check engine MERCEDES-BENZ GLS-Class SUV 2017 X166 Owner's Guide

RDo not install hired trailer couplings or other
detachable trailer couplings on the bumpers
of your vehicle.
RIf you no longer need the ball coupling,
remove it from the ball coupling recess. This
will reduce the risk of damage to the ball cou-
pling.
When towing a trailer, set the tire pressure on
the rear axle of the towing vehicle for the max-
imum load. You will find the values in the tire
pressure table in the fuel filler flap of the vehicle (
Ypage 364).
Please note that when towing a trailer, the fol-
lowing driving systems have limited availability
or are not available at all:
RParking Assist PARKTRONIC (Ypage 190)
RBlind Spot Assist (Ypage 207)
RActive Lane Keeping Assist (Ypage 213)
On vehicles without level control, the height of
the ball coupling will alter according to the load
placed on the vehicle. If necessary, use a trailer
with a height-adjustable drawbar.
You will find installing dimensions and loads
under "Technical data" (
Ypage 387).
Driving tips
Observe the information on ESP®trailer stabili-
zation (Ypage 68) and on pulling away with a
trailer (Ypage 141).
The maximum permissible speed for vehicle/
trailer combinations depends on the type of
trailer. Before beginning the journey, check the
trailer's documents to see what the maximum
permissible speed is. Observe the legally pre-
scribed maximum speed in the relevant country.
For certain Mercedes-Benz vehicles, the maxi-
mum permissible rear axle load is increased
when towing a trailer. See "Technical data" to
find out whether this applies to your vehicle
(
Ypage 387). If you utilize any of the added
maximum rear axle load when towing a trailer,
the vehicle/trailer combination may not exceed
a maximum speed of 60 mph (100 km/h) for
reasons concerning the operating permit. This
also applies in countries in which the permissi-
ble maximum speed for vehicle/trailer combi-
nations is above 60 mph (100 km/h).
When towing a trailer, your vehicle's handling
characteristics will be different in comparison
with when driving without a trailer. Use the left-hand steering wheel paddle shifter
to shift into a lowe
r g
ear in good time on long
and steep downhill gradients.
This also applies if you have activated cruise
control or Distance Pilot DISTRONIC.
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:
XDo not accelerate.
XDo not counter-steer.
XBrake if necessary.
RMaintain a greater distance from the vehicle
in front than when driving without a trailer.
RAvoid braking abruptly. If possible, brake gen-tly at first to allow the trailer to run on. Then,
increase the braking force rapidly.
RThe 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
GWARNING
If the ball coupling is not correctly installed
and secured, it can come loose during the
journey and endanger other road users. There is a risk of an accident and injury.
Always install and secure the ball coupling as
described. Before every journey, ensure that
the ball coupling is secured with the bolt and
the corresponding spring cotter.
GWARNING
If the ball coupling is not installed correctly or not secured with the bolt provided and the
corresponding spring cotter, the trailer may
come loose. There is a risk of an accident.
Towing a trailer223
Driving an d parking
Z

XSecure the bolt using spring cotterB.
XCheck the ball coupling, bolt and spring cotter
for correct installation.
If the ball coupling cannot be correctly mounted,
remove the ball coupling. Under these circum-
stances, the ball coupling must not be used for
trailer towing.
Have the entire trailer tow hitch checked at a
qualified specialist workshop.
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.
XShift the transmission to position P.
XApply the vehicle's electric parking brake.
XStart the engine.
XVehicles with AIRMATIC package: select
normal level and the Comfortdrive program.
XSwitch off the engine.
XClose the doors and tailgate.
XCouple up the trailer.
XEstablish the electrical connection between
the vehicle and the trailer.
XCheck that the trailer lighting system is work-
ing.
XPush 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:
RESP®
RParking Assist PARKTRONIC
RParking Pilot
RActive Blind Spot Assist
RActive Lane Keeping Assist
iVehicles with the AIRMATIC package: if you
couple up a trailer, the vehicle always remains
at normal level. When coupling up a trailer,
please observe the foll
owing:
RIf the normal level has not been set man-
ually, the vehicle is automatically lowered
to normal level. This is the case if a speed of
5 mph (8 km/h) is reached.
RThe
Sport drive program is not available.
These restrictions apply to all accessories
powered through a connection to the trailer
power socket of your vehicle, e.g. a bicycle
carrier.
Observe the maximum permissible trailer
dimensions (width and length).
Most U.S. states and all Canadian provinces
require by law:
RSafety 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.
RA separate brake system for certain types of
trailer.
RSafety 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 switch applies the
trailer brakes.
Towing a trailer225
Driving and parking
Z

