differential MERCEDES-BENZ G-CLASS SUV 2015 User Guide

The disadvantage of a differential is that the
wheels that have the least grip, get the most
drive. An example: a wheel of a driven axle is
on a snow-covered surface and therefore
does not have any traction. The differential
sends most of the drive force to this wheel
because the force takes the route of the low-
est resistance. The opposite wheel on this
axle, however, which stands on firm ground
and could therefore allow propulsion,
receives no driving power. 4ETS compen-
sates for this disadvantage. 4ETS provides
good steerability by automatically braking the
spinning wheel. 4ETS provides the wheel on
the firm surface with more drive force, which in turn provides propulsion. ESP ®
and 4ETS are traction systems that are
ideal for road driving and suitable for light off-
road driving. The LOW RANGEoff-road gear
also improves off-road capability.
More challenging off-road conditions require
additional measures such as locking one or
more differential. Your vehicle is equipped
with three differential locks:
R a central differential lock for the transfercase
R a differential lock for the front axle and
R a differential lock for the rear axle
Each differential lock can be engaged with the corresponding switch on the center console.
If the differential in the transfer case is
locked, the front and rear wheels rotate at the same speed. If the differential for the rear axle
is locked, both rear wheels rotate at the same
speed, regardless of their respective torque.
Note, engaging the differential lock greatly
impairs the vehicle's steerability.
Note, it is imperative to use the differential
function when driving on firm road surfaces.
Under no circumstances should the differen-
tial be locked when driving on firm road sur-
faces. Otherwise, the vehicle may not be
steerable and you could lose control of the
vehicle. Therefore, only engage the differen-
tial lock when driving off-road. You should
only engage the differential lock if activating 4ETS and ESP
®
driving systems and LOW
RANGE off-road gear prove to be insufficient.
Engaging the differential locks
Important safety notes
GWARNING
When differential locks are engaged on a firm,
high-grip surface, the vehicle's steerability is
greatly impaired. In particular, engaging the
differential locks when cornering could lead
to you losing control of the vehicle. There is a
risk of an accident.
Disengage the differential locks immediately
on firm surfaces with good grip.
GWARNING
When the differential locks are engaged, ABS,
4ETS, ESP ®
and BAS are deactivated. As a
result, the wheels could lock when braking
and the braking distance is increased. There is
a risk of an accident.
Disengage the differential locks immediately
on firm surfaces with good grip.
!Only engage the differential locks when:
R you are driving at walking pace.
R the driven wheels are not spinning.
R you are not driving on a firm road surface.
General notes
The switches are located on the center con- sole.
:Function indicator lamps (red)
;Differential lock for the front axle
Off-road driving systems135
Driving and parking
Z

=Differential lock for the transfer case
?Differential lock for the rear axle
AActivation indicator lamps (yellow)
Engage the differential locks: R off-road
R to deactivate ABS, 4ETS, ESP ®
and BAS
while off-road
R when fording
For more information on driving off-road, see the Digital Operator's Manual.
iYou can engage the differential locks in
the following order: =,? ,; .
Differential lock for the transfer case
X
To engage: switch the transfer case to the
LOW RANGE off-road driving position
( Y page 132).
X Press switch =.
If the transfer case is in the LOW RANGE
off-road position, the yellow activation indi- cator lamp under switch =lights up.
The å warning lamp in the instrument
cluster lights up.
If the differential is locked, the red function indicator lamp above switch =lights up.
In the multifunction display you see the:
ABS not available differential
lockedmessage.
The å!÷ warning lamps light up
in the instrument cluster.
The differential lock for the transfer case is
engaged.
4ETS, ESP ®
, BAS and ABS are deactivated.
The vehicle's ability to steer is severely
restricted. Drive carefully and accelerate gen-
tly for optimum traction.
iYou can now engage the differential lock
for rear axle ?and the differential lock for
front axle ;as required.
Differential lock for the rear axle
X
To engage: press switch ?.
Yellow activation indicator lamp Alights
up first, followed by red function indicator
lamp :of switch ?.
The differential lock for the rear axle is
engaged.
Differential lock for the front axle
X To engage: press switch ;.
First, the yellow activation indicator lamp
lights up, followed by the red function indi- cator lamp.
The differential lock for the front axle is
engaged.
Disengaging the differential locks
You can disengage the differential locks in the
following order: ;,? ,= .
X To simultaneously disengage all differ-
ential locks: press switch=.
Yellow activation indicator lamps Aand
red function indicator lamps :go out.
After approximately three seconds of nor-
mal driving, ABS, 4ETS, ESP ®
and BAS are
activated.
The
ABSnotavailabledifferential
lockedmessage disappears in the multi-
function display and the å,! and
÷ warning lamps in the instrument clus-
ter go out.
X Shift the transfer case to the HIGH RANGE
on-road position ( Ypage 132).
iIf red function indicator lamps :do not
go out when disengaging the differential
locks, stop the vehicle safely as soon as
possible, in accordance with the traffic con- ditions. Then, continue driving and the load
change can release the differential lock.
136Off-road driving systems
Driving an d parking

