overheating MERCEDES-BENZ GLS 2019 Owners Manual

X
Press button 0043.
The head restraint retracts, the backrest folds
forwards and the seat folds forwards.
The seat can be manually returned to its initial position (Y page 103). Adjusting the multicontour seat
The multicontour seat can be adjusted via the
multimedia system (see the Digital Operator's
Manual). Adjusting the 4-way lumbar support
0043
Raises the backrest contour
0044 Softens the backrest contour
0087 Lowers the backrest contour
0085 Hardens the backrest contour
You can adjust the contour of the front seat
backrests individually to provide optimum sup-
port for your back. Seat heating and seat ventilation
Switching the seat heating on/off G
WARNING
Repeatedly switching on the seat heating can
cause the seat cushion and backrest pads to
become very hot. The health of persons with
limited temperature sensitivity or a limited
ability to react to high temperatures may be
affected or they may even suffer burn-like
injuries. There is a risk of injury.
Therefore, do not switch the seat heating on
repeatedly.
To protect against overheating, the seat heating may temporarily deactivate after being switched
on again repeatedly. 0043
Driver's and front-passenger seat 0043
Rear seats
The three red indicator lamps in the button indi- cate the heating level you have selected.
The system automatically switches down from
level 3to level 2after approximately eight
minutes. 106
SeatsSeats, steering wheel and mirrors

In addition to driving style, the actual consump-
tion is affected by other factors, such as:
R load
R tire pressure
R cold start
R choice of route
R electrical consumers switched on
These factors are not included in the ECO dis-
play.
An economical driving style specially requires
driving at moderate engine speeds.
Achieving a higher value in the categories
"Acceleration" and "Constant":
R observe the gearshift recommendations.
R drive the vehicle in the Comfortdrive pro-
gram.
On long journeys at a constant speed, e.g. on the highway, only the outer area for "constant" will
change.
The ECO display summarizes the driving style
from the start of the journey to its completion.
Therefore, there are more marked changes in
the outer areas at the start of a journey. On lon-
ger journeys, there are fewer changes. For more
marked changes, perform a manual rest
(Y page 234).
For further information on the ECO display, see (Y page 234). Braking
Important safety notes 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.
Do not shift down for additional engine brak-
ing on a slippery road surface.
Downhill gradients !
On long and steep gradients, you must
reduce the load on the brakes by shifting to a
lower gear in good time. This allows you to
take advantage of the engine's braking effect. This helps you to avoid overheating the
brakes and wearing them out excessively.
When you take advantage of engine braking, a
drive wheel may not turn for some time, e.g.
on a slippery road surface. This could cause
damage to the drive train. This type of damage
is not covered by the Mercedes-Benz war-
ranty.
Do not depress the brake pedal continuously
while the vehicle is in motion, e.g. causing the
brakes to rub by constantly applying light pres-
sure to the pedal. This results in excessive and
premature wear to the brake pads.
Use the left-hand steering wheel paddle shifter
to shift into a lower gear in good time on long
and steep downhill gradients. This is especially
important if the vehicle is laden.
This also applies if you have activated cruise
control, the limiter or Active Distance Assist
DISTRONIC.
This will use the braking effect of the engine, so that less braking will be required to maintain the
speed. This relieves the load on the brake sys-
tem and prevents the brakes from overheating
and wearing too quickly.
Heavy and light loads G
WARNING
If you rest your foot on the brake pedal while
driving, the braking system can overheat. This increases the stopping distance and can even
cause the braking system to fail. There is a
risk of an accident.
Never use the brake pedal as a footrest. Never
depress the brake pedal and the accelerator
pedal at the same time.
! Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If the brakes have been subjected to a heavy
load, do not stop the vehicle immediately. Drive on for a short while. This allows the airflow to
cool the brakes more quickly.
Wet roads If you have driven for a long time in heavy rain
without braking, there may be a delayed reac-
tion from the brakes when braking for the first Driving tips
163Driving and parking Z

