overheating MERCEDES-BENZ GL-Class 2015 X166 Owner's Manual

fewer changes. For more dynamic changes,
carry out a manual reset.
For further information on the ECO display,
see (Y page 278). 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
early to a lower gear. This allows you to take advantage of the engine braking effect and
helps avoid overheating and excessive
wear of the brakes.
When you take advantage of the engine
braking effect, a drive wheel may not turn
for some time, e.g. on a slippery road sur-
face. This could cause damage to the drive train. This type of damage is not covered bythe Mercedes-Benz warranty.
Do not depress the brake pedal continuously while the vehicle is in motion, e.g. causing the
brakes to rub by constantly applying light
pressure to the pedal. This results in exces-
sive and premature wear to the brake pads.
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 air-
flow 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
time. This may also occur after the vehicle has been washed or driven through deep water.
You then have to depress the brake pedal
more firmly. Maintain a greater distance from
the vehicle in front.
After driving on a wet road or having the vehi- cle washed, brake firmly while paying atten-
tion to the traffic conditions. This will warm up the brake discs, thereby drying them more
quickly and protecting them against corro-
sion.
Limited braking performance on salt-
treated roads If you drive on salted roads, a layer of salt
residue may form on the brake discs and
brake pads. This can result in a significantly
longer braking distance.
R
Brake occasionally to remove any possible
salt residue. Make sure that you do not
endanger other road users when doing so.
R Carefully depress the brake pedal and the
beginning and end of a journey.
R Maintain a greater distance to the vehicle
ahead. 196
Driving tipsDriving and parking

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 off-road program 2 on vehicles
with the ON&OFFROAD package
R you shift the transmission to position N
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 dis-
play for approximately five seconds.
i When you switch off the engine, the last
speed stored is cleared. DISTRONIC PLUS
General notes DISTRONIC PLUS regulates the speed and
automatically helps you maintain the dis-
tance to the vehicle detected in front. DIS-
TRONIC PLUS 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 the engine. This relieves the load on
the brake system and prevents the brakes
from overheating and wearing too quickly.
If DISTRONIC PLUS detects a slower-moving
vehicle in front, your vehicle is braked in order
to maintain the preset distance to the vehicle in front.
If DISTRONIC PLUS detects that there is a risk
of a collision, you will be warned visually and acoustically. DISTRONIC PLUS 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 to increase the distance to the vehicle in front or take evasive action provided it is
safe to do so.
For DISTRONIC PLUS to assist you, the radar
sensor system must be operational.
If there is no vehicle in front, DISTRONIC
PLUS operates in the same way as cruise
control in the speed range between 20 mph
(Canada: 30 km/h) and 120 mph (Canada:
200 km/h). If a vehicle is driving in front of
you, it operates in the speed range between
0 mph (0 km/h) and 120 mph (Canada:
200 km/h).
Do not use DISTRONIC PLUS while driving on roads with steep gradients.
As DISTRONIC PLUS transmits radar waves, it
can resemble the radar detectors of the
responsible authorities. You can refer to the
relevant chapter in the Operator's Manual if
questions are asked about this.
i USA only:
This device has been approved by the FCC as a "Vehicular Radar System". The radar
sensor is intended for use in an automotiveradar system only. Removing, tampering
with, or altering the device will void any
warranties, and is not permitted by the
FCC. Do not tamper with, alter, or use in
any non-approved way.
Any unauthorized modification to this
device could void the user’s authority to
operate the equipment.
i Canada only: This device complies with
RSS-210 of Industry Canada. Operation is
subject to the following two conditions:
1. This device may not cause harmful inter-
ference, and
2. this device must accept any interference received, including interference that may
cause undesired operation of the device.
Removal, tampering, or altering of the
device will void any warranties, and is not
permitted. Do not tamper with, alter, or use in any non-approved way. 206
Driving systemsDriving and pa
rking

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.
R Maintain a greater distance from the vehi-
cle in front than when driving without a
trailer.
R Avoid braking abruptly. If possible, brake
gently at first to allow the trailer to run on.
Then, increase the braking force rapidly.
R The values given for gradient-climbing
capabilities from a standstill refer to sea
level. When driving in mountainous areas,
note that the power output of the engine
and, consequently, the vehicle's gradient-
climbing capability, decreases with
increasing altitude. Installing the ball coupling
G
WARNING
If the ball coupling is not correctly installed
and secured, it can come loose during the
journey and endanger other road users. There is a risk of an accident and injury.
Always install and secure the ball coupling as
described. Before every journey, ensure that
the ball coupling is secured with the bolt and
the corresponding spring cotter. G
WARNING
If the ball coupling is not installed correctly or not secured with the bolt provided and the
corresponding spring cotter, the trailer may
come loose. There is a risk of an accident.
Always install and secure the ball coupling as
described. Before every journey, ensure that
the ball coupling is secured with the bolt and
the corresponding spring cotter. G
WARNING
If the ball coupling is not installed and secured
correctly the trailer may come loose. There is
a risk of an accident.
Install and secure the ball coupling as descri-
bed in the ball coupling installation instruc-
tions. Make sure that the ball coupling is
installed and secured correctly before every
journey. Cover cap
X Pull protective cap 0043in the direction of the
arrow, out of the ball coupling recess.
X Place protective cap 0043in the ball coupling
recess. 266
Towing a trailerDriving and parking

Further information on coolants can be
found in the Mercedes-Benz Specifications for Service Products, MB BeVo 310.1, e.g.
on the Internet at
http://bevo.mercedes-benz.com. Or con-
tact a qualified specialist 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
replacement confirmed in the Maintenance
Booklet.
Comply with the important safety precautions for service products when handling coolant
(Y page 447).
The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It performs the
following tasks:
R corrosion protection
R antifreeze protection
R raising the boiling point
If the coolant has antifreeze protection down to -35 ‡(-37 †), the boiling point of the cool-
ant during operation is approximately 266 ‡
(130 †).
The antifreeze/corrosion inhibitor concentra- tion in the engine cooling system should:
R be at least 50%. This will protect the engine
cooling system against freezing down to
approximately -35 ‡ (-37 †).
R not exceed 55% (antifreeze protection
down to -49 ‡[-45 †]). Other wise, heat
will not be dissipated as effectively.
Mercedes-Benz recommends an antifreeze/
corrosion inhibitor concentrate in accord-
ance with MB Specifications for Service Prod-
ucts 310.1.
i When the vehicle is first delivered, it is fil-
led with a coolant mixture that ensures adequate antifreeze and corrosion protec-
tion.
i The coolant is checked with every main-
tenance interval at a qualified specialist
workshop.
Filling capacities Model Capacity
GL 450
Approx. 10.9 US qt
(10.3 l) GL 450 4MATIC
GL 550 4MATIC
Approx. 12.0 US qt
(11.4 l) GL 350 Blue-
TEC 4MATIC
Approx. 12.2 US qt
(11.5 l) AMG vehicles
Approx. 13.1 US qt
(12.4 l) i
Use MB 325.0 or MB 326.0 antifreeze/
corrosion inhibitor. Windshield washer system
Important safety notes G
WARNING
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.
! Do not add distilled or de-ionized water to
the washer fluid container. Otherwise, the
level sensor may be damaged.
! Only MB SummerFit and MB WinterFit
washer fluid should be mixed together. The
spray nozzles may otherwise become
blocked.
When handling washer fluid, observe the
important safety notes on service products
(Y page 447). Service products and filling capacities
453Technical data Z