brake sensor MERCEDES-BENZ S550 2007 W221 Owner's Manual

71 Safety and Security
Driving safety systems
BAS
The Brake Assist System (BAS) operates in
emergency situations. If you apply the
brakes very quickly, the BAS automatically
provides full brake boost, thereby poten-
tially reducing the braking distance.
Apply continuous full braking pressure
until the emergency braking situation is
over.
The ABS will prevent the wheels from
locking.
When you release the brake pedal, the
brakes function again as normal. The BAS
is then deactivated.
For more information, see “Practical hints”
section (
page 544).
BAS Plus*
BAS Plus operates in emergency braking
situations and uses radar sensors to as-
sess the traffic situation.When you step quickly on the brake pedal
in an emergency braking situation,
BAS Plus automatically regulates the
brake pressure to a level that is suitable for
the traffic situation.
If BAS Plus requires a particularly high
brake pressure, PRE-SAFE
® is activated at
the same time.

Step on the brake pedal until the emer-
gency braking situation is over.
During this process, ABS prevents the
wheels from locking up.
Once you take your foot off the brake ped-
al or when there is no longer a risk of colli-
sion, the brake pedal functions again as
usual. BAS Plus is deactivated.
EBP
The Electronic Brake Proportioning (EBP)
enhances braking effectiveness by allow-
ing the rear brakes to supply a greater pro-
portion of the braking effort in straight line
breaking without a loss of vehicle stability.
Warning!
G
When the BAS is malfunctioning, the brake
system is still functioning normally, but with-
out the additional brake boost available that
BAS would normally provide in an emergen-
cy braking maneuver. Therefore, the braking
distance may increase.
Warning!
G
The BAS cannot prevent the natural laws of
physics from acting on the vehicle, nor can
it increase braking efficiency beyond that af-
forded by the condition of the vehicle brakes
and tires or the traction afforded. The BAS
cannot prevent accidents, including those
resulting from excessive speed in turns, fol-
lowing another vehicle too closely, or hydro-
planing. Only a safe, attentive, and skillful
driver can prevent accidents.
The capabilities of a BAS equipped vehicle
must never be exploited in a reckless or dan-
gerous manner which could jeopardize the
user’s safety or the safety of others.

352 Controls in detailWindshield wipersIntermittent wiping
Only switch on intermittent wiping under
wet weather conditions or in the presence
of precipitation.
Set the wiper switch to position U
or V.The wipers move across the wind-
shield. Afterward, the wiping intervals
are determined by the wetness of the
windshield.
After the initial wipe, pauses between
wipes are automatically controlled by the
rain sensor.
Single wipe
Press the combination switch briefly in
the direction of arrow2.
The windshield wipers wipe one time
without washer fluid.
Wiping with windshield washer fluid
Press the combination switch in the di-
rection of arrow2 past the resistance
point.
The windshield wiper operates with
washer fluid.
For information on filling up the washer
reservoir, see “Windshield washer system
and headlamp cleaning system”
(
page 498).
i
When the windshield wipers are switched on
and you brake the vehicle to a stop, the wipers
operate more slowly.
!
Do not leave windshield wipers in intermit-
tent setting when the vehicle is taken to an auto-
matic car wash or during windshield cleaning.
Wipers will operate in the presence of water
sprayed on the windshield, and windshield wip-
ers 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 windows.
You should therefore switch off the windshield
wipers when weather conditions are dry.
i
Intermittent wiping is interrupted when the
vehicle is at a standstill and a front door is
opened. This protects persons getting into or out
of the vehicle from being sprayed.
Intermittent wiping will be continued when


all doors are closed and the automatic trans-
mission is set to positionD orR
or


the wiper setting is changed using the com-
bination switch
i
To prevent smears on the windshield, wipe
with windshield washer fluid every now and then
even when it is raining.

385 Controls in detail
Driving systems
DISTRONIC Plus*
When activated, the DISTRONIC Plus adap-
tive cruise control system increases driv-
ing convenience afforded by the cruise
control during travel on expressways and
other major roads.

If the DISTRONIC Plus distance sensor
detects a slower moving vehicle direct-
ly ahead, your vehicle speed will be re-
duced so that you follow that vehicle at
a preset distance.