Display messagesPossible causes/consequences andMSolutions
Differential lock
only available in
LOW RANGE
The LOW RANGE button has been pressed. The transfer case is in
the LOW RANGE off-road driving position and a differential lock is
engaged.
X Disengage the differential locks ( Ypage 134).
X Repeat the gearshift process.
TC NEUTRAL
ON
The transfer case is in the Neutralneutral position.
A warning tone will also sound when the driver's door is opened
and the brake pedal is not depressed.
X Close the driver's door.
X Secure the vehicle against rolling away ( Ypage 110).
X Shift the transfer case according to driving conditions(Y page 132).
Preselected difZ
ferential lock
ESP unavailable
A differential lock has been engaged. The differential gear has not
yet locked the respective differential. The activation indicator
lamp (yellow) ( Ypage 134) of the switch lights up.
ESP is unavailable.
ABS is still available.
Differential lock
active
ABS and ESP
unavailable
A differential lock was engaged and the differential gear has
locked the respective differential. The activation indicator lamp
(yellow) and function indicator lamp (red) ( Ypage 134) on the
switch light up.
ABS and ESP are unavailable.
Display messages157
On-board computer and displays
Z

ProblemPossible causes/consequences andMSolutions
!
The yellow ABS warning
lamp is lit while the
engine is running. A
warning tone alsosounds.EBD is malfunctioning. Therefore, ABS, BAS, ESP ®
, the HOLD
function, hill start assist, adaptive brake lights and ESP ®
trailer
stabilization, for example, are also unavailable.
GWARNING
The brake system continues to function normally, but without the functions listed above. The wheels could therefore lock if you
brake hard, for example.
The steerability and braking characteristics may be severely affec-ted. The braking distance in an emergency braking situation can increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop.
!
The yellow ABS warning
lamp is lit while the
engine is running.You have engaged the differential locks. ABS is deactivated.
X Disengage the differential locks.
Subsequently ABS is reactivated.
$ (USA only)
J (Canada only)
֌!
The yellow brake warn-
ing lamp, the yellow ESP ®
and ESP ®
OFF
warning lamps and the
yellow ABS warning
lamp are lit while the
engine is running.ABS and ESP ®
are malfunctioning. BAS, EBD, the HOLD function,
hill start assist, the adaptive brake lights and ESP ®
trailer stabili-
zation, for example, are therefore unavailable.
GWARNING
The brake system continues to function normally, but without the functions listed above. The front and rear wheels could therefore
lock if you brake hard, for example.
The steerability and braking characteristics may be severely affec-ted. The braking distance in an emergency braking situation can increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop.
Warning and indicator lamps in the instrument cluster165
On-board computer and displays
Z

ProblemPossible causes/consequences andMSolutions
֌
The yellow ESP®
and
ESP ®
OFF warning
lamps are lit while the
engine is running.ESP ®
, BAS, the HOLD function, hill start assist and ESP ®
trailer
stabilization are temporarily unavailable.
BAS and the adaptive brake lights may also have failed.
self-diagnosis is not yet complete.
GWARNING
The brake system continues to function normally, but without the functions listed above.
The braking distance in an emergency braking situation can thus increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Carefully drive a suitable distance, making slight steering move-
ments at a speed above 12 mph (20 km/h).
The functions mentioned above are available again when the
warning lamp goes out.
If the warning lamp is still on:
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop.
å
The yellow ESP ®
OFF
warning lamp is lit while the engine is running.The differential lock is engaged. ABS, ESP ®
, 4ETS and BAS have
been deactivated. X Disengage the differential lock. ESP ®
, 4ETS and BAS are subsequently reactivated.
X Observe the additional display messages in the multifunction
display.
6
The red restraint sys-
tem warning lamp is lit
while the engine is run-ning.The restraint system is faulty.
GWARNING
The air bags or Emergency Tensioning Devices may either be trig-
gered unintentionally or, in the event of an accident, may not be triggered.
There is an increased risk of injury.
X Drive on carefully.
X Have the restraint system checked at a qualified specialist
workshop immediately.
For further information about the restraint system, see( Y page 42).
Warning and indicator lamps in the instrument cluster167
On-board computer and displays
Z