Air Injection Control Valve: Description and Operation

GF14.30-P-2020MAR Component Description Of Air Pump Switchover Valve
ENGINE 156.981 in MODEL 230.470 as of Model Year 09 /Modification Year 08 model refinement package





View of the engine from the front

Y32 Air pump switchover valve

Location
The switchover valve is located at the front of the engine, on the right near the oil filter housing.

Task
The switchover valve actuates the air shutoff valve using vacuum from the intake manifold for air injection.





Design

1 Aeration connection
2 Vacuum pressure supply connection
3 Connection to the air shutoff valves

a Armature disk
b Return spring
c Housing
d Solenoid (coil with resistance of about 28)
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 (vacuum applied to the air shutoff valve)
B Air pump switchover valve deenergized (air shutoff valve ventilated)

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.
The voltage supply takes place from "circuit 87 M2".

When energized, the armature (a) is drawn by the solenoid (d) and the rubber seal (f) closes off connection 1. The connection between connections 2 and 3 is opened and the vacuum from the variable intake manifold builds up in the air shutoff valves.

When de-energized, connection 2 is closed off by the rubber seal (f) and the connection is restored between connections 1 and 3.
This causes air to be admitted again to the air shutoff valves (through connection 3).
A check valve ensures that vacuum is not allowed to form (or remain) in the switchover valve. Thus actuation of the air shutoff valves by means of vacuum is guaranteed under all operating conditions.