[Tannaton]

As he said it needs to go on some Volvo or Volvo compatible gear.

These symptoms are a first for me - never ever heard of a [electronically managed] Volvo engine revving out of control, with the exception of diesel runaway when the turbo leaks oil into the inlet tract, but you would have a lot of smoke from the exhaust if that was the case.

Notice a throttle sensor error but I'd say that's unlikely the cause as Volvo cars have redundant sensors on the throttle - one digital and one analogue circuit. Almost aircraft levels of redundancy.

However in the absence of an obvious cause, you can't really rule anything out...

I'd disconnect the throttle sensor, i *think* the car should start but just tick over. I'd also try reading sensor values, which you should be able to do with a basic diagnostic, the MAF, APS, TPS and Brake pedal sensor - with the ignition on but engine not started.

And finally, don't buy any new parts until you've got a firm diagnosis, poke and hope substitution in the absence of diagnosis and/or experience will just empty your wallet on these cars. Spending £50-£80 to get it on proper gear will in 8 out of 10 cases tell you exactly what the problem is.