2018 MERCEDES-BENZ G-CLASS check engine light

RBefore tackling steep downhill gradients, shift
the automatic transmission to a low gear.
By doing so, you will use the braking effect of
the engine to reduce the speed. 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.
RObserve the notes on driving in mountainous
terrain (Ypage 132).
RCheck that the service brake is working nor-
mally after a long downhill stretch.
When driving at speeds below 37 mph
(60 km/h), off-road ABS is activated and the
front wheels lock cyclically during braking. The
digging-in effect achieved in the process
reduces the stopping distance on off-road ter-
rain. This limits steering capability.
Driving systems
Cruise control
General notes
Cruise control maintains a constant road speed
for you. It brakes automatically in order to avoid
exceeding the set speed. Change into a lower
gear in good time on long and steep downhill
gradients.
This is especially important if the vehicle is
laden. 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).
Do not activate cruise control on off-road jour-
neys.
Important safety notes
Cruise control can neither reduce the risk of an
accident if you fail to adapt your driving style nor override the laws of physics. Cruise control can-
not take into account the road, traffic and
weather conditions. Cruise control is only an
aid. You are responsible for maintaining a safe
distance to the vehicle in front, for vehicle
speed, for braking in good time and for staying in
lane. Do not use cruise control:
Rin road and traffic conditions that do not allow
you to maintain a constant speed, e.g. in
heavy traffic, on winding roads or on rough
terrain
Ron slippery road surfaces. Braking or accel-
erating could cause the drive wheels to lose
traction and the vehicle could then skid
Rin 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.
iThe speed indicated in the speedometer
may differ slightly from the speed stored.
Cruise control lever
:Activates or increases speed
;Activates or reduces speed
=Deactivates cruise control
?Activates at the current speed/last stored
speed
When you activate cruise control, the stored
speed is shown in the multifunction display for
five seconds.
Speedometer with segments: when cruise
control is activated, the segments from the
stored speed to the end of the scale light up.
Storing, maintaining and calling up a
speed
Storing and maintaining the current
speed
You can store the current speed if you are driv-
ing faster than 20 mph (30 km/h).
Driving systems133
Driving and parking
Z

XMake sure the ECO start/stop function is
switched off (Ypage 108).
XPress LOW RANGE button;.
Once the shifting procedure has been com-
pleted, the LOW RANGE
transfer case position
is shown in the multifunction display.
Indicator lamp :lights up.
XShift the automatic transmission to position
h.
Switching off the off-road gear ratio
GWARNING
If you do not wait for the transfer case gear
change process to complete, the transfer
case could remain in the neutral position. The power transmission to the driven wheels is
then interrupted. There is a danger of the
vehicle rolling away unintentionally. There is a
risk of an accident.
Wait until the transfer case shift process is
completed.
!Proceed with the shifting process only
when:
Rthe engine is running
Rthe vehicle is rolling
Rthe automatic transmission is in selector
lever position i
Ryou are not driving faster than 43 mph
(70 km/h)
You could otherwise damage the transfer
case.
XPress button ;.
Once the shifting procedure has been com-
pleted, the HIGH
RANGEtransfer case position
is shown in the multifunction display.
Indicator lamp :goes out.
If the shifting procedure is unsuccessful, the
multifunction display may show the following
messages:
RTC Shift Conditions Not Fulfilled
You have not met one or more shift condi-
tions.
RTC NEUTRAL On
The transfer case has canceled the shifting
procedure and is in Neutral.
RTC Shift Canceled
The transfer case has canceled the gear
change process.
XCarry out the gear change process again.
Make sure to meet all conditions for changing
gears.
RTC Malfunction Visit Workshop
There is a malfunction in the transfer case.
XDo not shift the transfer case.
XHave the vehicle checked as soon as possible
at a qualified specialist workshop.
Shifting to neutral
GWARNING
If you do not wait for the transfer case gear
change process to complete, the transfer
case could remain in the neutral position. The power transmission to the driven wheels is
then interrupted. There is a danger of the
vehicle rolling away unintentionally. There is a
risk of an accident.
Wait until the transfer case shift process is
completed.
XTurn the SmartKey to position 2in the igni-
tion lock.
XApply the parking brake.
XDepress the brake pedal.
XShift the automatic transmission to position
i.
XPress and hold LOW RANGE button ;for
approximately ten seconds.
When the shift procedure is complete, the
multifunction display shows the TC
NEUTRALOnmessage for five seconds.
If the shifting procedure is unsuccessful, the
multifunction display may show the following
messages (
Ypage 183).
If the transfer case is in Neutral, the SmartKey
is in the ignition lock and you open the driver's
door, the TC NEUTRAL On
message appears in
the multifunction display. If you then release the
parking brake, a warning tone will sound.
150Off-road driving systems
Driving and parking