If there is no vehicle directly ahead of
you, DISTRONIC Plus will function in
the same way as cruise control
(page 380).
DISTRONIC Plus functions within a speed
range of 0 to 124 mph (0 to 200 km/h).
Warning!
G
DISTRONIC Plus is a convenience system.
Its speed adjustment reduction capability is
intended to make cruise control more effec-
tive and usable when traffic speeds vary. It
is not however, intended to, nor does it, re-
place the need for extreme care. The re-
sponsibility for the vehicle speed and the
distance to the vehicle ahead, including
most importantly brake operation to assure
safe stopping distance, always rests with
the driver.
DISTRONIC Plus cannot take street and traf-
fic conditions into account.
Complex driving situations are not always
fully recognized by DISTRONIC Plus. This
could result in wrong or missing distance
warnings.
Warning!
G
The DISTRONIC Plus adaptive cruise control
is no substitute for active driving involve-
ment. It does not react to pedestrians or sta-
tionary objects, nor does it recognize or
predict the curvature and lane layout or the
movement of vehicles ahead.
DISTRONIC Plus can only apply a maximum
of 40% of the vehicle’s braking power.
DISTRONIC Plus may not detect narrow ve-
hicles possibly driving in front of you, such
as motorcycles and vehicles driving in an
offset formation.
It is the driver’s responsibility at all times to
be attentive to road, weather and traffic con-
ditions and to provide the steering, braking
and other driving inputs necessary to retain
control of the vehicle.
High-frequency sources such as toll sta-
tions, speed measuring systems etc. can
cause the DISTRONIC Plus system to tem-
porarily cease functioning properly.

395 Controls in detail
Driving systems
Setting to last stored speed (“Resume”
function)
Briefly pull the DISTRONIC Plus lever in
the direction of arrow4 (
page 390).
DISTRONIC Plus is set to the last
stored speed.
DISTRONIC Plus resumes the last set
speed or if no speed is stored, it will set
and store the current speed.

Remove your foot from the accelerator
pedal.Deactivating DISTRONIC Plus
There are several ways to deactivate the
DISTRONIC Plus system:

Briefly tip the DISTRONIC Plus lever in
the direction of arrow3 (
page 390).
or

Step on the brake pedal.
DISTRONIC Plus will be deactivated.
The last speed set will be stored into
memory.
If the vehicle has been stopped by DIS-
TRONIC Plus and a malfunction occurs in
the system, the message “Brake immedi-
ately” will appear on the multifunction dis-
play. Step on the brake immediately to
prevent the vehicle from rolling. DISTRON-
IC Plus is then switched off and the mes-
sage disappears.
Warning!
G
The speed stored in memory should only be
set again if prevailing road conditions per-
mit. Possible acceleration or deceleration
differences arising from returning to preset
speed could cause an accident and/or seri-
ous injury you and others.i
Upon switching off the engine, the last
stored speed is deleted.
i
The following message will appear in the
multifunction display for approximately
5 seconds:
DISTRONIC PLUS Off
The last stored speed is deleted when you turn
off the engine.
i
DISTRONIC Plus deactivates automatically
when:


the vehicle is secured with the electric park-
ing brake


the vehicle speed is below 20 mph
(30 km/h) and no preceding vehicle is de-
tected


the ESP
® is in operation or switched off with
the ESP® switch (
page 73)


you set the automatic transmission toP, R,
or N while driving


the radar sensors are switched off
(page 256).
The segments in the multifunction display go out,
an acoustic warning sounds, and the message
“DISTRONIC PLUS Off” appears in the multifunc-
tion display for approximately 5 seconds.

