MERCEDES-BENZ G-CLASS 2018 Repair Manual

Braking
XIf ABS intervenes:continue to depress the
brake pedal vigorously until the braking sit-
uation is over.
XTo make a full brake application: depress
the brake pedal with full force.
If ABS intervenes when braking, you will feel a
pulsing in the brake pedal.
The pulsating brake pedal can be an indication
of hazardous road conditions, and functions as a
reminder to take extra care while driving.
Off-road ABS
ESP®automatically activates the ABS system
specifically suited to off-road terrain.
At speeds below 37 mph (60 km/h), the front
wheels lock cyclically during braking. The dig-
ging-in effect achieved in the process reduces
the stopping distance on off-road terrain. This
limits steering capability.
BAS (Brake Assist System)
General information
BAS operates in emergency braking situations.
If you depress the brake pedal quickly, BAS
automatically boosts the braking force, thus
shortening the stopping distance.
Important safety notes
iObserve the "Important safety notes" sec-
tion (Ypage 58).
GWARNING
If BAS is malfunctioning, the braking distance
in an emergency braking situation is
increased. There is a risk of an accident.
In an emergency braking situation, depress
the brake pedal with full force. ABS prevents
the wheels from locking.
Braking
XKeep the brake pedal firmly depressed until
the emergency braking situation is over.
ABS prevents the wheels from locking. The brakes will function as usual once you
release the brake pedal. BAS is deactivated.
ESP®(Electronic Stability Program)
General notes
iObserve the "Important safety notes" sec-
tion (Ypage 58).
ESP
®monitors driving stability and traction, i.e.
power transmission between the tires and the
road surface.
If ESP
®detects that the vehicle is deviating from
the direction desired by the driver, one or more
wheels are braked to stabilize the vehicle. The
engine output is also modified to keep the vehi-
cle on the desired course within physical limits.
ESP
®assists the driver when pulling away on
wet or slippery roads. ESP®can also stabilize
the vehicle during braking.
4ETS (Electronic Traction System)
iObserve the "Important safety notes" sec-
tion (Ypage 58).
4ETS traction control is part of ESP
®.
Traction control brakes the drive wheels indi-
vidually if they spin. This enables you to pull
away and accelerate on slippery surfaces, for
example if the road surface is slippery on one
side. In addition, more drive torque is transfer-
red to the wheel or wheels with traction.
Traction control remains active, even if you
deactivate ESP
®.
Important safety notes
iObserve the "Important safety notes" sec-
tion (Ypage 58).
GWARNING
If ESP
®is malfunctioning, ESP®is unable to
stabilize the vehicle. Additionally, further driv-
ing safety systems are deactivated. This
increases the risk of skidding and an accident.
Drive on carefully. Have ESP
®checked at a
qualified specialist workshop.
Driving safety systems59
Safety
Z

!Only operate the vehicle for a maximum of
ten seconds on a brake test dynamometer.
Switch off the ignition.
Application of the brakes by ESP
®may oth-
erwise destroy the brake system.
!A function or performance test should only
be carried out on a two-axle dynamometer.
Before you operate the vehicle on such a
dynamometer, please consult a qualified
workshop. You could otherwise damage the
drive train or the brake system.
If the å ESP
®OFF warning lamp lights up
continuously, ESP®is deactivated.
If the ÷ ESP®warning lamp lights up contin-
uously, ESP®is not available due to a malfunc-
tion.
Observe the information on warning lamps
(
Ypage 196) and display messages which may
be displayed in the instrument cluster
(
Ypage 175).
Only use wheels with the recommended tire
sizes. Only then will ESP
®function properly.
If differential locks are switched on, ABS, BAS
and ESP
®switch off automatically.
Characteristics of ESP®
General information
If the ÷ ESP®warning lamp goes out before
beginning the journey, ESP®is automatically
active.
If ESP
®intervenes, the ÷ESP®warning lamp
flashes in the instrument cluster.
If ESP
®intervenes:
XDo not deactivate ESP®under any circum-
stances.
XOnly depress the accelerator pedal as far as
necessary when pulling away.
XAdapt your driving style to suit the prevailing
road and weather conditions.
ECO start/stop function
The ECO start/stop function switches the
engine off automatically when the vehicle stops
moving. The engine starts automatically when
the driver wants to pull away again. ESP
®
remains in its previously selected status, e.g. if
ESP®was deactivated before the engine was
automatically switched off.
Deactivating/activating ESP®
Important safety notes
iObserve the "Important safety notes" sec-
tion (Ypage 58).
You can select between the following states of
ESP
®:
RESP®is activated.
RESP®is deactivated.
GWARNING
If you deactivate ESP
®, ESP®no longer sta-
bilizes the vehicle. There is an increased risk
of skidding and an accident.
Only deactivate ESP
®in the situations descri-
bed in the following.
It may be best to deactivate ESP
®in the follow-
ing situations:
Rwhen using snow chains
Rin deep snow
Ron sand or gravel
Roff-road
Spinning the wheels results in a cutting action
which provides better grip.
Activate ESP
®as soon as the situations descri-
bed above no longer apply. ESP®will otherwise
not be able to stabilize the vehicle if the vehicle
starts to skid or a wheel starts to spin.
!Avoid spinning the driven wheels for an
extended period with ESP®deactivated. You
could otherwise damage the drivetrain.
Deactivating/activating ESP®
60Driving safety systems
Safety

