brake MERCEDES-BENZ GLC 2017 Repair Manual

When Standard is selected, no warning vibra-
tion occurs if: R
you switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time. R
a driving safety system intervenes, e.g. ABS,
BAS or ESP ®
.
Adaptive
When Adaptive is selected, no warning vibra-
tion occurs if: R
you switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time. R
a driving safety system intervenes, e.g. ABS,
BAS or ESP ®
.R
you accelerate hard, e.g. kickdown. R
you brake hard. R
you steer actively, e.g. swerve to avoid an
obstacle or change lanes quickly. R
you cut the corner on a sharp bend.
In order that you are warned only when neces-
sary and in good time if you cross the lane mark-
ing, the system recognizes certain conditions
and warns you accordingly.
The warning vibration occurs earlier if: R
you approach the outer lane marking on a
bend. R
the road has very wide lanes, e.g. a highway. R
the system detects solid lane markings.
The warning vibration occurs later if: R
the road has narrow lanes. R
you cut the corner on a bend.
Driving Assistance PLUS package
General notes The Driving Assistance PLUS package consists
of DISTRONIC PLUS ( Y
page 164), Active Blind
Spot Assist ( Y
page 197) and Active Lane Keep-
ing Assist ( Y
page 200).
Active Blind Spot Assist
General notes
Active Blind Spot Assist uses a radar sensor
system, pointed toward the rear of the vehicle,
to monitor the area to the sides of the vehicle
which the driver is unable to see. A warning lamp lights up in the exterior mirrors and draws your
attention to vehicles detected in the monitored
area. If you then switch on the corresponding
turn signal to change lane, you will also receive
an optical and audible warning. If a risk of lateral
collision is detected, corrective braking may
help you avoid a collision. Before a course-cor-
recting brake application, Active Blind Spot
Assist evaluates the space in the direction of
travel and at the sides of the vehicle. For this,
Active Blind Spot Assist uses the forward-facing
radar sensors.
Active Blind Spot Assist supports you from a
speed of approximately 20 mph (30 km/h).
Important safety notes Active Blind Spot Assist is only an aid and is not
a substitute for attentive driving.
G WARNING
Active Blind Spot Assist does not react to: R
vehicles overtaken too closely on the side,
placing them in the blind spot area R
vehicles which approach with a large speed
differential and overtake your vehicle
As a result, Active Blind Spot Assist may nei-
ther give warnings nor intervene in such sit-
uations. There is a risk of an accident.
Always observe the traffic conditions care-
fully, and maintain a safe lateral distance.
i USA only: This device has been approved by
the FCC as a "Vehicular Radar System". The
radar sensor is intended for use in an auto-
motive radar system only. Removal, tamper-
ing, or altering of the device will void any war-
ranties, and is not permitted by the FCC. Do
not tamper with, alter, or use in any non-
approved way.
Any unauthorized modification to this device
could void the user's authority to operate the
equipment.
i Canada only: This device complies with
RSS-210 of Industry Canada. Operation is
subject to the following two conditions:
1. This device may not cause interference,
and
2. This device must accept any interference
received, including interference that may
cause undesired operation of the device.Driving systems 197
Driving and parking Z

If you select the reverse gear, Active Blind Spot
Assist is not operational.
The brightness of the warning lamps is auto-
matically adapted to the brightness of the sur-
roundings.
When Active Blind Spot Assist is activated, gray
radar waves propagating backward appear next
to the vehicle in the assistance display in the
multifunction display. Above a speed of 20 mph
(30 km/h), the color of the radar waves in the
assistance display changes to green D . Active
Blind Spot Assist is then ready for use.
Visual and acoustic collision warning If you switch on the turn signals to change lanes
and a vehicle is detected in the side monitoring
range, you receive a visual and acoustic collision
warning. You will then hear a double warning
tone and red warning lamp C flashes. If the turn
signal remains on, detected vehicles are indica-
ted by the flashing of red warning lamp C .
