2008 MERCEDES-BENZ S-Class brake sensor

70 Safety and SecurityDriving safety systemsBAS Plus*
The Brake Assist System Plus (BAS Plus)
operates in emergency braking situations
and uses radar sensors* to assess the traf-
fic situation. BAS Plus assists you in brak-
ing at speeds above approximately 20 mph
(30 km/h).
When travelling in Canada in a vehicle not
registered in Canada, you must switch off
the radar sensor system* (
page 307).
Canadian law does not permit the use of
the radar sensor system* (
page 307) for
vehicles from outside of Canada. When you
switch off the radar sensor system*, the
following functions are deactivated:


BAS Plus


DISTRONIC Plus* (
page 451)


Park Assist* (
page 476)


PRE-SAFE
® Brake* (
page 77)BAS Plus detects obstacles that are in your
driving path for a sufficient period of time
to permit the system to recognize these
obstacles. If you approach the detected
obstacle quickly, BAS Plus calculates the
level of brake power boost appropriate for
the circumstance to supply when the driv-
er applies the brakes.
i
USA only:
This device has been approved by the FCC as a
“Vehicular Radar System”. The radar sensor is
intended for use in an automotive radar system
only. Removal, tampering, or altering of the de-
vice will void any warranties, and is not permitted
by the FCC. Do not tamper with, alter, or use in
any non-approved way.
Any unauthorized modification to this device
could void the user’s authority to operate the
equipment.
i
Canada only:
This device complies with RSS-210 of Industry
Canada. Operation is subject to the following
two conditions:
(1) This device may not cause interference, and
(2) this device must accept any interference re-
ceived, including interference that may
cause undesired operation of the device.
Removal, tampering, or altering of the device will
void any warranties, and is not permitted. Do not
tamper with, alter, or use in any non-approved
way.
Any unauthorized modification to this device
could void the user’s authority to operate the
equipment.
Warning!
G
BAS Plus is a convenience system designed
to assist the driver during vehicle operation.
The responsibility for the vehicle speed and
the distance to the vehicle ahead, including
most importantly brake operation to assure
safe stopping distance, always remains with
the driver.
Always pay attention to traffic conditions
even while BAS Plus is switched on. Other-
wise, you may not be able to recognize
dangerous situations until it is too late and
could cause an accident resulting in person-
al or fatal injury to you or others.

71 Safety and Security
Driving safety systems
When you step quickly on the brake pedal
in an emergency braking situation,
BAS Plus automatically regulates the
brake power boost to a level that is suit-
able for the traffic situation.
If BAS Plus requires a particularly high
brake power boost, PRE-SAFE
® is activat-
ed at the same time.

Keep constant pressure on the brake
pedal until the emergency braking situ-
ation is over.
During this process, ABS prevents the
wheels from locking up.
The brakes will resume normal operation
after


the brake pedal is released


no obstacles are detected in your path


the system no longer senses a risk of a
collision
BAS Plus is deactivated.BAS Plus can react to stationary obstacles
such as standing or parked vehicles at
road speeds of up to approximately
40 mph (70 km/h).
BAS Plus can only assist you when the
radar sensors are switched on and func-
tional. You can check whether the sensors
are active by switching on DISTRONIC
Plus* (
page 451) or using the “Radar
Sensors” menu (
page 307) in the instru-
ment cluster control system.
After a hard collision or damage to the
front of the vehicle from an accident, have
the adjustment and operation of the radar
sensors checked by an authorized
Mercedes-Benz Center.
If BAS Plus is not available due to a radar
sensor malfunction, the braking system
will continue to function normally with full
brake boost and full standard BAS
function.
Warning!
G
BAS Plus will only respond with brake assis-
tance if it has clearly detected an object. De-
tection can be impeded by

dirty or covered sensors


snowfall or heavy rain


disturbance from other radar sources


strong radar reflection such as in park-
ing garages
BAS Plus uses radar signals that are not re-
flected well by narrow objects and absorp-
tive materials. For this reason BAS Plus will
not react to

persons and animals


approaching traffic or cross-traffic
BAS Plus may not detect narrow vehicles
driving in front of you, such as motorcycles
and vehicles driving offset from your vehicle
center.

