My independent Mercedes-Benz servicing garage tells me that the Sensotronic Brake Control unit on my 2004 E320CDI (90,000 miles) needs replacement at a cost of £900 or more. I've read on various MB forums on the internet that Mercedes-Benz may replace this unit under an extended warranty, as it is both a known problem and a safety issue. I took the car into Mercedes-Benz Central Manchester yesterday and they confirmed that the SBC unit had reached the end of its programmed life, but that Mercedes would bear the full cost of replacement. I picked up the car today thinking that they would at least bill me for labour or the diagnostic check but to my surprise there was no charge at all, and I got a full car wash and useful 'vehicle health check' thrown in. The documentation showed that the cost of parts and installation of the SBC unit should have been over £2000.