There are no further warning tones.
Course-correcting brake application
If Active Blind Spot Assist detects a risk of a lat-
eral collision in the monitoring range, a course-
correcting brake application is carried out. This
is meant to assist you in avoiding a collision.
G WARNING
A course-correcting brake application cannot
always prevent a collision. There is a risk of an
accident.
Always steer, brake or accelerate yourself,
especially if Active Blind Spot Assist warns
you or makes a course-correcting brake appli-
cation. Always maintain a safe distance at the
sides. If a course-correcting brake application occurs,
red warning lamp C flashes in the exterior mir-
ror and a double warning tone sounds. In addi-
tion, a display underlining the danger of a side
collision appears in the multifunction display.
In very rare cases, the system may make an
inappropriate brake application. A course-cor-
recting brake application may be interrupted at
any time by countersteering slightly or acceler-
ating.
The course-correcting brake application is avail-
able in the speed range between 20 mph
(30 km/h) and 120 mph (200 km/h).
Either no braking application, or a course-cor-
recting brake application adapted to the driving
situation occurs if: R
there are vehicles or obstacles, e.g. crash
barriers, located on both sides of your vehicle. R
a vehicle approaches you too closely at the
side. R
you have adopted a sporty driving style with
high cornering speeds. R
you clearly brake or accelerate. R
a driving safety system intervenes, e.g. ESP ®
or PRE-SAFE ®
Brake. R
ESP ®
is switched off. R
a loss of tire pressure or a defective tire is
detected.
Switching on Active Blind Spot Assist X
Make sure that Active Blind Spot Assist is
activated in the on-board computer
( Y
page 221). X
Switch on the ignition.
Warning lamps C in the exterior mirrors light
up red for approximately 1.5 seconds.
Gray radar waves propagating backwards
appear next to the vehicle in the assistance
graphic in the multifunction display D .
Above a speed of 20 mph (30 km/h), the color
of the radar waves in the assistance display
changes to green D . Active Blind Spot Assist
is then ready for use.Driving systems 199
Driving and parking Z

Active Lane Keeping Assist Genera l notes
Active Lan e Keepin g Assis t monitors th e area in
fron t of your vehicl e by mean s of multifunction
camera C at th e to p of th e windshield. Various
differen t areas to th e front, rear and side of your
vehicl e are also monitore d wit h th e aid of th e
radar sensor system. Active Lan e Keepin g
Assis t detects lan e marking s on th e road and
can warn you before you leav e your lan e unin-
tentionally. If you do no t reac t to th e warning , a
lane-correcting application of th e brakes can
bring th e vehicl e bac k int o th e original lane.
This function is available in th e range between
40 mph and 12 0 mph (60 km/h and 20 0 km/h).
Important safety notes If you fail to adapt your drivin g style, Active Lan e
Keepin g Assis t can neither reduce th e ris k of an
acciden t no r override th e laws of physics . Active
Lan e Keepin g Assis t canno t tak e accoun t of
road and weather conditions. It may no t recog-
niz e traffic situations. Active Lan e Keepin g
Assis t is only an aid. You are responsibl e for th e
distanc e to th e vehicl e in front, for vehicl e
speed, for braking in goo d time and for stayin g in
your lane.
Active Lan e Keepin g Assis t canno t continuously
keep your vehicl e in it s lane.
G WARNIN G
Active Lan e Keepin g Assis t canno t always
clearly detec t lan e markings. In suc h cases, Active Lan e Keepin g Assis t
can : R
giv e an unnecessary warning and then
mak e a course-correcting brak e application
to th e vehicl e R
no t giv e a warning or interven e
There is a ris k of an accident.
Always pay particular attention to th e traffic
situation and keep within th e lane, especially
if Active Lan e Keepin g Assis t alerts you. Ter -
minate th e intervention in a non-critical driv-
ing situation .
