Mines going into the garage I bought it from a week on Monday, had the car a few month but the problem has been there since I got it.
I've got the exact same symptoms, they don't think it's the mechtronic, they said with that the car would go into limp mode and the PNDS would be flashing.
From reading others experiences I'm convinced it's the mechtronic unit.
They're going to reset it to see if that sorts, I'm just entertaining and letting them rule that out first.
He plugged it in to vcds and because it said no fault it won't be the mechtronic.