Towing a trailer
There are numerous legal requirements con-
cerning the towing of a trailer, e.g. speed restric-tions. Make sure that your car/trailer combina-
tion complies with the local regulations:
Rin your place of residence
Rin the location to which you are driving
The police and local authorities can provide reli- able information.
Observe the following when towing a trailer:
RTo gain driving experience and to become
accustomed to the new handling characteris-
tics, you should practice the following in a
traffic-free location:
-cornering
-stopping
-backing up
RBefore driving, check:
-trailer tow hitch
-safety switch for braked trailers
-safety chains
-electrical connections
-lights
-wheels
RAdjust the exterior mirrors to provide an
unobstructed view of the rear section of the
trailer.
RIf the trailer has electronically controlled
brakes, pull away carefully. Brake manually
using the brake controller and check whether
the brakes function correctly.
RSecure any objects on the trailer to prevent
the cargo from slipping when the vehicle is in
motion.
RWhen you couple up a trailer, check at regular
intervals that the load is firmly secured. If the
tra
iler is equipped with trailer lights and
brakes, check the trailer to ensure that these
are working.
RBear in mind that the handling will be less
stable when towing a trailer than when driving
without one. Avoid sudden steering move-
ments.
RThe vehicle/trailer combination is heavier,
accelerates more slowly, has a decreased
gradient climbing capability and a longer
braking distance.
It is more susceptible to side winds and
requires more careful steering.
RIf possible, do not brake suddenly, but instead depress the brake pedal moderately at first so
that the trailer can activate its brakes. Then
increase the pressure on the brake pedal.
RIf the automatic transmission repeatedly
shifts between gears on uphill or downhill gra-
dients, shift to a lower gear using the left-hand
steering wheel paddle shifter.
A lower gear and lower speed reduce the risk
of engine failure.
RWhen driving downhill, shift to a lower gear toutilize the engine's braking effect.
Avoid continuous brake application as this
may overheat the vehicle brakes and, if instal-
led, the trailer brakes.
RIf the coolant temperature increases dramat-
ically while the air-conditioning system is
switched on, switch off the air-conditioning
system.
Coolant heat can also be dissipated by open-
ing the windows and switching the ventilation blower and the interior temperature to the
highest level.
RWhen overtaking, pay particular attention to
the extended length of your vehicle/trailer
combination.
Due to the length of the vehicle/trailer com-
bination, you require additional road space in
relation to the vehicle you are overtaking
before you can change back to the original
lane.
Decoupling a trailer
GWARNING
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.
GWARNING
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-
226Towing a trailer
Driving an d parking

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.
XShift the transmission to position P.
XApply the vehicle's electric parking brake.
XStart the engine.
XClose the doors and tailgate.
XApply the trailer's parking brake.
XDetach the trailer cable and decouple the
trailer.
XSwitch off the engine.
Permissible trailer loads and drawbar
loads
Weight specifications
Maximum allowable gross mass
The gross vehicle weight of the trailer is calcu-
lated by adding the weight of the trailer to the
weight of the load and equipment on the trailer. You will find installing dimensions and loads
under "Technical data" (
Ypage 387).
Permissible noseweight
You will find installing dimensions and loads
under "Technical data" (Ypage 387).
Loading a trailer
RWhen loading the trailer, make sure that nei-
ther the permissible gross weight of the trailer
nor the gross vehicle weight are exceeded.
The permissible gross vehicle weight is indi-
cated on the identification plate located on
the B-pillar on the driver's side of the vehicle.
You can find the maximum permissible values
on the type plates of your vehicle and the
trailer. When calculating how much weight the vehicle and trailer may carry, pay atten-
tion to the respective lowest values.
RThe trailer drawbar load on the ball coupling
must be added to the rear axle load to avoid
exceeding the permissible gross axle weight.
The permissible gross vehicle weight is indi-
cated on the identification plate located on
the B-pillar on the driver's side of the vehicle.
iMercedes-Benz recommends a trailer load
where the trailer drawbar noseweight
accounts for 8 % to 15 % of the trailer's per-
missible gross weight.
iThe weight of additional accessories, pas-
sengers, and cargo reduces the permissible
trailer load and drawbar load for your vehicle.
Checking the vehicle and trailer weight
RTo check that the weights of the towing vehi-
cle and the trailer comply with the maximum
permissible values, have the vehicle/trailer
combination (including the driver, passen-
gers, and cargo with a fully laden trailer)
weighed on a calibrated weighbridge.
RCheck the gross axle weight rating of the front and rear axles, the gross weight of the trailer
and the trailer drawbar noseweight.
Removing the ball coupling
XRemove the spring cotter.
XRemove the bolt from the ball coupling
recess.
XRemove the ball coupling from the ball cou-
pling recess.
XClean the ball coupling if it is dirty.
XStow the ball coupling so that it cannot be
thrown around.
Observe the loading guidelines (
Ypage 294)
and the safety notes regarding stowage spaces
(
Ypage 294).
Information on cleaning and care of the trailer
tow hitch (
Ypage 329).
Trailer power supply
!
Accessories with a maximum power con-
sumption of 180 W can be connected to the
permanent power supply.
Towing a trailer227
Driving an d parking
Z

