check engine MERCEDES-BENZ R350 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

23 At a glance
Exterior view
ItemPage
1Tailgate119
Power tailgate*119
Cargo compartment

Loading instructions

Cargo tie-down rings

Hooks

Expanding

Cover blind

Cargo net*
289
290
291
292
299
301
Vehicle tool kit467
Spare wheel471
2Rear window defroster207
3Rear lamps481
4Fuel filler flap352
Refueling352
Fuel353,
540
ItemPage
5Exterior rear view mirrors
Adjusting48
Auto-dimming rear view
mirrors*203
Power folding*204
6Towing eye bolt467
Installing towing eye bolt515
7Tires and wheels363,
529
Checking tire inflation
pressure373
General information363
Flat tire492
Spare wheel471
8Hood
Opening356
Engine oil358
Coolant360
ItemPage
9Windshield wipers59
Wiper blades, replacing489
Wiper blades, cleaning409
aWindshield
Cleaning with wiper fluid61
Cleaning409
bPower tilt/sliding sunroof*248
Panorama roof with power
tilt/sliding panel*252
cDoors
Locking and unlocking110
Opening and closing118
Locking/unlocking in an
emergency474
dFront lamps480
eHeadlamp cleaning system*203

40 Getting started
Unlocking
SmartKey
Starter switch
0For removing SmartKey
1Power supply for some electrical
consumers, such as seat adjustment
2Ignition (power supply for all electrical
consumers) and driving position
All lamps (except high beam headlamp
indicator lamp and turn signal indicator
lamps unless activated) in the instru-
ment cluster come on. If a lamp in the
instrument cluster fails to come on
when the ignition is switched on, have
it checked and replaced if necessary. If
a lamp in the instrument cluster remains on after starting the engine or
comes on while driving, refer to “Lamps
in instrument cluster” (
page 414).
3Starting position
iWhen you switch on the ignition, the
indicator and warning lamps (except high beam
headlamp indicator lamp and turn signal indica-
tor lamps unless activated) in the instrument
cluster come on. The indicator and warning
lamps (except high beam headlamp indicator
lamp and turn signal indicator lamps if activated)
will go out when the engine is running.
This indicates that the respective systems are
operational.
iIf the SmartKey does not belong to the
vehicle, the SmartKey can be turned in the
starter switch. However, the ignition does not
switch on and the engine does not start.
iWhen the SmartKey is removed from the
starter switch and the automatic transmission is
in a position other thanP, the automatic
transmission automatically shifts toP.
!If the SmartKey cannot be turned in
the starter switch, the battery may not be
sufficiently charged.

Check the battery and charge it if necessary
(
page 503).

Get a jump start (page 511).
To prevent accelerated battery discharge or a
completely discharged battery, always remove
the SmartKey from the starter switch when the
engine is not in operation.

42 Getting started
Unlocking
Position 0
Before you press the KEYLESS-GO
start/stop button, the vehicle’s on-board
electronics have status0 (as with
SmartKey removed).
Position 1
Press the KEYLESS-GO start/stop
button once.
This supplies power for some electrical
consumers, such as seat adjustment.Ignition (or Position 2)
Press the KEYLESS-GO start/stop
button twice.
This supplies power for all electrical
consumers.
All lamps (except high beam headlamp
indicator lamp and turn signal indicator
lamps unless activated) in the instru-
ment cluster come on. If a lamp in the
instrument cluster fails to come on
when the ignition is switched on, have
it checked and replaced if necessary. If
a lamp in the instrument cluster
remains on after starting the engine or
comes on while driving, refer to “Lamps
in instrument cluster” (
page 414).For information on starting the engine
using the KEYLESS-GO start/stop button,
see “Starting with KEYLESS-GO*”
(
page 54).
For more information on KEYLESS-GO, see
“SmartKey with KEYLESS-GO*”
(
page 113).
iIf you now press the KEYLESS-GO
start/stop button

once more, the ignition (position2) is
switched on

twice more, the power supply is again
switched off
iIf you now press the KEYLESS-GO
start/stop button once more, the power supply
is again switched off.
iWhen you switch on the ignition, the
indicator and warning lamps (except high beam
headlamp indicator lamp and turn signal indica-
tor lamps unless activated) in the instrument
cluster come on. The indicator and warning
lamps (except high beam headlamp indicator
lamp and turn signal indicator lamps if activated)
will go out when the engine is running.
This indicates that the respective systems are
operational.

