ECU MERCEDES-BENZ GLS 2017 Repair Manual

Cargo compartment cover
Important safety notes
G WARNING
On its own, the cargo compartment cover
cannot secure or restrain heavy objects,
items of luggage and heavy loads. You could
be hit by an unsecured load during sudden
changes in direction, braking or in the event of
an accident. There is an increased risk of
injury or even fatal injury.
Always store objects so that they cannot be
flung around. Secure objects, luggage or
loads against slipping or tipping over, e.g. by
using tie downs, even if you are using the
cargo compartment cover.
! When loading the vehicle, make sure that
you do not stack the load in the cargo com-
partment higher than the lower edge of the
side windows. Do not place heavy objects on
top of the cargo compartment cover.
The cargo compartment cover may be installed
behind the 2nd or 3rd row of seats.
Extending/retracting the cargo com-
partment cover
X
To extend: pull the cargo compartment cover
back by grab handle C and clip it into retain-
ers D on the left and right.X
To retract: unhook the cargo compartment
cover from left-hand and right-hand retain-
ers D .X
Guide cargo compartment cover forwards by
grab handle C until it is completely rolled up. Installing/removing the cargo compart-
ment cover X
To remove: make sure that cargo compart-
ment cover C is rolled up. X
Push end cap

Roof carrier
Important safety notes
G WARNING
When you load the roof, the center of gravity
of the vehicle rises and the driving character-
istics change. If you exceed the maximum roof
load, the driving characteristics, as well as
steering and braking, will be greatly impaired.
There is a risk of an accident.
Never exceed the maximum roof load and
adjust your driving style.
! Mercedes-Benz recommends that you only
use roof carriers that have been tested and
approved for Mercedes-Benz vehicles. This
helps to prevent damage to the vehicle.
Position the load on the roof carrier in such a
way that the vehicle will not sustain damage
even when it is in motion.
Depending on the vehicle equipment, ensure
that when the roof carrier is installed you can: R
raise the sliding sunroof fully R
open the panorama roof with power tilt/
sliding panel fully R
open the tailgate fully
You will find information on the maximum roof
load in the "Technical data" section
( Y
page 384).
An incorrectly secured roof carrier or roof load
may become detached from the vehicle. You
must therefore ensure that you observe the roof
carrier manufacturer's installation instructions.
Attaching the roof carrier X
Secure the roof carrier to roof rails C . In
doing so, observe the manufacturer's instal-
lation instructions.
Features
Cup holder
Important safety notes
G WARNING
If you transport objects in the vehicle interior
and these are not adequately secured, they
could slip or be flung around and thereby
strike vehicle occupants. In addition, cup
holders, open stowage spaces and mobile
phone brackets may not always be able to
hold the objects placed in them in the event of
an accident. There is a risk of injury, particu-
larly in the event of sharp braking or sudden
changes of direction. R
Always stow objects in such a way that they
cannot be tossed about in these or similar
situations. R
Always make sure that objects do not pro-
trude out of the stowage spaces, luggage
nets or stowage nets. R
Ensure that closable stowage spaces are
shut before beginning your journey. R
Always stow and secure heavy, hard, poin-
ted, sharp-edged, fragile or large objects in
the cargo compartment.
Observe the loading guidelines ( Y
page 294).
! Only use the cup holders for containers of
the right size and which have lids. The drinks
could otherwise spill.
! Do not expose drinks bottles in the cup
holder in the center console to continuous,
strong and direct sunlight. The passenger
compartment in the area of the center con-
sole can otherwise be damaged by the con-
centrated and reflected sunlight.
Do not keep the KEYLESS-GO key in the tem-
perature-controlled cup hol der ( Y
page 303).
Otherwise, the KEYLESS-GO key will not be rec-
ognized.302
Features
Stowage and features

The stowage compartments in the doors provide
space for bottles with a capacity of up to
34 fl. oz. (1.0 l).
The bottles are not secured or prevented from
tipping over. Therefore, do not place any open
drink containers in the stowage compartments.
Cup holder in the front-compartment
center console
C
Cup holderD
Cover X
To open: slide cover D to its foremost posi-
tion. X
To close: pull cover D back as far as it will go.
You can remove the cup holder's rubber mat for
cleaning. Clean with clear, lukewarm water only.
Temperature-controlled cup holder in
the front-compartment center console
C
Cup holder
D
Residual heat indicator lamp

