Mercedes control unit -  

ESP+PLM ABS Module

023 545 00 32   0 265 109 071

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. Bargain price alert here, on a hard to find ECU! Comes with a 30 day functionality warranty.  These unlts may need to be programed before it will work in your car.