display MERCEDES-BENZ GL-Class 2015 X166 Repair Manual

Servicing the brakes
!
If the red brake warning lamp lights up in
the instrument cluster and you hear a warn- ing tone while the engine is running, the
brake fluid level may be too low. Observe
additional warning messages in the multi-
function display.
The brake fluid level may be too low due to brake pad wear or leaking brake lines.
Have the brake system checked immedi-
ately. This work should be carried out at a
qualified specialist workshop.
! A function or performance test should
only be carried out on a 2-axle dynamom-
eter. If you are planning to have the vehicle tested on such a dynamometer, contact an
authorized Mercedes-Benz Center to
obtain further information first. Otherwise,
you could damage the drive train or the
brake system.
! Because ESP ®
is an automatic system,
the engine and ignition must be switched
off (SmartKey in position 0or 1or Start/
Stop button in position 0or 1) when the
electric parking brake is being tested on a
brake dynamometer (maximum
10 seconds).
Braking triggered automatically by ESP ®
may seriously damage the brake system.
All checks and maintenance work on the
brake system must be carried out at a quali-
fied specialist workshop. Consult a qualified
specialist workshop to arrange this.
Have brake pads installed and brake fluid
replaced at a qualified specialist workshop.
If the brake system has only been subject to
moderate loads, you should test the function- ality of your brakes at regular intervals. To doso, depress the brake pedal firmly when driv-
ing at a high speed. This improves the grip of
the brake pads.
You can find a description of Brake Assist
(BAS) on (Y page 69) or of BAS PLUS on
(Y page 69). Mercedes-Benz recommends that you only
have brake pads/linings installed on your
vehicle which have been approved for
Mercedes-Benz vehicles or which correspond
to an equivalent quality standard. Brake
pads/linings which have not been approved
for Mercedes-Benz vehicles or which are not
of an equivalent quality could affect your vehi-
cle's operating safety.
Mercedes-Benz recommends that you only
use brake fluid that has been specially
approved for your vehicle by Mercedes-Benz,
or which corresponds to an equivalent quality standard. Brake fluid which has not been
approved for Mercedes-Benz vehicles or
which is not of an equivalent quality could
affect your vehicle's operating safety.
High-performance brake system for
AMG vehicles The high-performance brake system is only
available on AMG vehicles.
The high-performance brake system is
designed for heavy loads. This may lead to
noise when braking. This will depend on:
R speed
R braking force
R environmental conditions, such as temper-
ature and humidity
The wear of individual components of the
brake system, such as the brake pads/linings
or brake discs, depends on the individual driv-
ing style and operating conditions.
For this reason, it is impossible to state a
mileage that will be valid under all circum-
stances. An aggressive driving style will lead
to high wear. You can obtain further informa- tion about this from your authorized
Mercedes-Benz Center.
New and replaced brake pads and discs only
reach their optimum braking effect after sev-
eral hundred kilometers of driving. Compen-
sate for this by applying greater force to the
brake pedal. Keep this in mind, and adapt Driving tips
197Driving and parking Z

your driving and braking accordingly during
this break-in period.
Excessive heavy braking results in corre-
spondingly high brake wear. Observe the
0026 brake wear warning lamp in the instru-
ment cluster and note any brake status mes-
sages in the multifunction display. Especially
for high performance driving, it is important to maintain and have the brake system checkedregularly. Driving on wet roads
Hydroplaning If water has accumulated to a certain depth
on the road surface, there is a danger of
hydroplaning occurring, even if:
R you drive at low speeds.
R the tires have adequate tread depth.
For this reason, in the event of heavy rain or in
conditions in which hydroplaning may occur,
you must drive in the following manner:
R lower your speed.
R avoid ruts.
R avoid sudden steering movements.
R brake carefully.
Driving on flooded roads !
Do not drive through flooded areas.
Check the depth of any water before driving through it. Drive slowly through standing
water. Otherwise, water may enter the
vehicle interior or the engine compartment.
This can damage the electronic compo-
nents in the engine or the automatic trans- mission. Water can also be drawn in by the
engine's air suction nozzles and this can
cause engine damage.
i Vehicles with the AIRMATIC package:
set the raised level before driving through
standing water. Off-road fording !
Under no circumstances should you
accelerate before entering the water. The
bow wave could cause water to enter and
damage the engine and other assemblies.
! Do not open any of the vehicle's doors
while fording. Otherwise, water could get
into the vehicle interior and damage the
vehicle's electronics and interior equip-
ment.
R Establish how deep the water is and the
characteristics of the body of water before
fording.
R Vehicles with the AIRMATIC package:
select the highest possible vehicle level.
R Shift to a lower gear using the left-hand
steering wheel paddle shifter.
R Avoid high engine speeds.
R Enter and exit the water at a flat place and
at a steady walking pace.
R Drive slowly and at an even speed through
the water.
R Do not stop.
R Water offers a high degree of resistance,
and the ground is slippery and in some
cases unstable. Therefore, it is difficult and
dangerous to pull away in the water.
R Ensure that a bow wave does not form as
you drive.
R Clean any mud from the tire tread after
fording.
R Apply the brakes to dry them after fording.
Always observe the fording depth values
(Y page 456). Winter driving
G
WARNING
If you shift down on a slippery road surface in an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
There is an increased danger of skidding and
accidents. 198
Driving tipsDriving and pa
rking

