2014 MERCEDES-BENZ GL check engine light

Problems with the engine
ProblemPossible causes/consequences andPPSolutions
The engine does not
start. The starter motor
can be heard.
RThere is a malfunction in the engine electronics.
RThere is a malfunction in the fuel supply.
XTry to start the engine again (Ypage 169). Avoid excessively
long and frequent attempts to start the engine as these will drain
the battery.
If the engine does not start after several attempts:
XConsult a qualified specialist workshop.
The engine does not
start. You cannot hear
the starter motor.
The on-board voltage is too low because the battery is too weak
or discharged.
XJump-start the vehicle (Ypage 395).
If the engine does not start despite attempts to jump-start it:
XConsult a qualified specialist workshop.
The starter motor was exposed to a thermal load that was too high.
XAllow the starter motor to cool down for approximately two
minutes.
XTry to start the engine again.
If the engine still does not start:
XConsult a qualified specialist workshop.
The engine is not
running smoothly and
is misfiring.
There is a malfunction in the engine electronics or in a mechanical
component of the engine management system.
XOnly depress the accelerator pedal slightly.
XHave the cause rectified immediately at a qualified specialist
workshop.
Otherwise, non-combusted fuel may get into the catalytic
converter and damage it.
The coolant
temperature gauge
shows a value above
248 ‡ (120 †).
The coolant level is too low. The coolant is too hot and the engine
is no longer being cooled sufficiently.
XStop as soon as possible and allow the engine and the coolant
to cool down.
XCheck the coolant level (Ypage 373). Observe the warning
notes as you do so and add coolant if necessary.
172Driving
Driving and parking

increases the stopping distance and can even
cause the braking system to fail. There is a
risk of an accident.
Never use the brake pedal as a footrest. Never
depress the brake pedal and the accelerator
pedal at the same time.
!Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If the brakes have been subjected to a heavy
load, do not stop the vehicle immediately.
Drive on for a short while. This allows the
airflow to cool the brakes more quickly.
Wet roads
If you have driven for a long time in heavy rain
without braking, there may be a delayed
reaction from the brakes when braking for the
first time. This may also occur after the
vehicle has been washed or driven through
deep water.
You then have to depress the brake pedal
more firmly. Maintain a greater distance from
the vehicle in front.
After driving on a wet road or having the
vehicle washed, brake firmly while paying
attention to the traffic conditions. This will
warm up the brake discs, thereby drying them
more quickly and protecting them against
corrosion.
Limited braking performance on salt-
treated roads
If you drive on salted roads, a layer of salt
residue may form on the brake discs and
brake pads. This can result in a significantly
longer braking distance.
RBrake occasionally to remove any possible
salt residue. Make sure that you do not
endanger other road users when doing so.
RCarefully depress the brake pedal and the
beginning and end of a journey.
RMaintain a greater distance to the vehicle
ahead.
Servicing the brakes
!If the red brake warning lamp lights up in
the instrument cluster and you hear a
warning tone while the engine is running,
the brake fluid level may be too low.
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
immediately. This work should be carried
out at a qualified specialist workshop.
!A function or performance test should
only be carried out on a 2-axle
dynamometer. If you are planning to have
the vehicle tested on such a dynamometer,
contact an authorized Mercedes-Benz
Center to obtain further information first.
Otherwise, you could damage the drive
train or the brake system.
!Because ESP®is an automatic system,
the engine and ignition must be switched
off (SmartKey in position0or1or Start/
Stop button in position0or1) when the
electric parking brake is being tested on a
brake dynamometer (maximum
10 seconds).
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
qualified specialist workshop. Consult a
qualified specialist workshop to arrange this.
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
functionality of your brakes at regular
intervals. To do so, press firmly on the brake
pedal when driving at a high speed. This
improves the grip of the brake pads.
You can find a description of Brake Assist
(BAS) on (Ypage 68) or of BAS PLUS on
(Ypage 68).
194Driving tips
Driving and parking

