2018 MERCEDES-BENZ G-CLASS service

If you need to do any work inside the engine
compartment:
Rswitch off the ignition
Rnever reach into the area where there is a
risk of danger from moving components,
such as the fan rotation area
Rremove jewelry and watches
Rkeep items of clothing and hair, for exam-
ple, away from moving parts
GWARNING
The cooling system is pressurized, particularly
when the motor is warm. If you open the cap,
you could be scalded if hot coolant sprays out.
There is a risk of injury.
Let the engine cool down before you open the
cap. Wear gloves and eye protection. Slowly
open the cap to relieve pressure.
GWARNING
Opening the hood when the engine is over-
heated or when there is a fire in the engine
compartment could expose you to hot gases
or other service products. There is a risk of
injury.
Let an overheated engine cool down before
opening the hood. If there is a fire in the
engine compartment, keep the hood closed
and contact the fire department.
Checking coolant level
Checking the coolant level (example)
XPark the vehicle on a level surface. Only check the coolant level when the vehicle
is on a level surface and the engine has cooled
down.
XTurn the SmartKey to position 2in the igni-
tion lock (Ypage 105).
XCheck the coolant temperature display in the
instrument cluster.
The coolant temperature must be below
158 ‡ (70 †).
XSlowly turn cap :half a turn counter-clock-
wise and allow excess pressure to escape.
XTurn cap :further counter-clockwise and
remove it.
If the coolant is at the level of marker bar =
in the filler neck when cold, there is enough
coolant in coolant expansion tank ;.
If the coolant level is approximately 0.6 in
(1.5 cm) above marker bar =in the filler neck
when warm, there is enough coolant in cool-
ant expansion tank ;.
XIf necessary, add coolant that has been tested
and approved by Mercedes-Benz.
XReplace cap:and turn it clockwise as far as
it will go.
For further information on coolant, see
(
Ypage 286).
Adding washer fluid to the windshield
washer system/headlamp cleaning
system
GWARNING
Windshield washer concentrate could ignite if it comes into contact with hot engine compo-
nents or the exhaust system. There is a risk of
fire and injury.
Make sure that no windshield washer con-
centrate is spilled next to the filler neck.
234Engine compartment
Maintenance and care

Example: adding liquid to the windshield
washer system
XTo open:pull cap:upwards by the tab and
open.
XAdd the premixed washer fluid.
XTo close: press cap :onto the filler neck
until it engages.
The washer fluid reservoir is used for both the
windshield washer system and the headlamp
cleaning system.
If the washer fluid level drops below the recom-
mended minimum of 3.7 US qt (3.5 l), a message
appears in the multifunction display prompting
you to add washer fluid (
Ypage 191).
Further information on washer fluid
(
Ypage 287).
Brake fluid level
!If you notice that the brake fluid level in the
brake fluid reservoir has fallen to the MIN
mark or less, check the brake system imme-
diately for leaks. Also check the thickness of
the brake linings. Visit a qualified specialist
workshop immediately.
Do not add brake fluid. This does not correct
the error.
Only check the brake fluid level when the vehicle
is stationary and on a level surface. The brake
fluid level is correct if the level is between MAX
mark :and MIN mark ;on the brake fluid
reservoir.
Maintenance
Service interval display
Service messages
You can obtain up-to-date information concern-
ing the servicing of your vehicle from a qualified
specialist workshop, e.g. an authorized
Mercedes-Benz Center or at
http://www.mbusa.com (USA only).
The ASSYST service interval display informs you
of the next service due date.
If a service due date has been exceeded, you
also hear a warning tone.
The multifunction display shows a service mes-
sage for several seconds, e.g.:
Service A In 999,999 km
Service A in .. Days
Service A Due
Service A Exceeded 999,999 km
Service A Exceeded .. Days
Maintaining the time-dependent service sched-
ule:
XBefore disconnecting the battery, note down
the service due date displayed.
or
XAfter reconnecting the battery, subtract the
battery disconnection periods from the ser-
vice date shown on the display.
The service interval display should not be con-
fused with the 4engine oil level display.
The symbol and the letter indicate which type of
service is due:
¯ Minor service A
±
Major service B
The ASSYST service interval display does not
take into account any periods of time during
which the battery is disconnected.
Maintenance235
Maintenance and care
Z

