cooling MERCEDES-BENZ GL 2012 User Guide

Activating/deactivating air-
recirculation mode
You can deactivate the flow of fresh air if
unpleasant odors are entering the vehicle
from outside. The air already inside the
vehicle will then be recirculated.
The operation of air-recirculation mode is the
same for all control panels.GWARNING
Fogged windows impair visibility,
endangering you and others. If the windows
begin to fog on the inside, switching off the
air recirculation mode immediately should
clear interior window fogging. If interior
window fogging persists, make sure the air
conditioning is activated, or press the ¬
button.
XTurn the SmartKey to position 2 in the
ignition lock.XTo activate: press the d button.
The indicator lamp in the d button lights
up.
i Air-recirculation mode is activated
automatically at high outside
temperatures. When air-recirculation mode
is activated automatically, the indicator
lamp in the d button is not lit.
Outside air is added after about 30
minutes.
XTo switch off: press the d button.
The indicator lamp in the d button goes
out.i Air-recirculation mode deactivates
automatically:
R after approximately five minutes if
outside temperatures are less than about
41 ‡ (5 †)
R after approximately five minutes if
cooling with air dehumidification is
deactivated
R after approximately 30 minutes if outside
temperatures are over about
41 ‡ (5 †)
i The air-recirculation mode is not
deactivated automatically at outside
temperatures above 79 ‡ (26 †). After
approximately 30 minutes, outside air is
added. 21
Activating/deactivating the residual
heat function
It is possible to make use of the residual heat
of the engine to continue heating the
stationary vehicle for up to 30 minutes after
the engine has been switched off. The heating
time depends on the temperature that has
been set.
i The blower will run at a low speed
regardless of the airflow setting.
i If you activate the residual heat function
at high temperatures, only the ventilation
will be activated. The blower runs at
medium speed.
XTurn the SmartKey to position 0 in the
ignition lock or remove it.XTo activate: press the Á button.
The indicator lamp in the Á button lights
up.XTo switch off: press the Á button.
The indicator lamp in the Á button goes
out.21 Vehicles with automatic climate control144Operating the climate control systemClimate control

Display messagesPossible causes/consequences and M Solutionsb
AUTO Light
InoperativeThe light sensor is defective.XVisit a qualified specialist workshop.
USA only:
XSwitch off the daytime running lamps in the on-board computer
( Y page 224).XSwitch the lights on and off using the light switch.b
Switch Off LightsThe lights are still switched on when you leave the vehicle. A
warning tone also sounds.XTurn the light switch to $ or à .
or
XIf the rear fog lamp is switched on: press the light switch in to
the stop.
Engine
Display messagesPossible causes/consequences and M Solutions+
Top Up Coolant See
Operator's ManualThe coolant level is too low.XAdd coolant, observing the warning notes when doing so
( Y page 303).XIf the coolant needs to be refilled more often than usual, have
the engine coolant system checked at a qualified specialist
workshop.GWARNING
Do not spill antifreeze on hot engine parts. Antifreeze contains ethylene glycol which may burn
if it comes into contact with hot engine parts. You could be seriously burned.
! The coolant level is too low. Avoid making long journeys with too little coolant in the cooling
system. The engine will otherwise be damaged.
The display messages and the corresponding symbol that indicate that the coolant level is
too low must not be ignored.
244Display messagesOn-board computer and displays

Driving systemsDisplay messagesPossible causes/consequences and M Solutions°
Level Selection
Not PermittedYou cannot change the vehicle level, because:
R you are exceeding the permissible speed for the selected
vehicle level.
R you are towing a trailer.
R the trailer-coupling socket is being used, e.g. for a bicycle rack.XDrive more slowly and then select the desired vehicle level again
( Y page 189).XObserve the notes on towing a trailer ( Y page 210).°
Compressor Cooling
DownYou have selected a higher vehicle level. The compressor first
needs to cool down because of frequent level changes.XDrive in a manner appropriate for the current vehicle level.XMake sure that there is sufficient ground clearance.XAllow the compressor to cool down.
When the compressor has cooled down, the display message
disappears. The vehicle then continues rising to the selected
level.°
MalfunctionLevel control is defective.XDo not drive faster than 50 mph (80 km/h).XMake sure that there is sufficient ground clearance.XHave the vehicle checked at a qualified specialist workshop.Æ
Reduce speed to
under 12 MPHGRisk of accident
You are exceeding the speed permissible for the selected off-road
level.
XAdjust your driving style to the altered handling characteristics.XOnly make slight steering movements and avoid fast steering
movements.XDo not drive faster than 12 mph (20 km/h).°
Rising Max. 12 MPHThe vehicle is being adjusted to off-road level 3. The display
message informs you of the maximum speed permissible for off-
road level 3.XDo not drive faster than 12 mph (20 km/h).°
Max. 12 MPHYou are driving in off-road level 3. The display message informs
you of the maximum speed permissible for off-road level 3.XDo not drive faster than 12 mph (20 km/h).248Display messagesOn-board computer and displays

