2006 MERCEDES-BENZ R500 cooling

245 Controls in detail
3-zone automatic climate control*
Adjusting air distribution
Use the air distribution controls3 or5
to adjust the air distribution for the rear
passenger compartment.
The symbols on the controls represent the
following functions:Adjusting manually

Press the desired air distribution con-
trol.
The indicator lamp on button U
goes out.
Adjusting automatically

Press buttonU.
The indicator lamp on the button
comes on. The air distribution is adjust-
ed automatically.Setting the temperature
Use temperature controla (
page 244)
to separately adjust the air temperature of
the rear passenger compartment.
You should raise or lower the temperature
setting in small increments, preferably
starting at 72°F (22°C). The automatic cli-
mate control will adjust to the set temper-
ature as fast as possible.
iSwitch off the rear automatic climate
control for improved cooling or heating
output in the front passenger compart-
ment.
You can also switch off the rear auto-
matic climate control from the front
passenger compartment (
page 235).
Symbol
Function
Z
Directs air to the center air
vents
Y
Directs air to the footwells and
the side air vents
iThe rear automatic climate control will
not cool the air when the air condition-
ing is switched off (
page 242).

351 Operation
Engine compartment
Coolant level
The engine coolant is a mixture of water
and anticorrosion / antifreeze. To check
the coolant level, the vehicle must be
parked on level ground and the engine
must be cool.
1Cap
2Coolant expansion tank
3Indicator wall
4Coolant level

Using a rag, turn cap 1 slowly approx-
imately one half turn counterclockwise
to release any excess pressure.

Continue turning cap 1 counterclock-
wise and remove it.
Coolant level 4 is correct if the level:

for cold coolant: reaches the top of
indicator wall 3 visible through the
filling opening


for warm coolant: is approximately
0.6 in (1.5 cm) higher

Add coolant as required.

Replace and tighten cap 1.
For more information on coolant, see the
“Technical data” section (
page 525).
Warning!
G
In order to avoid any possibly serious burns:

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 gauge indi-
cates that the coolant is overheated.


Do not remove pressure cap on coolant
reservoir if coolant temperature is
above 158°F (70°C). Allow engine to
cool down before removing cap. The
coolant reservoir contains hot fluid and
is under pressure.


Using a rag, slowly open the cap approx-
imately
1/2 turn to relieve excess pres-
sure. If opened immediately, scalding
hot fluid and steam will be blown out un-
der pressure.


Do not spill antifreeze on hot engine
parts. Antifreeze contains ethylene gly-
col which may burn if it comes into con-
tact with hot engine parts.

433 Practical hints
What to do if …
Display symbol
Display messages
Possible cause/consequence
Possible solution
?
(USA only)
±
(Canada only)
Engine Service
There may be a malfunction in
the

fuel injection system


ignition system


exhaust system


fuel system

Have the engine checked by an autho-
rized Mercedes-Benz Light Truck Center.
B
Coolant
Check level
The coolant level is too low.

Add coolant (
page 351).

If you have to add coolant frequently,
have the cooling system checked by an
authorized Mercedes-Benz Light Truck
Center.
Warning!
G
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 can be seriously burned.
!Do not ignore the low engine coolant
level warning. Extended driving with
the message and symbol displayed
may cause serious engine damage not
covered by the Mercedes-Benz Limited
Warranty.
Do not drive without sufficient amount
of coolant in the cooling system. The
engine will overheat causing major
engine damage.

436 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause/consequence
Possible solution
Ï
Coolant
Visit workshop
The cooling fan for the coolant is
malfunctioning.

Observe the coolant temperature in the
multifunction display (
page 168).

Have the fan replaced as soon as possi-
ble.
G
Display malfunction
Visit workshop
The instrument cluster display is
malfunctioning.

Continue driving with added caution.

Visit an authorized Mercedes-Benz Light
Truck Center as soon as possible.
The displays for several systems
have malfunctioned. Some sys-
tems themselves may also have
malfunctioned.

Have the electronic systems checked by
an authorized Mercedes-Benz Light Truck
Center.
±
Display malfunction
Visit workshop
Certain electronic systems are
unable to relay information to
the control system. The follow-
ing systems may have failed:

Coolant temperature display


Tachometer


Cruise control display

Have the electronic systems checked by
an authorized Mercedes-Benz Light Truck
Center.
c

Door open
You are attempting to drive with
one or more doors open.

Close the doors.

453 Practical hints
What to do if …
Display symbol
Display messages
Possible cause/consequence
Possible solution
n
*
wait briefly
The vehicle level is too low.