XTo deactivate:press button:.
The å ESP®OFF warning lamp in the
instrument cluster lights up.
XTo activate: press button :.
The å ESP®OFF warning lamp in the
instrument cluster goes out.
Characteristics when ESP®is deactivated
If ESP®is deactivated and one or more wheels
start to spin, the ÷ESP®warning lamp in the
instrument cluster flashes. In such situations,
ESP
®will not stabilize the vehicle.
If you deactivate ESP®:
RESP®no longer improves driving stability.
REngine torque is no longer limited and the
drive wheels are able to spin.
RTraction control is still activated.
RESP®still provides support when you brake
firmly.
RMercedes-AMG vehicles: and are driving a
speed at above 62 mph (100 km/h), ESP®still
intervenes when one wheel reaches its grip
limit even though it is deactivated.
RAll other models: and are driving at a speed
above 37 mph (60 km/h), ESP®still inter-
venes when one wheel reaches its grip limit
even though it is deactivated.
Mercedes-AMG vehicles: if ESP
®is deactiva-
ted, it is reactivated automatically if you are
driving at a speed above 62 mph (100 km/h) or
you exceed a certain lateral acceleration.
All other models: if ESP
®is deactivated, it is
re
activated automatically if you are driving at a
speed above 37 mph (60 km/h) or you exceed a
certain lateral acceleration.
Trailer stabilization
General information
If your vehicle/trailer combination begins to
swerve, ESP®assists you in this situation. ESP®
slows the vehicle down by braking and limiting
the engine output until the vehicle/trailer com-
bination has stabilized.
Important safety notes
GWARNING
If road and weather conditions are poor,
trailer stabilization will not be able to prevent
the vehicle/trailer combination from swerv-
ing. Trailers with a high center of gravity can
tip over before ESP
®can detect this. There is
a risk of an accident.
Always adapt your driving style to the prevail-
ing road and weather conditions.
If your vehicle with trailer (vehicle/trailer com-
bination) begins to lurch, you can only stabilize
the vehicle/trailer combination by depressing
the brake firmly.
ESP
®trailer stabilization is active above speeds
of approximately 37 mph (60 km/h).
ESP
®trailer stabilization does not work if ESP®
is deactivated or malfunctioning.
EBD (electronic brake force distribu-
tion)
General information
EBD monitors and controls the brake pressure
on the rear wheels to improve driving stability
while braking.
Important safety notes
iObserve the "Important safety notes" sec-
tion (Ypage 58).
GWARNING
If EBD is malfunctioning, the rear wheels can
lock, e.g. under full braking. This increases the
risk of skidding and an accident.
You should therefore adapt your driving style
to the different handling characteristics. Have
the brake system checked at a qualified spe-
cialist workshop.
Observe information regarding indicator and
warning lamps (
Ypage 194) as well as display
messages (Ypage 176).
ADAPTIVE BRAKE
ADAPTIVE BRAKE provides increased braking
safety. In addition to the braking function,
ADAPTIVE BRAKE also has the HOLD function
(
Ypage 142) and hill start assist (Ypage 107).
Driving safety systems61
Safety
Z

