Another strange thing about this car (again a 1993 300TE w/3.2L M104 motor) is that the end of the ABS harness that is supposed to plug into the top of the ABS ECU does not actually fit the ECU socket correctly. The original ECU that is in the car and the replacement ECU I got the other day have a tooth at the engagement end of the plug like this:



But the end of the harness that is supposed to plug into this part of the ECU has no matching slot to engage with this tooth.



So in order to get the harness to actually plug into the ECU I have to undo the two screws that hold this aluminum piece onto the ECU and remove it so the toothed piece is not there.



I have called two different MB dealers to ask if the part number on the ECU matches with what my VIN number shows the car should have and they have confirmed the ECU (the original one and the replacement one) are correct for the car.