! Do not park your vehicle for a long period of
time directly after cleaning, particularly after
cleaning the wheel rim with wheel cleaner.
Wheel cleaner can lead to the increased cor-
rosion of the brake discs and pads. Therefore,
drive for a few minutes after cleaning. By
heating up the brakes, the brake discs and
pads dry. The vehicle can then be parked for a
long period of time.
Cleaning the windows
G WARNING
You could become trapped by the windshield
wipers if they start moving while cleaning the
windshield or wiper blades. There is a risk of
injury.
Always switch off the windshield wipers and
the ignition before cleaning the windshield or
wiper blades.
! Do not use dry cloths, abrasive products,
solvents or cleaning agents containing sol-
vents to clean the inside of the windows. Do
not touch the insides of the windows with
hard objects, e.g. an ice scraper or ring. There
is otherwise a risk of damaging the windows.
! Clean the water drainage channels of the
windshield and the rear window at regular
intervals. Deposits such as leaves, petals and
pollen may under certain circumstances pre-
vent water from draining away. This can lead
to corrosion damage and damage to elec-
tronic components. X
Clean the inside and outside of the windows
with a damp cloth and a cleaning product that
is recommended and approved by Mercedes-
Benz.
Cleaning wiper blades
G WARNING
You could become trapped by the windshield
wipers if they start moving while cleaning the
windshield or wiper blades. There is a risk of
injury.
Always switch off the windshield wipers and
the ignition before cleaning the windshield or
wiper blades. ! Do not pull the wiper blade. Otherwise, the
wiper blade could be damaged.
! Do not clean wiper blades too often and do
not rub them too hard. Otherwise, the graph-
ite coating could be damaged. This could
cause wiper noise.
! Hold the wiper arm securely when folding
back. The windshield could be damaged if the
wiper arm smacks against it suddenly. X
Fold the windshield wiper arms away from the
windshield ( Y
page 120). X
Carefully clean the wiper blades with a damp
cloth. X
Fold the windshield wiper arms back again
before switching on the ignition.
Cleaning the exterior lighting
! Only use cleaning agents or cleaning cloths
which are suitable for plastic light lenses.
Unsuitable cleaning agents or cleaning cloths
could scratch or damage the plastic light len-
ses. X
Clean the plastic lenses of the exterior light-
ing using a wet sponge and a mild cleaning
agent, e. g. Mercedes-Benz car shampoo or
cleaning cloths.
Cleaning the mirror turn signals
! Only use cleaning agents or cleaning cloths
that are suitable for plastic lenses. Unsuitable
cleaning agents or cleaning cloths could
scratch or damage the plastic lenses of the
mirror turn signals. X
Clean the plastic lenses of the mirror turn sig-
nals in the exterior mirror housing using a wet
sponge and mild cleaning agent, e.g.
Mercedes-Benz car shampoo or cleaning
cloths.
Cleaning the side running board
! Do not clean the aluminum inserts of the
side running board with alkaline or acidic
cleaners, such as wheel cleaner. Do not use
acidic wheel cleaners to remove brake dust.
The aluminum inserts could otherwise be
damaged. Care 327
Maintenance and care Z