damage to the engine or the catalytic
converter. Have excess oil siphoned off.
For further information on engine oil, see
( Y page 375).XReplace cap : on the filler neck and
tighten clockwise.
Ensure that the cap locks into place
securely.
Checking and adding other service
products
Checking the coolant level
Only check the coolant level when the vehicle
is on a level surface and the engine has cooled
down.
XTurn the SmartKey to position
2 (Y page 149) in the ignition lock.
On vehicles with KEYLESS-GO, press the
Start/Stop button twice ( Y page 149).XCheck the coolant temperature gauge in
the multifunction display.
The coolant temperature must be below
158 ‡ (70 †).GWARNING
In order to avoid any potentially serious burns:
R use extreme caution when opening the
hood if there are any signs of steam or
coolant leaking from the cooling system, or
if the coolant temperature display indicates
that the coolant is overheated.
R do not remove the pressure cap on the
coolant reservoir if the coolant temperature
is above 158 ‡ (70 †). Allow the engine to
cool down before removing the cap. The
coolant reservoir contains hot fluid and is
under pressure.
R using a rag, slowly turn the cap
approximately 1
/ 2 turn to relieve excess
pressure. If opened immediately, scalding
hot fluid and steam will be blown out under
pressure.
R do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which
may burn if it comes into contact with hot
engine parts.XSlowly turn cap : half a turn counter-
clockwise and allow excess pressure to
escape.XTurn cap : further counter-clockwise and
remove it.
If the coolant is at the level of marker bar
= in the filler neck when cold, there is
enough coolant in coolant expansion
tank ;.
If the coolant is approximately 0.6 in
(1.5 cm) above marker bar = in the filler
neck when warm, there is enough coolant
in coolant expansion tank ;.XIf necessary, add coolant that has been
tested and approved by Mercedes-Benz.XReplace cap : and turn it clockwise as far
as it will go.
For further information on coolant, see
( Y page 376).
Windshield washer system and
headlamp cleaning system
The washer fluid reservoir is used for both the
windshield washer system and the headlamp
cleaning system.
i Vehicle components and their service
products must match. You should,
Engine compartment303Maintenance and careZ

CapacitiesVehicle modelCapacityFuel, coolant,
lubricants etc.Engine oil and
filterGL 350 BlueTEC9.0 US qt (8.5 l)Approved engine
oilsGL 450
GL 5509.5 US qt (9.0 l)Power steeringAll modelsApproximately 1.1 US qt
(1.0 l)MB power steering
fluid or approved
Dexron III ATFCooling systemGL 350 BlueTECApproximately 10.0 US qt
(9.5 l)MB 326.0 corrosion
inhibitor/antifreeze
agentGL 450
GL 550Approximately 12.7 US qt
(12.0 l)Tank capacityAll models26.4 US gal (100.0 l)Gasoline engines:
premium-grade
unleaded gasoline
(at least 91 octane,
average value
between 96 RON/
86 MON)
Diesel engines:
ULTRA-LOW
SULFUR HIGHWAY
DIESEL FUEL (ULSD,
maximum sulfur
content 15 ppm)ReserveAll modelsApproximately 3.4 US gal
(13.0 l)DEF tankGL 350 BlueTEC8.3 US gal (31.7 l)DEF in accordance
with ISO 22241Service products and capacities371Technical dataZ

when the brakes are applied hard (e.g. when
driving downhill). This would impair braking
efficiency.
You should have the brake fluid renewed at
regular intervals. The brake fluid change
intervals can be found in the Service Booklet.
Only use brake fluid approved by Mercedes-
Benz. Information about approved brake
fluids can be obtained from any authorized
Mercedes-Benz Center.
Coolant
Important safety notes
The coolant is a mixture of water and
antifreeze/corrosion inhibitor. It performs
the following tasks:
R anti-corrosion protection
R antifreeze protection
R raising the boiling point
The engine cooling system is filled at the
factory with coolant which contains an
antifreeze/corrosion inhibitor that ensures
protection down to approximately -35 ‡
(-37 † ).
! Only add coolant that has been premixed
with the desired antifreeze protection.
Otherwise, the engine could be damaged.
Further information on coolants and on
filling can be found in the Mercedes-Benz
Specifications for Service Products, MB
Approval 310.1, e.g. on the Internet at
http://bevo.mercedes-benz.com . You can
also consult an authorized Mercedes-Benz
Center.
! Always use a suitable coolant mixture,
even in countries where high temperatures
prevail.
Otherwise, the cooling system will not be
sufficiently protected from corrosion, and
the boiling point will be too low.
If the coolant has antifreeze protection down
to -35 ‡ (-37 † ), the boiling point of the
coolant in the pressurized system is
approximately 266 ‡ (130 † ).
Your vehicle has a range of aluminum
components. Use of aluminum components
in the engine make it necessary to specifically
match the antifreeze/corrosion inhibitor in
these systems in order to protect the
aluminum parts. Using other antifreeze/
corrosion inhibitors without these
characteristics affects the service life.
The coolant must be used throughout the year
in order to maintain the necessary corrosion
protection and provide protection from
overheating. In the Service Booklet, you can
find information on the intervals for renewal.
The renewal interval is determined by the
coolant type and the engine cooling system
design. The renewal interval in the Service
Booklet is only valid if the coolant is renewed
or replenished with Mercedes-Benz approved
products. Therefore, only use MB 326.0
antifreeze/corrosion inhibitor or another
Mercedes-Benz approved product of the
same specification.
Information on other products with the same
specifications that are approved by
Mercedes-Benz can be obtained at an
authorized Mercedes-Benz Center or on the
Internet at
http://bevo.mercedes-benz.com .
The coolant is checked at every maintenance
interval at an authorized Mercedes-Benz
Center.
The antifreeze/corrosion inhibitor
concentration 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 to
-49 ‡ [-45 † ]); otherwise, heat will not
dissipate as effectively.
If the coolant level is too low, MB 326.0
antifreeze/corrosion inhibitor should be
added. Have the engine cooling system
checked for possible leaks.376Service products and capacitiesTechnical data