78 Safety and SecurityDriving safety systemsPRE-SAFE
® Brake will only assist you by
automatically initiating braking if the driver
and front passenger have their seat belts
fastened.
Using the radar sensors, PRE-SAFE
® Brake
detects obstacles that are in your driving
path for a sufficient period of time for the
system to recognize it. If you approach a
vehicle and PRE-SAFE
® Brake has estab-
lished that the distance to the vehicle
ahead at your current speed is so close
that PRE-SAFE
® Brake will not be capable
of slowing the vehicle sufficiently, the sys-
tem will initially warn you visually and
acoustically.When travelling in Canada in a vehicle not
registered in Canada, you must switch off
the radar sensor system* (
page 307).
Canadian law does not permit the use of
the radar sensor system* (
page 307) for
vehicles from outside of Canada. When you
switch off the radar sensor system*, the
following functions are deactivated:


BAS Plus* (
page 70)


DISTRONIC Plus* (
page 451)


Park Assist* (
page 476)


PRE-SAFE
® Brake
Always pay attention to traffic conditions
even while PRE-SAFE
® Brake is switched on.
Otherwise, you may not be able to recognize
dangerous situations until it is too late and
could cause an accident resulting in person-
al or fatal injury to you or others.
i
USA only:
This device has been approved by the FCC as a
“Vehicular Radar System”. The radar sensor is
intended for use in an automotive radar system
only. Removal, tampering, or altering of the de-
vice will void any warranties, and is not permitted
by the FCC. Do not tamper with, alter, or use in
any non-approved way.
Any unauthorized modification to this device
could void the user’s authority to operate the
equipment.
i
Canada only:
This device complies with RSS-210 of Industry
Canada. Operation is subject to the following
two conditions:
(1) This device may not cause interference, and
(2) this device must accept any interference re-
ceived, including interference that may
cause undesired operation of the device.
Removal, tampering, or altering of the device will
void any warranties, and is not permitted. Do not
tamper with, alter, or use in any non-approved
way.
Any unauthorized modification to this device
could void the user’s authority to operate the
equipment.


79 Safety and Security
Driving safety systems
When the distance to the forward vehicle is
too small, the distance warning lampl
lights up in the instrument cluster. If you
approach the forward vehicle very quickly,
you will hear a warning tone.
If you do not apply the brakes yourself or
maneuver around a sensed obstacle, the
vehicle will automatically initiate light
braking. PRE-SAFE
® (page 57) is activat-
ed when the distance to the vehicle ahead
at your current speed is so close that
PRE-SAFE
® Brake will not be capable of
slowing the vehicle sufficiently.
Warning!
G
PRE-SAFE
® Brake will only respond with
brake assistance if it has clearly detected an
object. Detection can be impeded by


dirty or covered sensors


snowfall or heavy rain


disturbance from other radar sources


strong radar reflection such as in park-
ing garages
PRE-SAFE
® Brake uses radar signals that
are not reflected well by narrow objects and
absorptive materials. For this reason BAS
Plus will not react to


persons and animals


approaching traffic or cross-traffic
PRE-SAFE
® Brake may not detect narrow ve-
hicles driving in front of you, such as motor-
cycles and vehicles driving offset from your
vehicle center.
Warning!
G
PRE-SAFE
® Brake brakes your vehicle with a
maximum of 13 ft/s
2 (4 m/s
2). This corre-
sponds to about 40% of the maximum decel-
eration ability of your vehicle. This
automatic braking is intended only to ini-
tiate the braking if the driver has not already
done so. The driver must apply the brakes in
order to prevent a collision.
PRE-SAFE
® Brake applies the brake pedal
automatically which results in the brake
pedal moving. Therefore keep driver’s foot
area clear at all times, including the area un-
der the brake pedal. Objects stored in this
area may impair pedal movement which
could interfere with the braking ability of the
PRE-SAFE® Brake.
Do not place your foot under the brake pedal
– your foot could become caught.