Towing a trailer
There are several legal requirements for towing
a trailer, e.g. the maximum permissible speed.
Make sure that your car/trailer combination
complies with the local regulations:
Rin your place of residence
Rat your destination
The police and local authorities can provide reli- able information.
In order to accumulate driving experience and
accustom yourself to the new handling charac-
teristics, practice the following at a location
where there is no traffic:
RCornering
RStopping
RBacking up
Before driving, check the following:
RTrailer tow hitch
RSafety switch for braked trailers
RSafety chains
RElectrical connections
RLighting system
RWheels and tires
RLoad-securing measures
Adjust the exterior mirrors to provide an unob-
structed view of the rear section of the trailer.
Trailers with electronically controlled
brakes: pull away carefully in the vehicle/trailer
combination, brake manually using the brake
controller and check whether the brakes func-
tion correctly.
Check the load securing measures on a regular
basis.
When towing a trailer, your vehicle's handling
characteristics will be different in comparison
with when driving without a tra
iler.
The vehicle/trailer combination:
Ris heavier
Ris restricted in its acceleration and gradient-
climbing capability
Rhas an increased braking distance
Ris affected more by strong crosswinds
Rdemands more sensitive steering
Rhas a larger turning radius
Avoid sudden steering movements.
Avoid braking abruptly. If possible, brake gently
at first to allow the trailer to run on. Then,
increase the braking force rapidly. When overtaking, pay particular attention to the
extended length of your vehicle/trailer combi-
nation.
Due to the length of the vehicle/trailer combi-
nation, you require additional road space when
overtaking before you can change back to the
original lane.
If the automatic transmission repeatedly shifts
between gears on uphill or downhill gradients,
shift to a lower gear.
Driving in a lower gear and at a reduced speed
decreases the risk of engine damage.
Avoid constant braking. Otherwise, the vehicle
brakes and possibly also the trailer brakes may
overheat.
When driving downhill, shift to a lower gear to
utilize the engine's braking effect.
If the coolant temperature increases dramati-
cally while the air-conditioni ng s
ystem is
switched on, switch off the air-conditioning sys- tem.
Coolant heat can also be dissipated by opening
the windows and switching the ventilation
blower and the interior temperature to the high-
est level.
Decoupling a trailer
GWARNING
If you uncouple a trailer with the overrun
brake engaged, you could trap your hand
between the vehicle and the trailer drawbar.
There is a risk of injury.
Do not uncouple a trailer if the overrun brake
is engaged.
!Do not disconnect a trailer with an engaged
overrun brake. Otherwise, your vehicle could
be damaged by the rebounding of the overrun
brake.
XApply the parking brake.
XMake sure that the automatic transmission is
set to position P.
XSecure the vehicle and trailer against rolling
away.
XClose all doors, including the rear door.
XRemove the trailer cable.
XRemove the safety chains, if there are any.
XUncouple the trailer.
158Towing a trailer
Driving an d parking