Important safety notes
GWARNING
If you operate information systems and com-
munication equipmen tintegrate din th evehi-
cle while driving ,you will be distracte dfrom
traffic conditions. You could also lose control
of th evehicle. Ther eis aris kof an accident.
Only operate th eequipmen twhen th etraffic
situation permits. If you are no tsur ethat this
is possible ,park th evehicl epayin gattention
to traffic condition sand operate th eequip-
men twhen th evehicl eis stationary.
You must observ eth elegal requirements for th e
country in whic hyou are currentl ydriving when
operating th eon-board computer.
GWARNIN G
If th einstrumen tcluste rhas faile dor mal-
functioned, you may no trecognize function
restriction sin systems relevan tto safety. The
operating safet yof your vehicl emay be
impaired .Ther eis aris kof an accident.
Drive on carefully. Hav eth evehicl echecke d
at aqualified specialist workshop immedi-
ately.
If th eoperating safet yof your vehicl eis
impaired ,pull ove ras soo nas it is saf eto do so.
Contac t aqualified specialist workshop.
The on-board computer only shows message sor
warning sfrom certain systems in th emultifunc-
tion display. You should therefor emak esur e
your vehicl eis operating safely at all times .
Fo ran overview, see th einstrumen tpanel illus-
tration (
Ypage 34).
Displays and operation
Instrument cluster lighting
The lighting in th einstrumen tcluster, in th edis-
plays and th econtrol sin th evehicl einterior can
be adjusted usin gth ebrightness control knob.
The brightness control knob is locate don th e
botto mleftof th einstrumen tcluste r
(
Ypage 34).
XTurn th ebrightness control knob clockwise or
counter-clockwise.
If you tur nth eligh tswitch to Ã,Tor
L, thebrightness is dependen tupon th e
brightness of th eambien tlight.
iThe ligh tsensor in th einstrumen tcluste r
automatically control sth ebrightness of th e
multifunction display.
In daylight, th edisplays in th einstrumen t
cluste rare no tilluminated.
Speedometer with segments
The segments in th espeedometer indicat e
whic hspee drange is available.
RCruis econtrol activated (Ypage 172):
The segments ligh tup from th estore dspee d
to th emaximum speed.
RDistanc ePilot DISTRONI Cis activated
(Ypage 174):
On eor two segments in th eset spee drange
ligh tup.
RDistanc ePilot DISTRONI Cdetects avehicl ein
fron tmoving mor eslowly than th estore d
speed:
The segments between th espee dof th evehi-
cle in fron tand th estore dspee dligh tup.
Tachometer
!
Do no tdriv ein th eoverrevving range, as this
could damag eth eengine.
The red ban din th etachometer indicates th e
engine's overrevving range.
The fuel suppl yis interrupted to protect th e
engin ewhen th ered ban dis reached.
Outside temperature display
You should pay special attention to road condi-
tion swhen temperatures are aroun dfreezing
point.
Bea rin min dthat th eoutside temperature dis-
play indicates th etemperature measured and
does no trecord th eroad temperature.
The outside temperature display is in th emulti-
function display (
Ypage 231).
Displays and operation229
On-board computer and displays
Z