RAlways keep the engine running and in gear
when driving on a downhill gradient.
Activate DSR (Ypage 256).
RAlways keep the doors, tailgate, windows
and sliding sunroof closed while driving.
RAdapt your speed to the terrain. The
rougher, steeper or more ruts on the
terrain, the slower your speed should be.
RDrive slowly and at an even speed through
the water. Ensure that a bow wave does not
form as you drive.
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.
RLook out for obstacles, such as rocks,
holes, tree stumps and furrows.
RCheck the depth of water before fording
rivers and streams.
RWhen fording, do not stop and do not
switch off the engine.
ROn sand, drive quickly to overcome the
rolling resistance. Otherwise the vehicle's
wheels could become stuck in loose
ground.
RDo not jump with the vehicle as this will
interrupt the vehicle's propulsion.
RAlways keep the engine running and in gear
when driving on a slope.
RDo not shift the automatic transmission to
transmission positionN.
iDo not use the HOLD function when
driving off-road, on steep uphill or downhill
gradients or on slippery or loose surfaces.
The HOLD function cannot hold the vehicle
on such surfaces.
Checklist before driving off-road
!If the engine oil warning lamp lights up
while the vehicle is in motion, stop the
vehicle in a safe place as soon as possible.
Check the engine oil level. The engine oil
warning lamp warning must not be ignored.
Continuing the journey while the symbol is
displayed could lead to engine damage.
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.
XDEF tank (BlueTEC vehicles):check the
level and top up 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. Therefore, check your rims before
driving off-road and replace them as
required.
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
workshop.
XVehicles with the ON&OFFROAD
package:activate the on-road program
(Ypage 258).
XDeactivate the LOW RANGE off-road gear
(Ypage 259).
XDeactivate DSR (Ypage 256).
XVehicles with the AIRMATIC package:
lower the vehicle to a ride height suitable
for the road conditions, e.g. to the
highway/high-speed level.
XClean the headlamps and rear lights and
check for damage.
XClean the front and rear license plates.
XClean the wheels/tires with a water jet and
remove any foreign objects.
198Driving tips
Driving an d parking

Observe the following rules when driving over
tree stumps, large stones and other
obstacles:
RSelect the LOW RANGE (Ypage 259) off-
road gear.
RRaise the vehicle level.
RAvoid high engine speeds.
RShift to a lower gear using the left-hand
steering wheel paddle shifter.
RDrive very slowly.
RDrive straight over the center of obstacles.
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 rules on off-road driving.
RDo not drive at an angle on slopes, inclines
or gradients, but instead follow the direct
line of fall. The maximum gradient-climbing
capability of your vehicle is 100%, which
corresponds to an approach/departure
angle of 45°. Note that the climbing ability
of your vehicle depends on the terrain
conditions.
RWhen driving down an incline, make use of
the engine's braking effect. Observe the
engine speed; do not overrev the engine.
RBefore driving on extreme uphill and
downhill gradients, select the LOW RANGE
off-road gear (Ypage 259).
RDrive slowly.
RAvoid high engine speeds. Drive at
appropriate engine speeds (maximum
3,000 rpm).
RUse the left-hand 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.
iHill start assist will aid you when pulling
away on a hill.
For further information about hill start
assist, see (Ypage 171).
Do not switch to transmission positionN
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 455).
Maximum gradient-climbing capability
Always observe the maximum gradient
climbing ability values (Ypage 455).
Hilltops
When driving up an uphill gradient, slightly
reduce pressure on the accelerator
immediately before reaching the brow of the
hill. Use the vehicle's own impetus to drive
over the top of the hill.
This style of driving prevents:
Rthe vehicle from lifting off the ground on the
brow of a hill
Rthe vehicle from traveling too quickly down
the other side
200Driving tips
Driving and parking

corresponding 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 lampCflashes. If
the turn signal remains on, vehicles detected
are indicated by the flashing of red warning
lampC. There are no further warning tones.
Switching on Blind Spot Assist
XMake sure that the radar sensor system
(Ypage 285) and Blind Spot Assist
(Ypage 281) are activated in the on-board
computer.
XTurn the SmartKey to position2in the
ignition lock.
Warning lampsCin 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
correctly established the electrical
connection. 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 theBlind Spot Assist CurrentlyBlind Spot Assist Currently
Unavailable See Operator's ManualUnavailable See Operator's Manual
message 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 position2in the
ignition lock
Rthe engine is not running
Rthe electrical connection to the trailer
has been established
Lane Keeping Assist
General notes
CLane Keeping Assist camera
Lane Keeping Assist monitors the area in
front of your vehicle by means of a
cameraCat the top of the windshield. Lane
Keeping Assist detects lane markings on the
road and warns you before you leave your
lane unintentionally.
If you selectkmkmon the on-board computer in
theDisplay Unit Speed-/OdometerDisplay Unit Speed-/Odometer
function (Ypage 282), Lane Keeping Assist
is active starting at a speed of 60 km/h. If the
Driving systems245
Driving and parking
Z

