brakes MERCEDES-BENZ CLA-Class 2014 C117 User Guide

Heavy and light loads
G
WARNING
If you rest your foot on the brake pedal while
driving, the braking system can overheat. This increases the stopping distance and can even
cause the braking system to fail. There is a
risk of an accident.
Never use the brake pedal as a footrest. Never
depress the brake pedal and the accelerator
pedal at the same time.
! Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If the brakes have been subjected to a heavy load, do not stop the vehicle immediately.
Drive on for a short while. This allows the air-
flow to cool the brakes more quickly.
Wet roads If you have driven for a long time in heavy rain
without braking, there may be a delayed reac- tion from the brakes when braking for the firsttime. This may also occur after the vehicle has
been washed or driven through deep water.
You have to depress the brake pedal more
firmly. Maintain a greater distance from the
vehicle in front.
After driving on a wet road or having the vehi-
cle washed, brake firmly while paying atten-
tion to the traffic conditions. This will warm up the brake discs, thereby drying them more
quickly and protecting them against corro-
sion.
Limited braking performance on salt-
treated roads If you drive on salted roads, a layer of salt
residue may form on the brake discs and
brake pads. This can result in a significantly
longer braking distance. R
Brake occasionally to remove any possible
salt residue. Make sure that you do not
endanger other road users when doing so.
R Carefully depress the brake pedal and the
beginning and end of a journey.
R Maintain a greater distance to the vehicle
ahead.
Servicing the brakes !
If the red brake warning lamp lights up in
the instrument cluster and you hear a warn- ing tone while the engine is running, the
brake fluid level may be too low. Observe
additional warning messages in the multi-
function display.
The brake fluid level may be too low due tobrake pad wear or leaking brake lines.
Have the brake system checked immedi-
ately. This work should be carried out at a
qualified specialist workshop.
! A function or performance test should
only be carried out on a 2-axle dynamom-
eter. If you are planning to have the vehicle tested on such a dynamometer, contact an
authorized Mercedes-Benz Center to
obtain further information first. Otherwise,
you could damage the drive train or the
brake system.
! As the ESP ®
system operates automati-
cally, the engine and the ignition must be
switched off (the SmartKey must be in posi-
tion 0or 1in the ignition lock) if:
R the electric parking brake is tested on a
brake dynamometer (for a maximum of
ten seconds)
R the vehicle is towed with the front axle
raised.
Braking triggered automatically by ESP ®
may seriously damage the brake system.
All checks and maintenance work on the
brake system must be carried out at a quali-
fied specialist workshop. Consult a qualified
specialist workshop to arrange this. Driving tips
163Driving and parking Z

Have brake pads installed and brake fluid
replaced at a qualified specialist workshop.
If the brake system has only been subject to
moderate loads, you should test the function- ality of your brakes at regular intervals.
You can find a description of Brake Assist
(BAS) on (Y page 64).
Mercedes-Benz recommends that you only
have brake pads/linings installed on your
vehicle which have been approved for
Mercedes-Benz vehicles or which correspond to an equivalent quality standard. Brake
pads/linings which have not been approved
for Mercedes-Benz vehicles or which are not
of an equivalent quality could affect your vehi-
cle's operating safety.
Mercedes-Benz recommends that you only
use brake fluid that has been specially
approved for your vehicle by Mercedes-Benz,
or which corresponds to an equivalent quality standard. Brake fluid which has not been
approved for Mercedes-Benz vehicles or
which is not of an equivalent quality could
affect your vehicle's operating safety.
Checking brake lining thickness You can measure the break pad/lining thick-
ness using a test gauge. Color-coding (green
or red) on the test gauge allows you to deter-
mine whether the brake pad/lining thickness is still sufficient. The test gauge is in the vehi-
cle document wallet in the glove box. Front wheel
Rear wheel
X Bring the vehicle and wheels into a suitable
position so that you can attach test gauge
0083.
X Secure the vehicle against rolling away
(Y page 157).
X Move the selector lever to position P.
X Switch off the engine.
X Place test gauge 0083between the wheel's
spokes on brake pad/lining 0087.164
Driving tipsDriving and parking

