36
The combi-valve
The combi-valve is bolted to the secondary air
duct of the cylinder head.
The air path from the secondary air pump to
the secondary duct of the cylinder head is
opened by the vacuum from the secondary air
injection valve.
Secondary air injection valve N112
The secondary air injection valve is an electro-
pneumatic valve. It is switched by the Motro-
nic control unit and controls the combi-valve.
To open the combi-valve, the secondary air
injection valve releases the intake manifold
vacuum.
To close the combi-valve, the secondary air
injection valve releases atmospheric pressure.
Secondary air pump V101
The secondary air pump relay J299 which the
Motronic control unit drives switches the elec-
tric current for the secondary air pump motor
V101. The fresh air which is mixed with the
exhaust gases is drawn out of the air filter
housing by the secondary air pump and
released by the combi-valve.
This valve also prevents hot exhaust gases
entering and damaging the secondary air
pump.
SSP207/16
SSP207/17
SSP207/19
Vacuum in control line
from secondary air
injection valve
Valve opened
Fresh air from
secondary air pump
To secondary air
port
Drive units
SSP207/18
Valve closed
Atmospheric pressure
in control line from
secondary air injection
valve
Exhaust gas