Mercedes ECU 

Up for sale is a Working, in excellent condition Mercedes Engine Control Unit. Mercedes Part number--

021 545 71 32   /   0 280 002 575

This unit is out of a w140 chassis s420. This should also work with most later s420 models with the M119 engine, however it is the buyers responsibility to find this out, as I don't know that for sure. -

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.