You should pay special attention to road con-
ditions when temperatures are around freez-
ing point.
For more information on driving with snow
chains, see (Y page 317).
For more information on driving with summer tires, see (Y page 316).
Observe the notes in the "Winter operation"
section (Y page 316). Driving systems
Cruise control
General notes Cruise control maintains a constant road
speed for you. It brakes automatically in order
to avoid exceeding the set speed. On long and
steep downhill gradients, especially if the
vehicle is laden, you must select a low gear in good time. For this, you will need to have
selected manual drive program M
(Y page 152). By doing so, you will make use
of the braking effect of the engine. This
relieves the load on the brake system and
prevents the brakes from overheating and
wearing too quickly.
Use cruise control only if road and traffic con- ditions make it appropriate to maintain a
steady speed for a prolonged period. You can store any road speed above 20 mph
(30 km/h).
Important safety notes If you fail to adapt your driving style, cruise
control can neither reduce the risk of an acci-
dent nor override the laws of physics. Cruise
control cannot take into account the road,
traffic and weather conditions. Cruise control
is only an aid. You are responsible for the dis-
tance to the vehicle in front, for vehicle speed, for braking in good time and for staying in
your lane. Do not use cruise control:
R in road and traffic conditions which do not
allow you to maintain a constant speed e.g.
in heavy traffic or on winding roads
R on slippery road surfaces. Braking or accel-
erating could cause the drive wheels to lose
traction and the vehicle could then skid
R when there is poor visibility, e.g. due to fog,
heavy rain or snow
If there is a change of drivers, advise the new
driver of the speed stored.
Cruise control lever 0043
To activate or increase speed
0044 To activate or reduce speed
0087 To deactivate cruise control
0085 To activate at the current speed/last
stored speed
When you activate cruise control, the stored
speed is shown in the multifunction display
for five seconds.
Activation conditions To activate cruise control, all of the following
activation conditions must be fulfilled:
R the electric parking brake must be
released.
R you are driving faster than 20 mph
(30 km/h).
R ESP ®
must be active, but not intervening.
R on vehicles with automatic transmission,
the selector lever must be in position D.166
Driving systemsDriving and parking

Storing, maintaining and calling up a
speed Storing and maintaining the current
speed
You can store the current speed if you are
driving faster than 20 mph (30 km/h).
X Accelerate the vehicle to the desired
speed.
X Briefly press the cruise control lever up 0043
or down 0044.
X Remove your foot from the accelerator
pedal.
Cruise control is activated. The vehicle
automatically maintains the stored speed.
i Cruise control may be unable to maintain
the stored speed on uphill gradients. The
stored speed is resumed when the gradient evens out. Cruise control maintains the
stored speed on downhill gradients by
automatically applying the brakes.
Storing the current speed or calling up the
last stored speed G
WARNING
If you call up the stored speed and it differs
from the current speed, the vehicle acceler-
ates or decelerates. If you do not know the
stored speed, the vehicle could accelerate or brake unexpectedly. There is a risk of an acci-
dent.
Pay attention to the road and traffic condi-
tions before calling up the stored speed. If you do not know the stored speed, store the
desired speed again.
X Briefly pull the cruise control lever towards
you 0085.
X Remove your foot from the accelerator
pedal.
The first time cruise control is activated, it
stores the current speed or regulates the
speed of the vehicle to the previously
stored speed. Setting a speed Keep in mind that it may take a brief moment
until the vehicle has accelerated or braked to the speed set.
X Press the cruise control lever up 0043for a
higher speed or down 0044for a lower speed.
X To adjust the set speed in 1 mph incre-
ments (1 km/h increments): briefly
press the cruise control lever up 0043or
down 0044to the pressure point.
Every time the cruise control lever is
pressed up 0043or down 0044the last speed
stored is increased or reduced.
X To adjust the set speed in 5 mph incre-
ments (10 km/h increments): briefly
press the cruise control lever up 0043or
down 0044to the pressure point.
Every time the cruise control lever is
pressed up 0043or down 0044the last speed
stored is increased or reduced.
i Cruise control is not deactivated if you
depress the accelerator pedal. For exam-
ple, if you accelerate briefly to overtake,
cruise control adjusts the vehicle's speed
to the last speed stored after you have fin- ished overtaking.
Deactivating cruise control There are several ways to deactivate cruise
control:
X Briefly press the cruise control lever for-
wards 0087.
or
X Brake.
Cruise control is automatically deactivated if: R the vehicle is secured with the electric
parking brake
R you are driving at less than 20 mph
(30 km/h)
R ESP ®
intervenes or you deactivate ESP ®
R you shift the transmission to position N
while driving Driving systems
167Driving and parking Z

