2017 MERCEDES-BENZ CLA-Class Warning light

Important safety notes
GWARNING
Eac htire, includin gth espar e(if provided),
should be checke dat least once every two
week swhen cold and inflated to th epressur e
recommended by th evehicl emanufacturer
on th eTir eand Loading Information placard
on th edriver' sdoor B-pillar or th etire pres-
sur elabel on th einside of th efuel filler flap .If
your vehicl ehas tires of adifferen tsiz ethan
th esiz eindicated on th eTir eand Loading
Information placard or, if available, th etire
pressur elabel, you should determine th e
proper tire pressur efor those tires .
As an added safet yfeature, your vehicl ehas
been equipped wit h atire pressur emonitoring
system (TPMS) that illuminate s alow tire pres-
sur etelltale when on eor mor eof your tires
are significantly underinflated. Accordingly,
when th elow tire pressur etelltale lights up,
you should stop and chec kyour tires as soo n
as possible ,and inflat ethem to th eproper
pressure. Drivin gon asignificantly underin-
flated tire causes th etire to overheat and can
lead to tire failure.
Underinflation also reduce sfuel efficiency
and tire tread life ,and may affec tth evehicle's
handlin gand stopping ability. Pleas enote that
th eTPM Sis no t asubstitut efor proper tire
mainte nance,a
nd it is th edriver' sresponsi-
bilit yto maintai ncorrec ttire pressure, eve nif
underinflation has no treached th elevel to
trigge rillumination of th eTPM Slow tire pres-
sur etelltale.
Your vehicl ehas also been equipped wit h a
TPM Smalfunction indicator to indicat ewhen
th esystem is no toperating properly. The
TPM Smalfunction indicator is combined wit h
th elow tire pressur etelltale. When th esys-
te m detects amalfunction ,th ewarning lamp
will flas hfor approximately aminute and then
remain continuously illuminated. This
sequenc ewill be repeated every time th evehi-
cle is started as lon gas th emalfunction
exists. When th emalfunction indicator is illu-
minated, th esystem may no tbe able to detec t
or signal low tire pressur eas intended.
TPM Smalfunction smay occur for avariet yof
reasons, includin gth einstallation of incom-
patible replacemen tor alternate tires or
wheels on th evehicl ethat preven tth eTPM S
from functioning properly. Always chec kth e
TPM Smalfunction telltale after replacing on e
or mor etires or wheels on your vehicl eto
ensur ethat th ereplacemen tor alternate Tires
and wheels allow th eTPM Sto continue to
function properly.
It is th edriver' sresponsibilit yto set th etire
pressur eto that recommended for cold tires
whic his suitable for th eoperating situation
(
Ypage 285). Not ethat th ecorrec ttire pressur e
for th ecurren toperating situation must first be
taught-in to th etire pressur emonitor. If asub-
stantial loss of pressur eoccurs, th ewarning
threshold for th ewarning message is aligned to
th etaught-in referenc evalues. Restart th etire
pressur emonitor after adjusting th epressur eof
th ecold tires (
Ypage 291). The curren tpres-
sures are saved as ne wreferenc evalues. As a
result , awarning message will appear if th etire
pressur edrops significantly.
The tire pressur emonit or d
oes no
twarn you of
an incorrectl yset tire pressure. Observ eth e
note son th erecommended tire pressur e
(
Ypage 285).
The tire pressur emonitor is no table to warn you
of asudde nloss of pressure, e.g. if th etire is
penetrated by aforeign object. In th eevent of a
sudde nloss of pressure, brin gth evehicl eto a
halt by braking carefully. Avoid abrup tsteering
movements.
The tire pressur emonitor has ayellow warning
lamp in th einstrumen tcluste rfor indicating
pressur eloss or amalfunction .Whether th e
warning lamp flashes or lights up indicates
whether atire pressur eis to olow or th etire
pressur emonitor is malfunctioning :
Rif thewarning lamp is lit continuously, th etire
pressur eon on eor mor etires is significantly
to olow. The tire pressur emonitor is no tmal-
functioning .
Rif thewarning lamp flashes for aroun d a
minute and then remain slit constantly, th e
tire pressur emonitor is malfunctioning .
In addition to th ewarning lamp , amessage
appear sin th emultifunction display. Observ e
290Tire pressure
Wheels and tires

