warning light MERCEDES-BENZ GLA-Class 2016 X156 Service Manual

Servicing the brakes
!The brake fluid level may be too low, if:
Rif the red brake warning lamp lights up inthe instrument cluster and
Ryou hear a warning tone while the engineis running
Observe additional warning messages in
the multifunction display.
The brake fluid level may be too low due to
brake pad wear or leaking brake lines.
Have the brake system checked immedi-
ately. Consult a qualified specialist work-
shop to arrange this.
!A function or performance test should
only be carried out on a 2-axle dynamom-
eter. If you wish to operate the vehicle on
such a dynamometer, please consult a
qualified specialist workshop in advance.
You could otherwise 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:
Rthe electric parking brake is tested on a
brake dynamometer (for a maximum of
ten seconds)
Rthe 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.
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 (
Ypage 66).
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 gage. Color-coding (green or
red) on the test gage allows you to determine
whether the brake pad/lining thickness is still
sufficient. The test gage is in the vehicle docu-
ment wallet in the glove box.
Front wheel
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Otherwise, your vehicle could be damaged
or bottom out and get stuck.
Observe the following rules when driving
along ruts in off-road terrain or on roads with
loose gravel:
RActivate the off-road program
(
Ypage 157).
RAvoid high engine speeds.
RShift to a lower gear using the left-hand
steering wheel paddle shifter.
RDrive slowly.
RWhere ruts are too deep, drive with the
wheels of one side on the center grassy
area, if possible.
Traveling uphill
Approach/departure angle
GWARNING
If you drive on a steep incline at an angle or
turn when driving on an incline, the vehicle
could slip sideways, tip and rollover. There is a risk of an accident.
Always drive on a steep incline in the line of
fall (straight up or down) and do not turn the
vehicle.
RObserve the warnings for off-road driving
(
Ypage 180).
RFollow the line of fall when driving on slopes
and steep inclines.
RBefore driving on extreme uphill and down-
hill gradients, select the off-road program
(
Ypage 157).
RDrive slowly.
RAccelerate gently and make sure that the
wheels are gripping.
RAvoid high engine speeds, except when
driving on sandy and muddy routes with
high driving resistance.
RUse the left-hand steering wheel paddle
shifter to shift to a lower gear appropriate
to the gradient.
RUse the left-hand steering wheel paddle
shifter to shift into a lower gear in good time
on long and steep downhill gradients.
Hill start assist will aid you when pulling away
on a hill. For further information about hill
start assist, see (
Ypage 153).
Do not switch to transmission position N
when driving off-road. If you try to brake the
vehicle using the service brake, you could
lose control of the vehicle. If the gradient is
too steep for your vehicle, drive back down in
reverse gear.
Always observe the approach/departure
angle values (
Ypage 384).
Maximum gradient-climbing capability
Always observe the maximum gradient climb- ing ability values (
Ypage 384).
Hilltops
When driving up an uphill gradient, slightly
reduce pressure on the accelerator immedi-
ately before reaching the brow of the hill.
Make use of the vehicle's own impetus to
travel over the brow.
This style of driving prevents:
Rthe vehicle from lifting off the ground on thebrow of a hill
Rthe vehicle from traveling too quickly downthe other side
Driving downhill
RDrive slowly.
RDo not drive at an angle down steep
inclines. Steer into the line of fall and drivewith the front wheels aligned straight. Oth-
erwise, the vehicle could slip sideways, tip
and rollover.
RShift to a lower gear using the left-hand
steering wheel paddle shifter before tack-
ling steep downhill gradients.
Driving tips183
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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

detected vehicle turns a corner and reveals
an obstacle or stationary vehicle, DISTRONIC
PLUS will not brake for these.
Crossing vehicles
DISTRONIC PLUS may detect vehicles that
are crossing your lane by mistake. Activating
DISTRONIC PLUS at traffic lights with cross-
ing traffic, for example, could cause your vehi-
cle to pull away unintentionally.
HOLD function
General notes
The HOLD function can assist the driver in the
following situations:
Rwhen pulling away, especially on steep
slopes
Rwhen maneuvering on steep slopes
Rwhen 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.
