2017 MERCEDES-BENZ GLS-Class SUV check engine

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
XShift the transmission to position P
(Ypage 146).
The transmission position display in the mul-
tifunction display shows P(
Ypage 148).
iYou can start the engine in transmission
position Pand N.
Starting procedure with the SmartKey
XTo start a diesel engine : turn the SmartKey
to position 2in the ignition lock (Ypage 138).
The % preglow indicator lamp in the instru-
ment cluster lights up.
XTurn the SmartKey to position 3in the ignition
lock and release it as soon as the engine is
running (
Ypage 138).
iVehicles 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.
XDepress the brake pedal and keep it
depressed.
XPress the Start/Stop button once
(Ypage 138).
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 (Ypage 139).
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:
Rthe SmartKey is in the ignition lock
Rpark position Pis selected
Rthe accelerator pedal is not depressed
Rthe anti-theft alarm system is not activated
Rthe panic alarm is not activated
Rthe hazard warning lamps are switched off
Rthe hood is closed.
Rthe doors are closed and locked
Rthe windows and sliding sunroof are closed
Also make sure that:
Rthe fuel tank is sufficiently filled
Rthe starter battery is sufficiently charged
140Driving
Driving and parking

ProblemPossible causes/consequences andMSolutions
Vehicles with a gasoline
engine:
The engine is not running
smoothly and is misfir-
ing.There is a malfunction in the engine electronics or in a mechanical
component of the engine management system.
XOnly depress the accelerator pedal slightly.
Otherwise, non-combusted fuel may get into the catalytic converter
and damage it.
XHave the cause rectified immediately at a qualified specialist work-
shop.
The coolant temperature
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.
XStop as soon as possible and allow the engine and the coolant to
cool down.
XCheck the coolant level (Ypage 322). Observe the warning notes
as you do so and add coolant if necessary.
DYNAMIC SELECT controller
Use the DYNAMIC SELECT controller to change
the drive program. Depending on the drive pro-
gram selected the following vehicle character-
istics will change:
Rthe drive (engine and transmission manage-
ment)
Rthe transmission
Rthe suspension
Rthe steering
Rthe availability of the ECO start/stop function
Each time you start the engine with the Smart-
Key or the Start/Stop button, the Comfortdrive
program is activated. For further information
about starting the engine, see (
Ypage 139).
XAll vehicles (except Mercedes-AMG vehi-
cles): turn DYNAMIC SELECT controller :as many times as necessary until the desired
drive program is selected.
The selected drive program appears in the
multifunction display. After five seconds the
display goes out.
In addition, the current drive program settings
are displayed in the multimedia system dis-
play.
Drive programs available (all vehicles
except Mercedes-AMG vehicles):
IndividualIndividual settings
SportSporty driving characteris-
tics
ComfortComfortable and economi-
cal driving characteristics
SlipperyOptimal driving characteris-
tics on slippery or snow-
covered roads
Off-roadOptimal driving characteris-
tics for easily negotiable off-
road terrain
Offroad Plus
(vehicles with
Off-Road Engi-
neering pack-
age)Optimal driving characteris-
tics for rough terrain
DYNAMIC SELECT controller145
Driving and parking
Z

Problems with the transmission
ProblemPossible causes/consequences andMSolutions
The transmission has
problems shifting gear.The transmission is losing oil.
XHave the transmission checked at a qualified specialist workshop
immediately.
7G-TRONIC:
The acceleration ability
is deteriorating.
The transmission no lon-
ger changes gear.The transmission is in emergency mode.
It is only possible to shift intosecondgear and reverse gear.
XStop the vehicle.
XShift the transmission to position P.
XSwitch off the engine.
XWait at least ten seconds before restarting the engine.
XShift the transmission to positionDor R.
If D is selected, the transmission shifts into secondgear; ifRis
selected, the transmission shifts into reverse gear.
XHave the transmission checked at a qualified specialist workshop
immediately.
9G-TRONIC:
The acceleration ability
is deteriorating.
The transmission no lon-
ger changes gear.The transmission is in emergency mode.
It is only partly possible to engage the gears or the transmission is in
position N.
XStop the vehicle.
XShift the transmission to position P.
XSwitch off the engine.
XWait at least ten seconds before restarting the engine.
XShift the transmission to positionDor R.
XHave the transmission checked at a qualified specialist workshop
immediately.
Transfer case
This section is only valid for vehicles with 4-
wheel drive (4MATIC). Power is always trans-
mitted to both axles.
!Performance tests may only be carried out
on a 2-axle dynamometer. The brake system
or transfer case could otherwise be damaged. Contact a qualified specialist workshop for a
performance test.
!Because ESP®is an automatic system, the
engine and ignition must be switched off
(SmartKey in position 0or 1or Start/Stop
button in position 0or 1) when the electric
parking brake is being tested on a brake dyna-
mometer (maximum 10 seconds).
Braking triggered automatically by ESP
®may
seriously damage the brake system.
!Vehicles with 4MATIC must not be towed
with either the front or the rear axle raised, as
doing so will damage the transmission.
Refueling
Important safety notes
GWARNING
Fuel is highly flammable. If you handle fuel
incorrectly, there is a risk of fire and explo-
sion.
You must avoid fire, open flames, creating
sparks and smoking. Switch off the engine
and, if applicable, the auxiliary heating before refueling.
Refueling153
Driving and parking
Z

