brake sensor MERCEDES-BENZ R350 2008 W251 Owner's Manual

274 Controls in detail
Driving systems
The most likely cause for a malfunctioning
system is a dirty sensor (located behind
the hood grille), especially at times of snow
and ice or heavy rain. In such a case,
Distronic will switch off, and the message
DISTRONIC Currently Unavailable See
Operator’s Manual
appears in the multi-
function display.
For cleaning and care of the Distronic sen-
sor, see “Cleaning the Distronic* system
sensor cover” (
page 407).Turns and bends
In turns or bends, Distronic may not detect
a moving vehicle in front, or it may detect
one too soon. This may cause your vehicle
to brake late or unexpectedly.Offset driving
A vehicle traveling in your lane but offset
from your direct line of travel may not be
detected by Distronic. There will be insuffi-
cient distance to the vehicle ahead.
iIf the message DISTRONIC Available
Again
appears during driving, the dirt (e.g.
slush) has dissolved; Distronic works again, if
you reactivate it (
page 268).

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.

282 Controls in detail
Driving systems
The Parktronic system is an electronic aid
designed to assist the driver during
parking maneuvers. It visually and audibly
indicates the relative distance between the
vehicle and an obstacle.
The Parktronic system is automatically
activated when you

switch on the ignition or start the
engine
and

release the parking brake
and

set the automatic transmission to
positionD,R, orNThe Parktronic system deactivates at
vehicle speeds exceeding approximately
11 mph (18 km/h). At lower vehicle
speeds, the Parktronic system turns on
again.
The Parktronic system also deactivates
when you set the automatic transmission
to positionP or depress the parking brake
pedal.
The Parktronic system monitors the
surroundings of your vehicle with six sen-
sors in the front bumper and four sensors
in the rear bumper.
1Sensors in the front bumperRange of the sensors
To function properly, the sensors must be
free of dirt, ice, snow and slush. Clean the
sensors regularly, being careful not to
scratch or damaging the sensors, see
“Cleaning the Parktronic* system sensors”
(
page 408).
Warning!G
Make sure no persons or animals are in the
area in which you are maneuvering. You
could otherwise injure them.
!During parking maneuvers, pay special
attention to objects located above or below the
height of the sensors (e.g. planters or trailer
hitches).
The Parktronic system will not detect such
objects at close range and damage to your
vehicle or the object may result.
Ultrasonic signals from outside sources (e.g.
working jackhammers, car wash or the air brakes
of trucks) may impair the operation of the
Parktronic system.

285 Controls in detail
Driving systems
Switching on
Press Parktronic switch1 once more.
Indicator lamp2 goes out.
Parktronic system malfunction
If only the red distance segments illumi-
nate and an acoustic warning sounds,
there is a malfunction in the Parktronic
system. The Parktronic system will auto-
matically switch off after 20 seconds and
the indicator lamp in the Parktronic switch
comes on.
Have the Parktronic system checked
by an authorized Mercedes-Benz Light
Truck Center as soon as possible.If only the red distance segments illumi-
nate and no acoustic warning sounds, the
Parktronic system sensors are dirty (e.g.
slush, snow or ice) or there is an interfer-
ence from other radio or ultrasonic signals
(e.g. working jackhammers, car wash or
the air brakes of trucks). The Parktronic
system will automatically switch off after
20 seconds and the indicator lamp in the
Parktronic switch comes on.
Switch off the ignition (page 39).
Clean the Parktronic system sensors
(
page 408).
Switch on the ignition (page 39).
or
Check the Parktronic system operation
at another location to rule out interfer-
ence from outside radio or ultrasonic
signals.
Rear view camera*
iThe Parktronic system switches on
automatically when you switch on the ignition
(
page 39).
Warning!G
The rear view camera is only an aid and may
display obstacles from a distorted perspec-
tive or inaccurately, or may not display ob-
stacles at all. The rear view camera does not
relieve you of the responsibility to be cau-
tious, take care and pay careful attention.
The rear view camera may not show objects
which are

very close to the rear bumper

under the rear bumper

above the tailgate handle
You are responsible for safety at all times
and must continue to pay attention to the
immediate surroundings when parking and
maneuvering. This includes the area behind,
in front of and beside the vehicle. Otherwise
you could endanger yourself or others.