The system may be impaire d or may no t function
if: R
there is poor visibility, e.g. due to insufficien t
illumination of th e road , or due to snow, rain ,
fog or spray R
there is glare, e.g. from oncomin g traffic, th e
sun or reflection from other vehicles (e.g. if
th e road surfac e is wet )R
th e windshield is dirty, fogged up, damaged or
covered, for instance by a sticker, in th e vicin-
it y of th e camera R
th e radar sensor s in th e fron t or rear bumpers
or th e radiato r trim are dirty, e.g. obscured by
snow R
there are no , several or unclear lan e marking s
for a lane, e.g. in areas wit h road construction
wor k R
th e lan e marking s are wor n away, dark or cov-
ere d up, e.g. by dir t or snowR
th e distanc e to th e vehicl e in fron t is to o small
a nd th e lan e marking s thus canno t be detec -
te d R
th e lan e marking s chang e quickly, e.g. lanes
branch off , cross on e another or mergeR
th e road is narrow and windin gR
there are highly variable shad e condition s on
th e roadway
If no vehicl e is detecte d in th e adjacent lan e and
broke n lan e marking s are detected, no lane-cor-
recting brak e application is made .
Warning vibration in th e steering wheel
A warning may be given if a fron t whee l passes
ove r a lan e marking . It will warn you by mean s of
intermittent vibration in th e steering whee l for
up to 1. 5 seconds.200
Driving systems
Driving and parking

Lane-correcting brake application If you leave your lane, under certain circumstan-
ces the vehicle will brake briefly on one side.
This is meant to assist you in bringing the vehicle
back to the original lane.
G WARNING
A lane-correcting brake application cannot
always bring the vehicle back into the original
lane. There is a risk of an accident.
Always steer, brake or accelerate yourself,
especially if Active Lane Keeping Assist warns
you or makes a lane-correcting brake appli-
cation.
If a lane-correcting brake application occurs,
display C appears in the multifunction display.
The brake application also slightly reduces vehi-
cle speed.
A lane-correcting brake application can be made
after driving over a lane marking detected as
being solid or broken. Before this, a warning
must be given by means of intermittent vibration
in the steering wheel. In addition, a lane with
lane markings on both sides must be recog-
nized.
In the case of a broken lane marking being
detected, a lane-correcting brake application
can only be made if a vehicle has been detected
in the adjacent lane. Oncoming vehicles, over-
taking vehicles and vehicles in adjacent lanes
can be detected.
A further lane-correcting brake application can
only occur after your vehicle has returned to the
original lane.
No lane-correcting brake application occurs if: R
you clearly and actively steer, brake or accel-
erate. R
you cut the corner on a sharp bend. R
you have switched on the turn signal. R
a driving safety system intervenes, e.g. ESP ®
,
PRE-SAFE ®
Brake or Active Blind Spot Assist. R
you have adopted a sporty driving style with
high cornering speeds or high rates of accel-
eration. R
ESP ®
is switched off. R
the transmission is not in position [ .R
on vehicles with a trailer tow hitch, the elec-
trical connection to the trailer has been cor-
rect ly established. R
a loss of tire pressure or a defective tire has
been detected and displayed. R
an obstacle has been detected in the lane in
which you are driving.
Active Lane Keeping Assist may not detect other
road users or traffic situations. An inappropriate
brake application may be interrupted at any time
if you: R
steer slightly in the opposite direction. R
switch on the turn signal. R
you brake or accelerate significantly.
A lane-correcting brake application is interrup-
ted automatically if: R
a driving safety system intervenes, e.g. ESP ®
,
PRE-SAFE ®
Brake or Active Blind Spot Assist. R
lane markings are no longer detected.
Activating/deactivating Active Lane
Keeping Assist
X
To activate: press button D .
Indicator lamp C lights up. The Lane Keep‐
ing Assist On message appears on the
multifunction display. If all conditions have
been satisfied, a warning or steering inter-
vention may be made.