the information on display messages
(Ypage 209).
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 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 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
XMake sure that the SmartKey is in position 2
in the ignition lock (Ypage 121).
XPress =or; on the steering wheel to
select the Serv.menu.
XPress the9or: button to select
Tire Pressure.
XPress the abutton.
The current tire pressure of each tire is shown
in the multifunction display.
If the vehicle was parked for longer than
20 minute s,the Tire pressure will be
displayed after driving a few minutesmessage is shown.
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
PressureMonitorActivemessage 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 yellow
tire pressure warning lamp then lights up.
RIf thePlease Correct Tire Pressuremessage 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.
RIf the Check Tire Pressuremessage
appears in the multifunction display, the tire
pressure in one or more tires has dropped
significantly. The tires must be checked.
RIf the TirePressureWarningTireFail‐uremessage 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
(
Ypage 209).
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.
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 cur-
rently set tire pressures as the reference valuesfor monitoring. In most cases, the tire pressure
monitor will automatically detect the new refer-
ence values after you have changed the tire
pressure. However, you can also set reference
values manually as described here. The tire
pressure monitor then monitors the new tire
pressure values.
XSet the tire pressure to the value recommen-
ded for the corresponding driving situation on
the Tire and Loading Information placard on
the driver's side B-pillar (
Ypage 285).
You can find more tire pressure values for
various operating conditions in the tire pres-
sure table inside the fuel filler flap
(
Ypage 138).
XMake sure that the tire pressure is correct on
all four wheels.
Tire pressure291
Wheels and tires
Z

PSI (pounds per square inch)
A standard unit of measure for tire pressure.
Aspect ratio
Relationship between tire height and tire width
in percent.
Tire pressure
This is pressure inside the tire applying an out-
ward force to each square inch of the tire's sur-
face. The tire pressure is specified in pounds per
square inch (psi), in kilopascal (kPa) or in bar.
The tire pressure should only be corrected when
the tires are cold.
Cold tire pressure
The tires are cold:
Rif the vehicle has been parked with the tires
out of direct sunlight for at least three hours
and
Rif the vehicle has not been driven further than
1 mile (1.6 km)
Tread
The part of the tire that comes into contact with
the road.
Bead
The tire bead ensures that the tire sits securely
on the wheel. There are several steel wires in the
bead to prevent the tire from coming loose fromthe wheel rim.
Sidewall
The part of the tire between the tread and the
bead.
Weight of optional extras
The combined weight of those optional extras
that weigh more than the replaced standard
parts and more than 2.3 kg (5 lbs). These
optional extras, such as high-performance
brakes, level control, a roof rack or a high-per-
formance battery, are not included in the curb
weight and the weight of the accessories.
TIN (Tire Identification Number)
This is a unique identifier which can be used by
a tire manufacturer to identify tires, for example
for a product recall, and thus identify the pur-
chasers. The TIN is made up of the manufactur-
er's identity code, tire size, tire type code and
the manufacturing date.
Load bearing index
The load bearing index (also load index) is a code
that contains the maximum load bearing capa-
city of a tire.
Traction
Traction is the result of friction between the tires
and the road surface.
Treadwear indicators
Narrow bars (tread wear bars) that are distrib-
uted over the tire tread. If the tire tread is level
with the bars, the wear limit of áin (1.6 mm)
has been reached.
Occupant distribution
The distribution of occupants in a vehicle at their
designated seating positions.
Total load limit
Nominal load and luggage load plus 68 kg
(150 lbs) multiplied by the number of seats in
the vehicle.
Changing a wheel
Flat tire
The "Breakdown assistance" section
(Ypage 266) contains information and notes on
how to deal with a flat tire. Information on driv-
ing with MOExtended tires in the event of a flat
tire can be found under "MOExtended tires (tires
with run-flat characteristics" (
Ypage 267).
Rotating the wheels
GWARNING
Interchanging the front and rear wheels may
severely impair the driving characteristics if
the wheels or tires have different dimensions. The wheel brakes or suspension components
may also be damaged. There is a risk of acci-
dent.
Rotate front and rear wheels only if the wheels and tires are of the same dimensions.
!On vehicles equipped with a tire pressure
monitor, electronic components are located
in the wheel.
Changing a wheel301
Wheels and tires
Z