407 Operation
Vehicle care
Ornamental moldings
For regular cleaning and care of ornamen-
tal moldings, use a use damp cloth.Headlamps, brake lamps, tail lamps,
side markers, turn signal lenses
Use a mild car wash detergent, such
as Mercedes-Benz approved Car
Shampoo, with plenty of water.Cleaning the Distronic* system sensor
cover
1Distronic system sensor cover
Switch off the ignition (page 39).
Use a mild car wash detergent, such as
Mercedes-Benz approved Car
Shampoo, with plenty of water and a
non-scratching cloth to clean sensor
cover1.
!Do not use chrome cleaner on ornamental
moldings. Although ornamental moldings may
have chrome appearance, they could be made of
anodized aluminum that will be damaged when
cleaned with chrome cleaner. Instead, use damp
cloth to clean those ornamental moldings.
Very dirty ornamental moldings of which you are
sure are chrome-plated, use a chrome cleaner.
If in doubt whether an ornamental molding is
chrome-plated, contact an authorized
Mercedes-Benz Light Truck Center.
!Only use window cleaning solutions that are
suitable for plastic lamp lenses. Window clean-
ing solutions which are not suitable may damage
the plastic lamp lenses of the headlamps. There-
fore, do not use abrasives, solvents or cleaners
that contain solvents.
Never apply strong force and only use a soft,
non-scratching cloth when cleaning the lenses.
Do not attempt to wipe dirty lenses with a dry
cloth or sponge.
Otherwise you may scratch or damage the lens
surface.

455 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
.3rd Brake LampThe high mounted brake lamp is
malfunctioning. This message
will only appear if a critical
number of LEDs have stopped
working.Contact an authorized Mercedes-Benz
Light Truck Center as soon as possible.
Active Headlamps
InoperativeThe active Bi-Xenon* headlamp
system is malfunctioning.Contact an authorized Mercedes-Benz
Light Truck Center as soon as possible.
AUTO Light
InoperativeThe light sensor is malfunction-
ing. The headlamps switch on
automatically.Contact an authorized Mercedes-Benz
Light Truck Center as soon as possible.
To switch off the headlamps
(U.S. vehicles only):
In the control system, set lamp operation
to manual mode (
page 144).
Switch off the headlamps using the
exterior lamp switch (
page 143).
Brake Lamp
LeftThe left brake lamp is malfunc-
tioning. A substitute bulb is
being used.Replace the bulb as soon as possible
(
page 480).
Brake Lamp
RightThe right brake lamp is malfunc-
tioning. A substitute bulb is
being used.Replace the bulb as soon as possible
(
page 480).

553 Index
H
Halogen headlamps see Headlamps
Hands-free microphone 33
Hard plastic trim items, cleaning 411
Hazard warning flasher 150
Head restraints
Active head restraint 86, 133
Front seats 45
Rear seats 135, 136
Headlamp cleaning system* 203, 362
Reservoir capacity 538
Headlamp shut-off delay see Delayed
shut-off, Exterior lamps
Headlamps
Automatic headlamp mode 144
Bi-Xenon* 481
Cleaning lenses 407
Cleaning system* 203, 362
Halogen 481
Light sensor, Messages in the
multifunction display 455
Manual headlamp mode 144
Messages in the multifunction
display 455–460
Replacing bulbs 480, 481
Switch 58, 143Headliner, Cleaning 411
Heated seats see Seats
Heated steering wheel* 318
High beam flasher 58, 148
High beam headlamps
Indicator lamp 29
Messages in the multifunction
display 456
Replacing 480
Switching on 58, 147
High mounted brake lamp 481
Hinged quarter windows* see
Power windows
Hood 356
Messages in the multifunction
display 452
Opening 356
Hooks
Loading 291
Horn 25
HVAC see Climate control or
Automatic climate control (3-zone)*
Hydroplaning 344I
Identification label see Labels
Ignition 40, 53, 66
Immobilizer 106
Indicator lamps see Lamps, Indicator and
warning
Infant and child restraint systems see
Children in the vehicle
Inflation pressure see Tires, Inflation
pressure
Information button see Tele Aid*
Infrared reflecting windshield* 336
Inside door handle 118
Instrument cluster 26, 154
Illumination brightness 154
Lamps 414
Messages in the multifunction
display 427–466
Multifunction display 157
Selecting language 174