Important safety notes
GWARNING
When leaving the vehicle, it can still roll away despite being braked by the HOLD function if:
Rthere is a malfunction in the system or in
the voltage supply.
Rthe HOLD function has been deactivated by
pressing the accelerator pedal or the brake
pedal, e.g. by a vehicle occupant.
Rthe electrical system in the engine com-
partment, the battery or the fuses have
been tampered with.
Rthe 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 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
Deactivating the HOLD function
(
Ypage 194).
Activation conditions
You can activate the HOLD function if:
Rthe vehicle is stationary
Rthe engine is running or if it has been auto-
matically switched off by the ECO start/
stop function
Rthe driver's door is closed or your seat belt
is fastened
Rthe electric parking brake is released
RDISTRONIC PLUS is deactivated
Rthe transmission is in position D,Ror Non
vehicles with automatic transmission
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Activating/deactivating DSR
If you activateDS Rand no spee dhas been
set ,th evehicl edecelerate sto 3mph
(6 km/ h).
Yo u can only activate DSR when driving at
speeds below 20 mph (30 km/h).
Activating DSR
XPress button :.
Indicator lamp ;lights up.
The status indicator in the multifunction
display shows, e.g. DSR 6 km/h
.
If the current vehicle speed is too high, the
DSR icon appears in the multifunction dis-
play. You will also see the message: Max.
Speed 30 km/h.
If you enter or exit a parking space using
Active Parking Assist, and press button :,
indicator lamp ;flashes. DSR can then not
be switched on.
Deactivating DSR
XPress button :.
Indicator lamp ;goes out.
The DSR symbol appears in the multifunc-
tion display with the Off
message.
DSR switches off automatically if you drive
faster than 22 mph (35 km/h). The DSR sym-
bol appears in the multifunction display with
the Off
message. You also hear a warning
tone.
Display in the assistance graphic
XSelect the Assistance Graphicfunction
using the on-board computer
(
Ypage 227).
When DSR is activated symbol :appears
in the assistance graphics display.
Changing the set speed while the vehi-
cle is in motion
When DSR is activated, you can change the
set speed to a value between 2 mph and
11 mph (Canada: between 4 km/h and
18 km/h) while the vehicle is in motion.
XTo increase or decrease in 1 mph incre- ments (Canada: 1 km/h increments):
briefly press the cruise control lever to the
pressure point, up :for a higher set speed
or down ;for a lower set speed.
The set value appears in the status indica-
tor of the multifunction display.
198Driving systems
Driving 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:
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.
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Z

Warning displays
:Segments on the left-hand side of the
vehicle
;Segments on the right-hand side of the
vehicle
=Segments showing operational readiness
The warning displays show the distance
between the sensors and the obstacle. The
warning display for the front area is located
on the dashboard above the center air vents.
The warning display for the rear area is loca-
ted on the headliner in the rear compartment. The warning display for each side of the vehi-
cle is divided into five yellow and two red seg-
ments. PARKTRONIC is operational if yellow
segments showing operational readiness =
light up.
Transmission
positionWarning display
DFront area activated
R, Nor the vehicle
is rolling back-
wardsRear and front areas
activated
PNo areas activated
One or more segments light up as the vehicle
approaches an obstacle, depending on the
vehicle's distance from the obstacle. From the:
Rsixth segment onwards, you will hear an
intermittent warning tone for approx-
imately two seconds.
Rseventh segment onwards, you will hear a
warning tone for approximately two sec-
onds. This indicates that you have now
reached the minimum distance.
Deactivating/activating PARKTRONIC
:Indicator lamp
;Deactivating/activating PARKTRONIC
If indicator lamp :lights up, PARKTRONIC is
deactivated.
iPARKTRONIC is automatically activated
when you turn the SmartKey to position 2in
the ignition lock.
202Driving systems
Driving and parking

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
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XStart the engine.
XRelease the electric parking brake.
XSwitch on the turn signal in the direction
you will drive out of the parking space.
