Glad you've gotten to the bottom of it!
Bit of a way out thought could you not create a new stable feed using standard components ?
As a positive you've helped the community and you know for future should you have an issue again
Immobilizer ? with new ecu?
The "moose test" slam on the brakes then floor the throttle (and steer round moose) ?
These days all cars are too much dependent on computers I think.
It's all very well when you plug in MultiECUScan and it gives you the correct code. Unlike when I had to change my throttle body, pedal and then ECU because the code couldn't be specific.
Well, 10 months down the line and the same P1220 fault came up again today. Twice.
First time we managed to get a local mechanic to reset it again (like last time). Took the car for a spin and about 2min down the road it came on again.
Left the car for a couple of hours and since then I've managed to do the 40 mile round trip to Plymouth - no engine management light, limp mode or anything at all! As if nothing was ever wrong in the first place...
A random glitch that just crops up every now and then I guess!
Now here is the interesting bit. Turns out that exactly the same process occurred to trigger the engine management light. My wife had to brake quite suddenly and then applied the throttle quickly after to get going.