Mas Unit Engine Systems Control Unit (190E & 300 Series)

Locate MAS unit in underhood component compartment area, near CIS-E control unit, behind battery. To remove MAS unit, turn top knob from position No. 1 to position No. 0 and lift/pull MAS unit out of electrical socket connector. To install MAS unit, push MAS unit into electrical socket connector and turn top knob from position No. 0 to position No. 1.