If you drive at speeds above 40 mph
(60 km/h) and lane markings are detected,Driving systems 201
Driving and parking Z

the lines in the assistance graphic
( Y
page 219) appear in green. Active Lane
Keeping Assist is ready for use. X
To deactivate: press button D .
Indicator lamp C goes out. The Active Lane
Keeping Assist is deactivated. The Lane
Keeping Assist Off message appears on
the multifunction display.
Selecting Standard or Adaptive setting X
In the DriveAssist menu on the on-board
computer, select the Active Lane Keep‐
ing Assist function ( Y
page 221).X
Select setting Standard or Adaptive .
When Standard is selected, no warning vibra-
tion occurs if: R
you switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time. R
a driving safety system intervenes, such as
ABS, BAS or ESP ®
.
When Adaptive
is selected, no warning vibra-
tion occurs if: R
you switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time. R
a driving safety system intervenes, e.g.
ABS, BAS or ESP ®
.R
you accelerate hard, e.g. kickdown. R
you brake hard. R
you steer actively, e.g. swerve to avoid an
obstacle or change lanes quickly. R
you cut the corner on a sharp bend.
In order that you are warned only when neces-
sary and in good time if you cross the lane mark-
ing, the system recognizes certain conditions
and warns you accordingly.
The warning vibration occurs earlier if: R
you approach the outer lane marking on a
bend. R
the road has very wide lanes, e.g. a highway. R
the system detects solid lane markings.
The warning vibration occurs later if: R
the road has narrow lanes. R
you cut the corner on a bend.
Towing a trailer
When you attach a trailer, make sure you have
correctly established the electrical connection. This can be accomplished by checking the trailer
lighting.
Towing a trailer
Important safety notes
G WARNING
Installing an unsuitable ball coupling may
result in overloading of the trailer tow hitch
and the rear axle. This applies especially if the
ball coupling in question is longer or angled
differently. This could seriously impair the
driving characteristics and the trailer can
come loose. There is a risk of an accident.
You should only ever install a ball coupling
that has the permissible dimensions and that
is designed to meet your trailer-towing
requirements. Do not modify the ball coupling
or the trailer tow hitch.
You will find the values approved by the manu-
facturer on the vehicle identification plates and
those for the towing vehicle under "Technical
data" ( Y
page 371).
G WARNING
When the vehicle/trailer combination begins
to lurch, you could lose control of it. The vehi-
cle/trailer combination could even rollover.
There is a risk of an accident.
On no account should you attempt to
straighten up the vehicle/trailer combination
by increasing the speed. Reduce vehicle
speed and do not countersteer. Apply the
brake as necessary.
! If you have a trailer tow hitch retrofitted,
changes to the engine cooling system may be
necessary, depending on the vehicle type.
If you have a trailer tow hitch retrofitted,
observe the anchorage points on the chassis
frame.
The installation of a trailer tow hitch is only per-
missible if a towing weight is specified in your
vehicle documents. If this is not the case, then
the vehicle is not approved for the towing of a
trailer.202
Towing a trailer
Driving an d parking

which the maximum permissible speed for vehi-
cle/trailer combinations is above 60 mph
(100 km/h).
When towing a trailer, your vehicle's handling
characteristics will be different in comparison to
when driving without a trailer and it will con-
sume more fuel.
Shift to a lower gear on long and steep downhill
gradients.
This also applies to: R
activated DISTRONIC PLUS R
activated cruise control
This will use the braking effect of the engine, so
that less braking will be required to maintain the
speed. This relieves the load on the brake sys-
tem and prevents the brakes from overheating
and wearing too quickly. If you need additional
braking, depress the brake pedal repeatedly
rather than continuously.
Driving tips If the trailer swings from side to side: X
Do not accelerate. X
Do not counter-steer. X
Brake if necessary. R
Maintain a greater distance from the vehicle
in front than when driving without a trailer. R
Avoid braking abruptly. If possible, brake gen-
tly at first to allow the trailer to run on. Then,
increase the braking force rapidly. R
The values given for gradient-climbing capa-
bilities from a standstill refer to sea level.
