Remove/install the resonance flap switchover valve at the intake manifold (engine 272) - AR09.20-P-1993VA

ENGINE 272.942 in MODEL 171.454 

ENGINE 272.963 in MODEL 171.456 

Fig 1: Identifying Resonance Flap Switchover Valve Components

Courtesy of MERCEDES-BENZ USA

	Remove/Install
1	Turn key in ignition switch to position "0".
2	Open engine hood		AR88.40-P-1000V
3	Remove air cleaner housing		AR09.10-P-1150VA
4	Remove the resonance intake manifold (7)	Cover openings in the cylinder heads. Objects that have entered the intake tract must always be removed before fitting the resonance intake manifold; otherwise there is a possibility of engine damage.	AR09.20-P-1961VA
5	Detach the pneumatic lines (1) from the variable intake manifold switchover valve (Y22/6)
6	Remove the lock washer (3)	Installation:  Replace lock washer.
7	Remove the electrical connector (5) at the variable intake manifold switchover valve (Y22/6)
8	Detach the variable intake manifold switchover valve (Y22/6) from the resonance intake manifold (7)
9	Install in the reverse order
	Check
	Risk of accident  caused by vehicle starting off by itself when engine is running. Risk of injury  caused by contusions and burns when working in engine during starting procedure	Secure vehicle to prevent it from moving. Wear closed and snug-fitting work clothes. Do not grasp hot or rotating parts.	-
10	Carry out an engine test run and check the intake tract and fuel system for leaks