warning lights MERCEDES-BENZ CLS 2017 Owner's Manual

Display messages
Possible causes/consequences and P Solutions
Radar Sensor s Dirty
See Operator' s Man ‐
ual The radar sensor system is malfunctioning .
Possibl e causes are: R
Dirt on sensor sR
Heavy rain or snow R
Whe n drivin g on inter-urban roads without traffic or infrastructure,
e.g. in desert-like area s
At least on e drivin g system or drivin g safet y system is malfunctioning
or is temporarily unavailable :R
COLLISION PREVENTION ASSIST PLU SR
PRE-SAF E ®
BrakeR
PRE-SAF E ®
PLU SR
Active Lan e Keepin g Assis tR
Active Blind Spot Assis tR
DISTRONI C PLU S wit h Steering Assis t and Stop&Go Pilo t
If th e radar sensor system in fron t is dirty, Active Blind Spot Assis t will
no t perfor m a course-correcting brak e application .
A warning tone also sounds.
Once th e caus e of th e problem is no longer present, th e drivin g and
drive safet y systems will be available again . The display message dis-
appears.
If th e display message does no t disappear :X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions.X
Secur e th e vehicl e against rollin g away ( Y
page 141).X
Switc h off th e engine.X
Clean all sensor s ( Y
page 274).X
Restart th e engine.
The display message disappears.
u SRS Malfunction Ser ‐
vic e Required The restrain t system is malfunctioning . The u warning lamp also
lights up in th e instrumen t cluster.
G WARNIN G
The air bags or Emergency Tensioning Devices may either be triggered
unintentionally or, in th e event of an accident, may no t be triggered .
There is an increased ris k of injury.X
Visit a qualified specialist workshop immediately.
Observ e th e additional information on restrain t systems ( Y
page 41).208
Display messages
On-board computer and displays

Display messages
Possible causes/consequences and P Solutions
u Front Lef t Malfunc‐
tio n Servic e
Required or F ron t
Right Malfunction
Servic e Required The restrain t system has malfunctioned at th e fron t on th e lef t or right .
The u warning lamp also lights up in th e instrumen t cluster.
G WARNIN G
The air bags or Emergency Tensioning Devices may either be triggered
unintentionally or, in th e event of an accident, may no t be triggered .
There is an increased ris k of injury.X
Visit a qualified specialist workshop immediately.
u Rea r Lef t Malfunc‐
tio n Servic e
Required or R ear
Right Malfunction
Servic e Required The restrain t system has malfunctioned at th e rear on th e lef t or right .
The u warning lamp also lights up in th e instrumen t cluster.
G WARNIN G
The air bags or Emergency Tensioning Devices may either be triggered
unintentionally or, in th e event of an accident, may no t be triggered .
There is an increased ris k of injury.X
Visit a qualified specialist workshop immediately.
u Lef t Sid e Curtai n
Airbag Malfunction
Servic e
Required or R igh t
Sid e Curtai n Airbag
Malfunction Servic e
Required The left-han d or right-hand window curtai n air bag is malfunctioning .
The u warning lamp also lights up in th e instrumen t cluster.
G WARNIN G
The lef t or right window curtai n air bag may either be triggered unin-
tentionally or, in th e event of an accident, may no t be triggered .
There is an increased ris k of injury.X
Visit a qualified specialist workshop immediately. Display messages 20 9
On-board computer and displays Z

Lights Display messages
Possible causes/consequences and P Solutions
I Check Left Low Beam The bulb in question is malfunctioning. X
Visit a qualified specialist workshop.
i LED light sources: the display message for the corresponding
lamp only appears when all the LEDs in the lamp have failed.
I Active Headlamps
Inoperative The active light function is faulty. X
Visit a qualified specialist workshop.
I Malfunction See
Operator's Manual The exterior lighting is malfunctioning. X
Visit a qualified specialist workshop.
I Auto Lamp Function
Inoperative The light sensor is defective. X
Visit a qualified specialist workshop.
I Switch Off Lights You leave the vehicle and the lights are switched on. A warning tone
also sounds. X
Turn the light switch to position X .
Adaptive Highbeam
Assist Currently
Unavailable See
Operator's Manual Adaptive Highbeam Assist is deactivated and temporarily inoperative.
Possible causes are: R
the windshield in the camera's field of vision is dirty R
visibility is impaired due to heavy rain, snow or fog X
Clean the windshield.
If the system detects that the camera is fully operational again, the
Adaptive Highbeam Assist Now Available message is displayed.
Adaptive Highbeam Assist is operational again.
Adaptive Highbeam
Assist Inoperative Adaptive Highbeam Assist is faulty. X
Visit a qualified specialist workshop.212
Display messages
On-board computer and displays