When driving in mountainous areas, note that
the power output of the engine and, conse-
quently, the vehicle's gradient-climbing capa-
bility, decreases with increasing altitude.
Installing the ball coupling
G WARNING
If the ball coupling is not correctly installed
and secured, it could come loose while driving
and endanger other road users. There is a risk
of an accident and injury.
Install and secure the ball coupling as descri-
bed in the ball coupling manufacturer's instal-
lation instructions. Make sure that the ball coupling is correctly installed and secured
before every journey.
G WARNING
If the ball coupling is not installed and secured
correctly the trailer may come loose. There is
a risk of an accident.
Install and secure the ball coupling as descri-
bed in the ball coupling installation instruc-
tions. Make sure that the ball coupling is
installed and secured correctly before every
journey.
X
Pull protective cap C in the direction of the
arrow, out of the ball coupling recess. X
Stow protective cap C so that it cannot be
thrown around. X
Observe the manufacturer's installation
instructions.
Observe the loading guidelines ( Y
page 278)
and the safety notes regarding stowage
spaces ( Y
page 278).
Coupling up a trailer
! Do not connect the trailer's brake system (if
featured) to the hydraulic brake system of the
towing vehicle, as the latter is equipped with
an anti-lock brake system. Doing so will result
in a loss of function of the brake systems of
both the vehicle and the trailer. X
Apply the vehicle's electric parking brake
manually. X
Start the engine. X
Shift the transmission to position ] .X
Vehicles with AIR BODY CONTROL: select
the Comfort drive program.204
Towing a trailer
Driving and parking

X
Switch off the engine. X
Close the doors and tailgate. X
Couple up the trailer. X
Establish the electrical connection between
the vehicle and the trailer. X
Check that the trailer lighting system is work-
ing. X
Push the combination switch upwards/down-
wards and check whether the corresponding
turn signal on the trailer flashes.
A trailer that is connected is recognized only
when the electrical connection is established
correctly and when the lighting system is work-
ing properly. The function of other systems also
depends on this, for example: R
ESP ®
R
PARKTRONIC R
Active Parking Assist R
Active Blind Spot Assist R
Active Lane Keeping Assist
Vehicles with AIR BODY CONTROL: if you couple
up a trailer, the vehicle always remains at high-
way level. Observe the following note when cou-
pling up a trailer: R
Unless highway level has been set manually,
the vehicle is automatically lowered to high-
way level. If a speed of 5 mph (8 km/h) has
been reached, this may be the case.
These restrictions apply to accessories that are
supplied with power via the trailer socket in your
vehicle, e.g. a rear bicycle rack.
Observe the maximum permissible trailer
dimensions (width and length).
Most U.S. states and all Canadian provinces
require by law: R
Safety chains between the towing vehicle and
the trailer. The chains should be cross-wound
under the trailer drawbar. They must be fas-
tened to the vehicle's trailer coupling, not to
the bumper or the axle.
Leave enough play in the chains to make tight
cornering possible. R
A separate brake system for certain types of
trailer. R
Safety switch for braked trailers. Check the
specific legal requirements applicable to your
state.
If the trailer becomes detached from the tow-
ing vehicle, the safety feature applies the
trailer brakes. Towing a trailer There are several legal requirements for towing
a trailer, e.g. the maximum permissible speed.
Make sure that your car/trailer combination
complies with the local regulations: R
in your place of residence R
at your destination
The police and local authorities can provide reli-
able information.
To accumulate driving experience and accustom
yourself to the new handling characteristics,
practice the following at a location where there
is no traffic: R
Cornering R
Stopping R
Backing up
Check the following before the journey: R
Trailer tow hitch R
Safety switch for braked trailers R
Safety chains R
Electrical connections R
Lighting system R
Wheels and tires R
Load securing
Adjust the exterior mirrors so that you have a
clear view of the rear section of the trailer.