Display messagesPossible causes/consequences andMSolutions
The yellow!warning lamp lights up and th ered F (USAonly)
or ! (Canada only) indicator lamp flashes .
It is no tpossibl eto apply th eelectric parking brak emanually.
XShift th etransmission to position P.
XVisitaqualified specialist workshop .
$(USA
only)
J( Canada
only)
Check Brake Fluid
Level
There is no tenough brak eflui din th ebrak eflui dreservoir .In addition ,
th e$ (USAonly) or J(Canada only) warning lamp lights up in
th einstrumen tcluste rand awarning tone sounds.
GWARNIN G
The braking effec 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 tcontinu edrivin g
under any circumstances.
XSecur eth evehicl eagainst rollin gaway (Ypage 159).
XConsult aqualified specialist workshop .
XDo notadd brak efluid .This does no tcorrec tth emalfunction .
#
CheckBrakePadWear
The brak epads/linings hav ereached their wear limit.
US Aonly: th e$ red brak esystem warning lamp is lit while th e
engin eis running.
XVisit aqualified specialist workshop .
G
Inoperative
Oneor mor emain features of th embrace system are malfunctioning .
XVisitaqualified specialist workshop .
ActiveBrakeAssistFunctionsCurrentlyLimitedSee Opera‐tor's Manual
Active Brake Assis twit hcross-traffic function is temporarily inopera-
tive.
Possibl ecauses are:
Rth eradar sensor system is temporarily inoperative, e.g. due to elec -
tromagneti cradiation emitted by nearby TV or radi ostation sor
other source sof electromagneti cradiation
Rth esystem is outside th eoperating temperature range
Rth eon-boar dvoltag eis to olow.
Whe nth ecauses state dabov eno longer apply, th edisplay message
disappears.
Active Brake Assis twit hcross-traffic function or PRE ‑S AF E
®PLU Sis
functional 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 159).
XRestart th eengine.
250Display messages
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
b
Switch On Headlamps
You are drivingwit hlow-beam headlamp sswitched off .
XTurn theligh tswitch to th eL orà position .
Adaptive HighbeamAssist CurrentlyUnavailable SeeOperator' sManual
Adaptive Highbea mAssis tis deactivated and temporarily inoperative.
Possibl ecauses are:
Rth ewindshield in th ecamera' sfield of vision is dirty
Rvisibilit yis impaire ddue to heav yrain ,snow or fog
XClean th ewindshield.
If th esystem detects that th ecamera is full yoperational again ,th e
Adaptive
HighbeamAssistNowAvailablemessage is displayed.
Adaptive Highbea mAssis tis operational again .
Adaptive HighbeamAssist InoperativeAdaptive HighbeamAssis tis faulty.
XVisit aqualified specialist workshop .
Engine
Display messagesPossible causes/consequences and MSolutions
+
CheckCoolantLevelSee Operator' sMan ‐ual
The coolan tlevel is to olow.
!Avoid making lon gjourneys wit hto olittl ecoolan tin th eengin e
coolin gsystem. The engin ewill otherwise be damaged.
XAd dcoolant, observing th ewarning note sbefore doin gso
(Ypage 322).
If you have to ad dcoolant frequently:
XContac t aqualified specialist workshop and hav eth eengin ecoolin g
system checked.
?The fan motor is malfunctioning .
XAt coolanttemperatures belo w24 8‡( 120 †), drive to the nearest
qualified specialist workshop.
XAvoid heavy loads on the engine as you do so, e.g. driving in moun-
tainous terrain and stop-and-go traffic.
Display messages257
On-board computer and displays
Z

Display messagesPossible causes/consequences andMSolutions
#
StopVehicl eSeeOperator' sManual
The battery is no longer bein gcharged and th ebattery charg elevel is
to olow.
A warning tone also sounds.
XPull ove rand stop th evehicl esafely and switch off th eengine, pay-
ing attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 159).
XObserv eth einstruction sin th e# See Operator' sManualdisplay message .
XConsultaqualified specialist workshop .
4
CheckEngineOilAtNextRefueling
The engin eoil level has dropped to th eminimum level.
A warning tone also sounds.
!Avoid lon gjourneys wit hto olittl eengin eoil. The engin ewill oth-
erwise be damaged.
XChec kth eoil level when next refueling, at th elatest (Ypage 321).
XIf necessary, add engin eoil (Ypage 321).
If th eengin eoil need stoppin gup mor eoften:
XContac t aqualified specialist workshop and hav eth eengin e
checked.
Information on approve dengin eoils can be obtained from any quali-
fie dspecialist workshop or on th eInternet at http://bevo.mercedes -
benz.com.
4
Check Engine OilLevel (Ad d 1quart)
Mercedes-AMG vehicles: th eengin eoil level is to olow.
!Avoid lon gjourneys wit hto olittl eengin eoil. The engin ewill oth-
erwise be damaged.
XChec kth eoil level when next refueling, at th elatest (Ypage 321).
XIf necessary, add engin eoil (Ypage 321).
If th eengin eoil need stoppin gup mor eoften:
XContac t aqualified specialist workshop and hav eth eengin e
checked.
Information on approve dengin eoils can be obtained from any quali-
fie dspecialist workshop or on th eInternet at http://bevo.mercedes -
benz.com.
4
Engine Oil LevelLow Sto pVehicl eTurnEngine Off
Mercedes-AMG vehicles: th eengin eoil level is to olow.
There is aris kof engin edamage.
XPull ove rand stop th evehicl esafely and switch off th eengine, pay-
ing attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 159).
XCheckth eengin eoil level (Ypage 321).
XIf necessary, add engin eoil (Ypage 321).
8
Fue lLevel Low
The fuel level has dropped int oth ereserv erange.
XRefue lat th eneares tgas station .
Display messages259
On-board computer and displays
Z

