2018 MERCEDES-BENZ GLS check engine light

Replacing the rear window wiper blade Removing a wiper blade X
Remove the SmartKey from the ignition lock. X
Fold wiper arm C away from the rear window
until it engages. X
Position wiper blade D at a right angle to
wiper arm C . X
Hold wiper arm C and press wiper blade D
in the direction of the arrow until it releases. X
Remove wiper blade D .
Installing a wiper blade X
Place new wiper blade D onto wiper arm C .X
Hold wiper arm C and press wiper blade D
in the opposite direction to the arrow until it
engages. X
Make sure that wiper blade D is seated cor-
rectly. X
Position wiper blade D parallel to wiper
arm C . X
Fold wiper arm C back onto the rear window.
Problems with the windshield wipers Problem
Possible causes/consequences and P Solutions
The windshield wipers
are jammed. Leaves or snow, for example, may be obstructing the windshield wiper
movement. The wiper motor has been deactivated. X
For safety reasons, you should remove the SmartKey from the igni-
tion lock.
or X
Switch off the engine using the Start/Stop button and open the
driver's door. X
Remove the cause of the obstruction. X
Switch the windshield wipers back on.
The windshield wipers
fail completely. The windshield wiper drive is malfunctioning. X
Select another wiper speed on the combination switch. X
Have the windshield wipers checked at a qualified specialist work-
shop.124
Windshield wipers
Lights and windshield wipers

ignite if in contact with the exhaust system or
parts of the engine that heat up. There is a risk
of fire.
Carry out regular checks to make sure that
there are no flammable foreign materials in
the engine compartment or in the exhaust
system.
General notes Vehicles with a gasoline engine: the catalytic
converter is preheated for up to 30 seconds
after a cold start. The sound of the engine may
change during this time.
Automatic transmission X
Shift the transmission to position ]
( Y
page 148).
The transmission position indicator on the
multifunction display shows ]
( Y
page 149).
i You can start the engine in transmission
position ] and \\ .
Starting procedure with the SmartKey X
To start a diesel engine: turn the SmartKey
to position H in the ignition lock
( Y
page 140).
The \( preglow indicator lamp in the instru-
ment cluster lights up. X
Turn the SmartKey to position I in the igni-
tion lock ( Y
page 140) and release it as soon
as the engine is running.
i Vehicles with a diesel engine: you can
start the engine without preglow if the engine
is warm.
Using KEYLESS-GO to start the engine The Start/Stop button can be used to start the
vehicle without inserting the SmartKey into the
ignition lock. The Start/Stop button must be
inserted in the ignition lock and the SmartKey
must be in the vehicle. This mode for starting the
engine operates independently of the ECO
start/stop automatic engine start function. X
Depress the brake pedal and keep it
depressed. X
Press the Start/Stop button once
( Y
page 140).
Vehicles with a gasoline engine: the engine
starts.
Vehicles with a diesel engine: preglow is
activated and the engine starts.
Starting procedure via smartphone Observe the important safety notes on starting
the engine ( Y
page 141).
You can also start your engine via your smart-
phone from outside the vehicle. In this case, the
previously selected climate control setting is
activated. In this way you can cool or heat the
interior of the vehicle before starting the jour-
ney.
Only start the engine via your smartphone if it is
safe to start and run the engine where your vehi-
cle is parked.
Observe the legal stipulations in the area where
your vehicle is parked. Engine start via smart-
phone may be limited to certain countries or
regions.
You can execute a maximum of two consecutive
starting attempts via your smartphone. If you
insert the SmartKey into the ignition lock, you
can carry out two more starting attempts.
Once you have started the engine, you can
switch the engine off via your smartphone at any
time.
You can only start the engine via your smart-
phone if: R
the SmartKey is in the ignition lock R
park position ] is selectedR
the accelerator pedal is not depressed R
the anti-theft alarm system is not activated R
the panic alarm is not activated R
the hazard warning lamps are switched off R
the hood is closed R
the doors are closed and locked R
the windows and sliding sunroof are closed
Also make sure that: R
the fuel tank is sufficiently filled R
the starter battery is sufficiently charged142
Driving
Driving and parking

This helps you to avoid overheating the
brakes and wearing them out excessively.
When you take advantage of engine braking, a
drive wheel may not turn for some time, e.g.
on a slippery road surface. This could cause
damage to the drive train. This type of damage
is not covered by the Mercedes-Benz war-
ranty.
Do not depress the brake pedal continuously
while the vehicle is in motion, e.g. causing the
brakes to rub by constantly applying light pres-
sure to the pedal. This results in excessive and
premature wear to the brake pads.
Use the left-hand steering wheel paddle shifter
to shift into a lower gear in good time on long
and steep downhill gradients. This is especially
important if the vehicle is laden.
This also applies if you have activated cruise
control, the speed limiter 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.
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 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 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 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 resi-
due 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
! The brake fluid level may be too low, if: R
if the red brake warning lamp lights up in
the instrument cluster and R
you hear a warning tone while the engine is
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 immediately.
Consult a qualified specialist workshop to
arrange this.
! A function or performance test should only
be carried out on a 2-axle dynamometer. If
you wish to operate the vehicle on such a
dynamometer, please consult a qualified spe-
cialist workshop in advance. You could oth-
erwise 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 electricDriving tips 167
Driving and parking Z