Hiding a service message
XTo hide the service message, press the%
back button on the multifunction steering
wheel (
Ypage 161).
Displaying service messages
Use the buttons on the multifunction steering
wheel.
XSwitch on the ignition.
XPress =or; to select the standard
display menu on the steering wheel
(
Ypage 163).
XPress 9or: to select the service
interval display.
The ¯ or± service symbol and the ser-
vice due date are displayed.
Points to remember
The specified maintenance interval takes only
the normal operation of the vehicle into
account. Under arduous operating conditions or
increased load on the vehicle, maintenance
work must be carried out more frequently, for
example:
Rregular city driving with frequent intermediate
stops
Rif the vehicle is primarily used to travel short
distances
Ruse in mountainous terrain or on poor road
surfaces
Rif the engine is often left idling for long periods
Under these or similar conditions, have, for
example, the air filter, engine oil and oil filter
replaced or changed more frequently. Under
arduous operating conditions, the tires must be
checked more often. Further information can be obtained at a qualified specialist workshop, e.g.
an authorized Mercedes-Benz Center.
Care
General notes
!
For cleaning your vehicle, do not use any of
the following:
Rdry, rough or hard cloths
Rabrasive cleaning agents
Rsolvents
Rcleaning agents containing solvents
Do not scrub.
Do not touch the surfaces or protective films
with hard objects, e.g. a ring or ice scraper.
You could otherwise scratch or damage the
surfaces and protective film.
!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.
HEnvironmental note
Dispose of empty packaging and cleaning
cloths in an environmentally responsible man-
ner.
Regular care of your vehicle is a condition for
retaining the quality in the long term.
Use care products and cleaning agents recom-
mended and approved by Mercedes-Benz.
Washing the vehicle and cleaning the
paintwork
Automatic car wash
GWARNING
Braking efficiency is reduced after washing
the vehicle. There is a risk of an accident.
After the vehicle has been washed, brake
carefully while paying attention to the traffic
conditions until full braking power is restored.
!When DISTRONIC PLUS or the HOLD func-
tion is activated, the vehicle brakes automat-
ically in certain situations.
To avoid damage to the vehicle, deactivate
DISTRONIC PLUS and the HOLD function in
the following or similar situations:
Rwhen towing the vehicle
Rin the car wash
!Never clean your vehicle in a Touchless
Automatic Car Wash as these use special
236Care
Maintenance and care

sparks are created, the hydrogen gas can
ignite. There is a risk of an explosion.
RMake sure that the positive terminal of a
connected battery does not come into con-
tact with vehicle parts.
RNever place metal objects or tools on a bat-tery.
RIt is important that you observe the descri-
bed order of the battery terminals when
connecting and disconnecting a battery.
RWhen jump-starting, make sure that the
battery poles with identical polarity are
connected.
RIt is particularly important to observe the
described order when connecting and dis-
connecting the jumper cables.
RNever connect or disconnect the battery
terminals while the engine is running.
GWARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten-
tion.
HEnvironmental 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, please observe the fol-
lowing:
RSecure the vehicle to prevent it from rolling
away.
RSwitch off the ignition.
RDisconnect the negative terminal first and
then the positive terminal.
The transmission is locked in position j
after disconnecting the battery.
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 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.
Battery (vehicle)247
Breakdown assistance
Z

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.
The vehicle will then use very little energy, thus
conserving battery power.
iIf the power supply has been interrupted,
e.g. due to a discharged battery, you will have
to:
Rreset the head restraints on the front seats (Ypage 76)
Rreset the function for automatically folding
the exterior mirrors in/out by folding the
mirrors out once (
Ypage 82)
Charging the battery
!
Only use battery chargers with a maximum
charging voltage of 14.8 V.
GWARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, open flames, creating
sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting.
Do not lean over a battery.
GWARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with plenty of clean water and seek medical atten-
tion.
GWARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing the vehicle or charging the battery, gases can escape from the battery. There is a risk of
an explosion.
Allow the frozen battery to thaw out before
charging it or jump-starting.
!Only charge the battery using the jump-
starting connection point.
The jump-starting connection point is in the
engine compartment (
Ypage 249).
XOpen the hood.
XConnect the battery charger to the positive
terminal and ground point in the same order
as when connecting the donor battery in the
jump-starting procedure (
Ypage 249).
Keep away from fire and open flames. Do not
lean over a battery. Never charge the battery if it
is still installed in the vehicle, unless you use a
battery charger which has been tested and
approved by Mercedes-Benz. A battery charger
unit specially adapted for Mercedes-Benz vehi-
cles and tested and approved by Mercedes-
Benz is available as an accessory. It permits the
charging of the battery in its installed position.
Contact an authorized Mercedes-Benz Center
for further information and availability. Read the
battery charger's operating instructions before
charging the battery.
If the warning and indicator lamps do not light up
on the instrument cluster when temperatures
are low, it is probably because the discharged
battery has frozen. In this case you may neither
jump-start the vehicle nor charge the battery.
The service life of a thawed-out battery may be
shorter. The starting characteristics can be
impaired, particularly at low temperatures. Have
the thawed-out battery checked at a qualified
specialist workshop.
248Battery (vehicle)
Breakdown assistance

