Hiya Mike and Rob, Quite so, at least, the honest dealers will replace under warranty. The more shady ones take advantage of the owners lack of knowledge and quote £900.00 to replace and code!!! Having then replaced the faulty one, I surmise that they then return it to G.M. for a new / reconditioned one for the shelf ( for free!) Additionally, I suspect that G.M. also pay the dealer for the time worked on the vehicle. I have 2 instances where this has happened. Yes, I know that the ECU is around £165 + VAT, I don't know where the £900.00 comes from. I steer well clear of both of these dealers, though I did speak to one of them on behalf of the customer and the price then dropped to simply the cost of coding the new unit. Strange, that! Regards Gwyn