Do not drive off.
The vehicle level control* has not yet
adjusted the vehicle level to the nec-
essary height required for driving.

Wait until the message disappears
from the multifunction display.
You may then drive off.
Compressor
cooling down
Level control was activated too long/too
frequently.

Let the compressor cool until the
message disappears.
The selected level will be set once the
compressor has cooled down.
Level selection
not permitted
You are driving too fast for the desired
level selection.

Reduce vehicle speed.

Set the next higher level
(page 271).
!When the message
Compressor cool-
ing down
appears in the multifunction
display, driving is still possible.
Keep in mind that the ride height of the
vehicle is not yet reached and you
could therefore damage the underbody
of the vehicle.
The selected level will be set once the
compressor has cooled down.

522 Technical dataFuels, coolants, lubricants, etc.
Model
Capacity
Fuels, coolants, lubricants, etc.
Cooling system
R350
R500
10 US qt (9.5 l)
11.1 US qt (10.5 l)
MB Anticorrosion / Antifreeze
Fuel Tank
including a reserve of
21.1 US gal (80.0 l)
approx. 3.4 US gal (13.0 l)
Premium unleaded gasoline:
Minimum Posted Octane 91
(Avg.of96RON/86MON)
Air conditioning system
R-134a refrigerant and special PAG lubricant oil
(never R-12)
Windshield washer and
headlamp cleaning
system*
8.2 US qt (7.8 l)
MB Windshield Washer Concentrate
1
1Use MB Windshield Washer Concentrate “S” and water for temperatures above freezing or MB Windshield Washer Concentrate “S” and commercially available
premixed windshield washer solvent / antifreeze for temperatures below freezing. Follow suggested mixing ratios (page 528).

525 Technical data
Fuels, coolants, lubricants, etc.
Gasoline additives
A major concern among engine manufac-
turers is carbon build-up caused by gaso-
line. Mercedes-Benz recommends only the
use of quality gasoline containing additives
that prevent the build-up of carbon depos-
its.
After an extended period of using fuels
without such additives carbon deposits
can build up, especially on the intake
valves and in the combustion area, leading
to engine performance problems such as:

Warm-up hesitation


Unstable idle


Knocking / pinging


Misfire


Power lossIn areas where carbon deposits may be
encountered due to lack of availability of
gasolines which contain these additives,
Mercedes-Benz recommends the use of
additives approved by us for use on
Mercedes-Benz vehicles. Refer to Factory
Approved Service Products pamphlet for a
listing of approved product(s). Follow
directions on product label.
Do not blend other specific fuel additives
with fuel. This only results in unnecessary
costs and may be harmful to the engine
operation.
Damage or malfunction resulting from
poor fuel quality or from blending addition-
al fuel additives other than those tested
and approved by us for use on
Mercedes-Benz vehicles listed in the Fac-
tory Approved Service Products pamphlet
are not covered by the Mercedes-Benz
Limited Warranty.
Coolants
The engine coolant is a mixture of water
and anticorrosion/antifreeze, which
provides:

Corrosion protection


Freeze protection


Boiling protection (by increasing the
boiling point)
The cooling system was filled at the factory
with a coolant providing freeze protection
to approximately -35°F (-37°C) and corro-
sion protection.
If the antifreeze mixture is effective to
-22°F (-30°C), the boiling point of the cool-
ant in the pressurized cooling system is
reached at approximately 266°F (130°C).

526 Technical dataFuels, coolants, lubricants, etc.The coolant solution must be used year
round to provide the necessary corrosion
protection and increase boil-over protec-
tion. Refer to Maintenance Booklet for
replacement interval.
To provide important corrosion protection,
the solution must be at least 45% anticor-
rosion/antifreeze (equivalent to freeze
protection to approx. - 22°F [-30°C]). If
you use a solution that is more than 55%
anticorrosion/antifreeze (freeze protec-
tion to approx. - 49°F [-45°C]), the engine
temperature will increase due to the lower
heat transfer capability of the solution.
Therefore, do not use more than this
amount of anticorrosion/antifreeze.If the coolant level is low, water and
MB 325.0 anticorrosion/antifreeze should
be used to bring it up to the proper level
(have cooling system checked for signs of
leakage). Please make sure the mixture is
in accordance with label instructions.
The water in the cooling system must meet
minimum requirements, which are usually
satisfied by normal drinking water. If you
are not sure about the water quality, con-
sult an authorized Mercedes-Benz Light
Truck Center.