On a 85 190 it probably only powers the ABS and the KE controller.
It does well without one because the fuel system only uses electronic control for correction of fuel mixture. It can be adjusted rich to overide lambda and have enough fuel mixture to handle acceleration and warm-up. Of course you will use at least 25% more fuel, probably closer to 50%. You also would flunk any serious emissions test and probably burn out your catalytic convertor within a year maybe a lot less a high speed.
Bosch Master, ASE Master, L1
33 years MB technician