check engine MERCEDES-BENZ GLA-Class 2017 X156 Owner's Guide

:Transmission position display
;Drive program display
If the transmission position display in the mul-
tifunction display is not working, you should
pull away carefully to check whether the
desired transmission position is engaged.
Ideally, you should select transmission posi-
tion Dand drive program Cor S.
Engaging park position P
XWhen the vehicle is stationary, press but-
ton :.
Transmission positions
BPark position
This prevents the vehicle from roll-
ing away when stopped.
Only shift the transmission into
position Pwhen the vehicle is sta-
tionary (
Ypage 159). The parking
lock should not be used as a brake
when parking. Always apply the
electronic parking brake in addi-
tion to the parking lock in order to
secure the vehicle.
If the vehicle electronics are mal-
functioning, the transmission may
be locked in position P. Have the
vehicle electronics checked imme-
diately at a qualified specialist
workshop.
Park position Pis automatically
engaged if:
Ryou switch off the engine using
the SmartKey and remove the
SmartKey
Ryou switch off the engine using
the SmartKey or using the Start/ Stop button and open the driv-
er's door or front-passenger
door
Rthe driver's door is opened when
the vehicle is stationary or driv-
ing at very low speed and the
transmission is in position Dor R
CReverse gear
Only shift the transmission into
position Rwhen the vehicle is sta-
tionary.
162Automatic transmission
Driving and parking

Problems with the transmission
ProblemPossible causes/consequences andMSolutions
The transmission has
problems shifting gear.The transmission is losing oil.
XHave the transmission checked at a qualified specialist work-
shop immediately.
The acceleration ability
is deteriorating.
The transmission no
longer shifts into all of
the gears.
Reverse gear can no
longer be engaged.The transmission is in emergency mode.
XStop the vehicle.
XShift the transmission to positionP.
XSwitch off the engine.
XWait at least ten seconds before restarting the engine.
XShift the transmission to positionD.
XHave the transmission checked at a qualified specialist work-
shop immediately.
Refueling
Important safety notes
GWARNING
Fuel is highly flammable. If you handle fuel
incorrectly, there is a risk of fire and explo-
sion.
You must avoid fire, open flames, creating
sparks and smoking. Switch off the engine
and, if applicable, the auxiliary heating before refueling.
GWARNING
Fuel is poisonous and hazardous to health.
There is a risk of injury.
You must make sure that fuel does not come into contact with your skin, eyes or clothing
and that it is not swallowed. Do not inhale fuel
vapors. Keep fuel away from children.
If you or others come into contact with fuel,
observe the following:
RWash away fuel from skin immediately
using soap and water.
RIf fuel comes into contact with your eyes,
immediately rinse them thoroughly with
clean water. Seek medical assistance with-
out delay.
RIf fuel is swallowed, seek medical assis-
tance without delay. Do not induce vomit-
ing.
RImmediately change out of clothing which
has come into contact with fuel.
GWARNING
Electrostatic buildup can create sparks and
ignite fuel vapors. There is a risk of fire and
explosion.
Always touch the vehicle body before opening
the fuel filler flap or touching the fuel pump
nozzle. Any existing electrostatic buildup is
thereby discharged.
!Do not use diesel to refuel vehicles with a
gasoline engine. Do not switch on the igni-
tion if you accidentally refuel with the
wrong fuel. Otherwise, the fuel will enter
the fuel system. Even small amounts of the
wrong fuel could result in damage to the
fuel system and the engine. Notify a quali-
fied specialist workshop and have the fuel
tank and fuel lines drained completely.
Refueling169
Driving and parking
Z