Important safety notes
GWARNING
If you operate information systems and com-
munication equipmen tintegrate din th evehi-
cle when driving ,you may be distracte dfrom
th etraffic situation .You could also lose con-
trol of th evehicle. Ther eis aris kof an acci-
dent.
Only operate this equipmen twhen th etraffic
situation permits. If you are no tsur ethat this
is possible ,park th evehicl epayin gattention
to traffic condition sand operate th eequip-
men twhen th evehicl eis stationary.
You must observ eth elegal requirements for th e
country in whic hyou are currentl ydriving when
operating th eon-board computer.
GWARNIN G
If th einstrumen tcluste rhas faile dor mal-
functioned, you may no trecognize function
restriction sin systems relevan tto safety. The
operating safet yof your vehicl emay be
impaired .Ther eis aris kof an accident.
Drive on carefully. Hav eth evehicl echecke d
at aqualified specialist workshop immedi-
ately.
If th eoperating safet yof your vehicl eis
impaired ,pull ove ras soo nas it is saf eto do so.
Contac t aqualified specialist workshop.
The on-board computer only shows message sor
warning sfrom certain systems in th emultifunc-
tion display. You should therefor emak esur e
your vehicl eis operating safely at all times .
Fo ran overview, see th einstrumen tpanel illus-
tration (
Ypage 32).
Displays and operation
Instrument cluster lighting
The brightness control knob is locate don th e
botto mleftof th einstrumen tcluste r
(
Ypage 32).
XTurn th ebrightness control knob clockwise or
counter-clockwise.
If th eligh tswitch is set to th eÃ, Tor
L position ,th ebrightness is dependen t
upon th ebrightness of th eambien tlight.
iThe ligh tsensor in th einstrumen tcluste r
automatically control sth ebrightness of th e
multifunction display.
In daylight, th edisplays in th einstrumen t
cluste rare no tilluminated.
Speedometer with segments
The segments in th espeedometer indicat e
whic hspee drange is available.
RCruis econtrol activated (Ypage 133):
The segments ligh tup from th estore dspee d
to th een dof th escale.
RDISTRONI CPLU Sactivated (Ypage 136):
On eor two segments in th eset spee drange
ligh tup.
RDISTRONI CPLU Sdetects avehicl ein front:
The segments between th espee dof th evehi-
cle in fron tand th estore dspee dligh tup.
Tachometer
!
Do no tdriv ein th eoverrevving range, as this
could damag eth eengine.
The red ban din th etachometer indicates th e
engine's overrevving range.
The fuel suppl yis interrupted to protect th e
engin ewhen th ered ban dis reached.
Outside temperature display
You should pay special attention to road condi-
tion swhen temperatures are aroun dfreezing
point.
Bea rin min dthat th eoutside temperature dis-
play indicates th etemperature measured and
does no trecord th eroad temperature.
The outside temperature display is in th emulti-
function display (
Ypage 162).
Changes in th eoutside temperature are dis-
played after ashort delay.
160Displays and operation
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
FrontPassengerAir‐bag Enable dSeeOperator' sManual
The 45indicator lamp does not remain lit if a special Baby-
Smart™-compatible child restraint system has been installed on the
front-passenger seat.
The BabySmart™ system is malfunctioning.
GWARNING
The front-passenger front air bag can be triggered unintentionally in
the event of an accident.
There is a risk of an accident.
XMake sure there is nothing between the seat cushion and the child
seat.
XCheck for correct installation of the child restraint system.
XIf the 45indicator lamps do not light up, have the Baby-
Smart™ system checked as soon as possible at a qualified special-
ist workshop.
Do not transport a child on the front-passenger seat until the air bag
deactivation system has been repaired.
RadarSensorsDirtySee Operator's Man‐ual
The radar sensor system is malfunctioning.
Possible causes are:
Rdirt on sensors
Rheavy rain or snow
Rwhen driving on inter-urban roads without traffic or infrastructure,
e.g. in desert-like areas
At least one driving system is malfunctioning or temporarily unavail-
able:
RDISTRONIC PLUS
A warning tone also sounds.
Once the cause of the problem is no longer present, the driving sys-
tems will be available again. The display message disappears.
If the display message does not disappear:
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 122).
XSwitch off the engine.
XClean all sensors (Ypage 239).
XRestart the engine.
The display message disappears.
Display messages179
On-board computer and displays
Z