405 Controls in detail
Driving systems
Parktronic system*
Parktronic is an electronic parking aid with
ultrasonic sensors that helps you while
parking.
It visually and audibly indicates the relative
distance between the vehicle and an ob-
stacle.
Parktronic is automatically activated when
you switch on the ignition, release the
electric parking brake or start the engine
and engage gear D, R or N.The Parktronic system deactivates at
speeds over approximately 11 mph
(18 km/h). At lower speeds the Parktronic
system turns on again.
Parktronic is also switched off when you
engage gear P or secure the vehicle in
place with the electric parking brake and
switch off the engine.
The Parktronic system monitors the sur-
roundings of your vehicle with six sensors
in the front bumper and four sensors in the
rear bumper.
1Sensors in the front bumper (Only visi-
ble without DISTRONIC Plus*)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 rests 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, es-
pecially at times of snow and ice, see
“Cleaning the Parktronic* system sensors”
(page 538).
Warning!
G
Make sure no persons or animals are in the
area in which you are maneuvering. You
could otherwise injure them.i
Interference caused by other ultrasonic sig-
nals (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.

406 Controls in detailDriving systemsRange of the sensorsFront sensors
Rear sensorsMinimum distance
If the system detects an obstacle in this
range, all the distance warning segments
illuminate and you hear a warning signal. If
the obstacle is closer than the minimum
distance, the actual distance may no long-
er be indicated by the system.i
To function properly, the sensors must be
free of dirt, ice, snow and slush. Clean the sen-
sors regularly, being careful not to scratch or
damage the sensors, see “Cleaning the Park-
tronic* system sensors” (
page 538).
Center
approx. 40 in (100 cm)
Corners
approx. 24 in (60 cm)
Center
approx. 48 in (120 cm)
Corners
approx. 32 in (80 cm)
!
During parking maneuvers, pay special at-
tention to objects located above or below the
height of the sensors (e.g. street curbs, painted
posts, or trailer hitches etc.). The Parktronic sys-
tem will not detect such objects at close range
and damage to your vehicle or the object may re-
sult.
Ultrasonic signals from outside sources (e.g.
truck air brakes, car wash, or jackhammers) may
impair the operation of the Parktronic system.
Center
approx. 8 in (20 cm)
Corners
approx. 6 in (15 cm)

409 Controls in detail
Driving systems
Park Assist*
Park Assist is an electronic parking aid
with radar sensors that helps you while
parking.
It visually and audibly indicates the relative
distance between the vehicle and an ob-
stacle.Park Assist is automatically activated
when the engine is running and the trans-
mission is in position D, R or N.
The Park Assist system deactivates at
speeds over approximately 11 mph
(18 km/h). At lower speeds the Parktronic
system turns on again.
Park Assist is also switched off when the
transmission is in position P or switch off
the engine.
While the transmission is in position N,
Park Assist is switched off if you secure the
vehicle in place with the electric parking
brake.
The Park Assist system monitors the sur-
roundings of your vehicle with four sensors
in the front bumper and two sensors in the
rear bumper.Warning!
G
Park Assist 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 rests with the driver.Warning!
G
Make sure no persons or animals are in the
area in which you are maneuvering. You
could otherwise injure them.!
Special attention must be paid to objects
with smooth surfaces or low silhouettes (e.g.
trailer couplings, painted posts, elevated cross-
bars or road curbs). Such objects may not be de-
tected by the system and can damage the
vehicle.
!
The operational function of the Park Assist
system can be affected by dirty sensors, espe-
cially at times of snow and ice.
Make sure that the area on the bumpers around
the sensors is free of dirt, ice and/or slush,
otherwise Park Assist may not function properly,
see “Cleaning the Park Assist* system sensors”
(
page 538).
!
High-frequency sources such as toll sta-
tions, speed measuring systems, etc. can cause
the Park Assist system to malfunction. You can
switch off the Park Assist using the Park Assist
button (
page 412) or switch off the radar sen-
sors (
page 256) to prevent possible malfunc-
tion.
i
In certain countries and near radio-astrolog-
ical facilities, you must switch off the radar sen-
sors (page 256).

411 Controls in detail
Driving systems
Warning indicators
Visual signals indicate to the driver the rel-
ative distance between the sensors and an
obstacle.
The warning indicator for the front area is
in the instrument cluster. The warning indi-
cator for the rear area is on the roof liner in
the rear.
1Left side of the vehicle
2Right side of the vehicle
3Indicator
Each warning indicator is divided into five
yellow and two red distance segments for
either side of the vehicle.
If yellow indicators 3 under the segments
are lit, Park Assist is ready to measure.The position of the gear selector lever de-
termines which warning indicators will be
activated.
As your vehicle approaches an object, one
or more distance segments will illuminate,
depending on the distance. When the sev-
enth distance segment illuminates, you
have reached the minimum distance.