60 Getting started
Driving
Switching on windshield wipers
Turn the combination switch to the
desired position depending on the
intensity of the rain.
MWindshield wipers off
USlow intermittent wiping
Rain sensor operation with low
sensitivity.
VFast intermittent wiping
Rain sensor operation with high
sensitivity.
uSlow continuous wiping
tFast continuous wipingIntermittent wiping
Only switch on intermittent wiping under
wet weather conditions or in the presence
of precipitation.
When you select intermittent wiping, the
rain sensor is activated. The rain sensor
automatically sets a suitable wiping
interval depending on the wetness of the
sensor surface.
Turn the combination switch to
positionU orV.
!Do not operate the windshield wipers when
the windshield is dry. Dust that accumulates on
a windshield might scratch the glass and/or
damage the wiper blades when wiping occurs on
a dry windshield. If it is necessary to operate the
windshield wipers in dry weather conditions,
always operate the windshield wipers with
windshield washer fluid (
page 61).
!If anything blocks the windshield wipers
(leaves, snow, etc.), switch them off
immediately.

For safety reasons, stop the vehicle in a safe
location and

remove the SmartKey from the starter
switch
or

turn off the engine by pressing the
KEYLESS-GO* start/stop button and
open the driver’s door (with the driver’s
door open, starter switch is in
position0, same as with SmartKey
removed from starter switch)
before attempting to remove any blockage.

Remove blockage.

Turn the windshield wipers on again.If the windshield wipers fail to function at all in
combination switch positionU orV,

set the combination switch to the next
higher wiper speed

have the windshield wipers checked at the
nearest authorized Mercedes-Benz Light
Truck Center
!Do not leave windshield wipers on an
intermittent setting when the vehicle is taken
to an automatic car wash or during windshield
cleaning. Windshield wipers will operate in the
presence of water sprayed on the windshield,
and windshield wipers may be damaged as a
result.
!If you have set intermittent wiping, dirt on
the surface of the rain sensor or optical effects
may cause the windshield wipers to wipe in an
undesired fashion. This could then damage the
windshield wiper blades or scratch the wind-
shield. You should therefore switch off the wind-
shield wipers when weather conditions are dry.

63 Getting started
Driving
The coolant temperature is above
248°F (120°C)
The coolant is too hot and is no longer
cooling the engine.
Stop the vehicle in a safe location as
soon as possible and turn off the
engine. Allow engine and coolant to
cool.
Check the coolant level and add
coolant if necessary (
page 360).In case of accident
If the vehicle is leaking fuel:
Do not start the engine under any
circumstances.
Notify local fire and/or police authori-
ties.
If the extent of the damage cannot be
determined:
Contact an authorized Mercedes-Benz
Light Truck Center or call Roadside
Assistance.
If no damage can be determined on the

major assemblies

fuel system

engine mount:
Start the engine in the usual manner.

78 Safety and Security
Occupant safety
Warning!G
If the 59indicator lamp illumi-
nates when an adult or someone larger than
a small individual is in the front passenger
seat, have the front passenger reposition
himself or herself in the seat until the
59 indicator lamp goes out, or
check whether objects are caught under or
around the seat.
More information about air bag display
messages (
page 438).
In the event of a collision, the air bag control
unit will not allow front passenger front air
bag deployment when the OCS classified
the front passenger seat occupant as being
up to or less than the weight of a typical
12-month-old child in a standard child re-
straint or if the front passenger seat is
sensed as being empty.
When the OCS senses that the front passen-
ger seat occupant is classified as being up
to or less than the weight of a typical
12-month-old child in a standard child
restraint, the 59indicator
lamp will illuminate when the engine is
started and remain illuminated, indicating
that the front passenger front air bag is de-
activated.
When the OCS senses that the front passen-
ger seat is classified as being empty, the
59indicator lamp will illumi-
nate when the engine is started and remain
illuminated, indicating that the front passen-
ger front air bag is deactivated.When the OCS senses that the front passen-
ger seat occupant is classified as being
heavier than the weight of a typical
12-month-old child seated in a standard
child restraint or as being a small individual
(such as a young teenager or a small adult),
the 59 indicator lamp will illu-
minate for approximately 6 seconds when
the engine is started and then, depending on
occupant weight sensor readings from the
seat, remain illuminated or go out. With the
59 indicator lamp illuminated,
the front passenger front air bag is deacti-
vated. With the 59indicator
lamp out, the front passenger front air bag is
activated.
When the OCS senses that the front passen-
ger seat occupant is classified as an adult or
someone larger than a small individual, the
59 indicator lamp will illumi-
nate for approximately 6 seconds when the
engine is started and then go out, indicating
that the front passenger front air bag is acti-
vated.