If cruise control is deactivated, you will hear a
warning tone. You will see the Cruise Con‐
Cruise Con‐
trol Off
trol Off message in the multifunction dis-
play for approximately five seconds.
i When you switch off the engine, the last
speed stored is cleared. DISTRONIC PLUS
General notes DISTRONIC PLUS regulates the speed and
automatically helps you maintain the dis-
tance to the vehicle detected in front. Vehi-
cles are detected with the aid of the radar
sensor system. DISTRONIC PLUS brakes
automatically so that the set speed is not
exceeded.
Change into a lower gear in good time on long and steep downhill gradients. This is espe-
cially important if the vehicle is laden. By
doing so, you will make use of the braking
effect of the engine. This relieves the load on
the brake system and prevents the brakes
from overheating and wearing too quickly.
If DISTRONIC PLUS detects that there is a risk
of a collision, you will be warned visually and acoustically. DISTRONIC PLUS cannot pre-
vent a collision without your intervention. An
intermittent warning tone will then sound and
the distance warning lamp will light up in the instrument cluster. Brake immediately in
order to increase the distance to the vehicle
in front or take evasive action provided it is
safe to do so.
DISTRONIC PLUS operates in range between 0 mph (0 km/h) and 120 mph (200 km/h).
Do not use DISTRONIC PLUS while driving on roads with steep gradients.
As DISTRONIC PLUS transmits radar waves, it
can resemble the radar detectors of the
responsible authorities. You can refer to the
relevant chapter in the Operator's Manual if
questions are asked about this. i
This device complies with RSS-210 of
Industry Canada. Operation is subject to
the following two conditions:
1. This device may not cause harmful inter- ference, and
2. this device must accept any interference
received, including interference that may
cause undesired operation of the device.
Removal, tampering, or altering of the
device will void any warranties, and is not
permitted. 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.
Important safety notes G
WARNING
DISTRONIC PLUS does not react to:
R people or animals
R stationary obstacles on the road, e.g. stop-
ped or parked vehicles
R oncoming and crossing traffic
As a result, DISTRONIC PLUS may neither give
warnings nor intervene in such situations.
There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake. G
WARNING
DISTRONIC PLUS cannot always clearly iden- tify other road users and complex traffic sit-
uations.
In such cases, DISTRONIC PLUS may:
R give an unnecessary warning and then
brake the vehicle
R neither give a warning nor intervene
R accelerate unexpectedly
There is a risk of an accident.
Continue to drive carefully and be ready to
brake, in particular when warned to do so by
DISTRONIC PLUS. 168
Driving systemsDriving and parking

G
WARNING
DISTRONIC PLUS brakes your vehicle with up to 50% of the maximum possible deceleration.
If this braking force is insufficient, DISTRONIC
PLUS warns you visually and audibly. There is a risk of an accident.
In such cases, apply the brakes yourself and
try to take evasive action.
! If DISTRONIC PLUS or the HOLD function
is activated, the vehicle brakes automati-
cally in certain situations. To prevent dam-
age to the vehicle, deactivate DISTRONIC
PLUS and the HOLD function in the follow- ing or other similar situations:
R when towing the vehicle
R in the car wash
If you fail to adapt your driving style, DIS-
TRONIC PLUS can neither reduce the risk of
accident nor override the laws of physics.
DISTRONIC PLUS cannot take into account
the road, traffic and weather conditions. DIS- TRONIC PLUS is only an aid. You are respon-
sible for the distance to the vehicle in front,
for vehicle speed, for braking in good time and for staying in your lane.
Do not use DISTRONIC PLUS:
R in road and traffic conditions which do not
allow you to maintain a constant speed e.g.
in heavy traffic or on winding roads
R on slippery road surfaces. Braking or accel-
erating could cause the drive wheels to lose
traction and the vehicle could then skid
R when there is poor visibility, e.g. due to fog,
heavy rain or snow
DISTRONIC PLUS may not detect narrow
vehicles driving in front, e.g. motorcycles, or
vehicles driving on a different line.
In particular, the detection of obstacles can
be impaired if:
R dirt on the sensors or anything else cover-
ing the sensors
R there is snow or heavy rain R
there is interference by other radar sources
R strong radar reflections, for example, in
parking garages
If DISTRONIC PLUS no longer detects a vehi- cle in front, DISTRONIC PLUS may unexpect-
edly accelerate the vehicle to the stored
speed.
This speed may:
R be too high if you are driving in a filter lane
or an exit lane
R be so high when driving in the right-hand
lane that you overtake vehicles in the left-
hand lane
R be so high when driving in the left-hand lane
that you overtake vehicles in the right-hand lane
If there is a change of drivers, advise the new
driver of the speed stored.
Cruise control lever 0043
To store the current speed or a higher
speed
0044 To store the current speed or a lower
speed
0087 To deactivate DISTRONIC PLUS
0085 To store the current speed or call up the
last stored speed
0083 To set the specified minimum distance Driving systems
169Driving and parking Z

