Air Injection Control Valve: Description and Operation

GF14.30-P-2020AMG Air Pump Switchover Valve, Component Description
ENGINE 156.980 in MODEL 164, 251 up to Model Year 8
ENGINE 156.982 in MODEL 209
ENGINE 156.983 in MODEL 211, 219
ENGINE 156.984 in MODEL 216, 221 up to Model Year 8





Location

Y32 Air pump switchover valve

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

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





Design

1 Ventilation connection (atmospheric)
2 Vacuum supply connection from variable intake manifold
3 Connection to the air shutoff valves
a Armature disk
b Return spring
c Housing
d Solenoid (coil with resistance of approx. 28 ohms)
e Electrical connection
f Rubber seal





Function
1 Ventilation connection (atmospheric)
2 Vacuum supply connection from variable intake manifold
3 Connection to the air shutoff valves
4 Electrical connection
A Air pump switchover valve energized (air shutoff valves discharged with vacuum)
B Air pump switchover valve deenergized (air shutoff valves aerated)

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 deenergized state the link is restored between connection (1) and (3), through which connection (3) is aerated.