2016 MERCEDES-BENZ GL-Class check engine light

When driving on steep gradients, the
engine oil level must be sufficiently high to
ensure a correct oil supply in the vehicle.
XDEF tank (BlueTEC vehicles):check the
level and add if necessary (
Ypage 186).
XTire-changing tool kit: check that the jack
is working and make sure you have the lug
wrench, a robust tow cable and a folding
spade 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.
Driving over rough terrain places greater
demands on your vehicle than driving on nor-
mal 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.
XVehicles with the ON&OFFROAD pack-
age: activate the on-road program
(
Ypage 258).
XDeactivate the LOW RANGE off-road gear
(
Ypage 259).
XDeactivate DSR (Ypage 257).
XLower the vehicle level again to a level suit- able to the road conditions, e.g. to the high-
way level.
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 jetand 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 for extended periods across
sand, mud, gravel, water or in similarly dirty
conditions, have the brake discs, wheels,
brake pads/linings and axle joints checked
and cleaned.
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 on sand
Observe the following rules when driving on
sand:
RVehicles with the ON&OFFROAD pack-
age: select off-road program 1
(
Ypage 258).
RSelect a higher vehicle level.
RAvoid high engine speeds.
RUse the left-hand steering wheel paddle
shifter to shift to a lower gear appropriate
to the terrain.
200Driving tips
Driving and parking

RBefore driving on extreme uphill and down-
hill gradients, select the LOW RANGE off-
road gear (
Ypage 259).
RDrive slowly.
RAvoid high engine speeds. Drive at appro-
priate engine speeds (maximum
3,000 rpm).
RUse the left-hand steering wheel paddle
shifter to shift into a lower gear in good time
on long and steep downhill gradients.
RCheck the brakes after prolonged off-road
driving.
Hill start assist will aid you when pulling away
on a hill. For further information about hill
start assist, see (
Ypage 168).
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 456).
Maximum gradient-climbing capability
Always observe the maximum gradient climb- ing ability values (
Ypage 456).
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 drive with the front wheels aligned straight. Oth-
erwise, the vehicle could slip sideways, tip
and rollover.
RShift to a lower gear using the left-hand
paddle shifter before tackling steep down-
hill gradients.
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.
iThe special off-road ABS setting enables a
precise, brief and repeated locking of the
front wheels. This causes them to dig into
loose earth. Be aware that the front wheels
easily skid across the ground surface if
completely braked and therefore lose their
ability to steer.
Driving systems
Intelligent Drive
Mercedes-Benz Intelligent Drive stands for
innovative driver assistance and safety sys-
tems which enhance comfort and support the
driver in critical situations. With these intelli-
gent co-ordinated systems Mercedes-Benz
has set a milestone on the path towards
autonomous driving.
Mercedes-Benz Intelligent Drive embraces all
elements of active and passive safety in one
well thought out system – for the safety of the vehicle occupants and that of other road
users.
Further information on driving safety systems
(
Ypage 68).
Cruise control
General notes
Cruise control maintains a constant road
speed for you. It brakes automatically in order to avoid exceeding the set speed. You must
202Driving systems
Driving and parking

:Yellow indicator lamp/red warning lamp
When Blind Spot Assist is activated, indicator
lamp :in the exterior mirrors lights up yel-
low at speeds of up to 20 mph (30 km/h). At
speeds above 20 mph (30 km/h), the indica-
tor lamp goes out and Blind Spot Assist is
operational.
If a vehicle is detected within the blind spot
monitoring range at speeds above 20 mph
(30 km/h), warning lamp :on the corre-
sponding side lights up red. This warning is
always emitted when a vehicle enters the
blind spot monitoring range from behind or
from the side. When you overtake a vehicle,
the warning only occurs if the difference in
speed is less than 7 mph (12 km/h).
The yellow indicator lamp goes out if reverse
gear is engaged. In this event, Blind Spot
Assist is no longer active.
The brightness of the indicator/warning
lamps is adjusted automatically according to
the ambient light.
Collision warning
If a vehicle is detected in the monitoring range
of Blind Spot Assist and you switch on the
corresponding turn signal, a double warning
tone sounds. Red warning lamp :flashes. If
the turn signal remains on, detected vehicles
are indicated by the flashing of red warning
lamp :. There are no further warning tones.
Switching on Blind Spot Assist
XMake sure that Blind Spot Assist is activa-
ted in the on-board computer
(
Ypage 282).
XTurn the SmartKey to position 2in the igni-
tion lock.
Warning lamps :in the exterior mirrors
light up red for approximately 1.5 seconds
and then turn yellow.
Towing a trailer
When you attach a trailer, make sure you have
cor rect
ly established the electrical connec-
tion. This can be accomplished by checking
the trailer lighting. In this event, Blind Spot
Assist is deactivated. The indicator lamp in
the exterior mirrors lights up yellow, and the
Blind
SpotAssistCurrentlyUnavail‐
able See Operator's Manualmessage
appears in the multifunction display.
iYou can deactivate the indicator lamps in
the exterior mirrors.
To do so, switch off Blind Spot Assist when:
Rthe SmartKey is in position 2in the igni-
tion lock
Rthe engine is not running
Lane Keeping Assist
General notes
:Lane Keeping Assist camera
Lane Keeping Assist monitors the area in
front of your vehicle with camera :, which is
mounted at the top of the windshield. Active
Lane Keeping Assist detects lane markings on
246Driving systems
Driving and parking

