There is also an ECU for the dash which is to the right of the accelerator behind the panel. Not cheap to replace either, I think the main ECU is over £1000 and the dash ECu is £5-600!!
I'd talk to Richard Bright, Aftersales Manager of Hexham Horesless Cariiages. You won't find a better, fairer or more knowledgeable and accommodating bloke!