I can't believe it I've just had exactly the same problem. Driving down the motorway, all of a sudden loss of power, then no acceleration. Engine light came on and is still on. Pulled over onto hard shoulder, switched off and waited a minute, switched on and it was okay again for 2 mins, then again it happened. 4 time I had to do this until I got home. Looks like I will have to get a diag done from what you've said.
I had the same problems with my 2004 2.2 TiD and took it to an independant Saab garage expecting a hefty bill, but it turned out to be the EGR (Exhaust Gas Recirculation) valve and cost about £35 to get fixed.....no problems after getting it changed over. I can now overtake without the fear of losing power!
Take your car to a diesel specialist rather then a garage, they know what they are doing so are usually cheaper.
Quite right. Someone recently said that taking your modern car to any old independent garage is like asking someone who knows about typewriters to look at your computer. They only think they know what they're talking about.