sudden loss of pressure, bring the vehicle to a
halt by braking carefully. Avoid abrupt steering
movements.
The tire pressure monitor has a yellow warning
lamp in the instrument cluster for indicating
pressure loss or a malfunction. Whether the
warning lamp flashes or lights up indicates
whether a tire pressure is too low or the tire
pressure monitor is malfunctioning: R
if the warning lamp is lit continuously, the tire
pressure on one or more tires is significantly
too low. The tire pressure monitor is not mal-
functioning. R
if the warning lamp flashes for approximately
a minute and then remains lit constantly, the
tire pressure monitor is malfunctioning.
In addition to the warning lamp, a message
appears in the multifunction display. Observe
the information on display messages
( Y
page 268).
It may take up to ten minutes for a malfunction
of the tire pressure monitor to be indicated. A
malfunction will be indicated by the tire pres-
sure warning lamp flashing for approximately
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 gage. The
tire pressures shown by the on-board computer
refer to those measured at sea level. At high
altitudes, the tire pressure values indicated by a
pressure gage 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 transmit-
ting 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 H
( Y
page 135) in the ignition lock.X
Press the Y or e button on the steering
wheel to select the Serv. menu. X
Press the c or d button to select
Tire Pressure . X
Press v .
The current tire pressure of each tire is shown
in the multifunction display.
If the vehicle has been parked for longer than
20 minutes, the Tire pressure will be
displayed after driving a few minutes
message appears.
After a teach-in process, the tire pressure mon-
itor 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
display message is shown instead of the tire
pressure display. The tire pressures are already
being monitored.
If an emergency spare wheel is mounted, the
system may continue to show the tire pressure
of the wheel that has been removed for a few
minutes. If this occurs, note that the value dis-
played for the position where the spare wheel is
mounted is not the same as the current tire
pressure of the emergency spare wheel.
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 yellow
tire pressure warning lamp then lights up. R
If the Please Correct Tire Pressure
message appears in the multifunction display,
the tire pressure in at least one tire is too low.
The tire pressure must be corrected when the
opportunity arises. R
If the Check Tires message appears in the
multifunction display, the tire pressure in at
least one tire has dropped significantly. The
tires must be checked. R
If the Warning Tire Malfunction message
appears in the multifunction display, the tire
pressure in at least one tire has dropped sud-
denly. The tires must be checked.
Be sure to observe the instructions and safety
notes in the display messages in the "Tires" sec-
tion ( Y
page 268).
If the wheel positions on the vehicle are rotated,
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 pres-
sures are displayed for the correct positions.360
Tire pressure
Wheels and tires