Front area:
As soon as the first red segment lights
up, you will hear an intermittent warn-
ing tone for approx. two seconds. Once
the second red segment lights up, you
will hear a continuous warning tone.
You have reached the minimum dis-
tance.


Rear area:
As soon as the first red segment lights
up, you will hear an intermittent warn-
ing tone for approx. two seconds. Once
the second red segment lights up, you
will hear a continuous warning tone.
You have reached the minimum dis-
tance.
Gear selector
lever position
Warning indicator
D
Front area activated
R
Front and rear area
activated
N
With the electric park-
ing brake engaged:
neither activated.
With the electric park-
ing brake released:
front and rear area acti-
vated.
P
Neither activated
i
During strong rainfall, the warning indicators
and warning tones may be triggered, for exam-
ple, by water splashing into the area of the sen-
sors.

412 Controls in detailDriving systemsCollision warning
Park Assist can detect obstacles from a
considerable distance. If you drive in re-
verse towards an obstacle, you will hear a
warning tone. You must then brake in or-
der to avoid a collision. The warning tone
for a collision will not sound when the vehi-
cle is at a standstill very close to the obsta-
cle. In this case, you will hear a
corresponding tone for the warning indica-
tor in the rear area.Switching Park Assist system on/off
The Park Assist system can be switched off
manually.
The Park Assist button with the indicator
lamp is located on the control panel on the
right-hand side of the instrument cluster.
1Park Assist button
2Indicator lamp

Switching off Park Assist system:
Press button 1.
Indicator lamp 2 comes on.

Switching on Park Assist system:
Press button 1 again.
Indicator lamp 2 goes out.
i
During strong rainfall, the collision warning
may be triggered, for example, by water splash-
ing into the area of the sensors.
i
When the indicator lamp is on, the Park
Assist system is switched off.
i
The Park Assist system is automatically
switched on when the ignition (
page 315) and
radar sensors are switched on (page 256).

512 OperationTires and wheelsThe TPMS only functions on wheels that
are equipped with the proper electronic
sensors. It monitors the tire inflation pres-
sure, as selected by the driver, in all four
tires. A warning is issued to alert you to a
decrease in pressure in one or more of the
tires.
Tire inflation pressure inquiries are made
using the multifunction display. The
present inflation pressures are displayed
only after a few minutes of travel time.
Switch on the ignition (
page 315).

Press( or& to select the menu
“Service”.

Press$ or% to select “Tire
pressure”.

Press#.
i
Possible differences between the readings
of a tire inflation pressure gauge of an air hose,
e.g. gas station equipment, and the vehicle’s
control system can occur. Usually the readings
issued by the control system are more precise.
i
The menu overview can be found on
(
page 243).
i
When the message “Tire pressures dis-
played after driving a few minutes” appears in
the display, the individual inflation pressure val-
ues are matched with the tires. The individual
values are displayed after a few minutes driving.Warning!
G
It is the driver’s responsibility to calibrate
the TPMS on the recommended cold infla-
tion pressure. Underinflated tires affect the
ability to steer or brake the vehicle. You
might lose control over the vehicle.
i
With a spare wheel without wheel sensor
mounted, the system may still indicate the tire
inflation pressure of the removed wheel for some
minutes. If this happens, keep in mind that the
indicated value where the spare wheel is mount-
ed does not reflect the actual spare tire inflation
pressure.Warning!
G
The TPMS does not indicate a warning for
wrongly selected inflation pressures. Always
adjust tire inflation pressure according to
the placard on the driver’s door B-pillar or, if
available, the supplemental tire pressure in-
formation on the inside of the fuel filler flap.
The TPMS is not able to issue a warning due
to a sudden dramatic loss of pressure (e.g.
tire blowout caused by a foreign object). In
this case bring the vehicle to a halt by care-
fully applying the brakes and avoiding
abrupt steering maneuvers.