Further information on driving safety systems
(Y page 66). Cruise control
General notes Cruise control maintains a constant road speed
for you. It brakes automatically in order to avoid exceeding the set speed. You must select a
lower gear in good time on long and steep down-
hill gradients, especially if the vehicle is laden or towing a trailer. 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 anyroad speed above 20 mph (30 km/h).
i Cruise control should not be activated when
driving off-road.
Important safety notes If you fail to adapt your driving style, cruise con-
trol can neither reduce the risk of an accident
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 distance 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
Activates or increases speed
0044 Activates or reduces speed
0087 Deactivates cruise control
0085 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.
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 005B.
R DSR must be deactivated.
R the Offroad Plus drive program must be deac-
tivated (vehicles with the Off-road Engineer-
ing 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 0043or
down 0085.
X Remove your foot from the accelerator pedal.
Cruise control is activated. The vehicle auto-
matically maintains the stored speed.
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 Driving systems
171Driving and parking Z

stored speed on downhill gradients by auto-
matically applying the brakes.
Storing or calling up a 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 0087.
X Remove your foot from the accelerator pedal.
Cruise control is operational and when first
activated stores the current speed or regu-
lates the speed of the vehicle to the stored
speed.
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 0043 or 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 0044
beyond the pressure point.
Every time the cruise control lever is pressed
up 0043 or down 0044the last speed stored is
increased or reduced.
i Cruise control is not deactivated if you
depress the accelerator pedal. For example, if
you accelerate briefly to overtake, cruise con-
trol adjusts the vehicle's speed to the last
speed stored after you have finished overtak-
ing. Deactivating cruise control There are several ways to deactivate cruise con-
trol:
X Briefly press the cruise control lever for-
wards 0043.
or X Brake.
Cruise control is automatically deactivated if: R you engage the electric parking brake
R you are driving at less than 20 mph (30 km/h)
R ESP ®
intervenes or you deactivate ESP ®
R you activate DSR
R you activate the Offroad Plus program (vehi-
cles with the Off-road Engineering Package)
R you shift the transmission to position 005C
while driving
If cruise control is deactivated, you will hear a
warning tone. You will see the Cruise Con‐ Cruise Con‐
trol Off
trol Off message in the multifunction display
for approximately five seconds.
i When you switch off the engine, the last
speed stored is cleared. Active Distance Assist DISTRONIC
General notes Active Distance Assist DISTRONIC regulates the
speed and automatically helps you maintain the
distance from the vehicle detected in front.
Vehicles are detected with the aid of the radar
sensor system. Active Distance Assist
DISTRONIC brakes automatically so that the set
speed is not exceeded.
You must select a lower gear in good time on
long and steep downhill gradients, especially if
the vehicle is laden or towing a trailer. By doing so, you will make use of the braking effect of theengine. This relieves the load on the brake sys-
tem and prevents the brakes from overheating
and wearing too quickly.
If Active Distance Assist DISTRONIC detects
that there is a risk of a collision with the vehicle
in front, you will be warned visually and audibly.
Active Distance Assist DISTRONIC cannot pre-
vent a collision without your intervention. An
intermittent warning tone will then sound and
the distance warning lamp will light up in the
instrument cluster. Brake immediately in order 172
Driving systemsDriving and parking

