warning light MERCEDES-BENZ CLA 2017 Repair Manual

Battery (vehicle)
Important safety notes Special tools and expert knowledge are required
when working on the battery, e.g. removal and
installation. You should therefore have all work
involving the battery carried out at a qualified
specialist workshop.
G WARNING
Work carried out incorrectly on the battery
can lead, for example, to a short circuit and
thus damage the vehicle electronics. This can
lead to function restrictions applying to
safety-relevant systems, e.g the lighting sys-
tem, the ABS (anti-lock braking system) or the
ESP ®
(Electronic Stability Program). The oper-
ating safety of your vehicle may be restricted.
You could lose control of the vehicle, for
example: R
when braking R
in the event of abrupt steering maneuvers
and/or when the vehicle's speed is not
adapted to the road conditions
There is a risk of an accident.
In the event of a short circuit or a similar inci-
dent, contact a qualified specialist workshop
immediately. Do not drive any further. You
should have all work involving the battery car-
ried out at a qualified specialist workshop.
For further information about ABS and ESP ®
,
see ( Y
page 60) and ( Y
page 63).
G WARNING
Electrostatic build-up can lead to the creation
of sparks, which could ignite the highly explo-
sive gases of a battery. There is a risk of an
explosion.
Before handling the battery, touch the vehicle
body to remove any existing electrostatic
build-up.
The highly flammable gas mixture forms when
charging the battery as well as when jump-start-
ing. Always make sure that neither you nor the bat-
tery is electrostatically charged. A build-up of
electrostatic charge can be caused, for exam-
ple: R
by wearing clothing made from synthetic
fibers R
due to friction between clothing and seats R
if you push or pull the battery across the car-
pet or other synthetic materials R
if you rub the battery with a cloth
G WARNING
During the charging process, a battery produ-
ces hydrogen gas. If a short circuit occurs or
sparks are created, the hydrogen gas can
ignite. There is a risk of an explosion. R
Make sure that the positive terminal of a
connected battery does not come into con-
tact with vehicle parts. R
Never place metal objects or tools on a bat-
tery. R
It is important that you observe the descri-
bed order of the battery terminals when
connecting and disconnecting a battery. R
When jump-starting, make sure that the
battery poles with identical polarity are
connected. R
It is particularly important to observe the
described order when connecting and dis-
connecting the jumper cables. R
Never connect or disconnect the battery
terminals while the engine is running.
G WARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten-
tion.
H Environmental note
Batteries contain dangerous
substances. It is against the
law to dispose of them withBattery (vehicle) 271
Breakdo wn assis tance Z

G WARNING
During charging and jump-starting, explosive gases can escape from the battery. There is a risk
of an explosion.
Particularly avoid fire, open flames, creating sparks and smoking. Ensure there is sufficient ven-
tilation while charging and jump-starting. Do not lean over a battery.
G WARNING
During the charging process, a battery produces hydrogen gas. If a short circuit occurs or sparks
are created, the hydrogen gas can ignite. There is a risk of an explosion. R
Make sure that the positive terminal of a connected battery does not come into contact with
vehicle parts. R
Never place metal objects or tools on a battery. R
It is important that you observe the described order of the battery terminals when connecting
and disconnecting a battery. R
When jump-starting, make sure that the battery poles with identical polarity are connected. R
It is particularly important to observe the described order when connecting and disconnecting
the jumper cables. R
Never connect or disconnect the battery terminals while the engine is running.
G WARNING
A discharged battery can freeze at temperatures below freezing point. When jump-starting the
vehicle or charging the battery, gases can escape from the battery. There is a risk of an explosion.
Allow the frozen battery to thaw out before charging it or jump-starting.
! Avoid repeated and lengthy starting attempts. Otherwise, the catalytic converter could be
damaged by the non-combusted fuel.
If the indicator/warning lamps do not light up in the instrument cluster at low temperatures, it is very
likely that the discharged battery has frozen. In this case you may neither jump-start the vehicle nor
charge the battery. Let the battery thaw first. The service life of a thawed-out battery may be shorter.
The starting characteristics can be impaired, particularly at low temperatures. Have the thawed-out
battery checked at a qualified specialist workshop.
Do not start the vehicle using a rapid charging device. If your vehicle's battery is discharged, the
engine can be jump-started from another vehicle or from a second battery using jumper cables.
Observe the following points: R
The battery is not accessible in all vehicles. If the other vehicle's battery is not accessible, jump-
start the vehicle using a second battery or a jump-starting device. R
You may only jump-start the vehicle when the engine and exhaust system are cold. R
Do not start the engine if the battery is frozen. Let the battery thaw first. R
Only jump-start from batteries with a 12 V voltage rating. R
Only use jumper cables that are not damaged and have a sufficient cross-section and insulated
terminal clamps. R
Make sure that the two vehicles do not touch.274
Jump-starting
Breakdown assistance