Display messagesPossible causes/consequences andMSolutions
CThere is onlyaver ysmall amount of fuel in th efuel tank.
XRefue lat th eneares tgas station without fail .
8
Gas Cap Loose
The fuel filler cap is notclosed correctl yor th efuel system is leaking .
XCheckthat th efuel filler cap is correctl yclosed .
If th efuel filler cap is not correctl yclosed :
XCloseth efuel filler cap .
If th efuel filler cap is correctl yclosed :
XVisitaqualified specialist workshop .
8
Ultra Low-sulfurDiesel FuelOnl y
Vehicles wit h adiesel engine: th efuel level has fallen belo wthe
reserv erange.
XRefue lat th eneares tgas station .
XOnly use commercially available vehicular ULTRA-LOW SULFUR
HIGHWAY DIESEL FUEL (ULSD ,15 ppm sulfur MAXIMUM) .
¸
ReplaceAir Filter
Vehicles wit h adiesel engine: th eengin eair filter is dirty and mus tbe
replaced.
XVisit aqualified specialist workshop .
!
Check FuelFilter
Vehicles wit h adiesel engine: there is water in th efuel filter. The water
mus tbe draine doff .
XVisit aqualified specialist workshop .
Ø
Check Additive SeeOperator'sManual
The DE Ftan kis almost empty.
XHav eth eDE Ftan kfilled immediately at aqualified specialist work-
sho p (Ypage 156).
Ø
RemainingStarts :16
The DEFlevel has fallen to aminimum .You can start th eengin e a
further 16 times .
XHaveth eDE Ftan kfilled immediately at aqualified specialist work-
sho p (Ypage 156).
iYou can start th eengin e afurther 16 times .If DE Fis no tadded ,it
will then no tbe possibl eto restar tth eengine. Refill th eDE Ftan k
wit happroximately 1gal (3. 8l) DE F (
Ypage 156).
260Display messages
On-board computer and displays

Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
÷NThe yellow ESP®warning lamp flashes while the vehicle is in motion.
ESP®or traction control has intervened because there is a risk of skidding or at
least one wheel has started to spin.
Cruise control or Distance Pilot DISTRONIC is deactivated.
XWhen pulling away, only depress the accelerator pedal as far as necessary.
XEase off the accelerator pedal while the vehicle is in motion.
XAdapt your driving style to suit the road and weather conditions.
XDo not deactivate ESP®.
In rare cases (
Ypage 67), it may be best to deactivate ESP®.
Observe the important safety notes on ESP®(Ypage 67).
åN The yellow ESP®OFF warning lamp is lit while the engine is running.
ESP®is deactivated.
GWARNING
If ESP
®is switched off, ESP®is unable to stabilize the vehicle.
Further driving systems or driving safety systems are thus restricted, e.g. Active
Blind Spot Assist. The system does not perform course-correcting brake applica-
tions.
There is an increased risk of skidding and an accident.
XReactivate ESP®.
In rare cases (
Ypage 67), it may be best to deactivate ESP®.
Observe the important safety notes on ESP®(Ypage 67).
XAdapt your driving style to suit the road and weather conditions.
If ESP
®cannot be activated:
XDrive on carefully.
XContact a qualified specialist workshop and have ESP®checked.
280Warning and indicator lamps in the instrument cluster
On-board computer and displays