Up for sale is a Working, in excellent condition Mercedes ECU. Bosch Part number-- 0 281 001 009 (0281001009), mercedes part number-- 002 545 60 32  /  0025456032  . This ECU came out of a 1985 c W123 chassis Mercedes 300TD Turbo Diesel. This should fit many 84-85 W123 300D 300TD as well as W126 300SD models. May fit other models/years, but as always your best bet is to match the part number to the one on your ECU. 

A defective or water damaged unit can cause a variety of different issues with these cars, tach, egr, turbo boost pressure, transmission shift timing & points can all be affected by this as this is what controls these functions in this car. This is usually a pretty reliable unit though Incredibly expensive if you need one.These are generally fairly reliable units even after 20+ years, however they can easily be damaged by wiring faults or voltage spikes (caused by a bad alternator), water damage or a variety of other issues. If yours does not have problems, I tell our customers to keep an extra ECU in the garage, you might some day be glad you did... These units now have to be special ordered from most dealers new for big $$ (often times several thousand bucks!), and finding a good one second hand is getting to be very difficult. If you plan on driving one of these 84 or 85 Merc. Turbo diesels into future, this will be a "must have" as these cars get more and more difficult to find parts for. The 84-85 model Mercedes cars were probably some of the best cars ever made, keep yours on the road.