2018 MERCEDES-BENZ CLA warning light

shown in the Serv. menu of the multifunction
display, see illustration (example).
For information on the message display, refer to
the "Checking the tire pressure electronically"
section ( Y
page 296).
Important safety notes
G WARNING
Each tire, including the spare (if provided),
should be checked at least once every two
weeks when cold and inflated to the pressure
recommended by the vehicle manufacturer
on the Tire and Loading Information placard
on the driver's door B-pillar or the tire pres-
sure label on the inside of the fuel filler flap. If
your vehicle has tires of ad ifferent size than
the size indicated on the Tire and Loading
Information placard or, if available, the tire
pressure label ,y ou should determine the
proper tire pressure for those tires.
As an added safety feature, your vehicle has
been equipped with at ire pressure monitoring
system (TPMS) that illuminates al ow tire pres-
sure telltale when one or more of your tires
are significantly underinflated. Accordingly,
when the low tire pressure telltale lights up,
you should stop and check your tires as soon
as possible ,a nd inflate them to the proper
pressure. Driving on as ignificantly underin-
flated tire causes the tire to overheat and can
lead to tire failure.
Underinflation also reduces fuel efficiency
and tire tread life, and may affect the vehicle's
handling and stopping ability. Please note that
the TPMS is not as ubstitute for proper tire
maintenance, and it is the driver's responsi-
bility to maintain correct tire pressure, even if
underinflation has not reached the level to trigger illumination of the TPMS low tire pres-
sure telltale.
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate when
the system is not operating properly. The
TPMS malfunction indicator is combined with
the low tire pressure telltale. When the sys-
tem detects am alfunction, the warning lamp
will flash for approximately am inute and then
remain continuously illuminated. This
sequence will be repeated every time the vehi-
cle is started as long as the malfunction
exists. When the malfunction indicator is illu-
minated, the system may not be able to detect
or signal low tire pressure as intended.
TPMS malfunctions may occur for av ariety of
reasons, including the installation of incom-
patible replacement or alternate tires or
wheels on the vehicle that prevent the TPMS
from functionin gp roperly. Always check the
TPMS malfunction telltale after replacing one
or more tires or wheels on your vehicle to
ensure that the replacement or alternate Tires
and wheels allow the TPMS to continue to
function properly.
It is the driver's responsibility to set the tire
pressure to that recommended for cold tires
which is suitable for the operating situation
( Y
page 290). Note that the correct tire pressure
for the current operating situation must first be
taught-in to the tire pressure monitor. If as ub-
stantial loss of pressure occurs, the warning
threshold for the warning message is aligned to
the taught-in reference values. Restart the tire
pressure monitor after adjusting the pressure of
the cold tires ( Y
page 297). The current pres-
sures are saved as new reference values. As a
result, aw arning message will appea rift he tire
pressure drops significantly.
The tire pressure monitor does not warn you of
an incorrectly set tire pressure. Observe the
notes on the recommended tire pressure
( Y
page 290).
The tire pressure monitor is not able to warn you
of as udden loss of pressure, e.g. if the tire is
penetrated by af oreign object. In the event of a
sudden loss of pressure, bring the vehicle to a
halt by braking carefully .A void abrupt steering
movements. Tire pressure 295
Wheels and tires Z

The tire pressure monitor has ay ellow warning
lamp in the instrument cluster for indicating
pressure loss or am alfunction. Whether the
warning lamp flashes or lights up indicates
whether at ire 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 around a
minute and then remains lit constantly, the
tire pressure monitor is malfunctioning.
In addition to the warning lamp, am essage
appears in the multifunction display .O bserve
the information on display messages
( Y
page 211).
It may take up to ten minutes for am alfunction
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 af ew minutes of
driving.
The tire pressure values indicated by the on-
board computer may differ from those meas-
ured at ag as station with ap ressure 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.
The operation of the tire pressure monitor can
be affected by interferenc ef rom radio transmit-
ting equipment (e.g. radio headphones, two-way
radios) that may be being operated in or near the
vehicle.
Checking the tire pressur ee lectroni-
cally X
Make sure that the SmartKey is in position H
in the ignition lock ( Y
page 122).X
Press Y or e on the steerin gw heel 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 af ew minutes
message is shown.
After at each-in process, the tire pressure mon-
itor automatically detect sn ew wheels or new
sensors. As long as ac lear 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 .T he tire pressures are already being
monitored.
If an emergenc ys pare wheel is mounted, the
system may continue to show the tire pressure
of the wheel that has been removed for af ew
minutes. If this occurs, not et hat the value dis-
played for the position where the spare wheel is
mounted is not the same as the current tire
pressure of the emergenc ys pare wheel.
Tire pressur em onitor warning mes-
sages If the tire pressure monitor detect sap ressure
loss in one or more tires, aw arning message is
shown in the multifunction display .T he 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
opportunit ya rises. R
If the Check Tire Pressure message
appears in the multifunction display ,t he tire
pressure in one or more tires has dropped
significantly. The tires must be checked. R
If the Tire Pressure Warning Tire Fail‐
ure message appears, 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 211).
If the wheel positions on the vehicle are rotated,
the tire pressures may be displayed for the
wrong positions for as hort time. This is rectified
after af ew minutes of driving, and the tire pres-
sures are displayed for the correc tp ositions.296
Tir ep re ssure
Wheels and tires