Activating DISTRONIC PLUS
Activation conditions
To activate DISTRONIC PLUS, all of the fol-
lowing activation conditions must be fulfilled:
R the engine must be started. It may take up
to two minutes after pulling away before
DISTRONIC PLUS is operational.
R the electric parking brake must be
released.
R ESP ®
must be active, but not intervening.
R Active Parking Assist must not be activa-
ted.
R the transmission must be in position D.
R the driver's door must be closed when you
shift from Pto Dor your seat belt must be
fastened.
R the front-passenger door and rear doors
must be closed.
Activating
X Briefly pull the cruise control lever towards
you 0085or press it up 0043or down 0044.
DISTRONIC PLUS is selected.
X Press the cruise control lever repeatedly
up 0043 or down 0044until the desired speed is
set.
X Remove your foot from the accelerator
pedal.
Your vehicle adapts its speed to that of the
vehicle in front, but only up to the desired
stored speed.
i If you do not fully release the accelerator
pedal, the DISTRONIC
DISTRONIC PLUS PLUSPassive
Passive mes-
sage appears in the multifunction display.
The set distance to a slower-moving vehicle in front will then not be maintained. You will
be driving at the speed you determine by
the position of the accelerator pedal.
You can also activate DISTRONIC PLUS when
stationary. The lowest speed that can be set is
18 mph (30 km/h).
X Briefly pull the cruise control lever towards
you 0085or press it up 0043or down 0044.
DISTRONIC PLUS is selected. Activating at the current speed/last
stored speed G
WARNING
If you call up the stored speed and it differs
from the current speed, the vehicle acceler-
ates or decelerates. If you do not know the
stored speed, the vehicle could accelerate or brake unexpectedly. There is a risk of an acci-
dent.
Pay attention to the road and traffic condi-
tions before calling up the stored speed. If you do not know the stored speed, store the
desired speed again.
X Briefly pull the cruise control lever
(Y page 169) towards you 0085.
X Remove your foot from the accelerator
pedal.
DISTRONIC PLUS is activated. The first
time it is activated, the current speed is
stored. Otherwise, it sets the vehicle cruise
speed to the previously stored value.
Driving with DISTRONIC PLUS Pulling away and driving
i The vehicle can also pull away when it is
facing an unidentified obstacle or is driving
on a different line from another vehicle. The vehicle then brakes automatically. There is
a risk of an accident. Be ready to brake at all
times.
If you depress the brake, DISTRONIC PLUS is
deactivated unless your vehicle is stationary.
X If you want to pull away with DIS-
TRONIC PLUS: remove your foot from the
brake pedal.
X Briefly pull the cruise control lever
(Y page 169) towards you 0085.
or
X Accelerate briefly.
Your vehicle pulls away and adapts its
speed to that of the vehicle in front.
If no vehicle is detected in front, your vehi-
cle accelerates to the set speed. 170
Driving systemsDriving and pa
rking

If there is no vehicle in front, DISTRONIC
PLUS operates in the same way as cruise
control.
If DISTRONIC PLUS detects that the vehicle in front has slowed down, it brakes your vehicle.
In this way, the distance you have selected is
maintained.
If DISTRONIC PLUS detects a faster-moving
vehicle in front, it increases the driving speed. The vehicle is only accelerated up to the
speed you have stored.
Selecting the drive program
DISTRONIC Plus supports a sporty driving
style when you have selected the S or M driv-
ing program (Y page 150). Acceleration
behind the vehicle in front or to the set speed is then noticeably more dynamic. If you have
selected the E driving program, the vehicle
accelerates more gently. This setting is rec-
ommended in stop-and-start traffic.
Changing lanes
If you change to the passing lane, DISTRONIC
PLUS supports you when:
R you are driving faster than 43.5 mph
(70 km/h)
R DISTRONIC PLUS is maintaining the dis-
tance to a vehicle in front
R you switch on the appropriate turn signal
R DISTRONIC PLUS does not detect a danger
of collision
If these conditions are fulfilled, your vehicle is
accelerated. Acceleration will be interrupted
if changing lanes takes too long or if the dis-
tance between your vehicle and the vehicle in front becomes too small.
i When changing lanes, DISTRONIC PLUS
monitors the left lane on left-hand drive
vehicles and the right lane on right-hand
drive vehicles. Stopping G
WARNING
When leaving the vehicle, even if it is braked
only by DISTRONIC PLUS, it could roll away if:
R there is a malfunction in the system or in
the voltage supply.
R DISTRONIC PLUS has been deactivated
with the cruise control lever, e.g. by a vehi-
cle occupant or from outside the vehicle.
R the electrical system in the engine com-
partment, the battery or the fuses have
been tampered with.
R the battery is disconnected.
R the accelerator pedal has been depressed,
e.g. by a vehicle occupant.
There is a risk of an accident.
If you wish to exit the vehicle, always turn off
DISTRONIC PLUS and secure the vehicle
against rolling away.
For further information on deactivating DIS-
TRONIC PLUS (Y page 173).
If DISTRONIC PLUS detects that the vehicle in front is stopping, it brakes your vehicle until it is stationary.
Once your vehicle is stationary, it remains
stationary and you do not need to depress the
brake.
i After a time, the electric parking brake
secures the vehicle and relieves the service
brake.
i Depending on the specified minimum dis-
tance, your vehicle will come to a standstill
at a sufficient distance behind the vehicle in
front. The specified minimum distance is
set using the control on the cruise control
lever. Driving systems
171Driving and parking Z