Check the engine oil level. The engine oil
warning lamp warning must not be ignored. Continuing the journey while the symbol is
displayed could lead to engine damage.
X Engine oil level: check the engine oil level
and add oil if necessary.
When driving on steep gradients, the
engine oil level must be sufficiently high to
ensure a correct oil supply in the vehicle.
X DEF tank (BlueTEC vehicles): check the
level and top up if necessary (Y page 188).
X Tire-changing tool kit: check that the jack
is working and make sure you have the lug
wrench, a robust tow cable and a folding
spade in the vehicle.
X Wheels and tires: check the tire tread
depth and tire pressure.
X Check for damage and remove any foreign
objects, e.g. small stones, from the
wheels/tires.
X Replace any missing valve caps.
X Replace dented or damaged wheels.
X Rims: dented or bent rims can result in a
loss of tire pressure and damage the tire
bead. Therefore, check your rims before
driving off-road and replace them as
required.
Checklist after driving off-road !
If you detect damage to the vehicle after
driving off-road, have the vehicle checked
immediately at a qualified specialist work-
shop.
X Vehicles with the ON&OFFROAD pack-
age: activate the on-road program
(Y page 259).
X Deactivate the LOW RANGE off-road gear
(Y page 261).
X Deactivate DSR (Y page 258).
X Vehicles with the AIRMATIC package:
lower the vehicle to a ride height suitable
for the road conditions, e.g. to the high-
way/high-speed level. X
Clean the headlamps and rear lights and
check for damage.
X Clean the front and rear license plates.
X Clean the wheels/tires with a water jet and
remove any foreign objects.
X Clean the wheels, wheel housings and the
vehicle underside with a water jet; check
for any foreign objects and damage.
X Check whether twigs or other parts of
plants have become trapped. These
increase the risk of fire and can damage
fuel pipes, brake hoses or the rubber bel-
lows of the axle joints and propeller shafts.
X After the trip, examine without fail the
entire undercarriage, wheels, tires, brakes,
bodywork structure, steering, chassis and
exhaust system for damage.
X After driving for extended periods across
sand, mud, gravel, water or in similarly dirty
conditions, have the brake discs, wheels,
brake pads/linings and axle joints checked
and cleaned.
X If you detect strong vibrations after off-road
travel, check for foreign objects in the
wheels and drive train and remove them if
necessary. Foreign objects can disturb the
balance and cause vibrations.
Driving over rough terrain places greater
demands on your vehicle than driving on nor-
mal roads. After driving off-road, check the
vehicle. This allows you to detect damage
promptly and reduce the risk of an accident to
yourself and other road users.
Driving on sand Observe the following rules when driving on
sand:
R Vehicles with the ON&OFFROAD pack-
age: select off-road program 1
(Y page 259).
R Vehicles with the AIRMATIC package:
select a raised vehicle level.
R Avoid high engine speeds. Driving tips
201Driving and pa rking Z

