Mark - certainly sounds like the likely culprit, just got to decide if I'm feeling brave enough to do this myself. Everything is pretty tight - looks like the intercooler will have to come off.

MarkD

yeah, it pretty much has to come of every time you open the rear lid

It is a bit tight getting to that sensor but a little patience is all it takes.
If you don't use a cut off socket you might want to grind down or cut an allen wrench to make it a little easier. Not required though. Depends on the size of the hands and arms involved

You might want to start by removing the plug and putting a short wire jumper across the connector just to confirm it is the problem.
It might be physically damaged if the roller that rides on the belt froze up. I've seen that happen.
Good luck!