brake sensor MERCEDES-BENZ GLA-Class 2017 X156 User Guide

trol Offmessage in the multifunction dis-
play for approximately five seconds.
iWhen 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 to avoid exceeding the set
speed or to maintain the designated distance
from the vehicle in front.
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.
Important safety notes
GWARNING
DISTRONIC PLUS does not react to:
Rpeople or animals
Rstationary obstacles on the road, e.g. stop- ped or parked vehicles
Roncoming 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.
GWARNING
DISTRONIC PLUS cannot always clearly iden-
tify other road users and complex traffic sit-
uations.
In such cases, DISTRONIC PLUS may:
Rgive an unnecessary warning and then
brake the vehicle
Rneither give a warning nor intervene
Raccelerate or brake 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.
GWARNING
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 isa 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.
186Driving systems
Driving and parking

To prevent damage to the vehicle, deacti-
vate DISTRONIC PLUS and the HOLD func-tion in the following or other similar situa-
tions:
Rwhen towing the vehicle
Rin the car wash
If you fail to adapt your driving style,
DISTRONIC 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.
DISTRONIC PLUS is only an aid. You are
responsible 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:
Rin road and traffic conditions which do not
allow you to maintain a constant speed, e.g.
in heavy traffic or on winding roads
Ron slippery road surfaces. Braking or accel-
erating could cause the drive wheels to lose
traction and the vehicle could then skid
Rwhen 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:
Rthere is dirt on the sensors or anything else covering the sensors
Rthere is snow or heavy rain
Rthere is interference by other radar sources
Rthere are 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:
Rbe too high if you are driving in a filter lane
or an exit lane
Rbe so high when driving in the right-hand
lane that you overtake vehicles in the left-
hand lane
Rbe 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
:To activate or increase speed
;To activate or reduce speed
=To deactivate DISTRONIC PLUS
?To activate at the current speed/last
stored speed
ATo set the specified minimum distance
Activating DISTRONIC PLUS
Activation conditions
To activate DISTRONIC PLUS, all of the fol-
lowing activation conditions must be fulfilled:
Rthe engine must be started. It may take up
to two minutes after pulling away before
DISTRONIC PLUS is operational.
Rthe electric parking brake must be
released.
RESP®must be active, but not intervening.
RActive Parking Assist must not be activa-
ted.
Rthe transmission must be in position D.
Driving systems187
Driving and parking
Z

Displaying the assistance graphic
XSelect theAssistance Graphicfunction
using the on-board computer
(
Ypage 227).
When the off-road program is activated,
symbol :appears in the assistance
graphic display.
Driving dynamics display (vehicles
with Off-Road Engineering package)
General notes
The driving dynamics display allows you to
see the selected drive program and additional
information about the vehicle's operating sta-
tus in the Audio 20 or COMAND display.
Vehicles with Audio 20:
RDrive program selected
RAngle of inclination
RSteering angle
RUphill or downhill gradient in percentage
RDSR status indicator
Vehicles with COMAND:
RDrive program selected
RAccelerator pedal position shown in %
RBrake pedal position shown in %
RAngle of inclination
RSteering angle
RUphill or downhill gradient in percentage
RLevel control
RCompass with angle scale
RDSR status indicator
Activating the driving dynamics display
XSwitch on Audio 20 or COMAND; see the
separate Audio 20 or COMAND operating
instructions.
XPress button :.
The driving dynamics display appears in the
Audio 20 or COMAND display.
PARKTRONIC
Important safety notes
PARKTRONIC is an electronic parking aid with
ultrasonic sensors. It monitors the area
around your vehicle using six sensors in the
front bumper and six sensors in the rear
bumper. PARKTRONIC indicates visually and
audibly the distance between your vehicle
and an object.
PARKTRONIC is only an aid. It is not a replace-
ment for your attention to your immediate
surroundings. You are always responsible for
safe maneuvering, parking and exiting a park- ing space. When maneuvering, parking or
pulling out of a parking space, make sure that
there are no persons, animals or objects in
the area in which you are maneuvering.
!When parking, pay particular attention to
objects above or below the sensors, such
as flower pots or trailer drawbars.
PARKTRONIC does not detect such objects
when they are in the immediate vicinity of
the vehicle. You could damage the vehicle
or the objects.
200Driving system s
Driving an d 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:
Rswitch on the ignition
Rshift the transmission to position D,Ror N
Rrelease the electric parking brake
Range of the sensors
General notes
PARKTRONIC does not take objects into con-
sideration that are:
Rbelow the detection range, e.g. people, ani-
mals or objects.
Rabove the detection range, e.g. overhang-
ing loads, truck overhangs or loading
ramps.
:Sensors in the front bumper, left-hand
side (example)
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
(
Ypage 317). Range
Front sensors
CenterApprox. 40 in (approx.
100 cm)
CornersApprox. 24 in (approx.
60 cm)
Rear sensors
CenterApprox. 48 in (approx.
120 cm)
CornersApprox. 32 in (approx.
80 cm)
Minimum distance
CenterApprox. 8 in (approx.
20 cm)
CornersApprox. 6 in (approx.
15 cm)
If there is an obstacle within this range, the
relevant warning displays light up and a warn-
ing tone sounds. If the distance falls below
the minimum, the distance may no longer be
shown.
Driving systems201
Driving and parking
Z