plenty of clean water and seek medical atten-
tion.
H Environmental note
Batteries contain dangerous
substances. It is against the
law to dispose of them with
the household rubbish. They
must be collected separately
and recycled to protect the
environment.
Dispose of batteries in an
environmentally friendly
manner. Take discharged
batteries to a qualified spe-
cialist workshop or a special
collection point for used bat-
teries.
! Have the battery checked regularly at a
qualified specialist workshop.
Observe the service intervals in the Mainte-
nance Booklet or contact a qualified specialist
workshop for more information.
! Always have work on batteries carried out at
a qualified specialist workshop. Should it, in
exceptional circumstances, be absolutely
necessary to disconnect the 12-volt battery
yourself, observe the following: R
secure the vehicle to prevent it from rolling
away. R
switch off the ignition. R
always disconnect the negative terminal
clamp first, followed by the positive termi-
nal clamp.
After the battery has been disconnected, the
transmission is locked in position P .
After the work has been done, install the bat-
tery and replace the cover of the positive ter-
minal clamp firmly.
Comply with safety precautions and take pro-
tective measures when handling batteries. Risk of explosion.
Fire, open flames and smoking are
prohibited when handling the bat-
tery. Avoid creating sparks.
Battery acid is caustic. Avoid contact
with skin, eyes or clothing.
Wear suitable protective clothing,
especially gloves, apron and face-
guard.
Rinse any acid spills immediately
with clear water. Contact a physician
if necessary.
Wear eye protection.
Keep children away.
Observe this Operator's Manual.
For safety reasons, Mercedes-Benz recom-
mends that you only use batteries which have
been tested and approved for your vehicle by
Mercedes-Benz. These batteries provide
increased impact protection to prevent vehicle
occupants from suffering acid burns should the
battery be damaged in the event of an accident.
In order for the battery to achieve the maximum
possible service life, it must always be suffi-
ciently charged.
Like other batteries, the vehicle battery may
discharge over time if you do not use the vehicle.
In this case, have the battery disconnected at a
qualified specialist workshop. You can also
charge the battery with a charger recommended
by Mercedes-Benz. Contact a qualified special-
ist workshop for further information.
Have the battery condition of charge checked
more frequently if you use the vehicle mainly for
short trips or if you leave it standing idle for a
lengthy period. Consult a qualified specialist
workshop if you wish to leave your vehicle
parked for a long period of time.
Remove the SmartKey if you park the vehicle
and do not require any electrical consumers.Battery (vehicle) 337
Breakdown assistance Z

R
If the battery is fully discharged, leave the battery that is being used to jump-start connected for
a few minutes before attempting to start. This charges the battery slightly. R
Make sure that the two vehicles do not touch.
Make sure that: R
The jumper cables are not damaged. R
Bare parts of the terminal clamp do not come into contact with other metal parts while the jumper
cables are connected to the battery. R
The jumper cables cannot come into contact with parts which can move when the engine is
running, such as the V-belt pulley or the fan. X
Secure the vehicle by applying the electric parking brake. X
Shift the transmission to position P .X
Make sure that the ignition is switched off. All indicator lamps in the instrument cluster must be
off. When using the SmartKey, turn the SmartKey to position 0 in the ignition lock and remove it
( Y
page 138).X
Switch off all electrical consumers, e.g. rear window defroster, lighting, etc. X
Open the hood.
Position number

i Jumper cables and further information regarding jump-starting can be obtained at any qualified
specialist workshop.
Towing and tow-starting
Important safety notes
G WARNING
Functions relevant to safety are restricted or
no longer available if: R
the engine is not running. R
the brake system or the power steering is
malfunctioning. R
there is a malfunction in the voltage supply
or the vehicle's electrical system.
If your vehicle is being towed, much more
force may be necessary to steer or brake.
There is a risk of an accident.
In such cases, use a tow bar. Before towing,
make sure that the steering moves freely.
G WARNING
When towing or tow-starting another vehicle
and its weight is greater than the permissible
gross weight of your vehicle, the: R
the towing eye could detach itself R
the vehicle/trailer combination could roll-
over.
There is a risk of an accident.
When towing or tow-starting another vehicle,
its weight should not be greater than the per-
missible gross weight of your vehicle.
Details on the permissible gross vehicle weight
of your vehicle can be found on the vehicle iden-
tification plate ( Y
page 377).
! When Active Brake Assist, Distance Pilot
DISTRONIC or the HOLD function is activated,
the vehicle brakes automatically in certain
situations.
To avoid damage to the vehicle, deactivate
these systems in the following or similar sit-
uations: R
when towing the vehicle R
in the car wash ! Make sure that the electric parking brake is
released. If the electric parking brake is faulty,
visit a qualified specialist workshop.
! Only secure the tow rope or tow bar at the
towing eyes, or the trailer tow hitch, if availa-
ble. You could otherwise damage the vehicle.
! Observe the following points when towing
with a tow rope: R
Secure the tow rope on the same side on
both vehicles. R
Ensure that the tow cable is not longer than
legally permitted. Mark the tow cable in the
middle, e.g. with a white c loth (30 x 30
cm).
This will make other road users aware that
the vehicle is being towed. R
Only secure the tow cable to the towing
eye. R
Observe the brake lamps of the towing
vehicle while driving. Always maintain a dis-
tance so that the tow rope does not sag. R
Do not use steel cables or chains to tow
your vehicle. You could otherwise damage
the vehicle.
! Do not use the trailer tow hitch for recovery
or towing. Do not use the towing eye for
recovery. this could damage the vehicle. If in
doubt, have the vehicle recovered using a
crane.
! When towing, pull away slowly and
smoothly. Pull the towed vehicle as straight as
possible and not at an acute angle. Excessive
tractive power could damage the vehicles.
When towing, it is preferable to use a rigid tow-
ing bar as opposed to a tow rope. A rigid towing
bar helps to keep the tractive power low.
! When towing vehicles with KEYLESS-GO,
use the key instead of the Start/Stop button.
Otherwise, the automatic transmission may
shift to position P when the driver's or front-
passenger door are opened, which could lead
to damage to the transmission.
! Do not tow with sling-type equipment. This
could damage the vehicle.
! Vehicles with differential locks: make sure
the differential locks are in automatic mode.Towing and tow-starting 341
Breakdown assistance Z

