CITROËN DS4 Owner's Handbook Manual page 177

Sensor(s) not detected or faulty
A message appears in the screen,
accompanied by an audible signal, to identify
the wheel or wheels which are not detected or
to indicate a malfunction in the system.
Contact a CITROËN dealer or a qualified
workshop to replace the faulty sensor(s).
This message is also displayed when
one of the wheels is away from the
vehicle (being repaired) or when one
or more wheels without a sensor are
fitted.
If your vehicle is equipped with a spare
wheel, this is not fitted with a sensor.
All repairs and changing of tyres on a
wheel fitted with this system must be
carried out by a CITROËN dealer or a
qualified workshop.
If, when changing a tyre, you install a
wheel which is not detected by your
vehicle (example: fitting of snow tyres),
you must have the system reinitialised
by a CITROËN dealer or a qualified
workshop.
This system does not avoid the need
to have the tyre pressures checked
regularly (refer to the "Identification
markings" section) to ensure that
the optimum dynamic performance
of the vehicle is maintained and
prevent premature wear of the
tyres, particularly in arduous driving
conditions (heavy load, high speed).
The tyre pressures must be checked
cold, at least once a month. Remember
to check the pressure of the spare
wheel.
The tyre under-inflation detection
system may experience temporary
interference due to electro-magnetic
emissions on a frequency close to that
used by the system.
175
Safety