2008 MERCEDES-BENZ S-Class brake

466 Controls in detailDriving systemsThe 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 Plus will switch off, and the
message:
“DISTRONIC PLUS
Currently Unavailable
See Oper. Manual”
appears in the multifunction display.
For cleaning and care of the
DISTRONIC Plus sensor, see “Cleaning the
DISTRONIC Plus*/ PRE-SAFE
® Brake*
system sensors (USA only)” (page 619).Another cause might be that the radar sen-
sors have been manually switched off in
the instrument cluster control system.
Please verify that the radar sensors are
switched on (
page 307).Turns and bends
In turns or bends, DISTRONIC Plus 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.
Warning!
G
DISTRONIC Plus should not be used in
snowy or icy road conditions.
i
If the message:
“DISTRONIC PLUS
Currently Unavailable
See Oper. Manual”
disappears during driving and the last speed
stored flashes for approximately 5 seconds, the
dirt (e.g. slush) has dissolved; DISTRONIC Plus is
again available.

468 Controls in detailDriving systemsObstacles and stationary vehicles
DISTRONIC Plus does not brake for obsta-
cles or stationary vehicles. If, for example,
the vehicle detected in front of you chang-
es lanes to bypass an obstacle or station-
ary vehicle in front of it, DISTRONIC Plus
will not brake for the obstacle or stationary
vehicle.Cross-traffic
DISTRONIC Plus may inadvertently detect
crossing vehicles. If you switch on DIS-
TRONIC Plus, for example, at a traffic light
with cross-traffic, the vehicle may sudden-
ly start to drive off.
Airmatic
Airmatic automatically selects the opti-
mum suspension tuning and ride height for
your vehicle.
Airmatic consists of two components:

Level control system


Adaptive Damping System (ADS)
The ADS automatically selects the opti-
mum damping for the respective driv-
ing conditions. At the same time the
suspension is set to either sporty or
comfort.

473 Controls in detail
Driving systems
The Parktronic system 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.
The Parktronic system is automatically ac-
tivated when you switch on the ignition, re-
lease the electronic parking brake or start
the engine and engage drive positionD, re-
verse gearR or neutral positionN.The Parktronic system deactivates at
speeds over approximately 11 mph
(18 km/h). At lower speeds the Parktronic
system turns on again.
The Parktronic system also deactivates
when you set the automatic transmission
to park positionP or secure the vehicle in
place with the electronic 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*)Range of the sensors!
The operational function of the Parktronic
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 Parktronic may not function properly,
see “Cleaning the Parktronic* system sensors”
(
page 619).
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.
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 619).

474 Controls in detailDriving systemsFront 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.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, Parktronic is ready to measure.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)

477 Controls in detail
Driving systems
Park Assist is an electronic parking aid
with radar sensors that helps you while
parking.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)
It visually and audibly indicates the relative
distance between the vehicle and an ob-
stacle.
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.
!
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 driving systems sensors”
(
page 620).
!
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 480) or switch off the radar sen-
sors (
page 307) to prevent possible malfunc-
tion.

478 Controls in detailDriving systemsPark Assist is automatically activated
when the engine is running and the trans-
mission is in drive position D, reverse
gearR or neutral positionN.
The Park Assist system deactivates at
speeds over approximately 10 mph
(16 km/h). At lower speeds the Parktronic
system turns on again.
Park Assist is also switched off when you
set the automatic transmission to P or
switch off the engine.
While the transmission is in neutral
positionN, Park Assist is switched off if
you secure the vehicle in place with the
electronic 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.Range of the sensors
The sensors of the Park Assist system are
integrated in the front and rear bumpers.
Make sure that the bumpers are clear of
dirt, ice and slush in the area of the sen-
sors, as otherwise, Park Assist may not
function properly, see “Cleaning the driv-
ing systems sensors” (
page 620).

479 Controls in detail
Driving systems
Front sensors
Rear sensorsWarning 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.i
Due to the sensors’ broad detection range,
it is possible that Park Assist also detects the fol-
lowing obstacles and issues a warning:


obstacles in the ground, e.g. sewer canal
covers, rails, bumps in the road or gutters


obstacles moving upward quickly, e.g. rolling
garage doors
Center
approx. 40 in (100 cm)
Corners
approx. 24 in (60 cm)
Center
approx. 50 in (125 cm)
Corners
approx. 24 in (60 cm)
!
While parking, pay particular attention to ob-
jects over or underneath the sensors, e.g. flower
boxes, an elevated crossbar or a trailer tow
hitch. Park Assist does not detect such nearby
objects. You could otherwise damage the vehicle
or the objects.
Gear selector
lever position
Warning indicator
D
Front area activated
R
Front and rear area
activated
N
With the electronic
parking brake engaged:
neither activated.
With the electronic
parking brake released:
front and rear area acti-
vated.
P
Neither activated

480 Controls in detailDriving systems

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


Rear area:
As soon as the first red segment lights
up, you will hear an intermittent warn-
ing tone for approximately two sec-
onds. Once the second red segment
lights up, you will hear a continuous
warning tone. You have reached the
minimum distance.Collision 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
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.
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.