Jump starting
For the jump-starting procedure, use only the jump-starting connection point in the engine com-
partment, consisting of a positive terminal and a ground point.
GWARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do not inhale any battery gases. Do not lean over the
battery. Keep children away from batteries. Wash away battery acid immediately with plenty of
clean water and seek medical attention.
GWARNING
During charging and jump-starting, explosive gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, open flames, creating sparks and smoking. Ensure there is sufficient ven-
tilation while charging and jump-starting. Do not lean over a battery.
GWARNING
During the charging process, a battery produces hydrogen gas. If a short circuit occurs or sparks
are created, the hydrogen gas can ignite. There is a risk of an explosion.
RMake sure that the positive terminal of a connected battery does not come into contact with
vehicle parts.
RNever place metal objects or tools on a battery.
RIt is important that you observe the described order of the battery terminals when connecting
and disconnecting a battery.
RWhen jump-starting, make sure that the battery poles with identical polarity are connected.
RIt is particularly important to observe the described order when connecting and disconnecting
the jumper cables.
RNever connect or disconnect the battery terminals while the engine is running.
GWARNING
A discharged battery can freeze at temperatures below freezing point. When jump-starting the
vehicle or charging the battery, gases can escape from the battery. There is a risk of an explosion. Allow the frozen battery to thaw out before charging it or jump-starting.
!Avoid repeated and lengthy starting attempts. Otherwise, the catalytic converter could be
damaged by the non-combusted fuel.
If the warning and indicator lamps do not light up on the instrument cluster when temperatures are
low, it is probably because the discharged battery has frozen. In this case, you may neither charge
the battery nor jump-start the vehicle. The service life of a thawed-out battery may be shorter. The
starting characteristics can be impaired, particularly at low temperatures. Have the thawed-out
battery checked at a qualified specialist workshop.
Jump starting249
Breakdown assistance
Z

Rbulges on tires
Rdeformation or severe corrosion on wheels
Regularly check the tire tread depth and the
condition of the tread across the whole width of
the tire (
Ypage 258). In order to inspect the
inner side of the tire surface, turn the steering
wheel to full lock.
All wheels must have a valve cap to protect the valve against dirt and moisture. Do not install
anything onto the valve other than the standard
valve cap or a valve cap approved by Mercedes-
Benz for your vehicle. Do not use any other valve
caps or systems, e.g. tire pressure monitoring
systems.
You should regularly check the pressure of all
your tires including the spare wheel, particularly
prior to long trips. Adjust the tire pressure as
necessary (
Ypage 260).
The service life of tires depends, among other
things, on the following factors:
RDriving style
RTire pressure
RDistance covered
Notes on tire tread
GWARNING
Insufficient tire tread will reduce tire traction.
The tire is no longer able to dissipate water.
This means that on wet road surfaces, the risk
of hydroplaning increases, in particular where speed is not adapted to suit the driving con-
ditions. There is a risk of accident.
If the tire pressure is too high or too low, tires
may exhibit different levels of wear at differ-
ent locations on the tire tread. Thus, you
should regularly check the tread depth and
the condition of the tread across the entire
width of all tires.
Minimum tire tread depth for:
RSummer tires: âin (3 mm)
RM+S tires: ãin (4 mm)
For safety reasons, replace the tires before
the legally prescribed limit for the minimum
tire tread depth is reached.
Marking :shows where the bar indicator
(arrow) for tread wear is integrated into the tire
tread.
Treadwear indicators (TWI) are required by law. Six indicators are positioned on the tire tread.
They are visible once a tread depth of approx-
imately áin (1.6 mm) has been reached. If this
is the case, the tire is so worn that it must be
replaced.
Selecting, mounting and replacing
tires
ROnly mount tires and wheels of the same type
and make.
ROnly mount tires of the correct size onto the
wheels.
RBreak in new tires at moderate speeds for the
first 60 miles (100 km). The new tires only
reach their full performance after this dis-
tance.
RDo not drive with tires which have too little
tread depth, as this significantly reduces the
traction on wet roads (hydroplaning).
RReplace the tires after six years at the latest,
regardless of wear. This also applies to the
spare wheel.
Winter operation
General notes
Have your vehicle winter-proofed at a qualified
specialist workshop at the onset of winter.
Observe the notes in the "Changing a wheel"
section (
Ypage 275).
258Winter operation
Wheels and tires