Protection against theft
Immobilizer
The immobilizer prevents your vehicle from
being started without the correct SmartKey.
XTo activate:remove the SmartKey from the
ignition lock.
XTo deactivate: switch on the ignition.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. The
engine can be started by anyone with a valid
SmartKey that is left inside the vehicle.
iThe immobilizer is always deactivated when
you start the engine.
In the event that the engine cannot be started
(yet the vehicle's battery is charged), the sys-
tem is not operational. Contact an authorized
Mercedes-Benz Center or call
1-800-FOR-MERCedes (in the USA) or
1-800-387-0100 (in Canada).
ATA (anti-theft alarm system)
XTo arm: lock the vehicle with the SmartKey.
Indicator lamp :flashes. The alarm system
is armed after approximately 15 seconds.
XTo disarm: unlock the vehicle with the Smart-
Key.
iIf you then do not open a side door or the
rear door, the alarm system switches back on
again after approximately 40 seconds.
A visual and audible alarm is triggered if the
alarm system is armed and you open:
Ra door
Rthe vehicle with the mechanical key
Rthe rear door
Rthe hood The alarm is also triggered if:
Rthe position of the vehicle is changed.
Ra window is smashed.
The alarm is not switched off, even if you close the open door that triggered it, for example.
XTo stop the alarm: press the%or&
button on the SmartKey.
The alarm is stopped.
or
XInsert the SmartKey into the ignition lock.
The alarm is stopped.
iIf the alarm continues for more than
30 seconds, the mbrace emergency call sys-
tem automatically notifies the Customer
Assistance Center. This is done either by text
message or data connection.
The emergency call system sends the mes-
sage or data provided that:
Ryou have subscribed to the mbrace service.
Rthe mbrace service has been activated
properly.
Rthe necessary mobile phone network is
available.
62Protection against theft
Safety

SmartKey
Important safety notes
GWARNING
If children are left unsupervised in the vehicle,
they could:
Ropen the doors, thus endangering other
people or road users.
Rget out and disrupt traffic.
Roperate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they:
Rrelease the parking brake.
Rshifting the automatic transmission out of
park position P
RStart the engine.
There is a risk of an accident and injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children or animals unattended in the
vehicle. Always keep the SmartKey out of
reach of children.
GWARNING
If you attach heavy or large objects to the
SmartKey, the SmartKey could be uninten-
tionally turned in the ignition lock. This could
cause the engine to be switched off. There is a risk of an accident.
Do not attach any heavy or large objects to the
SmartKey. Remove any bulky key rings before
inserting the SmartKey into the ignition lock.
!Keep the SmartKey away from strong mag-
netic fields. Otherwise, the remote control
function could be affected.
Strong magnetic fields can occur in the vicin-
ity of powerful electrical installations.
Do not keep the SmartKey:
Rwith electronic devices, e.g. a mobile phone
or another SmartKey.
Rwith metallic objects, e.g. coins or metal foil.
Rinside metallic objects, e.g. a metal case.
This can affect the functionality of the Smart- Key. A check which periodically establishes a radio
connection between the vehicle and the Smart-
Key determines whether a valid SmartKey is in
the vehicle. This occurs, for example:
Rwhen starting the engine
Rwhile driving
SmartKey functions
:&
Locks the vehicle
;%Unlocks the vehicle
The SmartKey centrally locks/unlocks:
Rthe doors
Rthe rear door
Rthe fuel filler flap
XTo unlock centrally: press the%button.
If you do not open the vehicle within approx-
imately 40 seconds of unlocking:
Rthe vehicle is locked again.
Rprotection against theft is reactivated.
XTo lock centrally: press the&button.
The turn signals flash once when unlocking and
three times when locking.
You can also set an audible signal to confirm
that the vehicle has been locked. The audible
signal can be activated and deactivated using
the on-board computer (
Ypage 170).
You will receive visual and acoustic locking con-
firmation if all components were able to be
locked.
When the surround lighting is activated via the
on-board computer, it lights up when it is dark
after the vehicle is unlocked with the SmartKey (
Ypage 169).
SmartKey63
Opening and closing
Z

