check engine light MERCEDES-BENZ GL 2016 User Guide

Problem
Possible causes/consequences and P Solutions
Vehicles with a gaso-
line engine:
The engine is not run-
ning smoothly and is
misfiring. There is a malfunction in the engine electronics or in a mechanical
component of the engine management system. X
Only depress the accelerator pedal slightly.
Otherwise, non-combusted fuel may get into the catalytic con-
verter and damage it. X
Have the cause rectified immediately at a qualified specialist
workshop.
The coolant tempera-
ture gage 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. X
Stop as soon as possible and allow the engine and the coolant to
cool down. X
Check the coolant level ( Y
page 373). Observe the warning
notes as you do so and add coolant if necessary.
Automatic transmission
Important safety notes
G WARNING
If the engine speed is above the idling speed
and you engage transmission position D or R ,
the vehicle could pull away suddenly. There is
a risk of an accident.
When engaging transmission position D or R ,
always firmly depress the brake pedal and do
not simultaneously accelerate.
G WARNING
The automatic transmission switches to neu-
tral position N when you switch off the engine.
The vehicle may roll away. There is a risk of an
accident.
After switching off the engine, always switch
to parking position P . Prevent the parked vehi-
cle from rolling away by applying the parking
brake. DIRECT SELECT lever
Overview of transmission positions
]
Park position with parking lock ^
Reverse gear \\
Neutral [
Drive
The DIRECT SELECT lever is on the right of the
steering column.
The DIRECT SELECT lever always returns to
its original position. The current transmission
position P , R , N or D appears in the transmis-
sion position display in the multifunction dis-
play ( Y
page 174).Automatic transmission 173
Driving and parking Z

Heavy and light loads
G WARNING
If you rest your foot on the brake pedal while
driving, the braking system can overheat. This
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 air-
flow 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 reac-
tion 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 vehi-
cle washed, brake firmly while paying atten-
tion to the traffic conditions. This will warm up
the brake discs, thereby drying them more
quickly and protecting them against corro-
sion.
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. R
Brake occasionally to remove any possible
salt residue. Make sure that you do not
endanger other road users when doing so. R
Carefully depress the brake pedal and the
beginning and end of a journey. R
Maintain 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 warn-
ing tone while the engine is running, the
brake fluid level may be too low. Observe
additional warning messages in the multi-
function 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. 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 dynamom-
eter. 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 position 0 or 1 or Start/
Stop button in position 0 or 1 ) 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 quali-
fied specialist workshop. Consult a qualified
specialist workshop to arrange this.
Have brake pads installed and brake fluid
replaced at a qualified specialist workshop. Driving tips 195
Driving and parking Z

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 Read this section carefully before driving your
vehicle off-road. Practice by driving over more
gentle off-road terrain first.
Familiarize yourself with the characteristics
of your vehicle and the gear shift operation
before driving through difficult terrain.
The following driving systems are specially
adapted to off-road driving: R
Off-road program 1 and 2 (vehicles with the
ON&OFFROAD package) ( Y
page 258)R
LOW RANGE off-road gear (vehicles with
the ON&OFFROAD package)
( Y
page 259) R
Differential lock (vehicles with the
ON&OFFROAD package) ( Y
page 259)R
Off-road ABS ( Y
page 69)R
Off-road 4ETS ( Y
page 73)R
AIRMATIC package (vehicle level)
( Y
page 218) R
DSR (Downhill Speed Regulation)
( Y
page 257)
Observe the following notes: R
Stop the vehicle before starting to drive
along an off-road route. R
Select a vehicle level that is suitable for the
terrain. To avoid damaging the vehicle, make sure there is always sufficient ground
clearance. R
Check that items of luggage and loads are
stowed safely and are well secured
( Y
page 345). R
Always keep the engine running and in gear
when driving on a downhill gradient. Acti-
vate DSR ( Y
page 257). R
Always keep the engine running and in gear
when driving on a slope. R
Adapt your speed to the terrain. The
rougher, steeper or more ruts on the ter-
rain, the slower your speed should be. R
Do not jump with the vehicle as this will
interrupt the vehicle's propulsion. R
Drive 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. R
Look out for obstacles, such as rocks,
holes, tree stumps and furrows. R
Always keep the doors, the tailgate, the
side windows and the sliding sunroof
closed while the vehicle is in motion. R
Do not shift the automatic transmission to
transmission position N .R
Observe the notes on off-road fording
( Y
page 197).
i Do not use the HOLD function when driv-
ing off-road, on steep uphill or downhill gra-
dients 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 vehi-
cle 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. X
Engine oil level: check the engine oil level
and add oil if necessary. Driving tips 199
Driving and parking Z

