snow chains MERCEDES-BENZ R320 2008 W251 Owner's Manual

Contents
Oxidation catalyst
(diesel engine).............................. 349
Emission control .......................... 350
Coolant temperature .................... 350
At the gas station .............................. 352
Refueling ...................................... 352
Check regularly and before a
long trip........................................ 354
Engine compartment ......................... 356
Hood ............................................ 356
Engine oil ..................................... 358
Transmission fluid level ................ 360
Coolant level ................................ 360
Windshield/rear window washer
system and headlamp cleaning
system* ....................................... 362
Tires and wheels ................................ 363
Important guidelines .................... 363
Tire care and maintenance........... 364
Direction of rotation ..................... 365
Loading the vehicle ...................... 366
Recommended tire inflation
pressure ....................................... 371
Checking tire inflation pressure ... 373
Tire labeling.................................. 384
Load identification ....................... 388DOT, Tire Identification Number
(TIN) .............................................. 388
Maximum tire load ........................ 390
Maximum tire inflation pressure ... 390
Uniform Tire Quality Grading
Standards (U.S. vehicles) .............. 391
Tire ply material ............................ 393
Tire and loading terminology......... 393
Rotating tires ................................ 396
Winter driving ..................................... 398
Winter tires ................................... 398
Snow chains.................................. 399
Maintenance....................................... 400
Maintenance service indicator
message ....................................... 400
Calling up the maintenance
service indicator display ............... 402
Resetting the maintenance
service indicator ........................... 402
Vehicle care........................................ 403
Cleaning and care of the vehicle ... 403
Practical hints.................................. 413
What to do if … ................................... 414
Lamps in instrument cluster ......... 414
Lamp in center console ................ 425
Vehicle status messages in the
multifunction display .................... 427
Where will I find ...? ............................ 467
First aid kit.................................... 467
Vehicle tool kit.............................. 467
Spare wheel .................................. 471
Unlocking / locking in an emergency .. 474
Unlocking the vehicle ................... 474
Locking the vehicle ....................... 475
Fuel filler flap ................................ 475
Resetting activated head restraints.... 477
Vehicles without Rear Seat
Entertainment Package................. 477
Vehicles with Rear Seat
Entertainment Package*............... 478
Replacing SmartKey batteries ............ 479
Replacing bulbs .................................. 480
Bulbs............................................. 480
Replacing bulbs for front lamps .... 483
Replacing bulbs for rear lamps ..... 487

99 Safety and Security
Driving safety systems
Driving safety systems
In this section you will find information on
the following driving safety systems:

ABS (Antilock Brake System)

BAS (Brake Assist System)

ESP® (Electronic Stability Program)

EBP (Electronic Brake Proportioning)
ABS
The Antilock Brake System (ABS) regulates
the brake pressure so that the wheels do
not lock during braking. This allows you to
maintain the ability to steer your vehicle.
The ABS is functional above a speed of
approximately 5 mph (8 km/h) indepen-
dent of road surface conditions.
On slippery road surfaces, the ABS will
respond even to light brake pressure.
The -indicator lamp in the instrument
cluster (
page 26) comes on when you
switch on the ignition. It goes out when the
engine is running.
Warning!G
The following factors increase the risk of
accidents:

Excessive speed, especially in turns

Wet and slippery road surfaces

Following another vehicle too closely
The driving systems described in this sec-
tion cannot reduce these risks or prevent
the natural laws of physics from acting on
the vehicle.
Always adjust your driving style to the
prevailing road and weather conditions and
keep a safe distance to other road users and
objects on the street.
iIn winter operation, the maximum effective-
ness driving systems described in this section is
only achieved with winter tires (
page 398) or
snow chains as required.
Warning!G
Do not pump the brake pedal. Use firm,
steady brake pedal pressure instead. Pump-
ing the brake pedal defeats the purpose of
the ABS and significantly reduces braking
effectiveness.

