2016 MERCEDES-BENZ GLS SUV coolant temperature

Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ?
N
The 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. The engine could be dam-
aged if the coolant temperature is too high.
X Stop the vehicle immediately, paying attention to road and traffic conditions,
and switch off the engine. Do not continue driving.
X Safeguard the vehicle against rolling away (Y page 168).
X Consult a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
299On-board computer and displays Z

Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
M Solutions ?
N
The red coolant warning lamp comes on while the engine is running.
The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator may be blocked or the electric engine radiator fan may be malfunctioning.
The coolant is too hot and the engine is not being cooled sufficiently.
X Observe the additional display messages in the multifunction display.
X Stop the vehicle immediately, paying attention to road and traffic conditions,
and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 168).
X Leave the vehicle and keep a safe distance from the vehicle until the engine has
cooled down.
X Check the coolant level and top up the coolant, observing the warning notes
(Y page 335).
X If you have to top up the coolant frequently, have the engine cooling system
checked.
X Make sure that the air supply to the engine radiator is not blocked, e.g. by frozen
slush.
X Do not start the engine again until the coolant temperature is below 120 †. The
engine may otherwise be damaged.
X Drive to the nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving in mountainous terrain
and stop-start traffic. ?
N
The red coolant warning lamp comes on while the engine is running.
The coolant temperature has exceeded 120 †. The airflow to the engine radiator may be blocked or the coolant level may be too low.
G WARNING
The engine is not being cooled sufficiently and may be damaged.
Never drive with an overheated engine. Driving when your engine is overheated
can cause any fluids that may have leaked into the engine compartment to catch fire.
In addition, steam from an overheated engine can cause serious burns, which can
occur just by opening the bonnet.
There is a risk of injury.
X Observe the additional display messages in the multifunction display.
X Stop the vehicle immediately, paying attention to road and traffic conditions,
and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 168).
X Leave the vehicle and keep a safe distance from the vehicle until the engine has
cooled down.
X Check the coolant level and top up the coolant, observing the warning notes
(Y page 335).
X If you have to top up the coolant frequently, have the engine cooling system
checked. 300
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions X
Make sure that the air supply to the engine radiator is not blocked, e.g. by frozen
slush.
X If the coolant temperature is below 120 †, you can continue driving to the
nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving in mountainous terrain
and stop-start traffic. Driving systems
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ·
N
The red distance warning lamp lights up while the vehicle is in motion.
The distance to the vehicle in front is too small for the speed selected.
X Increase the distance. ·
N
The red distance warning lamp lights up while the vehicle is in motion. A warning
tone also sounds.
You are approaching a vehicle, a pedestrian or a stationary obstacle in your line of travel at too high a speed.
X Be prepared to brake immediately.
X Pay careful attention to the traffic situation. You may have to brake or take
evasive action.
Further information on Distance Pilot DISTRONIC (Y page 184).
Further information on the distance warning function of Active Brake Assist
(Y page 70). Warning and indicator lamps in the instrument cluster
301On-board computer and displays Z

The following cause engine failure or damage
to the exhaust system:
R Use of engine oils and oil filters that have
not been expressly approved for the service
system
R Replacement of engine oil and oil filter after
the replacement interval specified by the
service system has expired
R Use of engine oil additives
! Do not add too much oil. Topping up with too
much engine oil can result in damage to the
engine or to the catalytic converter. Have
excess engine oil siphoned off. Example: engine oil filler cap
X Turn cap :anti-clockwise and remove it.
X Top up the engine oil.
If the oil level is at or below the MIN mark on
the oil dipstick, top up with 1.0 lof engine oil.
X Replace cap :on the filler neck and turn
clockwise.
Make sure that the cap locks securely into
place.
X Check the oil level again with the oil dipstick
(Y page 334).
Further information on engine oil (Y page 385).Other service products
Important safety notes G
WARNING
Certain components in the engine compart-
ment could be very hot, e.g. the engine, the
radiator and parts of the exhaust system.
There is a risk of injury when accessing the
engine compartment. As far as possible, allow the engine to cool
down and only touch the components descri-
bed in the following. G
WARNING
The cooling system is pressurised, particu-
larly when the engine is warm. If you open the cap, you could be scalded if hot coolant
sprays out. There is a risk of injury.
Let the engine cool down before you open the
cap. Wear gloves and eye protection. Open
the cap slowly to release the pressure. G
WARNING
If windscreen washer concentrate comes into contact with hot components of the engine or
the exhaust system, it can ignite. There is a
risk of fire and injury.
Make sure the windscreen washer concen-
trate does not come into contact with the filler neck.
Checking the coolant level X
Park the vehicle on a level surface.
Check the coolant level only if the vehicle is
on a level surface and the engine has cooled
down.
X Turn the key to position 2in the ignition lock
(Y page 148).
On vehicles with KEYLESS-GO, press the
Start/Stop button twice (Y page 150).
X Check the coolant temperature gauge in the
multifunction display.
The coolant temperature must be below
70 †. Engine compartment
335Maintenance and care Z

Brake fluid
G
WARNING
The brake fluid continuously absorbs mois-
ture from the air. This results in the boiling
point of the brake fluid lowering. If the boiling
point of the brake fluid is too low, vapour
pockets may form when the brakes are sub-
jected to a heavy load. This would impair brak- ing efficiency. There is a risk of an accident.
Have the brake fluid renewed at the prescri-
bed intervals.
Comply with the important safety notes for ser- vice products when handling brake fluid
(Y page 381).
The brake fluid change intervals can be found in the Service Booklet.
Only use brake fluid approved by Mercedes-
Benz according to MB-Freigabe or 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 Book-
let. 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 top up
the antifreeze. 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. Further information on coolants can be found
in the Mercedes-Benz Specifications for Ser-
vice Products, MB Specifications for Service
Products 310.1, e.g. on the Internet at
http://bevo.mercedes-benz.com. Or contact
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 replace-
ment confirmed in the Service Booklet.
Observe the important safety notes for service
products when handling coolant (Y page 381).
The coolant is a mixture of water and anti-
freeze/anti-corrosion additive. It is responsible
for the following:
R corrosion protection
R antifreeze protection
R raising the boiling point
If antifreeze/corrosion inhibitor is present in the
correct concentration, the boiling point of the
coolant during operation will be approximately
130 †.
The antifreeze/anti-corrosion additive concen-
tration in the engine cooling system should:
R be at least 50%. This will protect the engine
cooling system against freezing down to
approximately -37 †.
R not exceed 55% (antifreeze protection down
to -45 †). Heat will otherwise not be dissipa- ted as effectively.
Mercedes-Benz recommends an antifreeze/
anti-corrosion additive concentrate in accord-
ance with MB Specifications for Service Prod-
ucts 310.1.
i When the vehicle is first delivered, it is filled
with a coolant mixture that ensures adequate
antifreeze and corrosion protection.
i The coolant is checked at every mainte-
nance interval at a qualified specialist work-
shop. 386
Service products and capacitiesTechnical data