AIRmatic suspension strut valve unit, location/task/function - GF32.31-P-4502E

MODELS 211, 240 with CODE (489a) Airmatic (semi-active air suspension) 

Fig 1: Locating AIRmatic Suspension Strut Valve Unit

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

AIRmatic valve unit, suspension strut, location	Integrated in crown of suspension strut.
AIRmatic valve unit, suspension strut, task	The valves of the valve unit control the vehicle level, level control, and spring rate.
AIRmatic valve unit, suspension strut, function		GF32.31-P-4502-01E