Opening the fuel filler flap
:Opening the fuel filler flap
;To insert the fuel filler cap
=Instruction label for fuel type to be refueled
?Tire pressure table
XSwitch off the engine.
XRemove the SmartKey from the ignition lock.
or, on vehicles with KEYLESS ‑GO:
XOpen the driver's door.
The vehicle electronics now have status 0.
This is the same as the SmartKey having been
removed.
The driver’s door can be closed again.
XPress the fuel filler flap in the direction of
arrow :.
The fuel filler flap swings up.
XTurn the fuel filler cap counterclockwise and
remove it.
XInsert the fuel filler cap into the holder
bracket on the inside of filler flap ;.
XCompletely insert the filler neck of the fuel
pump nozzle into the tank, hook in place and
refuel.
XOnly fill the tank until the pump nozzle
switches off.
Do not add any more fuel after the pump stops
filling for the first time. Otherwise, fuel may leak
out.
Vehicles with a diesel engine: the filler neck is
designed for refueling at diesel filling pumps.
Closing the fuel filler flap
XReplace the cap on the filler neck and turn
clockwise until it engages audibly.
XClose the fuel filler flap.
Close the fuel filler flap before locking the vehi-
cle.
If you are driving with the fuel filler cap open, the
8 reserve fuel warning lamp flashes. A mes-
sage appears in the multifunction display
(
Ypage 259).
In addition, the ;Check Engine warning
lamp may light up (
Ypage 283).
Refueling155
Driving and parking
Z

Problems with fuel and the fuel tank
ProblemPossible causes/consequences andMSolutions
Fuel is leaking from the
vehicle.GWARNING
The fuel line or the fuel tank is faulty.
Risk of explosion or fire.
XApply the electric parking brake.
XSwitch off the engine.
XRemove the SmartKey from the ignition lock.
or, on vehicles with KEYLESS‑GO:
XOpen the driver's door.
The on-board electronics now have status 0. This is the same as the
SmartKey having been removed.
XDo not restart the engine under any circumstances.
XConsult a qualified specialist workshop.
The engine does not
start.The fuel tank of a vehicle with a diesel engine has been run completely
dry.
XRefuel the vehicle with at least 5.3 US qt (5 liters) of diesel.
XTurn the ignition on for approximately ten seconds (Ypage 138).
XStart the engine continuously for up to ten seconds until it runs
smoothly.
If the engine does not start:
XTurn the ignition on again for approximately ten seconds
(Ypage 138).
XStart the engine again continuously for up to ten seconds until it
runs smoothly.
If the engine does not start after three attempts:
XConsult a qualified specialist workshop.
The fuel filler flap cannot
be opened.The fuel filler flap is not unlocked.
XUnlock the vehicle (Ypage 74).
The SmartKey battery is discharged or nearly discharged.
XUnlock the vehicle using the mechanical key (Ypage 76).
The fuel filler flap is unlocked, but the opening mechanism is jammed.
XConsult a qualified specialist workshop.
DEF (BlueTEC vehicles only)
General notes
To function properly, BlueTEC exhaust gas after-
treatment must be operated with the reducing
agent DEF. Adding DEF is one of the tasks per-
formed during maintenance. Under normal operating conditions, a tank of DEF lasts until
the next service due date.
When the supply of DEF is almost used up, the
Check Additive See Operator's Manualmessage is shown in the multifunction display.
If you drive the vehicle faster than 10 mph
(16 km/h), the
Check Additive See Opera‐
156Refueling
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
GWARNING
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.
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
!The brake fluid level may be too low, if:
Rif the red brake warning lamp lights up in
the instrument cluster and
Ryou 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 0or 1or Start/Stop
button in position 0or 1) when the electric
Driving tips165
Driving and parking
Z

