warning light MERCEDES-BENZ CLA 2017 Service Manual

i Parking Assist PARKTRONIC is automati-
cally activated when you turn the SmartKey to
position 2 in the ignition lock.
Problems with Parking Assist PARKTRONIC Problem
Possible causes/consequences and P Solutions
Only the red segments in
the Parking Assist
PARKTRONIC warning
displays are lit. You also
hear a warning tone for
approximately two sec-
onds.
Parking Assist
PARKTRONIC is then
deactivated and the indi-
cator lamp on the
PARKTRONIC button
lights up. Parking Assist PARKTRONIC has malfunctioned and has been deacti-
vated. X
If problems persist, have Parking Assist PARKTRONIC checked at a
qualified specialist workshop.
Only the red segments in
the Parking Assist
PARKTRONIC warning
displays are lit. Parking
Assist PARKTRONIC is
then deactivated. The Parking Assist PARKTRONIC sensors are dirty or there is inter-
ference. X
Clean the Parking Assist PARKTRONIC sensors ( Y
page 262).X
Switch the ignition back on.
The problem may be caused by an external source of radio or ultra-
sound waves. X
Check to see if Parking Assist PARKTRONIC works at a different
location.
Parking Pilot
General notes Parking Pilot is an electronic parking aid with
ultrasound. It measures the road on both sides
of the vehicle. A parking symbol indicates a suit-
able parking space. Active steering intervention
and brake application can assist you during
parking and when exiting a parking space. Park-
ing Assist PARKTRONIC is also available
( Y
page 160).
Important safety notes
Parking Pilot is only an aid. It is not a replace-
ment for your attention to your immediate sur-
roundings. You are always responsible for safe
maneuvering, parking and exiting a parking
space. Make sure that no persons, animals or
objects are in the maneuvering range. When Parking Assist PARKTRONIC is deactiva-
ted, Parking Pilot is also unavailable.
G WARNING
While parking or pulling out of a parking
space, the vehicle swings out and can drive
onto areas of the oncoming lane. This could
result in a collision with another road user.
There is a risk of an accident.
Pay attention to other road users. Stop the
vehicle if necessary or cancel the Parking Pilot
parking procedure.
! If unavoidable, you should drive over obsta-
cles such as curbs slowly and not at a sharp
angle. Otherwise, you may damage the
wheels or tires.162
Driving systems
Driving and parking

Blind Spot Assist monitors the area up to 10 ft
(3 m) behind your vehicle and directly next to it.
If the lanes are narrow, vehicles driving in the
lane beyond the lane next to your vehicle may be
indicated, especially if the vehicles are not driv-
ing in the middle of their lane. This may be the
case if the vehicles are driving on the inner side
of their lane.
Due to the nature of the system: R
warnings may be issued in error when driving
close to crash barriers or similar solid lane
borders. R
warnings may be interrupted when driving
alongside particularly long vehicles, e.g.
trucks, for a prolonged time.
Warning display
C
Warning display
Blind Spot Assist is not active at speeds below
approximately 20 mph (30 km/h). Vehicles in
the monitoring range are then not indicated.
When Blind Spot Assist is activated, indicator
lamp C in the exterior mirrors lights up yellow
at speeds of up to 20 mph (30 km/h). At speeds
above 20 mph (30 km/h), the indicator lamp
goes out and Blind Spot Assist is operational.
If a vehicle is detected within the blind spot
monitoring range at speeds above 20 mph
(30 km/h), warning lamp C on the correspond-
ing side lights up red. This warning is always
emitted when a vehicle enters the blind spot
monitoring range from behind or from the side.
When you overtake a vehicle, the warning only
occurs if the difference in speed is less than
7 mph (12 km/h).
The yellow indicator lamp goes out if reverse
gear is engaged. In this event, Blind Spot Assist
is no longer active. The brightness of the indicator/warning lamps
is adjusted automatically according to the ambi-
ent light.
Collision warning If a vehicle is detected in the monitoring range of
Blind Spot Assist and you switch on the corre-
sponding turn signal, a double warning tone
sounds. Red warning lamp C flashes. If the turn
signal remains on, vehicles detected are indica-
ted by the flashing of red warning lamp C .
There are no further warning tones.
Switching on Blind Spot Assist X
Make sure that Blind Spot Assist is activated
in the on-board computer ( Y
page 183).X
Turn the SmartKey to position 2 in the ignition
lock.
Warning lamps C in the exterior mirrors light
up red for approximately 1.5 seconds and
then turn yellow.
Lane Keeping Assist
General notes
Lane Keeping Assist monitors the area in front of
your vehicle by means of multifunction cam-
era C which is attached behind the top of the
windshield. Active Lane Keeping Assist detects
lane markings on the road and can warn you
before you leave your lane unintentionally.
This function is available in the range between
40 mph and 120 mph (60 km/h and 200 km/h).
A warning may be given if a front wheel passes
over a lane marking. It will warn you by means of
intermittent vibration in the steering wheel for
up to 1.5 seconds.172
Driving systems
Driving and parking