the combination switch, the hazard warning
lamp starts flashing again.
Transporting the vehicle
4MATIC vehicles/vehicles with auto-
matic transmission
! When the vehicle is loaded for transport, the
front and rear axles must be stationary and on
the same transportation vehicle. Positioning
over the connection point of the transport
vehicle is not permitted. The drive train may
otherwise be damaged.
All vehicles
! You may only secure the vehicle by the
wheels, not by parts of the vehicle such as
axle or steering components. Otherwise, the
vehicle could be damaged.
The towing eye can be used to pull the vehicle
onto a trailer or transporter for transporting pur-
poses. X
Turn the SmartKey to position 2 in the ignition
lock. X
Shift the automatic transmission to position
N .
As soon as the vehicle has been loaded: X
Prevent the vehicle from rolling away by
applying the electric parking brake. X
Shift the automatic transmission to posi-
tion P .X
Turn the SmartKey to position 0 in the ignition
lock and remove it. X
Secure the vehicle. Information on 4MATIC vehicles
! Vehicles with 4MATIC must not be towed
with either the front or the rear axle raised, as
doing so will damage the transmission.
Vehicles with 4MATIC may either be towed away
with both axles on the ground or be loaded up
and transported.
If the vehicle's transmission, front, or rear axle is
damaged, have the vehicle transported on a
truck or trailer.
In the event of damage to the electrical sys-
tem: if the battery is defective, the automatic
transmission will be locked in position P . To shift
the automatic transmission to position N , you
must provide power to the vehicle's electrical
system in the same way as when jump-starting
( Y
page 338).
Have the vehicle transported on a transporter or
trailer.
Tow-starting (emergency engine
starting)
! Vehicles with automatic transmission must
not be tow-started. You could otherwise dam-
age the automatic transmission.
You can find information on "Jump-starting"
under ( Y
page 338).
Fuses
Important safety notes
G WARNING
If you manipulate or bridge a faulty fuse or if
you replace it with a fuse with a higher amper-
age, the electric cables could be overloaded.
This could result in a fire. There is a risk of an
accident and injury.
Always replace faulty fuses with the specified
new fuses having the correct amperage.
! For the fuse boxes in the engine compart-
ment and under the rear bench seat, only use
fuses with the suffix "S". Otherwise, compo-
nents or systems could be damaged.
! Make sure that no moisture can enter the
fuse box when the cover is open. Fuses 343
Breakdown assistance Z