If "T" precedes the size description: these are
compact emergency spare wheels at high tire
pressure, to be used only temporarily in an
emergency.
Tire width:tire width:shows the nominal tire
width in millimeters.
Height-width ratio: height-width ratio;is the
ratio between tire height and tire width. The
aspect ratio is calculated by dividing the tire
width by the tire height. The resulting quotient is
given as a percentage.
Tire code: tire code=shows the tire type. "R"
represents radial tires; "D" represents diagonal
tires; "B" represents diagonal radial tires.
Optionally, tires with a maximum speed of over
149 mph (240 km/h) may have "ZR" in the size
description, depending on the manufacturer
(e.g. 245/40 ZR 18).
Rim diameter: rim diameter?is the diameter
of the bead seat, not the diameter of the rim
flange. The rim diameter is specified in
inches (in).
The load-bearing index: load-bearing indexA
(also load index), is a code that contains the
maximum load-bearing capacity of a tire.
Do not overload the tires by exceeding the
specified load limit. The maximum permissible
load can be found on the vehicle's Tire and
Loading Information placard on the B-pillar on
the driver's side (
Ypage 266).
Example:
Load-bearing index 91 indicates a maximum
load of 1,356 lb (615 kg) that the tires can bear.
Further information on the maximum tire load in
kilograms and pounds (
Ypage 272).
For further information on the load bearing
index, see "Load index" (
Ypage 272).
Speed rating: speed ratingBspecifies the
approved maximum speed of the tire.
iTire data is vehicle-specific and may deviate
from the data in the example.
Regardless of the speed rating, always observe
the speed limits. Drive carefully and adapt your driving style to the traffic conditions.
iSince 2009, tires in Europe which corre-
spond to the noise limitations of Directive
ECE-R 117 show an >>S<< (Sound) mark. This
marking is in accordance with the type
approval number and is not connected to the
speed ra

ting. Summer tires
IndexSpeed rating
Qup to 100 mph (160 km/h)
Rup to 106 mph (170 km/h)
Sup to 112 mph (180 km/h)
Tup to 118 mph (190 km/h)
Hup to 130 mph (210 km/h)
Vup to 149 mph (240 km/h)
Wup to 168 mph (270 km/h)
Yup to 186 mph (300 km/h)
ZR...Yup to 186 mph (300 km/h)
ZR...(..Y)over 186 mph (300 km/h)
ZRover 149 mph (240 km/h)
ROptionally, tires with a maximum speed of
over 149 mph (240 km/h) may have "ZR" in
the size description, depending on the man-
ufacturer (e.g. 245/40 ZR18).
The service specification is made up of load-
bearing index
Aand speed rating B.
RIf the size description of your tire includes
"ZR" and there are no service specifications,
ask the tire manufacturer in order to find out
the maximum speed.
If a service specification is available, the max-
imum speed is limited according to the speed
rating in the service specification. Example:
245/40 ZR18 97 Y.In this example, "97 Y" is
the service specification. The letter "Y" rep-
resents the speed rating and the maximum
speed of the tire is limited to 186 mph
(300 km/h).
RThe size description for all tires with maxi-
mum speeds of over 186 mph (300 km/h)
must include "ZR", andthe service specifica-
tion must be given in parentheses. Example:
275/40 ZR 18 (99 Y). Speed rating "(Y)" indi-
cates that the maximum speed of the tire is
over 186 mph (300 km/h). Ask the tire man-
ufacturer about the maximum speed.
All about wheels and tires271
Wheels and tires
Z