Problems with PARKTRONIC
ProblemPossible causes/consequences andMSolutions
Only the red segments
in the PARKTRONIC
warning displays are lit.
You also hear a warning
tone for approximately
two seconds.
PARKTRONIC is then
deactivated and the
indicator lamp on the
PARKTRONIC button
lights up.PARKTRONIC has malfunctioned and has switched off.
XIf problems persist, have PARKTRONIC checked at a qualified
specialist workshop.
Only the red segments
in the PARKTRONIC
warning displays are lit.
PARKTRONIC is then
deactivated.The PARKTRONIC sensors are dirty or there is interference.
XClean the PARKTRONIC sensors (Ypage 317).
XSwitch the ignition back on.
The problem may be caused by an external source of radio or
ultrasound waves.
XSee if PARKTRONIC functions in a different location.
Active Parking Assist
General notes
Active Parking Assist is an electronic parking
aid with ultrasound. It measures the road on
both sides of the vehicle. A parking symbol
indicates a suitable parking space. Active
steering intervention and brake application
can assist you during parking and when exit-
ing a parking space. You may also use
PARKTRONIC (
Ypage 200).
Important safety notes
Active Parking Assist is merely an aid. It is not
a replacement for your attention to your
immediate surroundings. 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 PARKTRONIC is switched off, Active
Parking Assist is also unavailable.
GWARNING
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 Active Park- ing Assist parking procedure.
!If unavoidable, you should drive over
obstacles such as curbs slowly and not at a
sharp angle. Otherwise, you may damage
the wheels or tires.
Active Parking Assist may possibly indicate
parking spaces which are not suitable for
parking, for example:
RWhere parking or stopping is prohibited
RIn front of driveways or entrances and exits
ROn unsuitable surfaces
Driving systems203
Driving and parking
Z