164 Controls in detail
Control system
Standard display menu
In the standard display, the main odometer
and the trip odometer appear in the multi-
function display.
1Trip odometer
2Main odometer
If you see another display, press
buttonè orÿ repeatedly until
the standard display appears.
Press buttonkorj to select
the functions in the standard display
menu.The following functions are available:Checking coolant temperature
Press buttonk orj repeatedly
until the coolant temperature appears
in the multifunction display.
FunctionPage
Checking tire inflation pressure373
Checking coolant temperature164
Calling up digital speedometer or
outside temperature165
Calling up maintenance service
indicator402
Warning!G

Driving when your engine is overheated
can cause some fluids which may have
leaked into the engine compartment to
catch fire. You could be seriously
burned.

Steam from an overheated engine can
cause serious burns which can occur
just by opening the hood. Stay away
from the engine if you see or hear steam
coming from it.
Stop the vehicle in a safe location away from
other traffic. Turn off the engine, get out of
the vehicle and do not stand near the vehicle
until the engine has cooled down.

194 Controls in detail
Automatic transmission
Transmission positions
The current transmission position appears
in the multifunction display.
1Current transmission position
!If the current transmission position does not
appear in the multifunction display due to a
malfunction, for example, make sure that the
automatic transmission is in the desired position
by carefully driving off with the transmission in
drive positionD and program modeS
(
page 200) selected. Do not limit the gear
range.
Effect
ìPark position
Shift into park positionP only
when vehicle is stopped. The
park position is not intended to
serve as a brake when the vehi-
cle is parked. Rather, the driver
should always set the parking
brake in addition to shifting into
park positionP to secure the
vehicle.
If the vehicle’s electrical system
is malfunctioning, the automatic
transmission could remain
locked in park positionP.
Have the vehicle checked as
soon as possible by an autho-
rized Mercedes-Benz Light
Truck Center.
!SmartKey:
If you turn off the engine using the SmartKey and

remove the SmartKey from the starter
switch
or

open a front door
the transmission will shift to park positionP
automatically.
Keep in mind that turning off the engine with the
SmartKey alone only will automatically shift the
transmission to neutral positionN.
!KEYLESS-GO*:
If you turn off the engine using the KEYLESS-GO
start/stop button and open a front door, the
transmission will shift to park positionP
automatically.
Keep in mind that turning off the engine using
the KEYLESS-GO start/stop button alone only
will automatically shift the transmission to
neutral positionN.

202 Controls in detail
Automatic transmission
Extending gear range
Briefly press right shift button2.
The transmission will shift to the next
higher gear as permitted by the shift
program. This action simultaneously
extends the gear range of the transmis-
sion.Canceling gear range limitPress and hold right shift button2
until the cipher for the current gear
range disappears from the multifunc-
tion display (
page 199).
The transmission will shift from the
current gear range directly to gear
rangeD.
Shifting into optimal gear range
Press and hold left shift button1.
The transmission will automatically
select the gear range suited for optimal
acceleration and deceleration. This will
involve shifting down one or more
gears.Emergency operation (Limp-Home
Mode)
If vehicle acceleration becomes less re-
sponsive or sluggish or the transmission
no longer shifts, the transmission is most
likely operating in limp-home (emergency
operation) mode. In this mode only second
gear and reverse gear can be selected.
Stop the vehicle in a safe location.
Shift to park positionP.
Turn off the engine.
Wait at least 10 seconds before
restarting.
Restart the engine.
Shift to drive positionD (for second
gear) or reverse gearR.
Have the transmission checked at an
authorized Mercedes-Benz Light Truck
Center as soon as possible.
iIf you press on the accelerator when the en-
gine has reached its rpm limit, the transmission
will upshift beyond any gear range limit selected.