Component description for an electric air pump - GF14.30-P-2000CY

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: Identifying Electric Air Pump & Shut Off Valves

Courtesy of MERCEDES-BENZ USA

The electric air pump is mounted upstream of the variable intake manifold.

Task

The electric air pump blows fresh air for air injection into the exhaust ducts of the cylinder heads.

The air injection allows afterburning in the exhaust ducts or in the firewall catalytic converters which brings the firewall catalytic converters more quickly up to operating temperature for a cold start.

Design

The electric air pump is an electrical vane pump.

Actuation (shown: engine compartment at left rear)

The electric air pump is actuated via the secondary air injection relay by the ME-SFI [ME] control unit (N3/10).

Fig 2: Identifying Engine Compartment Relays

Courtesy of MERCEDES-BENZ USA

Function

Fig 3: Electric Air Pump Function Diagram

Courtesy of MERCEDES-BENZ USA

With air injection released, the electric air pump is actuated over the secondary air injection relay parallel to the air pump switchover valve for a maximum of about (Y32) 40 s. The power consumption at 13 V is approx. 45 A.

Here the electric air pump draws filtered injected air out of the right air filter housing and delivers it via two pressure fitting through the air shutoff valve to the exhaust ducts.

Following actuation, air injection remains locked. A new enable of the air injection will only take place if the firewall catalytic convertors cool down again due to a sufficiently long stoppage of the engine. The electrical air pump thus has sufficient time to cool down again.

Diagnosis

Air injection can be released for diagnosis with DAS for a max. of 2 minutes (for a warm engine only shortly).

Prior to the next actuation, it is essential to maintain a cooling time of 30 minutes, otherwise the electric air pump may be damaged (overheated).