Valve For Suspension Struts N150 And N151 - Audi A6 242 Service Manual

Valve for suspension strut
rear left N150 and rear
right N151
Valves N150 and N151 are described as
transverse check valves and are combined in
one housing.
Both transverse check valves are so-called
2/2 way valves (2 connections and 2 switching
positions). The transverse check valves are
used to fill and discharge the air springs. The
valves are closed without current and prevent
an undesirable pressure equalisation
between the left and right-hand air springs.
This prevents the air spring pressure of the
outer wheel (higher air spring pressure)
escaping to the inside wheel (lower air spring
pressure) when cornering. This would result
in a momentary tilt of the vehicle.
The transverse check valves are always
controlled in unison during raising and
lowering as adjustment can only be
performed for the whole axle (see level
sensor).
Following a control process while the vehicle
is in driving operation (v >10km/h) the
transverse check valves are opened three
times for approx. 3 seconds at intervals of
approx. 12 seconds in order to equalise the
pressure between the left and right-hand air
springs.
If, for example, a control process takes place
while cornering, this will cause the rear axle
to tilt. The tilt is compensated by the opening
of the transverse check valves, as described
above (not in the case of a one-sided load).
N150
by control unit J197
242_012
The self-levelling system in the Audi A6
is not able to compensate for one-sided
loads (level difference between left and
right). To prevent differing pressures in
the air springs the transverse check
valves are opened as described after a
control process.
242_036
N151
51