Mercedes ECU Up for sale is a Working, in excellent condition Mercedes Engine Control Unit. Mercedes Part number-- 0 280 800 170 (0280800170), Bosch part number 004 545 39 32 (0045453932). This unit is out of a 420sel (w126 chassis). Not sure what year, your best bet is to check the part number of the ECU you are trying to replace with this items part number to make sure they are the same. 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 a very hard chore.