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.
XMake sure that the automatic transmission
is set 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 all doors and the tailgate.
XCouple up the trailer.
XEstablish all electrical connections.
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
coupling up a trailer, please observe the
following:
RUnless highway level has been set
manually, the vehicle is automatically
lowered to highway level. This is the case
if a speed of 5 mph(8km/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
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.
RA safety switch for braked trailers. Check
the specific legal requirements applicable
to your state.
If the trailer detaches from the towing
vehicle, the safety switch applies the
trailer's brakes.
Towing a trailer
There are numerous legal requirements
concerning the towing of a trailer, e.g. speed
restrictions. Make sure that your vehicle/
trailer combination complies with the local
requirements not only in your area of
residence but also at any location to which
you are traveling. The police and local
authorities can provide reliable information.
Please observe the following when towing a
trailer:
RIn order to accumulate driving experience
and accustom yourself to the new handling
characteristics, practice the following at a
location where there is no traffic:
-Cornering
-Stopping
-Backing up
RBefore driving, check:
-the trailer tow hitch
-the safety switch for braked trailers
-the safety chains
-electrical connections
-the lights
-the 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.
Towing a trailer267
Driving an d parking
Z

Useful information
iThis Operator's Manual describes all
models and all standard and optional
equipment of your vehicle available at the
time of publication of the Operator's
Manual. Country-specific differences are
possible. Please note that your vehicle may
not be equipped with all features
described. This also applies to safety-
related systems and functions.
iRead the information on qualified
specialist workshops: (Ypage 28).
Important safety notes
GWARNING
If you operate information systems and
communication equipment integrated in the
vehicle while driving, you will be distracted
from traffic conditions. You could also lose
control of the vehicle. There is a risk of an
accident.
Only operate the equipment when the traffic
situation permits. If you are not sure that this
is possible, park the vehicle paying attention
to traffic conditions and operate the
equipment when the vehicle is stationary.
GWARNING
If the instrument cluster has failed or
malfunctioned, you may not recognize
function restrictions in systems relevant to
safety. The operating safety of your vehicle
may be impaired. There is a risk of an
accident.
Drive on carefully. Have the vehicle checked
at a qualified specialist workshop
immediately.
You must observe the legal requirements for
the country in which you are currently driving
when operating the on-board computer.
The on-board computer only shows messages
or warnings from certain systems in the
multifunction display. You should therefore
make sure your vehicle is operating safely at
all times. Otherwise, a vehicle that is not
operating safely may cause an accident.
For an overview, see the instrument panel
illustration (Ypage 33).
Displays and operation
Instrument cluster lighting
The lighting in the instrument cluster, in the
displays and the controls in the vehicle
interior can be adjusted using the brightness
control knob.
The brightness control knob is located on the
bottom left of the instrument cluster
(Ypage 33).
XTurn the brightness control knob clockwise
or counter-clockwise.
If the light switch is set toX,`or
X, the brightness is dependent upon
the brightness of the ambient light.
iThe light sensor in the instrument cluster
automatically controls the brightness of
the multifunction display.
In daylight, the displays in the instrument
cluster are not illuminated.
Coolant temperature display
GWARNING
Opening the hood when the engine is
overheated or when there is a fire in the
engine compartment could expose you to hot
gases or other service products. There is a
risk of injury.
Let an overheated engine cool down before
opening the hood. If there is a fire in the
engine compartment, keep the hood closed
and contact the fire department.
!A display message is shown if the coolant
temperature is too high.
272Displays and operation
On-board computer and displays

ProblemPossible causes/consequences andPPSolutions
I(USA only)
$(Canada only)
The red electric parking
brake indicator lamp
flashes or lights up
and/or
$
warning lamp for the
electric parking brake
lights up.
XObserve the additional display messages in the multifunction
display.
u
The red SRS warning
lamp is lit while the
engine is running.
There is a malfunction in the SRS (Supplemental Restraint
System).
GWARNING
The air bags or Emergency Tensioning Devices may either be
triggered 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 SRS checked at a qualified specialist workshop
immediately.
For further information about SRS, see (Ypage 43).
332Warning and indicator lamps in the instrument cluster
On-board computer and displays