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
the Off-road drive program (vehicles without
Off-Road Engineering package)
( Y
page 219) R
Off-road and Off-road Plus drive programs
(vehicles with Off-Road Engineering package)
( Y
page 220) R
LOW RANGE off-road gear (vehicles with the
Off-Road Engineering package)
( Y
page 221) R
Differential lock (vehicles with the Off-Road
Engineering package) ( Y
page 221)R
Off-road ABS ( Y
page 67)R
Off-road 4ETS ( Y
page 70)R
Off-road ESP ®
( Y
page 71)R
AIRMATIC package (vehicle level)
( Y
page 188) R
DSR (Downhill Speed Regulation)
( Y
page 218)
Observe the following notes: R
Stop the vehicle before starting to drive along
an off-road route. If necessary, select the off-
road program ( Y
page 220) or shift to the
LOW RANGE off-road gear ( Y
page 221).R
Select a vehicle level that is suitable for the
terrain. To avoid damaging the vehicle, make
sure there is always sufficient ground clear-
ance. R
Check that items of cargo and loads are
stowed safely and are well secured
( Y
page 305). R
Always keep the engine running and in gear
when driving on a downhill gradient. Activate
DSR ( Y
page 218).R
Always keep the engine running and in gear
when driving down an incline. R
Adapt your speed to the terrain. The rougher,
steeper or more ruts on the terrain, the slower
your speed should be. R
Do not jump with the vehicle as this will inter-
rupt the vehicle's propulsion. R
Drive with extreme care on unfamiliar off-road
routes where visibility is poor. For safety rea-
sons, 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
Take care when turning on an uphill or down-
hill slope or when driving across a slope. The
vehicle could otherwise tip over. 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
position \\ . R
Observe the notes on off-road fording
( Y
page 169).
i Information about retrofitting special all-ter-
rain tires is available from any qualified spe-
cialist workshop.
i Do 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 sur-
faces.
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. X
Engine 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. X
DEF tank (BlueTEC vehicles): check the
level and add if necessary ( Y
page 158).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 tread depth and
pressure of the tires. 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. Driving tips 171
Driving and parking Z

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 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. X
If the Offroad or Offroad Plus drive program
is selected: select the Individual , Sport ,
Comfort or Slippery drive program
( Y
page 147).X
Deactivate the LOW RANGE off-road gear
( Y
page 221).X
Deactivate DSR ( Y
page 218).X
Lower the vehicle level again to a level suita-
ble to the road conditions, e.g. to the normal
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 bellows of the axle joints
and propeller shafts. X
After the trip, examine without fail the entire
undercarriage, wheels, tires, brakes, body-
wor k stru cture, 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
Select the Offroad drive program (vehicles
without Off-Road Engineering package)
( Y
page 219). R
Select the Offroad drive program (vehicles
with Off-Road Engineering package)
( Y
page 220). 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. R
Drive quickly to overcome the rolling resist-
ance. Otherwise the vehicle's wheels could
become stuck in loose ground. R
Drive in the tracks of other vehicles if possi-
ble. Make sure that: -
the tire ruts are not too deep. -
the sand is sufficiently firm. -
the ground clearance of the vehicle is suf-
ficient.
Tire ruts and gravel roads
! Check that the ruts are not too deep and
that your vehicle has sufficient clearance.
Otherwise, your vehicle could be damaged or
bottom out and get stuck.
Observe the following rules when driving along
ruts in off-road terrain or on roads with loose
gravel: R
Select the Offroad drive program (vehicles
without Off-Road Engineering package)
( Y
page 219). R
Select the Offroad drive program (vehicles
with Off-Road Engineering package)
( Y
page 220). R
Select a higher vehicle level. R
Avoid high engine speeds. R
Shift to a lower gear using the left-hand steer-
ing wheel paddle shifter. R
Drive slowly. R
Where ruts are too deep, drive with the
wheels of one side on the center grassy area,
if possible.172
Driving tips
Driving and parking

Hilltops When driving up an uphill gradient, slightly
reduce pressure on the accelerator immediately
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. Otherwise, the
vehicle could slip sideways, tip and rollover. R
Shift to a lower gear using the left-hand pad-
dle shifter before tackling steep downhill gra-
dients. 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 com-
pletely braked and therefore lose their ability
to steer.
Driving systems
Intelligent Drive Mercedes-Benz Intelligent Drive stands for inno-
vative driver assistance and safety systems
which enhance comfort and support the driver in
critical situations. With these intelligent co-ordi-
nated systems Mercedes-Benz has set a mile-
stone 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 vehi-
cle occupants and that of other road users. Further information on driving safety systems
( Y
page 66).
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 select a
lower gear in good time on long and steep down-
hill gradients, especially if the vehicle is laden or
towing a trailer. 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).
i Cruise control should not be activated when
driving off-road.
Important safety notes If you fail to adapt your driving style, cruise con-
trol can neither reduce the risk of an accident
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 distance to the
vehicle in front, for vehicle speed, for braking in
good time and for staying in your lane.
Do not use cruise control: R
in road and traffic conditions which do not
allow you to maintain a constant speed, e.g. in
heavy traffic or on winding roads R
on slippery road surfaces. Braking or accel-
erating could cause the drive wheels to lose
traction and the vehicle could then skid R
when 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.174
Driving systems
Driving and parking

