Air pump switchover valve, component description - GF14.30-P-2020AMG

WARNING: This page does not describe the selected car, but rather 28 other vehicles, including the 2012 Mercedes-Benz GL550, 2012 Mercedes-Benz GL450, 2011 Mercedes-Benz ML63, 2011 Mercedes-Benz ML550, and 2011 Mercedes-Benz ML350. However, it is still accessible from the selected car via links, so may be relevant.

ENGINE 156.980 in MODEL 164, 251

ENGINE 156.982 in MODEL 209

ENGINE 156.983 in MODEL 211, 219

ENGINE 156.984 in MODEL 216, 221

Location

The switchover valve is located at the front of the engine to the right of the oil filter.

Fig 1: Identifying Air Pump Switchover Valve

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Task

The switchover valve actuates the left and right air shutoff valves via a vacuum for the purpose of air injection.

Design

Fig 2: Identifying Air Pump Switchover Valve Components

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Function

Fig 3: Air Pump Switchover Valve Function Diagram - Engine 271.921 /940 /941 /944 /946 /948

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

When air injection is enabled, the switchover valve is actuated directly by the ME-SFI control unit (N3/10) using a ground signal.

Here the anchor plate (a) is pulled by the electromagnet (d) and the sealing rubber (f) shuts off the connection (1).

The connection between connection (2) and (3) is released and the vacuum pressure from the variable intake manifold builds up in the air shutoff valves.

In the de-energized state the link is restored between connection (1) and (3), through which connection (3) is aerated.