i
Cruise control should not be activated
when driving off-road.
Important safety notes If you fail to adapt your driving style, cruise
control can neither reduce the risk of an acci-
dent nor override the laws of physics. Cruise
control cannot take into account the road,
traffic and weather conditions. Cruise control is only an aid. You are responsible for the dis-
tance to the vehicle in front, for vehicle speed,
for braking in good time and for staying in
your lane.
Do not use cruise control:
R in road and traffic conditions which do not
allow you to maintain a constant speed e.g.
in heavy traffic or on winding roads
R on slippery road surfaces. Braking or accel-
erating could cause the drive wheels to lose traction and the vehicle could then skid
R when there is 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.
Cruise control lever 0043
To activate or increase speed
0044 To activate or reduce speed
0087 To deactivate cruise control
0085 To activate at the current speed/last
stored speed
When you activate cruise control, the stored
speed is shown in the multifunction display
for five seconds. Activation conditions To activate cruise control, all of the following
activation conditions must be fulfilled:
R the electric parking brake must be
released.
R you are driving faster than 20 mph
(30 km/h).
R ESP ®
must be active, but not intervening.
R the transmission must be in position D.
R DSR must be deactivated.
R off-road program 2 must be deactivated
(vehicles with the ON&OFFROAD package).
Storing, maintaining and calling up a
speed Storing and maintaining a speed
X
Accelerate the vehicle to the desired
speed.
X Briefly press the cruise control lever up 0043
or down 0044.
X Remove your foot from the accelerator
pedal.
Cruise control is activated. The vehicle
automatically maintains the stored speed.
You can accept the current speed if you are
driving faster than 20 mph (30 km/h).
i Cruise control may be unable to maintain
the stored speed on uphill gradients. The
stored speed is resumed when the gradient
evens out. Cruise control maintains the
stored speed on downhill gradients by
automatically applying the brakes. 204
Driving systemsDriving and pa
rking

the pressure point for a higher speed or
down
0087for a lower speed.
Every time the cruise control lever is
pressed up or down, the last speed stored
is increased or reduced.
X Remove your foot from the accelerator
pedal.
Your vehicle adapts its speed to that of the vehicle in front, but only up to the desired
stored speed.
When driving at speeds below 20 mph
(30 km/h), you can only activate DISTRONIC
PLUS if the vehicle in front has been detected
and is shown in the multifunction display. If
the vehicle in front is no longer detected and displayed, for example because it has
changed lanes, DISTRONIC PLUS is deactiva-
ted. You will hear a warning tone if this is the
case.
i If you do not fully release the accelerator
pedal, the DISTRONIC DISTRONIC PLUS
PLUSPassive
Passive mes-
sage appears in the multifunction display.
The set distance to a slower-moving vehicle
in front will then not be maintained. You will
be driving at the speed you determine by
the position of the accelerator pedal.
Activating at the current speed/last
stored speed G
WARNING
If you call up the stored speed and it differs
from the current speed, the vehicle acceler-
ates or decelerates. If you do not know the
stored speed, the vehicle could accelerate or brake unexpectedly. There is a risk of an acci-
dent.
Pay attention to the road and traffic condi-
tions before calling up the stored speed. If you do not know the stored speed, store the
desired speed again. X
Briefly pull the cruise control lever towards
you 0043.
X Remove your foot from the accelerator
pedal.
DISTRONIC PLUS is activated. The first
time it is activated, the current speed is
stored. Otherwise, it sets the vehicle cruise
speed to the previously stored value.
Driving with DISTRONIC PLUS Pulling away and driving
X
If you want to pull away with DIS-
TRONIC PLUS: remove your foot from the
brake pedal.
X Briefly pull the cruise control lever towards
you 0044or press it up 0043or down 0087.
or
X Accelerate briefly.
Your vehicle pulls away and adapts its
speed to that of the vehicle in front.
If there is no vehicle in front, DISTRONIC
PLUS operates in the same way as cruise
control. Driving systems
209Driving and parking Z