104 Safety and Security
Driving safety systems
Switching off the ESP®
To improve the vehicle’s traction, switch
off the ESP® in driving situations where it
would be advantageous to have the drive
wheels spin and thus cut into surfaces for
better grip such as:

when driving with snow chains

in deep snow

in sand or gravelWhen you switch off the ESP
®

the ESP® does not stabilize the vehicle

the engine output is not limited, which
allows the drive wheels to spin and
thus cut into surfaces for better grip

the Electronic Traction System will still
apply the brake to a spinning wheel

the ESP® continues to operate when
you are braking

you cannot activate the cruise control
or the Distronic* system

the cruise control or the Distronic*
system switch off if currently activatedThe ESP
® switch is located on the upper
part of the center console.
1ESP
® switch
With the engine running, press ESP®
switch1.
The ESP
®warning lampv in the in-
strument cluster comes on.
The ESP
® is deactivated.
Warning!G
The ESP® should not be switched off during
normal driving other than in the circum-
stances described below. Disabling of the
system will reduce vehicle stability in stan-
dard driving maneuvers.
Do not switch off the ESP
® when a spare
wheel is mounted.
Warning!G
Switch on the ESP® immediately if the afore-
mentioned circumstances do not apply any-
more. Otherwise the ESP
® will not stabilize
the vehicle when it is starting to skid or a
wheel is spinning.
iWhen the ESP® is switched off and one or
more drive wheels are spinning, the ESP® warn-
ing lamp v in the instrument cluster flashes.
However, the ESP
® will then not stabilize the
vehicle.

281 Controls in detail
Driving systems
Permanent four-wheel drive (4MATIC)*
Your vehicle is equipped with permanent
four-wheel drive (4MATIC). Both, the front
and rear axles, are powered at all times
when the vehicle is being operated. The
4MATIC improves traction in conjunction
with the ESP
® (page 101) and the
Electronic Traction System (
page 103).
Parktronic* (Parking assist)
Warning!G
If a drive wheel is spinning due to insuffi-
cient traction:

While driving off, apply as little throttle
as possible.

While driving, ease up on the accelera-
tor.

Adapt your speed and driving style to
the prevailing road conditions.
Failure to observe these guidelines could
cause the vehicle to skid.
The 4MATIC cannot prevent accidents re-
sulting from excessive speed.
!Operational or performance test must only
be conducted on a two-axle dynamometer. If
such tests are necessary, contact an authorized
Mercedes-Benz Light Truck Center. You could
otherwise seriously damage the brake system or
the transfer case which is not covered by the
Mercedes-Benz Limited Warranty.
!Because the ESP® operates automatically,
the engine and ignition must be shut off
(SmartKey in starter switch position0 or1 or
KEYLESS-GO* start/stop button in
position0or1) when testing the parking brake
on a brake test dynamometer and such testing
should be no longer than 10 seconds.
Active braking action through the ESP
® may
otherwise seriously damage the brake system
which is not covered by the Mercedes-Benz
Limited Warranty.
iIn winter operation, the maximum effective-
ness of the 4MATIC is only achieved with winter
tires (
page 398) or snow chains as required.
Warning!G
Parktronic is a supplemental system. It is
not intended to, nor does it replace, the
need for extreme care. The responsibility
during parking and other critical maneuvers
always remains with the driver.
Special attention must be paid to objects
with smooth surfaces or low silhouettes
(e.g. trailer couplings, painted posts, or road
curbs). Such objects may not be detected by
the system and can damage the vehicle.
The operational function of the Parktronic
system can be affected by dirty sensors,
especially at times of snow and ice, see
“Cleaning the Parktronic* system sensors”
(
page 408).
Interference caused by other ultrasonic
signals (e.g. working jackhammers, car
wash, or the air brakes of trucks) can cause
the system to send erratic indications, and
should be taken into consideration.

346 Operation
Driving instructions
Winter driving instructions
The most important rule for slippery or icy
roads is to drive sensibly and to avoid
abrupt acceleration, braking and steering
maneuvers. Do not use the cruise control
system under such conditions.
When the vehicle is in danger of skidding,
shift the automatic transmission to
positionN. Try to keep the vehicle under
control by corrective steering action.Road salts and chemicals can adversely af-
fect braking efficiency. Increased pedal
force may become necessary to produce
the normal brake effect.
Depressing the brake pedal periodically
when traveling at length on salt-strewn
roads can bring road-salt-impaired braking
efficiency back to normal.
If the vehicle is parked after being driven
on salt-treated roads, the braking
efficiency should be tested as soon as
possible after driving is resumed.
For more information, see “Winter driving”
(
page 398).
iFor information on driving with snow chains,
see “Snow chains” (
page 399).
Warning!G
On slippery road surfaces, never downshift
in order to obtain braking action. This could
result in drive wheel slip and reduced vehi-
cle control. Your vehicle’s ABS will not pre-
vent this type of control loss.
Warning!G
Make sure not to endanger any other road
users when carrying out these braking
maneuvers.
Warning!G
If the vehicle becomes stuck in snow, make
sure that snow is kept clear of the exhaust
pipe and from around the vehicle with the
engine running. Otherwise, deadly carbon
monoxide (CO) gases may enter vehicle
interior resulting in unconsciousness and
death.
To assure sufficient fresh air ventilation,
open a window slightly on the side of the
vehicle not facing the wind.
Warning!G
The outside temperature indicator is not
designed to serve as an ice-warning device
and is therefore unsuitable for that purpose.
Indicated temperatures just above the freez-
ing point do not guarantee that the road sur-
face is free of ice.