Display messagesPossible causes/consequences andMSolutions
$(USA
only)
J(Canada
only)
Check Brake Fluid
Level
There is no tenough brak eflui din th ebrak eflui dreservoir .
A warnin gtone sounds. The $(USAonly) or J(Canada
only) warnin glamp sin th einstrumen tcluster may also ligh tup.
GWARNIN G
The brakin geffec tmay be impaired.
There is aris kof an accident.
XPull ove rand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions. Do no tcontinue drivin g
under any circumstances.
XSecur eth evehicl eagainst rollin gaway (Ypage 171).
XConsult aqualified specialist workshop .
XDo notadd brak efluid. This does no tcorrec tth emalfunction .
#
Check Brake Pad
Wear
The brak epads/lining shav ereached their wear limit.
XVisit aqualified specialist workshop .
G
Inoperative
Oneor mor emain features of th embrace system are malfunc -
tioning.
XVisit aqualified specialist workshop .
Collision Preven‐
tionAssist Plu s
Currently Unavail‐
ableSee Opera‐
tor's Manual
COLLISION PREVENTION ASSIST PLU Sis temporarily no topera-
tional.
Possibl ecauses are:
Rth erada rsensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radi osta-
tion sor other source sof electromagnetic radiation .
Rthesystem is outside th eoperating temperature range.
Rth eon-boar dvoltag eis to olow.
Whe nth ecauses state dabov eno longer apply, th edisplay mes -
sage disappears.
COLLISION PREVENTION ASSIST PLU Sis operational again .
If th edisplay message does no tdisappear :
XPull overand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 171).
XRestart th eengine.
242Display messages
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
Collision Preven‐
tionAssist Plu s
Inoperative
COLLISION PREVENTION ASSIST PLU Sis temporarily inoperative
due to amalfunction .Adaptive Brake Assis tmay also hav efailed.
XVisit aqualified specialist workshop immediately.
Radar Sensor s
Dirty See Opera‐
tor's Manual
At leaston eof th efollowing drivin gsystems or drivin gsafet ysys-
tems is temporarily restricted or inoperative:
RCOLLISION PREVENTION ASSIST PLU S
RDISTRONIC PLUS
Possibl ecauses are:
Rth esensor sin th eradiato rtrim and/o rin th ebumpers are dirty
Rth efunction of th edrivin gsystem and/o rdrivin gsafet ysystem
is impaire ddue to heav yrain or snow.
A warnin gtone also sounds.
Whe nth ecauses state dabov eno longer apply, th edisplay mes -
sage disappears. Al ldrivin gsystems and drivin gsafet ysystems
are operative again .
If th edisplay message does no tdisappear :
XPull overand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 171).
XSwitchof fth eengine.
XClean th esensor sin th efollowing location s (Ypage 317):
Rin theradiato rtrim
Rin th efron tbumper
Rin th erear bumper, particularl yin th emiddle of th erear
bumper
XRestart th eengine.
The display message disappears.
6
SRS Malfunction
Servic eRequired
The restrain tsystem is faulty. The 6warnin glamp also lights
up in th einstrumen tcluster.
GWARNIN G
The air bags or Emergency Tensioning Devices may either be trig-
gered unintentionally or, in th eevent of an accident, may no tbe
triggered .
There is an increase dris kof injury.
XVisit aqualified specialist workshop immediately.
Fo rfurther information about th erestrain tsystem, see
(
Ypage 42) .
Display messages243
On-board computer and displays
Z

Display messagesPossible causes/consequences andMSolutions
DISTRONICPLUSCur‐
rentlyUnavailable
SeeOperator' sMan‐
ual
DISTRONIC PLU Sis temporarily inoperative.
Possibl ecauses are:
Rth erada rsensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radi osta-
tion sor other source sof electromagnetic radiation .
Rthesystem is outside th eoperating temperature range.
Rth eon-boar dvoltag eis to olow.
A warnin gtone also sounds.
Whe nth ecauses state dabov eno longer apply, th edisplay mes -
sage disappears.
DISTRONIC PLU Sis operational again .
If th edisplay message does no tdisappear :
XPull overand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 171).
XRestart th eengine.
DISTRONIC PLU S
Inoperative
DISTRONIC PLUSis defective. Adaptive Brake Assis tmay also
hav efailed.
A warnin gtone also sounds.
XVisit aqualified specialist workshop .
DISTRONICPLUSSus‐
pended
You hav edepressed th eaccelerato rpedal .DISTRONIC PLU Sis no
longer controllin gth espeed of th evehicle.
XRemove your foot from th eaccelerato rpedal .
DISTRONIC PLU S
- - -mph
An activation condition fo rDISTRONIC PLU Sis no tfulfilled .
XCheckth eactivation condition sfo rDISTRONIC PLU S
(
Ypage 186).
256Display messages
On-board computer and displays