XShift the transmission to positionDor R.
The Start Park Assist? Yes: OK No:
message appears in the multifunction dis-
play %.
XTo cancel the procedure: press the%
button on the multifunction steering wheel or pull away.
or
XTo exit a parking space using Active
Parking Assist: press theabutton on
the multifunction steering wheel.
The Park Assist Active Accelerate
andBrakeObserveSurroundingsmes-
sage appears in the multifunction display.
XLet go of the multifunction steering wheel.
XPull away, being ready to brake at all times.
Do not exceed a maximum speed of
approximately 6 mph (10 km/h) when exit-
ing a parking space. Otherwise Active Park-
ing Assist will be canceled.
XDepending on the message or as required, shift the transmission to position Dor R.
Active Parking Assist immediately steers in
the other direction. The Park Assist
Active Accelerate and Brake
ObserveSurroundingsmessage appears
in the multifunction display.
iYou will achieve the best results by wait-
ing for the steering procedure to complete
before pulling away.
If you back up after activation, the steering
wheel is moved to the straight-ahead posi-
tion.
XDrive forwards and back up as prompted by
the PARKTRONIC warning displays, several
times if necessary.
Once you have exited the parking space com-
pletely, the steering wheel is moved to the
straight-ahead position. You hear a tone and
the Park Assist Finished
message
appears in the multifunction display. You will then have to steer and merge into traffic on
your own. PARKTRONIC is still available. You
can take over the steering, before the vehicle
has exited the parking space completely. This
is useful, for example when you recognize
that it is already possible to pull out of the
parking space.
Canceling Active Parking Assist
XStop the movement of the multifunction
steering wheel or steer yourself.
Active Parking Assist will be canceled at
once. The Park Assist Canceled
mes-
sage appears in the multifunction display.
or
XPress the PARKTRONIC button
(
Ypage 202).
PARKTRONIC is switched off and Active
Parking Assist is immediately canceled.
The Park Assist Canceled
message
appears in the multifunction display.
Active Parking Assist is canceled automati-
cally if:
Rthe electric parking brake is engaged
Rtransmission position Pis selected
Rparking using Active Parking Assist is no
longer possible
Ryou are driving faster than 6 mph (10 km/h)
Ra wheel spins, ESP®intervenes or fails. The
÷ warning lamp lights up in the instru-
ment cluster
A warning tone sounds. The parking symbol
disappears and the multifunction display
shows the Park Assist Canceled
mes-
sage.
When Active Parking Assist is canceled, you
must steer and brake again yourself.
If a system malfunction occurs, the vehicle is
braked to a standstill. To drive on, depress the accelerator again.
Driving systems207
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!Objects not at ground level may appear to
be further away than they actually are, e.g.:
Rthe bumper of a parked vehicle
Rthe drawbar of a trailer
Rthe ball coupling of a trailer tow hitch
Rthe rear section of an HGV
Ra slanted post
Use the guidelines only for orientation.
Approach objects no further than the bot-
tom-most guideline.
:Yellow guide line at a distance of approx-
imately 13 ft (4.0 m) from the rear of the
vehicle
;White guide line without turning the steer-
ing wheel, vehicle width including the
exterior mirrors (static)
=Yellow guide line for the vehicle width
including the exterior mirrors, for current
steering wheel angle (dynamic)
?Yellow lane marking tires at current steer-
ing wheel angle (dynamic)
AYellow guide line at a distance of approx-
imately 3 ft (1.0 m) from the rear of the
vehicle
BVehicle center axle (marker assistance)
CBumper
DRed guide line at a distance of approx-
imately 12 in (0.30 m) from the rear of the
vehicle
:Front warning display
;Additional PARKTRONIC measurement
operational readiness indicator
=Rear warning display
Vehicles with PARKTRONIC: when
PARKTRONIC is operational (
Ypage 202),
additional measurement operational readi-
ness indicator ;appears in the Audio 20/
COMAND display. If the PARKTRONIC warn-
ing displays are active or light up, warning
displays :and =are also active or light up
correspondingly in the Audio 20/COMAND
display.
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