! When closing the cover, make sure that it is
lying correctly on the fuse box. Moisture seep-
ing in or dirt could otherwise impair the oper-
ation of the fuses.
The fuses in your vehicle serve to close down
faulty circuits. If a fuse blows, all the compo-
nents on the circuit and their functions stop
operating.
Blown fuses must be replaced with fuses of the
same rating, which you can recognize by the
color and value. The fuse ratings are listed in the
fuse allocation chart.
The fuse allocation chart is located in the fuse
box under the rear bench seat ( Y
page 345).
If a newly inserted fuse also blows, have the
cause traced and rectified at a qualified special-
ist workshop, e.g. an authorized Mercedes-Benz
Center.
Before changing a fuse Observe the important safety notes
( Y
page 343) X
Switch off the engine. X
Switch off all electrical consumers. X
Remove the SmartKey from the ignition lock.
or, in vehicles with KEYLESS-GO start-function
or KEYLESS ‑ GOX
Open 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. X
Secure the vehicle against rolling away
( Y
page 159).
All indicator lamps in the instrument cluster
must be off.
The fuses are located in various fuse boxes: R
Fuse box on the front-passenger side of the
dashboard R
Fuse box in the engine compartment on the
right-hand side of the vehicle, when viewed in
the direction of travel R
Fuse box under the rear bench seat Dashboard fuse box
! Do not use a pointed object such as a screw-
driver to open the cover in the dashboard. You
could damage the dashboard or the cover.
Mercedes-Benz recommends that you have this
work performed at a qualified specialist work-
shop, e.g. at an authorized Mercedes-Benz Cen-
ter.
X
Open the front-passenger door. X
To open: pull cover C outwards in the direc-
tion of the arrow and remove it. X
To close: clip in cover C on the front of the
dashboard. X
Fold cover C inwards until it engages.
Fuse box in the engine compartment
G WARNING
When the hood is open and the windshield
wipers are set in motion, you can be injured by
the wiper linkage. There is a risk of injury.
Always switch off the windshield wipers and
the ignition before opening the hood.344
Fuses
Breakdown assistance

Avoid tire pressures that are too high in all the
tires, including the spare wheel.
Overinflated tires may: R
increase the braking distance R
adversely affect handling R
wear excessively and/or unevenly R
have an adverse effect on ride comfort R
be more susceptible to damage
Maximum tire pressures
C
Example: maximum permissible tire pres-
sure
Never exceed the maximum permissible tire
inflation pressure. Always observe the recom-
mended tire pressure for your vehicle when
adjusting the tire pressure ( Y
page 349).
i The actual values for tires are vehicle-spe-
cific and may deviate from the values in the
illustration.
Checking the tire pressures
Important safety notes Observe the notes on tire pressure
( Y
page 349).
Information on air pressure for the tires on your
vehicle can be found: R
on the Tire and Loading Information placard
on the B-pillar on the driver's side R
in the tire pressure table in the fuel filler flap R
in the "Tire pressure" section Checking tire pressures manually To determine and set the correct tire pressure,
proceed as follows: X
Remove the valve cap of the tire that is to be
checked. X
Press the tire pressure gage securely onto the
valve. X
Read the tire pressure and compare it to the
recommended value on the Tire and Loading
Information placard or the tire pressure table
( Y
page 349). X
If the tire pressure is too low, increase the tire
pressure to the recommended value. X
If the tire pressure is too high, release air. To
do so, press down the metal pin in the valve,
using the tip of a pen for example. Then check
the tire pressure again using the tire pressure
checker. X
Screw the valve cap onto the valve. X
Repeat these steps for the other tires.
Tire pressure loss warning system
General notes While the vehicle is in motion, the tire pressure
loss warning system monitors the set tire pres-
sure using the rotational speed of the wheels.
This enables the system to detect significant
pressure loss in a tire. If the speed of rotation of
a wheel changes as a result of a loss of pressure,
a corresponding warning message will appear in
the multifunction display.
You can recognize the tire pressure loss warning
by the Run Flat Indicator Active Press
'OK' to Restart message which appears in
the Service menu of the multifunction display.
Information on the message display can be
found in the "Restarting the tire pressure loss
warning system" section ( Y
page 353).
Important safety notes
The tire pressure warning system does not warn
you of an incorrectly set tire pressure. Observe
the notes on the recommended tire pressure
( Y
page 349).
The tire pressure loss warning does not replace
the need to regularly check the tire pressure. An
even loss of pressure on several tires at the352
Tire pressure
Wheels and tires