!Overfilling the fuel tank could damage the
fuel system.
!Take care not to spill any fuel on painted
surfaces. You could otherwise damage the
paintwork.
!Use a filter when refueling from a fuel can.
Otherwise, the fuel lines and/or injection
system could be blocked by particles from
the fuel can.
Do not get into the vehicle again during the
refueling process. Otherwise, electrostatic
charge could build up again.
If you overfill the fuel tank, fuel could spray
out when the fuel pump nozzle is removed.
For further information on fuel and fuel quality (
Ypage 377).
Refueling
General information
The fuel filler flap is unlocked/locked auto-
matically when you unlock/lock the vehicle
with the SmartKey.
The position of the fuel filler cap is displayed
æ in the instrument cluster. The arrow on
the filling pump indicates the side of the vehi-
cle.
Opening the fuel filler flap
:To open the fuel filler flap
;Tire pressure table
=To insert the fuel filler cap
?Instruction label for fuel type to be refu-
eled
XVehicles without KEYLESS-GO: remove
the SmartKey from the ignition lock.
XVehicles with KEYLESS-GO start-func-
tion or KEYLESS-GO: open the driver's
door.
The on-board electronics now have status
0. This is the same as the SmartKey having
been removed.
XPress the fuel filler flap in the direction of
arrow :.
The fuel filler flap swings up.
XTurn the fuel filler cap counterclockwise
and remove it.
XInsert the fuel filler cap into the holder on
the inside of fuel filler flap =.
XCompletely insert the filler neck of the fuel
pump nozzle into the tank, hook in place
and refuel.
XOnly fill the tank until the pump nozzle
switches off.
Do not add any more fuel after the pump
stops filling for the first time. Otherwise, fuel
may leak out.
Closing the fuel filler flap
XReplace the cap on the filler neck and turn
clockwise until it engages audibly.
XClose the fuel filler flap.
Close the fuel filler flap before locking the
vehicle.
If you are driving with the fuel filler cap open,
the 8 reserve fuel warning lamp flashes. A
message appears in the multifunction display
(
Ypage 252).
In addition, the ;Check Engine warning
lamp may light up (
Ypage 275).
For further information on warning and indi-
cator lamps in the instrument cluster, see
(
Ypage 275).
170Refueling
Driving and parking

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
178Driving tips
Driving and parking

Rear wheel
XBringth evehicl eand wheels into asuitable
position so that you can attach test gage
A.
XSecur eth evehicl eagainst rollin gaway
(
Ypage 171).
XEngage park position P.
XSwitchoff th eengine.
XPlac etest gage Abetween th ewheel's
spoke son brak epad/linin g=.
XHold test gage Averticall yon brak e
disc :and slid emeasurin gpin ;onto
brak edisc :.
XChec kwhic hcolor field ?thearrow on
measurin gpin ;is pointing to .
Green: thebrak epad/linin gthickness is
sufficient.
Red :th ebrak epad/linin gthickness is no t
sufficient. Hav eth ebrak epads/lining
checke dat aqualified specialist workshop .
To avoid an inaccurat emeasurement:
Rmak esur eyou position th ewheels suitably
Rdo no tput th emeasurin gpin on arecess in
th ebrak edisc
Driving on wet road s
Hydroplaning
If water has accumulated to acertain dept h
on th eroa dsurface, there is adanger of
hydroplanin goccurring, eve nif:
Ryou drive at low speeds .
Rthetires hav eadequat etread depth.
Fo rthis reason ,in th eevent of heav yrain or in
condition sin whic hhydroplanin gmay occur ,
you mus tdrive in th efollowin gmanner:
Rlower your speed.
Ravoid ruts.
Ravoid sudden steerin gmovements.
Rbrak ecarefully.
Driving on flooded road s
!Bear in mindthat vehicles travelin gin
fron tor in th eopposit edirection creat e
waves. This may caus eth emaximum per -
missibl ewater dept hto be exceeded .
Failure to observ ethese note smay result in
damag eto th eengine, electrical systems
and transmission .
If you hav eto drive on stretches of roa don
whic hwater has collected, pleas ebear in
min dthat:
Rin th ecas eof standin gwater, th ewater
level may be no higher than th elower edge
of th evehicl ebody
Ryou should drive no faste rthan at awalkin g
pac e
Winter drivin g
GWARNING
If you shift down on aslipper yroa dsurfac ein
an attemp tto increase th eengine's brakin g
effect, th edrive wheels could lose their grip.
There is an increase ddanger of skiddin gand
accidents .
Do no tshift down for additional engin ebrak -
in g on aslipper yroa dsurface.
Driving tips179
Driving and parking
Z