Lights
Display messagesPossible causes/consequences andMSolutions
b
Example:Check LeftLow Beam
The bulb in question is malfunctioning.
XVisit a qualified specialist workshop.
or
XCheck whether you are permitted to replace the bulb yourself
(Ypage 89).
iLED light sources: the display message for the corresponding
lamp only appears when all the LEDs in the lamp have failed.
b
Malfunction SeeOperator's Manual
The exterior lighting is malfunctioning.
XVisit a qualified specialist workshop.
b
Auto Lamp FunctionInoperative
The light sensor is defective.
XVisit a qualified specialist workshop.
b
Switch Off Lights
The lights are still switched on when you leave the vehicle. A warning
tone also sounds.
XTurn the light switch to position Ã.
Engine
Display messagesPossible causes/consequences and MSolutions
+
CheckCoolantLevelSee Operator's Man‐ual
The coolant level is too low.
XAdd coolant, observing the warning notes before doing so
(Ypage 234).
XHave the coolant system checked at a qualified specialist workshop
if the coolant needs topping up more often than usual.
?The fan motor is malfunctioning.
XIf the coolant temperature is below the Hmark, drive to the nearest
qualified specialist workshop.
XAvoid heavy loads on the engine as you do so, e.g. driving in moun-
tainous terrain and stop-start traffic.
180Display messages
On-board computer and displays

Engine
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
;NThe yellow Check Engine warning lamp lights up while the engine is running.
There may be a malfunction, for example:
Rin the engine management
Rin the fuel injection system
Rin the exhaust system
Rin the ignition system
Rin the fuel system
The emission limit values may be exceeded and the engine may be in emergency
mode.
XVisit a qualified specialist workshop immediately.
In some states, you must immediately visit a qualified specialist workshop as soon as the yellow Check Engine warning lamp lights up. This is due to the legal require-
ments in effect in these states. If in doubt, check whether such legal regulations
apply in the state in which you are currently driving.
8N The yellow reserve fuel warning lamp lights up while the engine is running.
The fuel level has dropped into the reserve range.
XRefuel at the nearest gas station.
8N The yellow reserve fuel warning lamp flashes while the vehicle is in motion.
In addition, the ;Check Engine warning lamp may light up.
The fuel filler cap is not closed correctly or the fuel system is leaking.
XCheck that the fuel filler cap is correctly closed.
XIf the fuel filler cap is not correctly closed: close the fuel filler cap.
XIf the fuel filler cap is closed:visit a qualified specialist workshop.
?NThe red coolant warning lamp lights up while the engine is running and the
coolant temperature gauge is at the start of the scale.
The temperature sensor for the coolant temperature gauge is malfunctioning.
The coolant temperature is no longer being monitored. There is a risk of engine
damage if the coolant temperature is too high.
XPull over and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions. Do not continue driving under any circumstances.
XSecure the vehicle against rolling away (Ypage 122).
XConsult a qualified specialist workshop.
Warning and indicator lamps in the instrument cluster199
On-board computer and displays
Z

The hood release lever is located in the footwell
on the left-hand side of the vehicle when viewedin the direction of travel.
XMake sure that the windshield wipers are
turned off.
XPull release lever :on the hood.
The hood is released.
XLift the hood slightly.
XPush the handle of hood catch ;in the direc-
tion of the arrow and lift the hood.
The hood is opened and held open automati-
cally by the gas-filled strut.
Closing the hood
XLower the hood and let it fall from a height of
approximately 8 in (20 cm).
XCheck that the hood has engaged properly.
If the hood can be raised slightly, it is not
properly engaged. Open it again and close it
with a little more force.
Radiator
Do not cover up the radiator, such as with a
thermal mat or insect protection cover. Other-
wise, the values of the European on-board diag- nostics may be affected. Some of these read-
ings are required by law and must be accurate at
all times.
Engine oil
Important safety notes
GWARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and touch only the components described in the
following.
GWARNING
The engine compartment contains moving
components. Certain components, such as
the radiator fan, may continue to run or start
again suddenly when the ignition is off. There is a risk of injury.
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
If engine oil comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Make sure that engine oil is not spilled next to
the filler neck. Let the engine cool down and
thoroughly clean the engine oil off the com-
ponents before starting the engine.
Engine compartment231
Maintenance and care
Z