I was at the junkyard Saturday and I cleaned out a late model 190E 2.6.
As a result of lsmalley's thread I decided to peep the insides of a MAS Control Unit.
The MAS Control Unit is a pretty important unit. It handles several different functions, from what I've read/seen:
-Oxygen Sensor Signal and Heating
-Idle Speed Control
-Fuel Pump Control
-A/C Compressor
-On Board Diagnostics
Disassemble:
-Bend tab near I/O screw device so that you can turn the screw past it (might not be necessary, but its what I did)
-Extend fully
-Use screw driver or pliers to disconnect (by prying) metal casing from plastic housing.
-Clear out silicon
-Place a screw driver on each long side and it should pop out.
There are a few small value electrolytic capacitors that you might wanna change out since you have it open. Be sure to put the same value capacitance and equal or greater value voltage. You can use the same 85C rated caps or if you go up to 105C rated units and extend their lives quite a bit!
Here are the pics!
011 545 79 32 - M103 MAS Control Unit - Imgur