When driving on steep gradients, the
engine oil level must be sufficiently high to
ensure a correct oil supply in the vehicle. X
DEF tank (BlueTEC vehicles): check the
level and add if necessary ( Y
page 186).X
Tire-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. X
Wheels and tires: check the tire tread
depth and tire pressure. X
Check for damage and remove any foreign
objects, e.g. small stones, from the
wheels/tires. X
Replace any missing valve caps. X
Replace dented or damaged wheels. X
Rims: 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. X
Vehicles with the ON&OFFROAD pack-
age: activate the on-road program
( Y
page 258). X
Deactivate the LOW RANGE off-road gear
( Y
page 259). X
Deactivate DSR ( Y
page 257).X
Lower the vehicle level again to a level suit-
able to the road conditions, e.g. to the high-
way level. X
Clean the headlamps and rear lights and
check for damage. X
Clean the front and rear license plates. X
Clean the wheels and tires with a water jet
and remove any foreign objects. X
Clean the wheels, wheel housings and the
vehicle underside with a water jet; check
for any foreign objects and damage. X
Check 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. X
After the trip, examine without fail the
entire undercarriage, wheels, tires, brakes,
bodywork structure, steering, chassis and
exhaust system for damage. X
After 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. X
If 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: R
Vehicles with the ON&OFFROAD pack-
age: select off-road program 1
( Y
page 258). R
Select a higher vehicle level. R
Avoid high engine speeds. R
Use the left-hand steering wheel paddle
shifter to shift to a lower gear appropriate
to the terrain.200
Driving tips
Driving and parking

R
Before driving on extreme uphill and down-
hill gradients, select the LOW RANGE off-
road gear ( Y
page 259).R
Drive slowly. R
Avoid high engine speeds. Drive at appro-
priate engine speeds (maximum
3,000 rpm). R
Use the left-hand steering wheel paddle
shifter to shift into a lower gear in good time
on long and steep downhill gradients. R
Check 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 ( Y
page 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 ( Y
page 456).
Maximum gradient-climbing capability
Always observe the maximum gradient climb-
ing ability values ( Y
page 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: R
the vehicle from lifting off the ground on the
brow of a hill R
the vehicle from traveling too quickly down
the other side
Driving downhill R
Drive slowly. R
Do 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. R
Shift to a lower gear using the left-hand
paddle shifter before tackling steep down-
hill gradients. R
Activate 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. R
Check that the brakes are working normally
after a long downhill stretch.
i The 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
( Y
page 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 must202
Driving systems
Driving and parking

C
Yellow indicator lamp/red warning lamp
When Blind Spot Assist is activated, indicator
lamp C 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 C 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 C flashes. If
the turn signal remains on, detected vehicles
are indicated by the flashing of red warning
lamp C . There are no further warning tones.
Switching on Blind Spot Assist X
Make sure that Blind Spot Assist is activa-
ted in the on-board computer
( Y
page 282). X
Turn the SmartKey to position 2 in the igni-
tion lock.
Warning lamps C 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 rectly established the electrical connec-
t ion . 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 Spot Assist Currently Unavail‐
able See Operator's Manual message
appears in the multifunction display.
i You can deactivate the indicator lamps in
the exterior mirrors.
To do so, switch off Blind Spot Assist when: R
the SmartKey is in position 2 in the igni-
tion lock R
the engine is not running
Lane Keeping Assist
General notes
C
Lane Keeping Assist camera
Lane Keeping Assist monitors the area in
front of your vehicle with camera C , which is
mounted at the top of the windshield. Active
Lane Keeping Assist detects lane markings on246
Driving systems
Driving and parking

so will result in a loss of function of the
brake systems of both the vehicle and the
trailer. X
Shift the transmission to position P .X
Apply the vehicle's electric parking brake. X
Start the engine. X
Vehicles with the AIRMATIC package:
select highway level. X
Vehicles with ADS: set ADS to AUTO or
COMF .X
Switch off the engine. X
Close the doors and tailgate. X
Couple up the trailer. X
Establish the electrical connection
between the vehicle and the trailer. X
Check that the trailer lighting system is
working.
i Vehicles 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: R
Unless 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. R
High-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: R
Safety 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. R
A separate brake system for certain types
of trailer. R
Safety 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: R
in your place of residence R
in the location to which you are driving
The police and local authorities can provide
reliable information.
Observe the following when towing a trailer: R
To 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 R
Before driving, check: -
trailer tow hitch -
safety switch for braked trailers -
safety chains -
electrical connections -
lights -
wheels R
Adjust the exterior mirrors to provide an
unobstructed view of the rear section of the
trailer. R
If the trailer has electronically controlled
brakes, pull away carefully. Brake manually Towing a trailer 267
Driving and parking Z