C
Warning lamp
If Blind Spot Assist is activated, warning lamp C
in the exterior mirrors lights up yellow at speeds
of up to 20 mph (30 km/ h) . At speeds above
20 mph (30 km/h), the warning 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 correspond-
ing 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).
If you select the reverse gear, Blind Spot Assist
is not operational.
The brightness of the warning lamps is auto-
matically adapted to the brightness of the sur-
roundings.
Collision warning If a vehicle is detected in the monitoring range of
Blind Spot Assist and you switch on the corre-
sponding turn signal, a double warning tone
sounds. Red warning lamp C flashes. If the turn
signal remains on, detected vehicles are indica-
ted 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 activated
in the on-board computer ( Y
page 242).X
Turn the SmartKey to position H in the igni-
tion lock.
Warning lamps C in the exterior mirrors light
u p 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 deac-
tivated. The warning lamp lights up yellow in the
exterior mirrors and the Blind Spot Assist
Not Available When Towing a Trailer
See Operator's Manual message appears in
the multifunction display.
i You can deactivate the warning lamps in the
exterior mirrors.
To do so, switch off Blind Spot Assist when: R
the SmartKey is in position H 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. Lane Keeping Assist
detects lane markings on the road and can warn
you before you leave your lane unintentionally.
This function is available in the range between
40 mph and 120 mph (60 km/h and 200 km/h).
A warning may be given if a front wheel passes
over a lane marking. It will warn you by means of
intermittent vibration in the steering wheel for
up to 1.5 seconds.
Important safety notes
G WARNING
Lane Keeping Assist cannot always clearly
detect lane markings.Driving systems 211
Driving and parking Z

Course-correcting brake application If Active Blind Spot Assist detects a risk of a lat-
eral collision in the monitoring range, a course-
correcting brake application is carried out. This
is meant to assist you in avoiding a collision.
G WARNING
A course-correcting brake application cannot
always prevent a collision. There is a risk of an
accident.
Always steer, brake or accelerate yourself,
especially if Active Blind Spot Assist warns
you or makes a course-correcting brake appli-
cation. Always maintain a safe distance at the
sides.
If a course-correcting brake application occurs,
red warning lamp C flashes in the exterior mir-
ror and a double warning tone sounds. In addi-
tion, a display underlining the danger of a side
collision appears in the multifunction display.
In very rare cases, the system may make an
inappropriate brake application. A course-cor-
recting brake application may be interrupted at
any time by countersteering slightly or acceler-
ating.
The course-correcting brake application is avail-
able in the speed range between 20 mph
(30 km/h) and 120 mph (20 0 km/ h) .
Either no braking application, or a course-cor-
recting brake application adapted to the driving
situation occurs if: R
there are vehicles or obstacles, e.g. crash
barriers, located on both sides of your vehicle. R
a vehicle approaches you too closely at the
side. R
you have adopted a sporty driving style with
high cornering speeds. R
you clearly brake or accelerate. R
a driving safety system intervenes, e.g. ESP ®
or PRE-SAFE ®
Brake.R
ESP ®
is switched off.R
the offroad program is activated (vehicles
without the Offroad Engineering package). R
the Offroad or Offroad Plus drive program is
activated (vehicles with the Off-Road Engi-
neering package). R
the LOW RANGE offroad gear is activated
(vehicles with the Offroad Engineering pack-
age). R
a loss of tire pressure or a defective tire is
detected.
Switching on Active Blind Spot Assist X
Make sure that Active Blind Spot Assist
( Y
page 242) is activated in the on-board
computer. X
Turn the SmartKey to position H in the igni-
tion lock.
Warning lamps C in the exterior mirrors light
up red for approximately 1.5 seconds an d
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. Active Blind Spot Assist is then deacti-
vated. The indicator lamp lights up yellow in the
exterior mirrors and the Active Blind Spot
Asst. Not Available When Towing a
Trailer See Operator's Manual message
appears in the multifunction display.
Active Lane Keeping Assist
General notes
Active Lane Keeping Assist monitors the area in
front of your vehicle by means of multifunction
camera C at the top of the windshield. Various
different areas to the front, rear and side of your
vehicle are also monitored with the aid of the
radar sensor system. Active Lane Keeping
Assist detects lane markings on the road and
can warn you before you leave your lane unin-
tentionally. If you do not react to the warning, aDriving system s 215
Dr ivi ng an d parking Z