Hi Eric A big welcome from the UK.,I own a 2004 Mercedes e320 cdi. back in 2002-2006 these cars were fitted with an SBC unit in place of the regular abs system the idea being more reliable and responsive breaking which it does exceptionally well, however these units were with a counter which means after so many million taps on the brakes a warning malfunction message appears saying brake malfunction visit workshop their is absolutely nothing wrong with the brakes they work perfectly these units are none user serviceable and can only be obtained and fitted by Mercedes their was eventually a guarantee placed on them but only it the vehicle has been serviced by Mercedes from new; unfortunately my car has had several owners since new and servicing was not always carried out by MB I had to foot a bill of £1,500 this has been known as the kiss of death for so many of these older cars.
Kevin.