If the trailer is equipped with electronically con-
trolled brakes, pull away carefully in the car/
trailer combination. Brake manually using the
brake controller and check whether the brakes
function correctly.
Regularly check that the load is secure.
When towing a trailer, your vehicle's handling
characteristics will be different in comparison
with when driving without a trailer.
The vehicle/trailer combination: R
is heavier R
is restricted in its acceleration and gradient-
climbing capability R
has an increased braking distance R
is affected more by strong crosswinds R
demands more sensitive steering R
has a larger turning circle
Avoid sudden steering movements.
Avoid braking abruptly. If possible, brake gently
at first to allow the trailer to run on. Then,
increase the braking force rapidly.Towing a trailer 205
Driving and parking Z

When overtaking, pay particular attention to the
extended length of your vehicle/trailer combi-
nation.
Due to the length of the vehicle/trailer combi-
nation, you require additional road space when
overtaking before you can change back to the
original lane.
If the automatic transmission repeatedly shifts
between gears on uphill or downhill gradients,
shift to a lower gear.
Driving in a lower gear and at a reduced speed
decreases the risk of engine damage.
If the coolant temperature increases signifi-
cantly when climate control is switched on,
switch climate control off.
Coolant heat can also be dissipated by opening
the windows and switching the ventilation
blower and the interior temperature to the high-
est level.
Decoupling a trailer
G WARNING
If you uncouple a trailer with the overrun
brake engaged, you could trap your hand
between the vehicle and the trailer drawbar.
There is a risk of injury.
Do not uncouple a trailer if the overrun brake
is engaged.
G WARNING
Vehicles with level control:
The vehicle is lowered as soon as you discon-
nect the trailer cable. This could result in your
limbs or those of other people that are
between the vehicle body and tires or under-
neath the vehicle being trapped. There is a
risk of injury.
Make sure that nobody is in the immediate
vicinity of the wheel housings or under the
vehicle when you disconnect the trailer cable.
! Do not disconnect a trailer with an engaged
overrun brake. Otherwise, your vehicle could
be damaged by the rebounding of the overrun
brake. X
Apply the vehicle's parking brake manually. X
Shift the transmission to position ] . X
Close all doors and the tailgate. X
Switch off the engine. X
Secure the vehicle and trailer against rolling
away. X
Remove the trailer cable. X
Remove the safety chains, if there are any. X
Uncouple the trailer.
Removing the ball coupling X
Observe the manufacturer's installation
instructions. X
Press the protective cap into the ball coupling
recess. X
Make sure that the protective cap is firmly in
place.
Observe the loading guidelines ( Y
page 278)
and the safety notes regarding stowage spaces
( Y
page 278).
Information on cleaning and care of the trailer
tow hitch ( Y
page 316).
Trailer power supply
! Accessories with a maximum power con-
sumption of 180 W can be connected to the
permanent power supply.
You must not charge a trailer battery using the
power supply.
The trailer socket of your vehicle is equipped at
the factory with a permanent power supply.
The permanent power supply is supplied via
trailer socket pin 4.
The trailer's permanent power supply is
switched off in the event of low vehicle supply
voltage and after six hours at the latest.
A qualified specialist workshop can provide
more information about installing the trailer
electrics.
Permissible trailer loads and trailer
drawbar noseweights
Weight specifications
The gross trailer weight is calculated as the
weight of the trailer plus the weight of the load
and the trailer's equipment.206
Towing a trailer
Driving and parking

Activating/deactivating PRE-SAFE ®
Brake PRE ‑ S AF E ®
Brake is only available for vehicles
wit h th e Drivin g Assistanc e package.X
Press th e

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 ] .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 156).
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 transmission to position ] , as th e electric parking brak e
is no t applie d automatically.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 156).
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 .232
Display messages
On-board computer and displays