General notes The multimedia system section in this Opera-
tor's Manual describes the basic principles for
operation. More information can be found in the
Digital Operator's Manual.
Important safety notes
G WARNING
If you operate information systems and com-
munication equipment integrated in the vehi-
cle while driving, you will be distracted from
traffic conditions. You could also lose control
of the vehicle. There is a risk of an accident.
Only operate the equipment when the traffic
situation permits. If you are not sure that this
is possible, park the vehicle paying attention
to traffic conditions and operate the equip-
ment when the vehicle is stationary.
You must observe the legal requirements for the
country in which you are currently driving when
operating the multimedia system.
The multimedia system calculates the route to
the destination without taking the following into
account, for example: R
traffic lights R
stop and yield signs R
parking or stopping restrictions R
road narrowing R
other road and traffic rules and regulations
The multimedia system may give incorrect nav-
igation recommendations if the actual street/
traffic situation does not correspond with the
digital map's data.
For example: R
a diverted route R
the road layout or the direction of a one-way
street has been changed
For this reason, you must always observe road
and traffic rules and regulations during your
journey. Road and traffic rules and regulations
always have priority over multimedia system
driving recommendations.
Navigation announcements are intended to
direct you while driving without diverting your
attention from the road and driving. Please always use this feature instead of con-
sulting the map display for directions. Looking
at the icons or map display can distract you from
traffic conditions and driving, and increase the
risk of an accident.
This equipment complies with FCC radiation
exposure limits set forth for uncontrolled equip-
ment and meets the FCC radio frequency (RF)
Exposure Guidelines in Supplement C to OET65.
This equipment has very low levels of RF energy
that is deemed to comply without maximum
permissive exposure evaluation (MPE). How-
ever, it is recommended to insta ll it at a distance
of
at least 8 inches (approx. 20 cm) between the
radiation source and a person's body (not
including limbs such as hands, wrists, feet and
legs).
G WARNING
Modifications to electronic components, their
software as well as wiring can impair their
function and/or the function of other net-
worked components. In particular, systems
relevant to safety could also be affected. As a
result, these may no longer function as inten-
ded and/or jeopardize the operating safety of
the vehicle. There is an increased risk of an
accident and injury.
Never tamper with the wiring as well as elec-
tronic components or their software. You
should have all work to electrical and elec-
tronic equipment carried out at a qualified
specialist workshop.
If you make any changes to the vehicle elec-
tronics, the general operating permit is ren-
dered invalid.
Function restrictions
For safety reasons, some functions are restric-
ted or unavailable while the vehicle is in motion.
You will notice this, for example, because either
you will not be able to select certain menu items
or a message will appear to this effect.236
Function restrictions
Multimedia system

For information on the message display, refer to
the "Checking the tire pressure electronically"
section ( Y
page 301).
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 a different size than
the size indicated on the Tire and Loading
Information placard or, if available, the tire
pressure label, you should determine the
proper tire pressure for those tires.
As an added safety feature, your vehicle has
been equipped with a tire pressure monitoring
system (TPMS) that illuminates a low 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, and inflate them to the proper
pressure. Driving on a significantly 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 a substitute 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 a malfunction, the warning lamp
will flash for approximately a minute 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 a variety of
reasons, including the installation of incom-
patible replacement or alternate tires or
wheels on the vehicle that prevent the TPMS
from functioning properly. 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 295). Note that the correct tire pressure
for the current operating situation must first be
taught-in to the tire pressure monitor. If there is
a substantial loss of pressure, the warning
threshold for the warning message is aligned to
the reference values taught-in. Restart the tire
pre ssure moni tor after adjusting the pressure of
the
cold tires ( Y
page 302). The current pres-
sures are saved as new reference values. As a
result, a warning message will appear if the 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 295).
The tire pressure monitor is not able to warn you
of a sudden loss of pressure, e.g. if the tire is
penetrated by a foreign object. In the event of a
sudden loss of pressure, bring the vehicle to a
halt by braking carefully. Avoid abrupt steering
movements.300
Tire pressure
Wheels and tires

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 around 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 221).
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 123).X
Press the Y or e button on the steering
wheel to select the Service 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 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 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 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 oppor-
tunity arises. R
If the Check Tires 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 Warning Tire Malfunction message
appears in the multifunction display, the tire
pressure in one or more tires is dropping sud-
denly. The tires must be checked.
Observe the instructions and safety notes in the
display messages in the "Tires" section
( Y
page 221).
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. Tire pressure 301
Wheels and tires Z