Changing the settings of the locking
system
You can change the settings of the locking sys-
tem. This means that only the driver's door and
the fuel filler flap are unlocked when the vehicle
is unlocked. This is useful if you frequently travel
alone.
XTo change the setting:press and hold down
the % and& buttons simultaneously
for approximately six seconds until the bat-
tery check lamp (
Ypage 65) flashes twice.
If the setting of the locking system is changed
within the signal range of the vehicle, pressing
the & or% button:
Rlocks or
Runlocks the vehicle
The SmartKey now functions as follows:
XTo unlock the driver's door and fuel filler
flap: press the %button once.
XTo unlock centrally: press the%button
twice.
XTo lock centrally: press the&button.
XTo restore the factory settings: press and
hold the %and& buttons simultane-
ously for approximately six seconds until the
battery check lamp (
Ypage 65) flashes
twice.
Mechanical key
General notes
If the vehicle can no longer be unlocked with the
SmartKey, use the mechanical key.
If you use the mechanical key to unlock and
open the driver's door, the anti-theft alarm sys-
tem will be triggered. Switch off the alarm
(
Ypage 62).
If you unlock the vehicle using the mechanical
key, the fuel filler flap will not be unlocked auto-
matically.
XTo unlock the fuel filler flap: insert the
SmartKey into the ignition lock.
Removing the mechanical key
XPush release catch :in the direction of the
arrow and at the same time remove mechan- ical key ;from the SmartKey.
Further information on locking/unlocking the
driver's door (
Ypage 68).
Inserting the mechanical key
XPush mechanical key ;completely into the
SmartKey until it engages and release
catch :is back in its basic position.
SmartKey battery
Important safety notes
GWARNING
Batteries contain toxic and corrosive substan- ces. If batteries are swallowed, it can result in
severe health problems. There is a risk of fatalinjury.
Keep batteries out of the reach of children. If
a battery is swallowed, seek medical attention
immediately.
HEnvironmental note
Batteries contain dangerous
substances. It is against the
law to dispose of them with
the household rubbish. They
must be collected separately
64SmartKey
Opening and closing

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.
The SmartKey batteries contain perchlorate
material, which may require special handling
and regard for the environment. National guide-
lines must be observed during disposal. In Cal-
ifornia, see www.dtsc.ca.gov/
HazardousWaste/Perchlorate/index.cfm .
Mercedes-Benz recommends that you have the
batteries replaced at a qualified specialist work-
shop.
Checking the battery
XPress the &or% button.
The battery is working properly if battery
check lamp :lights up briefly.
The battery is discharged if battery check
lamp :does not light up briefly.
XChange the battery (Ypage 65).
If the SmartKey battery is checked within the
signal reception range of the vehicle, pressing
the & or% button:
Rlocks or
Runlocks the vehicle
iYou can get a battery at any qualified spe-
cialist workshop.
Replacing the battery
You require a CR 2025 3 V cell battery.
XTake the mechanical key out of the SmartKey
(Ypage 64).
XPress mechanical key ;in the direction of
the arrow into the opening in the SmartKey
until battery compartment cover :opens.
Do not hold battery compartment cover :
closed while doing so.
XRemove battery compartment cover :.
XRepeatedly tap the SmartKey against your
palm until battery=falls out.
XInsert the new battery with the positive ter-
minal facing upwards. Use a lint-free cloth to
do so.
XMake sure that the surface of the battery is
free of lint, grease and other contaminants.
XInsert the front tabs of battery compartment
cover :into the housing first and then press
to close it.
XInsert mechanical key ;into the SmartKey
(Ypage 64).
XCheck the function of all SmartKey buttons on
the vehicle.
SmartKey65
Opening and closing
Z

Problems with the SmartKey
ProblemPossible causes/consequences andMSolutions
You can no longer lock or
unlock the vehicle using
the SmartKey.The SmartKey battery is discharged or nearly discharged.
XCheck the SmartKey battery (Ypage 65) and replace it if necessary
(Ypage 65).
If this does not work:
XLock or unlock the vehicle using the mechanical key (Ypage 68).
There is interference from a powerful source of radio waves.
XLock or unlock the vehicle using the mechanical key (Ypage 68).
The SmartKey is faulty.
XLock or unlock the vehicle using the mechanical key (Ypage 68).
XHave the SmartKey checked at a qualified specialist workshop.
The engine cannot be
started using the Smart-
Key.The on-board voltage is too low
XSwitch off non-essential consumers, e.g. seat heating or interior
lighting, and try to start the engine again.
If this does not work:
XCheck the starter battery and charge it if necessary (Ypage 248).
or
XJump-start the vehicle (Ypage 249).
or
XConsult a qualified specialist workshop.
You have lost a Smart-
Key.XHave the SmartKey deactivated at a qualified specialist workshop.
XReport the loss immediately to the vehicle insurers.
XIf necessary, have the locks changed as well.
You have lost the
mechanical key.XReport the loss immediately to the vehicle insurers.
XIf necessary, have the locks changed as well.
Doors
Important safety notes
GWARNING
If children are left unsupervised in the vehicle,
they could:
Ropen the doors, thus endangering other
people or road users.
Rget out and disrupt traffic.
Roperate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they:
Rrelease the parking brake.
Rshifting the automatic transmission out of
park position P
RStart the engine.
There is a risk of an accident and injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children or animals unattended in the
vehicle. Always keep the SmartKey out of
reach of children.
66Doors
Opening and closing