R
is affected more by strong crosswinds
R demands more sensitive steering
R has a larger turning circle
This could impair the handling characteristics.
When towing a trailer, always adjust your speed to the current road and weather conditions. Do
not exceed the maximum permissible speed for
your vehicle/trailer combination. Notes on towing a trailer
General notes !
If you have a trailer tow hitch retrofitted,
changes to the cooling system and drive train may be necessary, depending on the vehicle
type.
If you have a trailer tow hitch retrofitted,
observe the anchorage points on the chassis
frame.
R Do not exceed the legally prescribed maxi-
mum speed for vehicle/trailer combinations
in the relevant country.
This lowers the risk of an accident.
R Only install an approved trailer coupling on
your vehicle.
More information on availability and installa-
tion can be obtained at any qualified special-
ist workshop.
R The bumpers of your vehicle are not suitable
for installing detachable trailer couplings.
R Do not install hired trailer couplings or other
detachable trailer couplings on the bumpers
of your vehicle.
R If you no longer need the ball coupling,
remove it from the ball coupling recess. This
will reduce the risk of damage to the ball cou-
pling.
When towing a trailer, set the tire pressure on
the rear axle of the towing vehicle for the max-
imum load. You will find the values in the tire
pressure table in the fuel filler flap of the vehicle (Y page 371).
Please note that when towing a trailer, the fol-
lowing driving systems have limited availability
or are not available at all:
R Parking Assist PARKTRONIC (Y page 189)
R Blind Spot Assist (Y page 207)
R Active Lane Keeping Assist (Y page 212)On vehicles without level control, the height of
the ball coupling will alter according to the load
placed on the vehicle. If necessary, use a trailer
with a height-adjustable drawbar.
You will find installing dimensions and loads
under "Technical data" (Y page 392).
Driving tips Also observe the notes on pulling away with a
trailer (Y
page 143).
The maximum permissible speed for vehicle/
trailer combinations depends on the type of
trailer. Before beginning the journey, check the
trailer's documents to see what the maximum
permissible speed is for your trailer. Observe the
legally permissible maximum speed in the rele-
vant country.
For certain Mercedes-Benz vehicles, the maxi-
mum permissible rear axle load is increased
when towing a trailer. See "Technical data" to
find out whether this applies to your vehicle
(Y page 392). If you utilize any of the added
maximum rear axle load when towing a trailer,
the vehicle/trailer combination may not exceed
a maximum speed of 60 mph (100 km/h) for
reasons concerning the operating permit. This
also applies in countries in which the maximum
permissible speed for car/trailer combinations
is greater than 60 mph (100 km/h).
When towing a trailer, your vehicle's handling
characteristics will be different in comparison
with when driving without a trailer.
Use the left-hand steering wheel paddle shifter
to shift into a lower gear in good time on long
and steep downhill gradients.
This also applies if you have activated cruise
control or Active Distance Assist DISTRONIC.
This will use the braking effect of the engine, so that less braking will be required to maintain the
speed. This relieves the load on the brake sys-
tem and prevents the brakes from overheating
and wearing too quickly. If you need additional
braking, depress the brake pedal repeatedly
rather than continuously.
Driving tips If the trailer swings from side to side:
X Do not accelerate.
X Do not counter-steer.
X Brake if necessary. 222
Towing a trailerDriving and parking

Model MB-Freigabe or
MB-Approval All models
229.5, 229.6
Mercedes‑AMG vehicles
229.5
Mercedes-AMG vehicles:
only use SAE 0W-40
or SAE 5W-40 engine oils.
i MB approval is indicated on the oil contain-
ers.
Filling capacities The following values refer to an engine oil
change, including the oil filter.
Model Capacity
GLS 550 4MATIC
Mercedes‑AMG
vehicles
9.0 US qt (8.5
l) All ot
her models 7.4 US qt (7.0
l) Ad
ditives !
Do not use any additives in the engine oil.
This could damage the engine. Brake fluid
G
WARNING
The brake fluid constantly absorbs moisture
from the air. This lowers the boiling point of
the brake fluid. If the boiling point of the brake fluid is too low, vapor pockets may form in the brake system when the brakes are applied
hard. This would impair braking efficiency.
There is a risk of an accident.
You should have the brake fluid renewed at
the specified intervals.
Comply with the important safety notes for ser- vice products when handling brake fluid
(Y page 384).
Use only brake fluid approved for Mercedes-
Benz according to MB-Freigabeor MB-Approval
331.0.
Information about approved brake fluid can be
obtained at any qualified specialist workshop or on the Internet at
http://bevo.mercedes-benz.com.
i Have the brake fluid regularly replaced at a
qualified specialist workshop in accordance
with the replacement intervals and the
replacement confirmed in the service report. Coolant
Important safety notes G
WARNING
If antifreeze comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Let the engine cool down before you add anti-
freeze. Make sure that antifreeze is not spilled
next to the filler neck. Thoroughly clean the
antifreeze from components before starting
the engine.
! Only add coolant that has been premixed
with the desired antifreeze protection. You
could otherwise damage the engine.
You can find additional notes on the coolant in
the following places:
R in the Mercedes-Benz Specifications for
Service Products, MB BeVo 310.1
- on the Internet at
http://bevo.mercedes-benz.com
- on the Mercedes-Benz BeVo app
R a qualified specialized workshop
! Always use a suitable coolant mixture, even
in countries where high temperatures prevail.
Otherwise, the engine cooling system is not
sufficiently protected from corrosion and
overheating.
i Have the coolant regularly replaced at a
qualified specialist workshop and the replace- ment confirmed in the service report.
Comply with the important safety notes for ser- vice products when handling coolant
(Y page 384). Service products and filling capacities
387Technical data Z