374 Operation
Tires and wheels
Install the valve cap.
Repeat this procedure for each tire.
Run Flat Indicator (Canada only)
While the vehicle is being driven, the Run
Flat Indicator monitors the set tire inflation
pressures by evaluating each wheel’s rota-
tional speed. This allows the system to de-
tect a significant loss of pressure in a tire.
If a wheel’s rotational speed changes due
to falling tire inflation pressure, you will
see a corresponding warning message in
the multifunction display.The Run Flat Indicator may function in a re-
stricted manner or with a delay

if snow chains are mounted to the
vehicle

in presence of ice and snow

if you are driving on a loose surface
(e.g. sand or gravel)

if you are driving in a very sporty
manner (involving rapid acceleration or
high speeds in curves)
iIf you have overfilled the tire, release tire in-
flation pressure by pushing the metal stem of the
valve with e.g. a tip of a pen. Then recheck the
tire inflation pressure with the tire gauge.Warning!G
When the multifunction display shows the
message
Tire Pressure Check Tires,
one or more of your tires is significantly un-
derinflated. You should stop and check your
tires as soon as possible, and inflate them to
the proper tire inflation pressure as in-
dicated on the vehicle’s Tire and Loading
Information placard or, if available, on the
tire inflation pressure label. Driving on a sig-
nificantly underinflated tire causes the tire
to overheat and can lead to tire failure. Un-
derinflation also reduces fuel efficiency and
tire tread life, and may affect the vehicle’s
handling and stopping ability. Each tire, in-
cluding the spare, should be checked
monthly when cold and set to the recom-
mended tire inflation pressure as specified
on the Tire and Loading Information placard
(
page 366) or on the tire inflation pres-
sure label located on the inside of the fuel
filler flap (
page 352).


399 Operation
Winter driving
Snow chains
Snow chains should only be driven on
snow-covered roads at speeds not to
exceed 30 mph (50 km/h). Remove chains
as soon as possible when driving on roads
without snow.
Please observe the following guidelines
when using snow chains:

Use of snow chains is not permissible
with all wheel/tire combinations
(
page 529).

Use snow chains in pairs and on rear
wheels only. Follow the manufacturer’s
mounting instructions.

Only use snow chains that are
approved by Mercedes-Benz. Your
authorized Mercedes-Benz Light Truck
Center will be glad to advise you on this
subject.

Use of snow chains may be prohibited
depending on location. Always check
local and state laws before installing
snow chains.

Do not use snow chains on the spare
wheel (
page 532).
Warning!G
If you use your spare tire when winter tires
are fitted on the other wheels, be aware that
the difference in tire characteristics may
very well impair turning stability and that
overall driving stability may be reduced.
Adapt your driving style accordingly.
Have the spare tire replaced with a winter
tire at the nearest authorized
Mercedes-Benz Light Truck Center.!Vehicles with Adaptive Damping
System (ADS)*: When driving with snow chains,
do not select SPORT mode (
page 276) as this
could result in damage to the vehicle.
!Some tire sizes do not leave adequate clear-
ance for snow chains. To help avoid serious dam-
age to your vehicle or tires, use of snow chains is
not permissible with the spare wheel.
!If snow chains are mounted to the front
wheels, they may scrape against the body or axle
components. The tires or the vehicle could be
damaged as a result.
iWhen driving with snow chains, you may
wish to deactivate the ESP® (page 104)
before setting the vehicle in motion. This will
improve the vehicle’s traction.