In such situations, have the vehicle
checked and repaired immediately at a
qualified specialist workshop. If on con-
tinuing your journey you notice that driving
safety is impaired, pull over and stop the
vehicle immediately, paying attention to
road and traffic conditions. In such cases,
consult a qualified specialist workshop.
The vehicle is only designed for easily nego-
tiable off-road terrain and poor road surfaces.
When driving off-road, substances such as
sand, mud and water or water mixed with oil
may get into the brakes. This could result in a
reduced braking effect or in total brake failure and also in increased wear and tear. The brak-
ing characteristics change depending on the
material ingressing the brakes. Clean the
brakes after driving off-road. If you detect a
reduced braking effect or grinding noises,
have the brake system checked in a qualified
specialist workshop as soon as possible.
Adapt your driving style to the different brak-
ing characteristics.
Driving off-road increases the likelihood of
damage to the vehicle, which, in turn, can lead
to failure of the mechanical assembly or sys-
tems. Adapt your driving style to suit the ter-
rain conditions. Drive carefully. Have damage
to the vehicle rectified immediately at a quali-
fied specialist workshop.
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.
General notes
HEnvironmental note
Protection of the environment is of primary
importance. Treat nature with respect.
Observe all prohibiting signs.
Read this section carefully before driving your
vehicle off-road. Off-road driving is only possible with the Off-
Road Engineering package (
Ypage 199).
The following driving systems are specially
adapted for driving over easily negotiable off-
road terrain:
ROff-road program (Ypage 199)
ROff-road ABS (Ypage 66)
ROff-road 4ETS (Ypage 69)
ROff-road ESP®(Ypage 72)
RDSR (Downhill Speed Regulation)
(
Ypage 197)
Observe the following notes:
RStop the vehicle before starting to drive
along an off-road route. If necessary, acti-
vate the off-road program (
Ypage 157).
RTo avoid damaging the vehicle, make sure
there is always sufficient ground clearance.
RCheck that items of luggage and loads are
stowed safely and are well secured
(
Ypage 285).
RAlways keep the engine running and in gear
when driving on a downhill gradient. Acti-
vate DSR (
Ypage 197).
RDrive slowly and evenly, if necessary at a
walking pace.
REnsure that the wheels are in contact with
the ground at all times.
RDrive with extreme care on unfamiliar off-
road routes where visibility is poor. For
safety reasons, get out of the vehicle first
and survey the off-road route.
RCheck the depth of water before fording
rivers and streams.
RWatch out for obstacles.
RTake care when turning on an uphill or
downhill slope or when driving across a
slope. The vehicle could otherwise tip over.
RAlways keep the side windows and the pan-
orama roof with power tilt/sliding panel
closed during the journey.
RDo not deviate from marked routes.
Do not use the HOLD function when driving
off-road, on steep uphill or downhill gradients or on slippery or loose surfaces. The HOLD
Driving tips181
Driving and parking
Z