so will result in a loss of function of the
brake systems of both the vehicle and the
trailer.
XShift the transmission to positionP.
XApply the vehicle's electric parking brake.
XStart the engine.
XVehicles with the AIRMATIC package:
select highway level.
XVehicles with ADS:set ADS toAUTOor
COMF .
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
working.
iVehicles with the AIRMATIC package:
with a trailer attached, the vehicle will
always remain at highway level. When cou-
pling up a trailer, please observe the fol-
lowing:
RUnless highway level has been set man-
ually, the vehicle is automatically low-
ered to highway level. This is the case if a
speed of 5 mph (8 km/h) is reached.
RHigh-speed level 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 fastened to the vehicle's trailer cou-
pling, 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
towing vehicle, the safety switch applies
the trailer brakes.
Towing a trailer
There are numerous legal requirements con-
cerning the towing of a trailer, e.g. speed
restrictions. Make sure that your car/trailer
combination complies with the local regula-
tions:
Rin your place of residence
Rin the location to which you are driving
The police and local authorities can provide
reliable information.
Observe the following when towing a trailer:
RTo gain driving experience and to become
accustomed to the new handling charac-
teristics, 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
Towing a trailer267
Driving and parking
Z

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 reg-
ular intervals that the load isfirmly secured.
If the trailer isequipped with trailer lights
and brakes, check the trailer to ensure that
these are working.
RBear inmind that the handlin g will be less
stable when towing a trailer than when driv-
ing without one. Avoid sudden steering
movements.
RThe vehicle/trailer combination isheavier,
accelerates more slowly, has a decreased
gradient cli mbing 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 moder-
ate lyat first so that the trailer can activate
it s brakes. Then increase the pressure on
the brake pedal.
RIf the automat ictransmission repeatedly
shifts between gears on uphill or downhill
gradients, shift to a lower gear using the
left-hand steering wheel paddleshifter.
A lower gear and lower speed reduce the
risk of engine failure.
RWhen drivingdown hill, shift to a lower gear
to uti lize the engine's braking effect.
Avoid co ntin
uous brake application as this
may overheat the vehicle brakes and, if
instal led,the trailer brakes.
RIfthe coolant temperature increases dra-
matical ly while the air-cond itioning system
is swit ched on, switch off the air-condition-
ing system.
Coolant heat can also bedissipated by
opening the windows and switching the ventilation
blower and the interior temper-
ature to the highest leve l.
RWhen overtaking, pay particular attention
to the extended length of your vehicle/
trailer combination.
Due to the length of the vehicle/trailer
combination, you require additional road
spaceinrelation to the vehicle you are
overtaking before you can change back to
the original lane.
Decoupling a trailer
GWARNIN G
If you uncouple atrailer wit hth eoverrun
brak eengaged ,you could trap your han d
between th evehicl eand th etrailer drawbar.
Ther eis aris kof injury.
Do no tuncouple atrailer if th eoverrun brak e
is engaged .
GWARNING
Vehicles wit hleve lcontrol :
The vehicl eis lowered as soo nas you discon -
nect th etrailer cable. This could result in your
limb sor those of other people that are
between th evehicl ebody and tires or under-
neath th evehicl ebein gtrapped .Ther eis a
ris kof injury.
Mak esure that nobody is in th eimmediat e
vicinity of th ewhee lhousing sor under th e
vehicl ewhen you disconnect th etrailer cable.
!Do not disconnect a trailer with an
engaged overrun brake. Otherwise, your
vehicle could bedamaged bythe rebound-
ing of the overrun brake.
XSh ift the transmission to position P.
XApply the vehicle's electr icparking brake.
XStart the engine.
XClose the doors and tailgate.
XApply the trailer's parking brake.
268Towing a trailer
Driving and parking

