Mercedes-Benz C-Class Operator's Manual page 322

Tire pressure
320
If the tire pressure monitor is
malfunctioning, it may take more than ten
minutes for the tire pressure warning lamp
to inform you of the malfunction by 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.
i
The tire pressure values indicated by the
on-board computer may differ from those
measured 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
values indicated by a pressure gauge are
higher than those shown by the on-board
computer. In this case, do not reduce the
tire pressures.
i
The operation of the tire pressure monitor
can be affected by interference from radio
transmitting equipment (e.g. radio
headphones, two-way radios) that may be
being operated in or near the vehicle.
Checking the tire pressure
electronically
Make sure that the SmartKey is in position
X
2( page 141) in the ignition lock .
Y
Press the = or ; button on the
X
steering wheel to select the
menu.
Press the 9 or : button to select
X
Tire Pressure.
Press the a button.
X
The current tire pressure of each tire is
shown in the multifunction display.
If the vehicle has been parked for over
20 minutes, the Tire pressures will be
displayed after driving a few
minutes message appears.
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
Monitor Active
instead of the tire pressure display. The tire
pressures are already being monitored.
i
If a spare wheel/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 displayed for
the position where the spare tire is
mounted is not the same as the spare
wheel/emergency spare wheel's current
tire pressure.
Tire pressure monitor warning
messages
If the tire pressure monitor detects a
significant pressure loss on one or more tires,
a warning message is shown in the
multifunction display. A warning tone also
sounds and the tire pressure warning lamp
lights up in the instrument cluster.
Each tire that is affected by a significant loss
of pressure is highlighted with a color.
If the following message appears in the
multifunction display:
Pressure:
Check the tire pressure on all four wheels
X
and correct it if necessary.
i
If the wheel positions on the vehicle are
Service
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 pressures
are displayed for the correct 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
reference values for monitoring. In most
cases, the tire pressure monitoring system
recognizes the new reference values
automatically.
Tire Pressure
display message is shown
Correct Tire