HOLD function
Important safety notes G
WARNING
When leaving the vehicle, it can still roll away despite being braked by the HOLD function if:
R there is a malfunction in the system or in
the voltage supply.
R the HOLD function has been deactivated by
pressing the accelerator pedal or the brake
pedal, e.g. by a vehicle occupant.
R the electrical system in the engine com-
partment, the battery or the fuses have
been tampered with.
R the battery is disconnected
There is a risk of an accident.
If you wish to exit the vehicle, always turn off the HOLD function and secure the vehicle
against rolling away.
! If DISTRONIC PLUS or the HOLD function
is activated, the vehicle brakes automati-
cally in certain situations. To prevent dam-
age to the vehicle, deactivate DISTRONIC
PLUS and the HOLD function in the follow-
ing or other similar situations:
R when towing the vehicle
R in the car wash
Deactivating the HOLD function
(Y page 177).
General notes The HOLD function can assist the driver in the
following situations:
R when pulling away, especially on steep
slopes
R when maneuvering on steep slopes
R when waiting in traffic
The vehicle is kept stationary without the
driver having to depress the brake pedal.
The braking effect is canceled and the HOLD
function deactivated when you depress the
accelerator pedal to pull away. Activation conditions You can activate the HOLD function if:
R
the vehicle is stationary
R the engine is running or if it has been auto-
matically switched off by the ECO start/
stop function
R the driver's door is closed or your seat belt
is fastened
R the electric parking brake is released
R the transmission position D,Ror Nis
engaged while driving a vehicle with an
automatic transmission
R DISTRONIC PLUS is deactivated
Activating the HOLD function Example: vehicles with a color multifunction dis-
play
X Make sure that the activation conditions
are met.
X Depress the brake pedal.
X Quickly depress the brake pedal further
until 0043appears in the multifunction dis-
play.
The HOLD function is activated. You can
release the brake pedal.
i If depressing the brake pedal the first
time does not activate the HOLD function,
wait briefly and then try again. 176
Driving systemsDriving and parking

The sensors may not detect snow and other
objects that absorb ultrasonic waves.
Ultrasonic sources such as an automatic
car wash, the compressed-air brakes on a
truck or a pneumatic drill could cause
PARKTRONIC to malfunction.
PARKTRONIC may not function correctly on uneven terrain.
PARKTRONIC is activated automatically when you:
R switch on the ignition
R shift the transmission to position D,Ror N
R release the electric parking brake
PARKTRONIC is deactivated at speeds above
11 mph (18 km/h) . It is reactivated at lower
speeds.
Range of the sensors General notes
PARKTRONIC does not take objects into con-
sideration that are:
R below the detection range, e.g. people, ani-
mals or objects
R above the detection range, e.g. overhang-
ing loads, truck overhangs or loading ramps 0043
Sensors in the front bumper, left-hand
side (example) Side view
Top view
The sensors must be free from dirt, ice or
slush. They can otherwise not function cor-
rectly. Clean the sensors regularly, taking
care not to scratch or damage them
(Y page 291).
Front sensors Center Approx. 40 in (approx.
100 cm)
Corners Approx. 24 in (approx.
60 cm)
Rear sensors
Center Approx. 48 in (approx.
120 cm)
Corners Approx. 32 in (approx.
80 cm)
Minimum distance
Center Approx. 8 in (approx.
20 cm)
Corners Approx. 8 in (approx.
20 cm) Driving systems
179Driving and parking Z