Important safety notes
G WARNIN G
If you operate information systems and com-
munication equipmen t integrate d in th e vehi-
cle while driving , you will be distracte d from
traffic conditions. You could also lose control
of th e vehicle. Ther e is a ris k of an accident.
Only operate th e equipmen t when th e traffic
situation permits. If you are no t sur e that this
is possible , park th e vehicl e payin g attention
to traffic condition s and operate th e equip-
men t when th e vehicl e is stationary.
You must observ e th e legal requirements for th e
country in whic h you are currentl y driving when
operating th e on-board computer.
G WARNIN G
If th e instrumen t cluste r has faile d or mal-
functioned, you may no t recognize function
restriction s in systems relevan t to safety. The
operating safet y of your vehicl e may be
impaired . Ther e is a ris k of an accident.
Drive on carefully. Hav e th e vehicl e checke d
at a qualified specialist workshop immedi-
ately.
The on-board computer only shows message s or
warning s from certain systems in th e multifunc-
tion display. You should therefor e mak e sur e
your vehicl e is operating safely at all times .
If th e operating safet y of your vehicl e is
impaired , pull ove r as soo n as it is saf e to do so.
Contac t a qualified specialist workshop.
Fo r an overview, see th e instrumen t panel illus-
tration ( Y
page 32).
Displays and operation
Instrument cluster lighting
The ligh t sensor in th e instrumen t cluste r auto -
matically control s th e brightness of th e multi-
function display. In daylight, th e displays in th e
instrumen t cluste r are no t illuminated.
The lighting in th e instrumen t cluster, in th e dis-
plays and th e control s in th e vehicl e interior can
be adjusted usin g th e brightness control knob. The brightness control knob is locate d on th e
botto m lef t of th e instrumen t cluste r
( Y
page 32). X
Turn th e brightness control knob clockwise or
counter-clockwise.
If th e ligh t switch is set to th e X , ` or
X position , th e brightness is dependen t
upon th e brightness of th e ambien t light.
Speedometer with segments The speedometer is divided int o segments on
vehicles wit h Distanc e Pilot DISTRONIC.
The segments in th e speedometer indicat e
whic h spee d range is available. R
Distanc e Pilot DISTRONI C is activated
( Y
page 150):
On e or two segments in th e set spee d range
ligh t up. R
Distanc e Pilot DISTRONI C detects a vehicl e in
fron t moving mor e slowly than th e store d
speed:
The segments between th e spee d of th e vehi-
cle in fron t and th e store d spee d ligh t up.
Tachometer
! Do no t driv e in th e overrevving range, as this
could damag e th e engine.
The red ban d in th e tachometer indicates th e
engine's overrevving range.
The engin e is limite d within a range to protect
th e engin e when th e red ban d is reached.
Outside temperature display You should pay special attention to road condi-
tion s when temperatures are aroun d freezing
point.
Bea r in min d that th e outside temperature dis-
play indicates th e temperature measured and
does no t record th e road temperature.
The outside temperature display is in th e multi-
function display ( Y
page 176).
Ther e is a short delay before a chang e in outside
temperature appear s in th e multifunction dis-
play.174
Displays and operation
On-board computer and displays

Display messages
Possible causes/consequences and P Solutions
The yellow $ warning lamp and th e red I (US A only) or $
(Canada only) indicator lamp ligh t up.
The electric parking brak e is malfunctioning .
To release: X
Switc h off th e ignition and tur n it bac k on .X
Releas e th e electric parking brak e manually.
or X
Releas e th e electric parking brak e automatically ( Y
page 141).
If th e electric parking brak e still canno t be released:X
Do no t drive on .X
Consult a qualified specialist workshop .
The red I (US A only) or $ (Canada only) indicator lamp flashes
and th e yellow $ warning lamp lights up.
The electric parking brak e is malfunctioning .
To release: X
Switc h off th e ignition and tur n it bac k on .X
Releas e th e electric parking brak e manually.
To apply : X
Switc h off th e ignition and tur n it bac k on .X
Apply th e electric parking brak e manually.
If th e red I (US A only) or $ (Canada only) indicator lamp con-
tinue s to flash: X
Do no t drive on .X
Secur e th e vehicl e against rollin g away ( Y
page 302).X
Shift th e transmission to position P .X
Turn th e fron t wheels toward s th e curb.X
Consult a qualified specialist workshop .192
Display messages
On-board computer and displays

