In addition to the warning lamp, a message
appears in the multifunction display. Observe
the information on display messages
( Y
page 250).
It may take up to ten minutes for a malfunc-
tion of the tire pressure monitor to be indica-
ted. A malfunction will be indicated by the tire
pressure warning lamp flashing for approx-
imately one minute and then remaining lit.
When the malfunction has been rectified, the
tire pressure warning lamp goes out after a
few minutes of driving.
The tire pressure values indicated by the on-
board computer may differ from those meas-
ured at a gas station with a pressure gauge.
The tire pressures shown by the on-board
computer refer to those measured at sea
level. At high altitudes, the tire pressure val-
ues indicated by a pressure gauge are higher
than those shown by the on-board computer.
In this case, do not reduce the tire pressures.
The operation of the tire pressure monitor can
be affected by interference from radio trans-
mitting equipment (e.g. radio headphones,
two-way radios) that may be being operated
in or near the vehicle.
Checking the tire pressure electroni-
cally X
Make sure that the SmartKey is in position
2 in the ignition lock ( Y
page 147).X
Press  Y or  e on the steering wheel
to select the Serv.
menu.X
Press the  c or  d button to select
Tire Pressure
.X
Press the  v button.
The current tire pressure of each tire is
shown in the multifunction display.
If the vehicle was parked for longer than
20 minutes, the Tire pressure will be
displayed after driving a few
minutes message is shown.
After a teach-in process, the tire pressure
monitor automatically detects new wheels or
new sensors. As long as a clear allocation of the tire pressure value to the individual
wheels is not possible, the Tire Pressure
Monitor Active message is shown instead
of the tire pressure display. The tire pressures
are already being monitored.
Tire pressure monitor warning mes-
sages If the tire pressure monitor detects a pressure
loss in one or more tires, a warning message
is shown in the multifunction display. The yel-
low tire pressure warning lamp then lights up. R
If the Please Correct Tire Pressure
message appears in the multifunction dis-
play, the tire pressure in at least one tire is
too low. The tire pressure must be correc-
ted when the opportunity arises. R
If the Check Tire Pressure message
appears in the multifunction display, the
tire pressure in one or more tires has drop-
ped significantly. The tires must be
checked. R
If the Tire Pressure Warning Tire
Failure message appears in the multi-
function display, the tire pressure in one or
more tires has dropped suddenly. The tires
must be checked.
Observe the instructions and safety notes in
the display messages in the "Tires" section
( Y
page 250).
If the wheel positions on the vehicle are rota-
ted, the tire pressures may be displayed for
the wrong positions for a short time. This is
rectified after a few minutes of driving, and
the tire pressures are displayed for the cor-
rect positions.
Restarting the tire pressure monitor
When you restart the tire pressure monitor, all
existing warning messages are deleted and
the warning lamps go out. The monitor uses
the currently set tire pressures as the refer-
ence values for monitoring. In most cases, the
tire pressure monitor will automatically
detect the new reference values after you338
Tire pressure
Wheels and tires