555 Index
Messages in the multifunction
display 453–454
Opening the power windows
(Summer opening feature) 244
Opening the tilt/sliding panel*
(Summer opening feature) 244
Opening the tilt/sliding sunroof*
(Summer opening feature) 244
Remote control 113
Replacing batteries 479
Selective settings 117
Start/stop button 41
Starter switch positions 39, 41
Starting the engine 54
Turning off engine 66
Unlocking and opening, Power
tailgate* 121
Kickdown 197
Kilopascal 394L
Labels 524
Certification label 524
Emission control information 525
Engine number 525
Paint code 524
Vehicle Identification Number
(VIN) 525
Lamps, exterior 481
Front 481
Light sensor, Messages in the multi-
function display 455
Messages in the multifunction
display 455–460
Rear 481
Lamps, Indicator and warning
ABS 27, 414, 415
Brakes 27, 415
Center console 31, 425
CHECK ENGINE 29, 417, 418
Distance warning lamp* 266
Engine diagnostics 29, 417, 418
ESP
®27, 419
Front passenger front
air bag off 76, 77, 81, 82, 425Fuel reserve 29, 424
High beam headlamps 29
Instrument cluster 26, 414
Parktronic* 283, 284
Preglow indicator, Diesel engine 29
Seat belt telltale 29, 82, 420
Seat heating* 139
Seat ventilation* 140
SRS 29, 70, 85, 424
Turn signals 27
Language, Setting 174
LATCH-type child seat anchors see
Children in the vehicle
Leather upholstery, Cleaning and
care of 412
License plate lamps 481
Messages in the multifunction
display 457
Replacing bulbs 481, 488
Light alloy wheels, Cleaning 410
Light sensor
Messages in the multifunction
display 455
Lighter see Cigarette lighter

558 Index
Odometer 155, 157
Oil level see Engine oil, Checking level
Oil see Engine oil
One-touch gearshifting 201
Operating safety 16
Operator’s Manual 10
Ornamental moldings, Cleaning 407
Outside temperature see Displays
Overdue maintenance service term 401
Overhead control panel 33
Oxidation catalyst (diesel engine) 349
P
Paintwork code 524
Paintwork, Cleaning 404
Panic alarm 98
Panorama roof with power tilt/sliding
panel* 252
Cleaning 410
Convenience closing feature 245
Opening/closing 253
Roller sunblinds 252
Stopping 253
Summer opening feature 244
Synchronizing 255Parcel nets 307
Parking 64, 343
Parking brake 56, 65
Lamps, Indicator and warning 415
Messages in the multifunction
display 446
Releasing 56
Parking lamps 481
Messages in the multifunction
display 458
Replacing bulbs 480
Parktronic* (Parking assist) 281
Cleaning system sensors 408
Minimum distance 283
Range 282
Sensor cover 408
Switching on/off 284
System malfunction 285
System sensors 282
Warning indicators 283
Parts service 522
PASS AIR BAG OFF indicator lamp see
Front passenger front air bag off
indicator lampPassenger compartment 347
Fuse box 520
Interior lighting 150
Passenger safety see Occupant safety
Pedals 339
Permanent four-wheel drive 281
Phone see Telephone*
Plastic and rubber parts, Cleaning 410
Poly-V-belt drive
Layout 526
Positions (Memory function*) see
Seats 142
Power assistance 340
Power outlets 314
Power seats see Seats
Power tilt/sliding sunroof* 248
Convenience closing feature 245
Opening/closing 248
Stopping 245
Summer opening feature 244
Synchronizing 250
Power washer 404

563 Index
Technical data 538
Air conditioning refrigerant 538
Brake fluid 537, 539
Coolant 537, 541
Dimensions, Vehicle 534
Electrical system 533
Engine 527
Engine oil 536, 538
Engine oil additives 538
Fuel requirements 540
Fuels, coolants, lubricants, etc. 536
Gasoline additives 540
Premium unleaded gasoline 539
Rims 529
Tires 529
Weights 535
Windshield washer and headlamp
cleaning* system 538, 544
Tele Aid* 322
Call priority 328
Emergency calls 323
Hands-free microphone 33
Information 326
Initiating an emergency call
manually 324Messages in the multifunction
display 461
Remote door unlock 328
Roadside Assistance 325
SOS button 324
Stolen Vehicle Recovery
services 329
System self-check 323
Telephone* 319
Answering a call 188
Changing mobile phone cradle 321
Dialing a number from the phone
book 188
Ending a call 188
Hands-free microphone 33
Inserting in cradle 320
Installing a different mobile phone
cradle 321
Messages in the multifunction
display 461
Operation 187
Phone book* 188
Redialing 189
Rejecting an incoming call 188
Removing from cradle 321Temperature
Coolant 164
Display mode, Status indicator 175
Interior temperature, setting see Cli-
mate control or Automatic climate
control (3-zone)*
Outside temperature 165
Sensor, Interior temperature 225
Sensor, Outside temperature 155
Tether attachment points
Children in the vehicle 87
3-zone automatic climate control* 222
Ticket holder 309
Tie-down rings 290
Tightening torque, Wheel bolts 501
Tilt/sliding panel* see Panorama roof with
power tilt/sliding panel*
Tilt/sliding sunroof* see Power tilt/sliding
sunroof*
Time 176
TIN 388, 395
Tire and Loading Information
Placard 367
Terminology 393
Tire Identification Number see TIN
Tire inflation pressure