parking brake is being tested on a brake dyna-
mometer (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 spe-
cialist workshop.
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 functional-
ity of your brakes at regular intervals. To do so,
depress the brake pedal firmly 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 64) or of BAS PLUS on (Ypage 69).
Mercedes-Benz recommends that you only have
brake pads/linings installed on your vehicle
which have been approved for Mercedes-Benz
vehicles or which correspond to an equivalent
quality standard. Brake pads/linings which have
not been approved for Mercedes-Benz vehicles
or which are not of an equivalent quality could
affect your vehicle's operating safety.
Mercedes-Benz recommends that you only use
brake fluid that has been specially approved for
your vehicle by Mercedes-Benz, or which corre-
sponds to an equivalent quality standard. Brake
fluid which has not been approved for
Mercedes-Benz vehicles or which is not of an
equivalent quality could affect your vehicle's
operating safety.
High-performance brake system
(Mercedes-AMG vehicles)
The high-performance brake system is designed
for heavy loads. This may lead to noise when
braking. This will depend on:
RSpeed
RBraking force
REnvironmental conditions, such as tempera-
ture and humidity
The wear of individual components of the brake
system, such as the brake pads/linings or brake
discs, depends on the individual driving style
and operating conditions.
For this reason, it is impossible to state a mile-
age that will be valid under all circumstances. An
aggressive driving style will lead to high wear. You can obtain further information about this
from your authorized Mercedes-Benz Center.
New and replaced brake pads and discs only
reach their optimum braking effect after several
hundred kilometers of driving. Compensate for
this by applying greater force to the brake pedal.
Keep this in mind, and adapt your driving and
braking accordingly during this break-in period.
Excessive heavy braking results in correspond-
ingly high brake wear. Observe the #brake
wear warning lamp in the instrument cluster and
note any brake status messages in the multi-
function display. Especially for high perform-
ance driving, it is important to maintain and have
the brake system checked regularly.
Driving on wet roads
Hydroplaning
If water has accumulated to a certain depth on
the road surface, there is a danger of hydro-
planing occurring, even if:
Ryou drive at low speeds.
Rthe tires have adequate tread depth.
For this reason, in the event of heavy rain or in
conditions in which hydroplaning may occur,
you must drive in the following manner:
Rlower your speed.
Ravoid ruts.
Ravoid sudden steering movements.
Rbrake carefully.
Driving on flooded roads
!Do not drive through flooded areas. Check
the depth of any water before driving through it. Drive slowly through standing water. Oth-
erwise, water may enter the vehicle interior or
the engine compartment. This can damage
the electronic components in the engine or
the automatic transmission. Water can also
be drawn in by the engine's air suction nozzles
and this can cause engine damage.
iVehicles with the AIRMATIC package:
select the raised vehicle level before driving
through a body of water.
166Driving tips
Driving and parking

Off-road driving
Important safety notes
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.
GWARNING
Flammable material such as leaves, grass or
twigs may ignite if they come into contact with
hot parts of the exhaust system. There is a risk of fire.
When driving off road or on unpaved roads,
check the vehicle's underside regularly. In
particular, remove parts of plants or other
flammable materials which have become
trapped. In the case of damage, contact a
qualified specialist workshop.
GWARNING
If the vehicle level is high, the vehicle center of gravity is raised. This could cause the vehicle
to tip over more easily on uphill or downhill
gradients. There is a risk of an accident.
Select the lowest possible vehicle level.
!There is a risk of damage to the vehicle if:
Rthe vehicle becomes stuck, e.g. on a high
curb or an unpaved road
Ryou drive too fast over an obstacle, e.g. a
curb, speed bumps or a pothole in the road
Ra heavy object strikes the underbody or
parts of the chassis
In situations like this, the body, the under-
body, chassis parts, wheels or tires could be
damaged without the damage being visible.
Components damaged in this way can unex-
pectedly fail or, in the case of an accident, no longer withstand the strain they are designed
to.
If the underbody paneling is damaged, com-
bustible materials such as leaves, grass or twigs can gather between the underbody and
the underbody paneling. If these materials
come in contact with hot parts of the exhaust
system, they can catch fire.
In such situations, have the vehicle checked
and repaired immediately at a qualified spe-
cialist workshop. If on continuing your jour-
ney you notice that driving safety is impaired,
pull over and stop the vehicle immediately,
paying attention to road and traffic condi-
tions. In such cases, consult a qualified spe-
cialist workshop.
When driving off-road, substances such as sand, mud and water or water mixed with oil may get
into the brakes. This could result in a reduced
braking effect or in total brake failure and also in
increased wear and tear. The braking charac-
teristics change depending on the material
ingressing the brakes. Clean the brakes after
driving off-road. If you detect a reduced braking
effect or grinding noises, have the brake system
checked in a qualified specialist workshop as
soon as possible. Adapt your driving style to the
different braking characteristics.
Driving off-road increases the likelihood of dam-
age to the vehicle, which, in turn, can lead to
failure of the mechanical assembly or syst

ems.
Adapt your driving style to suit the terrain con-
ditions. Drive carefully. Have damage to the
vehicle rectified immediately at a qualified spe-
cialist workshop.
Do not switch to transmission position Nwhen
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:
Rthe Offroad drive program (vehicles without
Off-Road Engineering package)
(
Ypage 217)
ROffroad andOffroad Plus drive programs
(vehicles with Off-Road Engineering package)
(
Ypage 218)
168Driving tips
Driving and parking