Unlocking and opening doors from
the inside
You can open a door from inside the vehicle
even if it has been locked. You can only open the
rear doors from inside the vehicle if they are notsecured by the child-proof locks (
Ypage 57). If
the vehicle has previously been locked with the
SmartKey, opening a door from the inside will
trigger the anti-theft alarm system. Switch off
the alarm (
Ypage 62).
Only open the door when the traffic situation
permits.
XFront doors: pull door handle ;.
If the door is locked, locking knob :pops up.
The door is unlocked and can be opened.
XRear doors: pull the locking knob of the rear
door up.
The door is unlocked.
XPull the door handle on the rear door.
Centrally locking and unlocking the
vehicle from the inside
You can centrally lock or unlock the vehicle from
the inside.
The central locking button does not lock or
unlock the fuel filler flap.
The switches are on the driver’s door.
XTo unlock: press button :.
XTo lock:press button ;.
If all the doors are closed, the vehicle locks.
The doors can be opened from the inside. You
can only open the rear doors from inside the
vehicle if they are not secured by the child-proof
locks (
Ypage 57)
You cannot unlock the vehicle centrally from the
inside if the vehicle has been locked with the
SmartKey.
If a locked door is opened from the inside, the
previous unlock status of the vehicle will be
taken into consideration if:
Rthe vehicle was locked using the locking but-
ton for the central locking, or
Rlocked automatically
The vehicle will be fully unlocked if it had previ-
ously been fully unlocked. If only the driver's
door had been previously unlocked, only the
door which has been opened from the inside is
unlocked.
Automatic locking feature
Doors67
Opening and closing
Z

XTo deactivate:press and hold button :for
approximately five seconds until a tone
sounds.
XTo activate: press and hold button ;for
approximately five seconds until a tone
sounds.
If you press one of the two buttons and do not
hear a tone, the relevant setting has already
been selected.
The vehicle is locked automatically when the
ignition is switched on and the wheels are turn-
ing.
You could therefore be locked out if:
Rthe vehicle is being pushed.
Rthe vehicle is being towed.
Rthe vehicle is being tested on a dynamometer.
You can also switch the automatic locking func-
tion on and off using the on-board computer
(
Ypage 170).
Locking/unlocking the driver's door
with the mechanical key
XInsert the mechanical key into the lock of the driver's door as far as it will go.
XTo unlock: turn the mechanical key counter-
clockwise as far as it will go to position 1.
XTo lock:turn the mechanical key clockwise as
far as it will go to position 2.
If you use the mechanical key to unlock and
open the driver's door, the anti-theft alarm sys-
tem will be triggered. Switch off the alarm
(
Ypage 62).
Rear door
Important safety notes
GWARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. If the rear
door is open when the engine is running, par-
ticularly if the vehicle is moving, exhaust
fumes could enter the passenger compart-
ment. There is a risk of poisoning.
Turn off the engine before opening the rear
door. Never drive with the rear door open.
GWARNING
If objects, luggage or loads are not secured or
not secured sufficiently, they could slip, tip
over or be flung around and thereby hit vehicle
occupants. There is a risk of injury, particu-
larly in the event of sudden braking or a sud-
den change in direction.
Always store objects so that they cannot be
flung around. Secure objects, luggage or
loads against slipping or tipping before the
journey.
!The tailgate swings out to the side when
opened. Therefore, make sure that there is
sufficient clearance.
Do not leave the SmartKey in the cargo com-
partment. Otherwise, you could lock yourself
out.
You should preferably place luggage or loads in
the cargo compartment. Observe the loading
guidelines (
Ypage 209).
Opening
The rear door must be unlocked before it can be opened.
XPress the %button on the SmartKey.
68Rear door
Opening and closing