Display messagesPossible causes/consequences andMSolutions
b
AUTOlightsinoper ‐
ative
The ligh tsensor is defective.
XVisit aqualified specialist workshop .
b
Switch off lights
You leaveth evehicl eand th eligh tis still switched on . Awarnin g
tone also sounds.
XTur nth eligh tswitch to th eà position .
Adaptive Highbeam
Assist Currently
Unavailable See
Operator' sManual
Adaptive Highbeam Assis tis deactivated and temporarily inoper -
ative. Possibl ecauses are:
Rth ewindshield in th ecamera' sfield of vision is dirty.
Rvisibility is 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 Highbeam Assist Now Available
message is dis-
played .
Adaptive Highbeam Assis tis operational again .
Adaptive Highbeam
Assist Inoperative
Adaptive Highbeam Assis tis faulty.
XVisit aqualified specialist workshop .
Engine
Display messagesPossible causes/consequences and MSolutions
+
Check Coolant
Level See Opera‐
tor's Manual
The coolantlevel is to olow.
!Avoid makin glon gjourneys wit hto olittl ecoolan tin th eengin e
coolin gsystem. The engin ewill otherwise be damaged.
XAd dcoolant, observin gth ewarnin gnote sbefore doin gso
(
Ypage 373).
XIf you need to add coolan tmor eofte nthan usual, hav eth e
engin ecoolan tsystem checke dat aqualified specialist work-
shop.
?The fan motor is faulty.
XAt coolan ttemperatures belo w24 8 ‡ (120†), drive to th e
neares tqualified specialist workshop .
XAvoid subjecting theengin eto heav yloads ,e.g. drivin gin moun-
tainous terrain ,and stop-and-g otraffic.
306Display messages
On-board computer and displays

ProblemPossible causes/consequences andMSolutions
F(USA only)
The red electric parking
brake indicator lamp
flashes or lights up
and/or
!
the yellow warning
lamp for the electric
parking brake lights up.XObserve the additional display messages in the multifunction
display.
6
The red restraint sys-
tem warning lamp is lit
while the engine is run-
ning.The restraint system is faulty.
GWARNING
The air bags or Emergency Tensioning Devices may either be trig-
gered unintentionally or, in the event of an accident, may not be
triggered.
There is an increased risk of injury.
XObserve the additional display messages in the multifunction
display.
XDrive on carefully.
XHave the restraint system checked immediately at a qualified
specialist workshop.
For further information about the restraint system, see
(
Ypage 44).
Warning and indicator lamps in the instrument cluster333
On-board computer and displays
Z

Engine
ProblemPossible causes/consequences andMSolutions
;
The yellow Check
Engine warning lamp
lights up while the
engine is running.There may be a malfunction, for example:
Rin the engine management
Rin the fuel injection system
Rin the exhaust system
Rin the ignition system (for vehicles with gasoline engines)
Rin the fuel system
The emission limit values may be exceeded and the engine may be
in emergency mode.
XHave the vehicle checked as soon as possible at a qualified
specialist workshop.
iIn some states, you must immediately visit a qualified special-
ist workshop as soon as the yellow Check Engine warning lamp
lights up. This is due to the legal requirements in effect in these
states. If in doubt, check whether such legal regulations apply in the state in which you are currently driving.
Vehicles with a diesel engine: the fuel tank has been run dry
(
Ypage 185).
XStart the engine three to four times after refueling.
If the yellow Check Engine warning lamp goes out, emergency
running mode is canceled. The vehicle need not be checked.
8
The yellow reserve fuel
warning lamp lights up
while the engine is run-
ning.The fuel level has dropped into the reserve range.
XRefuel at the nearest gas station.
8
The yellow reserve fuel
warning lamp flashes
while the vehicle is in
motion.
In addition, the ;
Check Engine warning
lamp may light up.The fuel system pressure is too low. The fuel filler cap is not closed
correctly or the fuel system is leaking.
XCheck that the fuel filler cap is correctly closed.
XIf the fuel filler cap is not correctly closed: close the fuel filler
cap.
XIf the fuel filler cap is closed: visit a qualified specialist work-
shop.
334Warning and indicator lamps in the instrument cluster
On-board computer and displays