2017 MERCEDES-BENZ GLC lights

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
PRE-SAF E ®
PLU SR
PRE-SAF E ®
BrakeR
COLLISION PREVENTION ASSIST 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 .
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 154).X
Switc h off th e engine.X
Clean all sensor s ( Y
page 315).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.
Fo r further information about th e restrain t system, see ( Y
page 43) .
u Front Lef t Malfunc‐
tio n Servic e
Required or Front
Right Malfunction
Servic e Required The restrain t system is malfunctioning 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. Display messages 23 5
On-board computer and displays Z

Display messages
Possible causes/consequences and P Solutions
u Rea r Lef t Malfunc‐
tio n Servic e
Required or Rea r
Right Malfunction
Servic e Required The rear left-han d or right-hand 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.
u Rea r Center Malfunc‐
tio n Servic e
Required The rear center 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.
u Lef t Sid e Curtai n
Airbag Malfunction
Servic e Required or
Right 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.236
Display messages
On-board computer and displays

Display messages
Possible causes/consequences and P Solutions
Fo r further information about th e Occupant Classification System, see
( Y
page 51) .
Lights Display messages
Possible causes/consequences and P Solutions
I Check Lef t Low Bea m
(Example) The bulb in question is malfunctioning .X
Visit a qualified specialist workshop .
or X
Chec k whether you are permitte d to replace th e bulb yourself
( Y
page 116).
i LE D ligh t sources: th e display message for th e correspondin g
lamp only appear s when all th e LEDs in th e lamp hav e failed.
I Active Headlamps
Inoperative The active ligh t function is malfunctioning .X
Visit a qualified specialist workshop .
I Malfunction See
Operator’ s Manual The exterio r lighting is malfunctioning .X
Visit a qualified specialist workshop .
Vehicles wit h trailer to w hitch : a fus e may hav e blown .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 154).X
Chec k th e fuses ( Y
page 333).X
If necessary, replace th e blown fuse. Observ e th e warning notes.
If th e display message remain s on show:X
Visit a qualified specialist workshop .
I Aut o Lam p Function
Inoperative The ligh t sensor is malfunctioning .X
Visit a qualified specialist workshop .
I Switch Off Lights You leav e th e vehicl e and th e lights are switched on . A warning tone
also sounds. X
Turn th e ligh t switch to th e X position .
I Switch On Headlamps You are drivin g wit h low-beam headlamp s switched off .X
Turn th e ligh t switch to th e X or X position .Display messages 23 9
On-board computer and displays Z

Safety systems Warning/
indicator
lamp Q Signal type
Possible causes/consequences and P Solutions
'M
Q ' (USA only), M (Canada only): the red brake system warning lamp is lit
while the engine is running.
A warning tone also sounds.
G WARNING
The brake boosting effect is malfunctioning and the braking characteristics may be
affected.
There is a risk of an accident. X
Pull over and stop the vehicle safely as soon as possible, paying attention to road
and traffic conditions. Do not continue driving under any circumstances. X
Secure the vehicle against rolling away ( Y
page 154).X
Consult a qualified specialist workshop. X
Observe the additional display messages in the multifunction display.
'M
Q ' (USA only), M (Canada only): the red brake system warning lamp lights
up while the engine is running.
A warning tone also sounds.
There is not enough brake fluid in the brake fluid reservoir.
G WARNING
The braking effect may be impaired.
There is a risk of an accident. X
Pull over and stop the vehicle safely as soon as possible, paying attention to road
and traffic conditions. Do not continue driving under any circumstances. X
Secure the vehicle against rolling away ( Y
page 154).X
Do not add brake fluid. Adding more will not correct the malfunction. X
Consult a qualified specialist workshop. X
Observe the additional display messages in the multifunction display.
'
Q USA only: the red brake system warning lamp is lit while the engine is running.
The multifunction display also shows a display message with the & symbol.
The brake pads/linings have reached their wear limit. X
Visit a qualified specialist workshop.258
Warning and indicator lamps in the instrument cluster
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.
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.268
Function restrictions
Multimedia system

Information on the message display can be
found in the "Checking the tire pressure elec-
tronically" section ( Y
page 345).
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 339). Note that the correct tire pressure
for the current operating situation must first be
taught-in to the tire pressure monitor. If a sub-
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 345). 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 339).
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
su dden loss of pressure, bring the vehicle to a
halt by braking carefully. Avoid abrupt steering
movements.344
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 250).
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 H
( Y
page 132) in the ignition lock. X
Press