Display messages
Possible causes/consequences and P Solutions
The yellow $ warning lamp lights up. The red I (US A only)
or $ (Canada only) indicator lamp flashes for about te n seconds
after th e electric parking brak e has been applie d or released. It then
goe s out or remain s lit .
The electric parking brak e is malfunctioning .X
Switc h off th e ignition and tur n it bac k on .X
Apply th e electric parking brake.
If it is no t possibl e to engage th e electric parking brake:X
Shift th e transmission to position P .X
Visit a qualified specialist workshop .
If it is no t possibl e to release th e electric parking brak e manually:X
Releas e th e electric parking brak e automatically ( Y
page 141).
If th e electric parking brak e still canno t be released:X
Consult a qualified specialist workshop .
The yellow $ warning lamp lights up. If you manually apply or
release th e electric parking brake, th e red I (US A only) or $
(Canada only) indicator lamp flashes .
The electric parking brak e is malfunctioning . It is no t possibl e to apply
th e electric parking brak e manually.X
Shift th e selector lever to P , as th e electric parking brak e is no t
applie d automatically. X
Visit a qualified specialist workshop .
I (USA
only)
$ ( Canada
only)
Parkin g Brake Inop‐
erativ e The yellow $ warning lamp lights up. The red I (US A only)
or $ (Canada only) indicator lamp flashes for about te n seconds
after th e electric parking brak e has been applie d or released. It then
goe s out or remain s lit .
The electric parking brak e is malfunctioning , e.g. because of over-
voltag e or undervoltage. X
Remove th e caus e for th e overvoltage or undervoltage, e.g. by
charging th e battery or restarting th e engine.X
Engage or release th e electric parking brake.
If it remain s impossible to apply or release th e electric parking brake:X
Switc h off th e ignition and tur n it bac k on .X
Engage or release th e electric parking brake.
If th e electric parking brak e still canno t be released:X
Consult a qualified specialist workshop .
If th e electric parking brak e still canno t be applied:X
Visit a qualified specialist workshop .Display messages 19 3
On-board computer and displays Z

Display messages
Possible causes/consequences and P Solutions
The yellow $ warning lamp lights up and th e red I (US A only)
or $ (Canada only) indicator lamp flashes .
It is no t possibl e to apply th e electric parking brak e manually.X
Shift th e transmission to position P .X
Visit a qualified specialist workshop .
' (USA
only)
M ( Canada
only)
Check Brake Fluid
Level There is no t enough brak e fluid in th e brak e fluid reservoir .
A warning tone sounds. The ' (US A only) or M (Canada only)
warning lamp s in th e instrumen t cluste r may also ligh t up.
G WARNIN G
The braking effec t may be impaired.
There is a ris k of an accident.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. Do no t continu e drivin g
under any circumstances. X
Secur e th e vehicl e against rollin g away ( Y
page 140).X
Consult a qualified specialist workshop .X
Do no t add brak e fluid . This does no t correc t th e malfunction .
& Check Brake Pad Wea r The brak e pads/linings hav e reached their wear limit.X
Visit a qualified specialist workshop .
S Inoperative On e or mor e main features of th e mbrace system are malfunctioning .X
Visit a qualified specialist workshop .
Active Brake Assist
Functions Currently
Limite d See Opera‐
tor's Manual Active Brake Assis t is temporarily inoperative.
Possibl e causes are: R
th e radar sensor system is temporarily inoperative, e.g. due to elec -
tromagneti c radiation emitted by nearby TV or radi o station s or
other source s of electromagneti c radiationR
th e system is outside th e operating temperature rangeR
th e on-boar d voltag e is to o low
Whe n th e causes state d abov e no longer apply, th e display message
disappears.
Active Brake Assis t is operational again .
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 140).X
Restart th e engine.
Active Brake
Assist : System Inop‐
erativ e Active Brake Assis t is unavailable due to a malfunction . Situation -
dependen t parking assistanc e may also hav e failed.X
Visit a qualified specialist workshop immediately.194
Display messages
On-board computer and displays

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
Active Brake Assis tR
Distanc e Pilo t DISTRONI C
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 140).X
Switc h off th e engine.X
Clean all sensor s ( Y
page 262).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 39) .
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 19 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 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.196
Display messages
On-board computer and displays

Display messages
Possible causes/consequences and P Solutions
I Check Front Lef t
Sidemarke r Lam p or
Check Front Right
Sidemarke r Lam p The fron t left-han d or fron t right-hand side marke r lamp is faulty.X
Visit a qualified specialist workshop .
I Check Rea r Lef t
Sidemarke r Lam p or
Check Rea r Right
Sidemarke r Lam p The rear left-han d or rear right-hand side marke r lamp is faulty.X
Visit a qualified specialist workshop .
I Check Lef t Daytim e
Runnin g Light or
Check Right Daytim e
Runnin g Light The lef t or right-hand daytime runnin g lamp is faulty.X
Chec k whether you are permitte d to replace th e bulb yourself
( Y
page 103).
or X
Visit a qualified specialist workshop .
I Active Headlamps
Inoperative The active ligh t function is faulty.X
Visit a qualified specialist workshop .
I Malfunction See
Operator' s Manual The exterio r lighting is malfunctioning .X
Visit a qualified specialist workshop .
I Aut o Lam p Function
Inoperative The ligh t sensor is defective. X
Visit a qualified specialist workshop .
I Switch Off Lights The lights are still switched on when you leav e th e vehicle. 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 20 1
On-board computer and displays Z

Warning and indicator lamps in the instrument cluster
General notes Some systems carry out a self-diagnosis when the ignition is switched on. Therefore, some indicator
and warning lamps may light up or flash temporarily. This behavior is non-critical.
These indicator and warning lamps only indicate a malfunction if they light up or flash after starting
the engine or whilst driving.
Safety
Seat belts Warning/
indicator
lamp Q Signal type
Possible causes/consequences and P Solutions