function cannot hold the vehicle on such sur-
faces.
Checklist before driving off-road
XEngine oil level:check the engine oil level
and add oil if necessary.
When driving on steep gradients, the
engine oil level must be sufficiently high to
ensure a correct oil supply in the vehicle.
XWheels and tires: check the tire tread
depth and tire pressure.
XCheck for damage and remove any foreign
objects, e.g. small stones, from the
wheels/tires.
XReplace any missing valve caps.
XReplace dented or damaged wheels.
XRims: dented or bent rims can result in a
loss of tire pressure and damage the tire
bead. Before driving off-road, check the
wheels and replace them if necessary.
Checklist after driving off-road
!If you detect damage to the vehicle after
driving off-road, have the vehicle checked
immediately at a qualified specialist work-
shop.
XDeactivate off-road program (Ypage 157).
XDeactivate DSR (Ypage 197).
XClean the headlamps and rear lights and
check for damage.
XClean the front and rear license plates.
XClean the wheels and tires with a water jet and remove any foreign objects.
XClean the wheels, wheel housings and the
vehicle underside with a water jet; check
for any foreign objects and damage.
XCheck whether twigs or other parts of
plants have become trapped. These
increase the risk of fire and can damage
fuel pipes, brake hoses or the rubber bel-
lows of the axle joints and propeller shafts.
XAfter the trip, examine without fail the
entire undercarriage, wheels, tires, brakes, bodywork structure, steering, chassis and
exhaust system for damage.
XAfter driving in sand, mud, gravel, water or
similar dirty conditions, have the following
checked and cleaned:
Rbrake discs
Rwheels
Rbrake pads
Raxle joints
XIf you detect strong vibrations after off-road
travel, check for foreign objects in the
wheels and drive train and remove them if
necessary. Foreign objects can disturb the
balance and cause vibrations.
Driving over poor road surfaces places
greater demands on your vehicle than driving
on normal roads. After driving off-road, check
the vehicle. This allows you to detect damage promptly and reduce the risk of an accident to
yourself and other road users.
Driving on sand
Observe the following rules when driving on
sand:
RActivate the off-road program
(
Ypage 157).
RAvoid high engine speeds.
RUse the left-hand steering wheel paddle
shifter to shift to a lower gear appropriate
to the terrain.
RDrive quickly to overcome the rolling resist-ance. Otherwise the vehicle's wheels could
become stuck in loose ground.
RDrive in the tracks of other vehicles if pos-
sible. Make sure that:
-the tire ruts are not too deep.
-the sand is sufficiently firm.
-the ground clearance of the vehicle is
sufficient.
Tire ruts and gravel roads
!Check that the ruts are not too deep and
that your vehicle has sufficient clearance.
182Driving tips
Driving and parking

RActivate DSR. If this is not sufficient, brake
gently. When doing so, make sure that the
vehicle is facing in the direction of the line
of fall.
RCheck that the brakes are working normally
after a long downhill stretch.
Off-road ABS is activated when the off-road
program is selected.
At speeds below 18 mph (30 km/h), the front
wheels lock cyclically during braking. The dig-
ging-in effect achieved in the process reduces the stopping distance on off-road terrain. The
steerability of the vehicle is considerably
reduced if the wheels lock.
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. You need to have previously selec-
ted manual gearshifting M(
Ypage 166). 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).
The speed indicated in the speedometer may
differ slightly from the speed stored.
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:
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
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 cruise control
?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:
Rthe electric parking brake must be
released.
RESP®must be active, but not intervening.
184Driving systems
Driving an d parking

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

Engine
Display messagesPossible causes/consequences andMSolutions
+
Check Coolant
Level See Opera‐
tor's Manual
The coolant level is too low.
!Avoid making long journeys with too little coolant in the engine
cooling system. The engine will otherwise be damaged.
XAdd coolant, observing the warning notes before doing so
(
Ypage 311).
If you have to add coolant frequently:
XContact a qualified specialist workshop and have the engine
cooling system checked.
?The fan motor is faulty.
XAt coolant temperatures below 248 ‡ (120 †), drive to the
nearest qualified specialist workshop.
XAvoid heavy loads on the engine as you do so, e.g. driving in
mountainous terrain and stop-start traffic.
?
Coolant Too Hot
Stop Vehicle Turn
Engine Off
The coolant is too hot.
A warning tone also sounds.
GWARNING
Do not drive when your engine is overheated. This can cause some
fluids which may have leaked into the engine compartment to
catch fire.
Steam from the overheated engine can also cause serious burns
which can occur just by opening the hood.
There is a risk of injury.
XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 171).
XWait until the engine has cooled down.
XMake sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
XDo not start the engine again until the display message goes out
and the coolant temperature is below 248 ‡ (120 †). Other-
wise, the engine could be damaged.
XPay attention to the coolant temperature display.
If the temperature increases again:
XVisit a qualified specialist workshop immediately.
Under normal operating conditions and with the specified coolant
level, the coolant temperature may rise to 248 ‡ (120†) .
Displa y messages251
On-board computer and displays
Z