I have a 06 petrol VRS and this issue has happened twice in the last 2 weeks. It will start ok, however I cannot turn the steering wheel (no power steering) it's as if the engine is off and you can't turn the wheel. The oil light begins flashing and there is an audible beeping noise from the dash. If I turn the ignition off and back on again everything is ok and back to normal. Any ideas of the problem? Cheers

If the PAS isn't running, the steering should feel much heavier, but still turn ok.

 

What you've said would make me suspect a steering angle sensor problem with an electro-hydraulic PAS, so get the codes read (properly; see VCDS forum).