Setting a speed
Keep in mind that it may take a brief moment
until the vehicle has accelerated or braked to
the speed set.
X Press the cruise control lever up 0043for a
higher speed or down 0044for a lower speed.
X To adjust the set speed in 1 mph incre-
ments (1 km/h increments): briefly
press the cruise control lever up 0043or
down 0044to the pressure point.
Every time the cruise control lever is
pressed up 0043or down 0044the last speed
stored is increased or reduced.
X To adjust the set speed in 5 mph incre-
ments (10 km/h increments): briefly
press the cruise control lever up 0043or
down 0044to the pressure point.
Every time the cruise control lever is
pressed up 0043or down 0044, the last speed
stored is increased or reduced.
i If you accelerate to overtake, DISTRONIC
PLUS adjusts the vehicle's speed to the last
speed stored after you have finished over-
taking. Setting the specified minimum distance You can set the specified minimum distance
for DISTRONIC PLUS by varying the time span between one and two seconds. With this func-
tion, you can set the minimum distance that
DISTRONIC PLUS keeps to the vehicle in
front, dependent on vehicle speed. You can
see this distance in the multifunction display
(Y page 213).
X To increase: turn control0044in direction
0087.
DISTRONIC PLUS then maintains a greater distance between your vehicle and the
vehicle in front.
X To decrease: turn control0044in direc-
tion 0043.
DISTRONIC PLUS then maintains a shorter distance between your vehicle and the
vehicle in front.
i Make sure that you maintain a sufficiently
safe distance from the vehicle in front.
Adjust the distance to the vehicle in front if necessary. Driving systems
211Driving and parking Z

Deactivating DISTRONIC PLUS
There are several ways to deactivate DIS-
TRONIC PLUS:
X Briefly press the cruise control lever for-
wards 0043.
or X Brake, unless the vehicle is stationary.
When you deactivate DISTRONIC PLUS, you
will see the DISTRONIC
DISTRONIC PLUS PLUSOff
Offmessage in
the multifunction display for approximately
five seconds.
i The last speed stored remains stored until
you switch off the engine.
i DISTRONIC PLUS is not deactivated if you
depress the accelerator pedal. If you accel-
erate to overtake, DISTRONIC PLUS
adjusts the vehicle's speed to the last
speed stored after you have finished over-
taking.
DISTRONIC PLUS is automatically deactiva-
ted if:
R you engage the electric parking brake or if
the vehicle is automatically secured with
the electric parking brake
R you are driving slower than 15 mph
(25 km/h) and there is no vehicle in front,
or if the vehicle in front is no longer detec-
ted
R ESP ®
intervenes or you deactivate ESP ®
R the transmission is in the P,Ror Nposition
R you pull the cruise control lever towards
you in order to pull away and the front- passenger door or one of the rear doors is
open
R you activate DSR
R you activate off-road program 2 on vehicles
with the ON&OFFROAD package
R the vehicle has skidded
If DISTRONIC PLUS is deactivated, you will
hear a warning tone. You will see the DIS‐
DIS‐
TRONIC TRONIC PLUS
PLUSOff
Offmessage in the multifunc-
tion display for approximately five seconds.
Displays in the instrument cluster Displays in the speedometer
Example: DISTRONIC PLUS displays in the speed-
ometer
When DISTRONIC PLUS is activated, one or
two segments 0044in the set speed range light
up.
If DISTRONIC PLUS detects a vehicle in front, segments 0044between speed of the vehicle in
front 0043and stored speed 0087light up.
i For design reasons, the speed displayed
in the speedometer may differ slightly from
the speed set for DISTRONIC PLUS. 212
Driving syste
msDriving and parking

Display when DISTRONIC PLUS is deacti-
vated 0043
Vehicle in front, if detected
0044 Distance indicator, current distance to
the vehicle in front
0087 Specified minimum distance to the vehi-
cle in front; adjustable
0085 Own vehicle
In the Assistance menu of the on-board com-
puter, you can select the assistance display.
X Select the Distance Display
Distance Display function
using the on-board computer
(Y page 283).
Display when DISTRONIC PLUS is activa-
ted 0043
Vehicle in front, if detected
0044 Specified minimum distance to the vehi-
cle in front; adjustable
0087 Own vehicle
0085 DISTRONIC PLUS activated
In the Assistance menu of the on-board com- puter, you can select the assistance display. X
Select the Distance Display Distance Display function
using the on-board computer
(Y page 283).
You will see the stored speed for about five
seconds when you activate DISTRONIC PLUS.
Tips for driving with DISTRONIC PLUS General notes
Pay particular attention in the following traffic
situations:
R cornering, going into and coming out of a
bend
R vehicles traveling on a different line
R other vehicles changing lanes
R narrow vehicles
R obstructions and stationary vehicles
R crossing vehicles
In such situations, brake if necessary. DIS-
TRONIC PLUS is then deactivated.
Cornering, going into and coming out of a bend The ability of DISTRONIC PLUS to detect vehi-
cles when cornering is limited. Your vehicle
may brake unexpectedly or late. Driving syste
ms
213Driving an d parking Z