using the brake controller and check
whether the brakes function correctly. R
Se cure any objects on the trailer to prevent
the cargo from slipping when the vehicle is
in motion. R
When you couple up a trailer, check at reg-
ular intervals that the load is firmly secured.
If the trailer is equipped with trailer lights
and brakes, check the trailer to ensure that
these are working. R
Bear in mind that the han dlin g will be less
st able when towing a trailer than when driv-
ing wit hout one. Avoid sudden steering
movements. R
The vehicle/trailer combination is heavier,
accelerates more slowly, has a decreased
gradient cli mbin g capability and a longer
braking dist ance.
It is more susceptible to side winds and
requires more careful steering. R
If poss ible, do not brake suddenly, but
instead depr ess the brake pedal moder-
ate ly at first so that the trailer can activate
it s brakes. Then increase the pressure on
the brake pedal. R
If the automat ic transmission repeat edly
shifts between gears on uphill or down hill
gradients, 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. R
When driv ing down hill, shift to a lower gear
to uti liz e the engine's braking effect.
Avoid continuous brake application as this
m ay
overheat the vehicle brakes and, if
instal led, the trailer brakes.R
If the coolant temperature increases dra-
matical ly while the air-cond it ioning system
is swit ched on, switch off the air-condition-
ing system.
Coolant heat can also be dissipated by
opening the win dows and switching the ventilation blowe r and the interior temper-
ature to the highest leve l.R
When 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
space in relation to the vehicle you are
overtaking before you can change back to
the original lane.
Decoupling a trailer
G WARNIN G
If you uncouple a trailer wit h th e overrun
brak e engaged , you could trap your han d
between th e vehicl e and th e trailer drawbar.
Ther e is a ris k of injury.
Do no t uncouple a trailer if th e overrun brak e
is engaged .
G WARNIN G
Vehicles wit h leve l control :
The vehicl e is lowered as soo n as you discon -
nect th e trailer cable. This could result in your
limb s or those of other people that are
between th e vehicl e body and tires or under-
neath th e vehicl e bein g trapped . Ther e is a
ris k of injury.
Mak e sure that nobody is in th e immediat e
vicinity of th e whee l housing s or under th e
vehicl e when you disconnect th e trailer cable.
! Do not disc onnect a trailer wit h an
engaged overrun brake. Otherwise, your
vehicle could be damaged by the reboun d-
ing of the overrun brake. X
Sh ift the transmission to position P .X
Ap ply the vehicle's electr ic parking brake.X
St art the engine. X
Close the doors and tailgate. X
Apply the trailer's parking brake.268
Towing a trailer
Driving and parking

Problem
Possible causes/consequences and P Solutions
I (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. X
Observe the additional display messages in the multifunction
display.
u
The red restraint sys-
tem warning lamp is lit
while the engine is run-
ning. The restraint system is faulty.
G WARNING
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. X
Observe the additional display messages in the multifunction
display. X
Drive on carefully. X
Have the restraint system checked immediately at a qualified
specialist workshop.
For further information about the restraint system, see
( Y
page 44).Warning and indicator lamps in the instrument cluster 333
On-board computer and displays Z

! Make sure that the windshield wipers are
not folded away from the windshield. You
could otherwise damage the windshield
wipers or the hood. X
Make sure that the windshield wipers are
turned off. X
Pull release lever C on the hood.
The hood is released.
X
Reach into the gap, pull hood catch han-
dle D up and lift the hood.
If you lift the hood by approximately 15 in
(40 cm), the hood is opened and held open
automatically by the gas-filled strut.
Closing the hood X
Lower the hood and let it fall from a height
of approximately 8 in (20 cm). X
Check that the hood has engaged properly.
If the hood can be raised slightly, it is not
properly engaged. Open it again and close
it with a little more force. Radiator Vehicles with a diesel engine: do not cover
the radiator, for example with a winter front or
bug cover. The readings of the on-board-diag-
nostic system may otherwise be inaccurate.
Some of these readings are required by law
and must be accurate at all times.
Engine oil
General notes Depending on your driving style, the vehicle
consumes up to 0.9 US qt (0.8 liters) of oil per
600 miles (1,000 km). The oil consumption
may be higher than this when the vehicle is
new or if you frequently drive at high engine
speeds.
Depending on the engine, the oil dipstick may
be in a different location.
When checking the oil level: R
park the vehicle on a level surface. R
the engine should be switched off for
approximately five minutes if the engine is
at normal operating temperature. R
if the engine is not at normal operating
temperature, e.g. if the engine was only
started briefly, wait about 30 minutes
before carrying out the measurement.
Checking the oil level using the oil dip-
stick
G WARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and
touch only the components described in the
following.Engine compartment 371
Maintenance and care Z