532 Technical data
Rims and tires
Spare wheel
ModelR 320 CDI 4MATIC
R 3501
R 350 4MATIC
R 550 4MATIC2
1USA only.2Canada only.
Rim (steel)6.5 B x 18 H2
Wheel offset1.58 in (40 mm)
Collapsible tire3
3Must not be used with snow chains.
195/75-18 106P
Recommended tire inflation pressure44 psi (3.0 bar)
!Please compare the recommended tire
inflation pressure for your vehicle with the tire
inflation pressure on the yellow label located on
the spare wheel rim.
If the tire inflation pressure on the yellow label
on the spare wheel rim differs from the values
given in this Operator’s Manual, inflate the
collapsible tire to the recommended tire inflation
pressure given on the yellow label on the spare
wheel rim.iPlease note that the tire inflation pressure of
the collapsible tire differs from the tire inflation
pressure of the road tires.

561 Index
Seats 128
Adjusting 43
Easy entry/exit feature 128
Heating* 139
Memory function* 141
Multicontour seat* 132
Ventilation* 140
Securing cargo 290
Selector lever see Gear selector lever
Self-test
Lamps in the instrument cluster 414
OCS 82
Tele Aid* 323
Service and warranty information 10
Service intervals see Maintenance, Service
indicator message 402
Service life
Tires 364
Vehicle battery 503
Service, Parts 522
Service see Maintenance
Service system see Maintenance SystemSettings
AIRMATIC* 276
Clock 176
Comfort functions* 183
Control system menus 160, 162
Control system
submenus 161, 163, 171
Date 176
Distance warning function* 185
Factory, SmartKey 112
Factory, SmartKey with
KEYLESS-GO* 116
Individual, Vehicle 170
Instrument cluster 174
Language, multifunction display 175
Lighting 177
Memory function* 141
Resetting all, Control system 171
Selective, SmartKey 112
Selective, SmartKey with
KEYLESS-GO* 117
Time 176
Vehicle level control* 277Shift program mode, Automatic
transmission 200
Shifting, Automatic transmission 190
Side impact air bags 76
Side marker lamps
Cleaning lenses 407
Messages in the multifunction
display 458
Replacing bulbs 480, 481
Side windows see Power windows
Sidewall 395
SmartKey see Key, SmartKey 110
SmartKey with KEYLESS-GO* see Key,
SmartKey with KEYLESS-GO* 113
Snow chains 399
Snow tires see Winter tires
Spare fuses 467
Spare wheel 471, 532
Inflating 499
Mounting 493
Wheel bolts 467, 498
Speed settings
Cruise control 261
Distronic* (Canada only) 268
Speedometer 27
Spinning see Tires, Direction of rotation

564 Index
Checking 373
Checking manually 373
Checking tire pressure electronically,
Advanced Tire Pressure Monitoring
System (Advanced TPMS)*, (Canada
only) 379
Checking tire pressure electronically,
Tire Pressure Monitoring System
(TPMS), (USA only) 376
Recommended tire inflation
pressure 371
Tires 363, 529
Advanced Tire Pressure Monitoring
System (Advanced TPMS)*, (Canada
only) 379
Air pressure 393
Care and maintenance 364
Cleaning 365
Collapsible tire, Spare wheel 532
Combination low tire pressure/TPMS
malfunction telltale, USA only 27
Direction of rotation, Spinning 365
Driving instructions 343
Hydroplaning 344
Important guidelines 363
Important notes, Tire inflation pressure 372
Inflation pressure 371, 373
Inspection 364
Load rating 384, 385, 395
Loading terminology 393
Loading the vehicle 366
Low tire pressure telltale 422
Ply composition and material
used 396
Retreads 363
Rims and tires 529
Rotating 396
Run Flat Indicator (Canada only) 374
Service life 364
Sizes 529
Snow chains 399
Spare wheel, Collapsible tire 532
Speed rating 345, 386, 396
Storing 365
Temperature 372, 392
Terminology 393
TIN 388, 395
Tire Identification Number see TIN
Tire Pressure Monitoring System
(TPMS)*, (USA only) 376
Total load limit 396TPMS malfunction telltale (USA
only) 422
Traction 344, 392, 396
Tread depth 365, 398
Treadwear indicators 365
Vehicle maximum load on 396
Wear pattern 397
Winter tires 398
Tongue Weight Rating see TWR
Tools 467
Top tether
Children in the vehicle 87
Towing eye bolts 515
Towing the vehicle 513
Tow-starting 511, 513
TPMS (USA only) 376
Traction 396
ETS/4-ETS, Driving safety
systems 103
Transmission see Automatic transmission
Traveling abroad 348
Tread 396
Tread depth 365
Treadwear indicators 396
Trip computer 185
Trip odometer 155