The individual vehicle levels differ from high-
way level as follows:
R highway level: +/–0 in (+/–0 mm)
R high-speed level: –0.6 in (–15 mm)
R off-road level 1: + 1.2 in (+ 30 mm)
R off-road level 2: + 2.3 in (+ 60 mm)
R off-road level 3: + 3.6 in (+ 90 mm)
Highway/high-speed level !
Make sure that there is enough ground
clearance when the vehicle is being low-
ered. It could otherwise hit the ground,
damaging the underbody. 0043
Selector wheel
0044 To raise the level
0087 Indicator lamps
0085 To lower the level
X Start the engine.
X Selector wheel 0043 0043engaged: briefly press
selector wheel 0043.
Selector wheel 0043extends.
If one or more indicator lamps 0087are on:
X Turn selector wheel 0043counter-clock-
wise 0085until all indicator lamps 0087that are
lit start to flash.
The vehicle is lowered to highway level. As soon as the next lowest level is reached,
the indicator lamp stops flashing and goes
out. During the adjustment, the
Lowering Loweringmes-
sage, for example, appears in the multifunc-
tion display.
If you press the 0038or0076 button on the
multifunction steering wheel, the message
will disappear. Once highway level has been
reached, all indicator lamps 0087go out.
The vehicle automatically selects highway
level if you are driving at a speed above
70 mph (115 km/h) or if you drive at a speed
between 62 mph (100 km/h) and 70 mph
(115 km/h) for approximately 20 seconds.
The vehicle is lowered to high-speed level if
you are traveling at higher speeds.
Off-road levels General notes
R Only select off-road level 3 for driving off-
road in particularly rough terrain.
R Adjust your driving style to the altered han-
dling characteristics.
R Do not drive at speeds above 12 mph
(20 km/h). 216
Driving systemsDriving and parking

Only select an off-road level when this is
appropriate for road conditions. Otherwise,
fuel consumption increases and handling may
be affected.
X Start the engine.
X Selector wheel 0043
0043 engaged: briefly press
selector wheel 0043.
Selector wheel 0043extends.
X To raise: turn selector wheel 0043clock-
wise 0044.
The vehicle is raised.
or
X To lower: turn selector wheel 0043counter-
clockwise 0085.
The vehicle is lowered.
Indicator lamps 0087for the desired off-road
level flash:
R Off-road level 1: the lower indicator lamp
flashes
R Off-road level 2: the lower and center indi-
cator lamps flash
R Off-road level 3: all three indicator lamps
flash
The vehicle adjusts to the off-road level selec-
ted. As soon as an off-road level is reached,
the corresponding indicator lamp stops flash- ing and lights up constantly.
Raising the vehicle
During the adjustment, the Vehicle Rising
Vehicle Rising
message, for example, appears in the multi-
function display.
The vehicle rises from highway level to off-
road level 1.
If you press the 0038or0076 button on the
multifunction steering wheel, the message
will disappear.
i Up to off-road level 2, you can hide the
messages using the 0038or0076 button
on the multifunction steering wheel.
Once off-road level 2 has been reached, the
lower and center indicator lamps of the selec- tor wheel are on. While the adjustment from off-road level 2 to
off-road level 3 is taking place, you will see a message such as the following in the multi-
function display: Vehicle Rising Max. Vehicle Rising Max.
Speed 12 mph (20 km/h)
Speed 12 mph (20 km/h).
The Max. Speed 12 mph (20 km/h) Max. Speed 12 mph (20 km/h) mes-
sage draws your attention to the maximum
speed permitted for off-road level 3.
Once off-road level 3 has been reached, you
will see a message shown in white in the mul-
tifunction display, for example: Max. Max.Speed
Speed
12 mph (20 km/h)
12 mph (20 km/h).
If you drive above 20 km/h at off-road level 3, you will see the following message shown in
red in the multifunction display: Vehicle Vehicle
Lowering
Lowering Max.
Max.Speed
Speed 12
12mph (
mph (20 20km/h)
km/h).
i You cannot clear these messages.
You also hear a warning. The vehicle is low-
ered and off-road level 3 is canceled.
If you continue to increase your speed, the
red message continues to be shown in the
multifunction display. The newly set level is
not displayed until the vehicle has been set to
a level suitable for the current speed. Driving systems
217Driving and parking Z