81 Safety and Security
Driving safety systems
PRE-SAFE
® Brake does not always clearly
interpret complex traffic situations. If a vi-
sual and/or acoustic warning is issued in
an uncritical driving situation, or if the ve-
hicle brakes lightly, you can interrupt the
PRE-SAFE® Brake maneuver by


pressing down all the way on the accel-
erator or using kickdown


releasing the brake pedalThe PRE-SAFE
® Brake maneuver is termi-
nated immediately when


you avoid the obstacle by evasive
steering


you drive less than 9 mph (15 km/h)


an obstacle can no longer be identified
ahead of you


the system no longer senses the risk of
a collisionAfter a hard collision or damage to the
front of the vehicle from an accident, have
the settings and operation of the radar
sensors checked by an authorized
Mercedes-Benz Center.
i
PRE-SAFE
® Brake will remain passive while
DISTRONIC Plus* is switched on (
page 451).

290 Control systemsInstrument cluster control system
Telephone* (
page 299)
Assistance* (
page 303)
Service (
page 304)
Settings (
page 305)
Commands/submenusDialing a number from the
phone book
Displaying the distance graph-
ic*, DISTRONIC Plus*
Calling up vehicle malfunction,
warning and system status
messages stored in memory
Setting daytime running lamp
mode (USA only)
Redialing
Activating/deactivating
PRE-SAFE
® Brake*
(vehicles with
DISTRONIC Plus* only)
Checking tire inflation pres-
sure
Switching additional speedome-
ter on or off
Answering a call
Switching on or off Rear View
Camera* automatically
Calling up maintenance ser-
vice display
Switching on or off radar
sensors*
Ending a call or rejecting an in-
coming call
Switching on or off Blind Spot
Assist*
Checking engine oil level*

307 Control systems
Instrument cluster control system
Switching radar sensors* on/off
If your vehicle is equipped with DISTRONIC
Plus*, BAS Plus*, or Park Assist* it is
equipped with a radar sensor system
which you can switch on and off.
When travelling in Canada in a vehicle not
registered in Canada, you must switch off
the radar sensor system. Canadian law
does not permit the use of the radar sensor
system for vehicles from outside of Cana-
da. When you switch off the radar sensor
system, the following functions are deacti-
vated:

BAS Plus* (
page 70)


PRE-SAFE
® Brake* (
page 77)


DISTRONIC Plus* (
page 451)


Park Assist* (
page 476)


Advanced Parking Guidance*
(page 481)


Blind Spot Assist* (
page 495)

Press ( or & to select the “Set-
tings” menu.

Press % or $ to select the “Ra-
dar Sensors” function.

Press #.

Press # again if you would like to
change the current status.
Depending on the previous status, the
radar sensors will be switched on or
off.
i
USA only:
This device has been approved by the FCC as a
“Vehicular Radar System”. The radar sensor is
intended for use in an automotive radar system
only. Removal, tampering, or altering of the de-
vice will void any warranties, and is not permitted
by the FCC. Do not tamper with, alter, or use in
any non-approved way.
Any unauthorized modification to this device
could void the user’s authority to operate the
equipment.
i
Canada only:
This device complies with RSS-210 of Industry
Canada. Operation is subject to the following
two conditions:
(1) This device may not cause interference, and
(2) this device must accept any interference re-
ceived, including interference that may
cause undesired operation of the device.
Removal, tampering, or altering of the device will
void any warranties, and is not permitted. Do not
tamper with, alter, or use in any non-approved
way.
Any unauthorized modification to this device
could void the user’s authority to operate the
equipment.
i
The selected status of the radar sensors re-
mains stored in memory even if the engine is
turned off and restarted.
i
The following message appears in the multi-
function display if the radar sensors are
switched off and you attempt to activate DIS-
TRONIC Plus*, Park Assist* or PRE-SAFE
®
Brake*:
“Radar Sensors
(See Oper. Manual)
Disabled”

409 Controls in detail
Windshield wipers
Intermittent wiping
Only switch on intermittent wiping under
wet weather conditions or in the presence
of precipitation.

Turn the combination switch to posi-
tion 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 (
page 408)
to the resistance point.
The windshield wipers wipe one time
without washer fluid.
Wiping with windshield washer fluid
Press the combination switch in the di-
rection of arrow2 (
page 408) 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 580).
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 on an inter-
mittent setting when the vehicle is taken to an
automatic car wash or during windshield clean-
ing. 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 transmission is set to drive
positionD or reverse gearR
or


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