Component description for the air pump switchover valve - GF14.30-P-2020CY

WARNING: This page is about a different car, the 2011 Mercedes-Benz C300, 2010 Mercedes-Benz C300, 2009 Mercedes-Benz C300, and 2008 Mercedes-Benz C300. However, it is still accessible from the selected car via links, so may be relevant.

ENGINE 272.911 in MODEL 204.0 up to Model Year 2008

ENGINE 272.921 in MODEL 204.0/2 up to Model Year 2008

ENGINE 272.947 in MODEL 204.0/2 up to Model Year 2008

ENGINE 272.948 in MODEL 204.0 up to Model Year 2008

ENGINE 272.961 in MODEL 204.0/2 up to Model Year 2008

ENGINE 272.971 in MODEL 204.0 up to Model Year 2008

Location

Fig 1: Locating Electric Air Pump, Air Pump Switch Over Valve And Check Valve

Courtesy of MERCEDES-BENZ USA

The switchover valve is located at the front on the right cylinder head.

Task

The switchover valve actuates the air shutoff valve with vacuum out of the variable intake manifold for air injection.

Design

Fig 2: Air Pump Switchover Valve Design

Courtesy of MERCEDES-BENZ USA

Function

Fig 3: Air Pump Switchover Valve Function Diagram

Courtesy of MERCEDES-BENZ USA

The switchover valve is actuated directly for a released air injection by the ME-SFI [ME] control unit (N3/10) by means of a ground signal. In this way the anchor disc (a) from the solenoid (d) is pulled in and the rubber seal (f) closes connection 1. The connection between connection 2 and connection 3 is released and vacuum from variable intake manifold is built up in the air shutoff valve.

In a de-energized condition, the connection between connection 1 and 3 is recreated, whereby the air shutoff valves (via connection 3) are again ventilated.

A check valve (128) ensures that the vacuum develops or remains in the vacuum switchover valve. Thus actuation of the air shutoff valves by means of vacuum is guaranteed under all operating conditions.