Important safety notes
G WARNIN G
Eac h tire, includin g th e spar e (if provided),
should be checke d at least once every two
week s when cold and inflated to th e pressur e
recommended by th e vehicl e manufacturer
on th e Tir e and Loading Information placard
on th e driver' s door B-pillar or th e tire pres-
sur e label on th e inside of th e fuel filler flap . If
your vehicl e has tires of a differen t siz e than
th e siz e indicated on th e Tir e and Loading
Information placard or, if available, th e tire
pressur e label, you should determine th e
proper tire pressur e for those tires .
As an added safet y feature, your vehicl e has
been equipped wit h a tire pressur e monitoring
system (TPMS) that illuminate s a low tire pres-
sur e telltale when on e or mor e of your tires
are significantly underinflated. Accordingly,
when th e low tire pressur e telltale lights up,
you should stop and chec k your tires as soo n
as possible , and inflat e them to th e proper
pressure. Drivin g on a significantly underin-
flated tire causes th e tire to overheat and can
lead to tire failure.
Underinflation also reduce s fuel efficiency
and tire tread life , and may affec t th e vehicle's
handlin g and stopping ability. Pleas e note that
th e TPM S is no t a substitut e for proper tire
mainte
nance , a nd it is th e d river' s responsi-
bilit y to maintai n correc t tire pressure, eve n if
underinflation has no t reached th e level to
trigge r illumination of th e TPM S low tire pres-
sur e telltale.
Your vehicl e has also been equipped wit h a
TPM S malfunction indicator to indicat e when
th e system is no t operating properly. The
TPM S malfunction indicator is combined wit h
th e low tire pressur e telltale. When th e sys-
te m detects a malfunction , th e warning lamp
will flas h for approximately a minute and then
remain continuously illuminated. This
sequenc e will be repeated every time th e vehi-
cle is started as lon g as th e malfunction
exists. When th e malfunction indicator is illu- minated, th e system may no t be able to detec t
or signal low tire pressur e as intended.
TPM S malfunction s may occur for a variet y of
reasons, includin g th e installation of incom-
patible replacemen t or alternate tires or
wheels on th e vehicl e that preven t th e TPM S
from functioning properly. Always chec k th e
TPM S malfunction telltale after replacing on e
or mor e tires or wheels on your vehicl e to
ensur e that th e replacemen t or alternate Tires
and wheels allow th e TPM S to continue to
function properly.
It is th e driver' s responsibilit y to set th e tire
pressur e to that recommended for cold tires
whic h is suitable for th e operating situation
( Y
page 285). Not e that th e correc t tire pressur e
for th e curren t operating situation must first be
taught-in to th e tire pressur e monitor. If a sub-
stantial loss of pressur e occurs, th e warning
threshold for th e warning message is aligned to
th e taught-in referenc e values. Restart th e tire
pressur e monitor after adjusting th e pressur e of
th e cold tires ( Y
page 291). The curren t pres-
sures are saved as ne w referenc e values. As a
result , a warning message will appear if th e tire
pressur e drops significantly.
The tire pressur e monit or d oes no t w
arn you of
an incorrectl y set tire pressure. Observ e th e
note s on th e recommended tire pressur e
( Y
page 285).
The tire pressur e monitor is no t able to warn you
of a sudde n loss of pressure, e.g. if th e tire is
penetrated by a foreign object. In th e event of a
sudde n loss of pressure, brin g th e vehicl e to a
halt by braking carefully. Avoid abrup t steering
movements.
The tire pressur e monitor has a yellow warning
lamp in th e instrumen t cluste r for indicating
pressur e loss or a malfunction . Whether th e
warning lamp flashes or lights up indicates
whether a tire pressur e is to o low or th e tire
pressur e monitor is malfunctioning :R
if th e warning lamp is lit continuously, th e tire
pressur e on on e or mor e tires is significantly
to o low. The tire pressur e monitor is no t mal-
functioning . R
if th e warning lamp flashes for aroun d a
minute and then remain s lit constantly, th e
tire pressur e monitor is malfunctioning .
In addition to th e warning lamp , a message
appear s in th e multifunction display. Observ e290
Tire pressure
Wheels and tires

the information on display messages
( Y
page 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 X
Make sure that the SmartKey is in position 2
in the ignition lock ( Y
page 121).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 minute s, the Tire pressure will be
displayed after driving a few minutes
message 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 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 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 Tire Pressure message
appears in the multifunction display, the 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 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 values
for 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. X
Set 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 ( Y
page 285).
You can find more tire pressure values for
various operating conditions in the tire pres-
sure table inside the fuel filler flap
( Y
page 138). X
Make sure that the tire pressure is correct on
all four wheels.Tire pressure 291
Wheels and tires Z