brake MERCEDES-BENZ S550 2007 W221 Service Manual

392 Controls in detailDriving systemsStarting off
When the vehicle in front of you starts off:
Remove your foot from the brake
pedal.

Pull DISTRONIC Plus lever briefly in di-
rection of arrow4.
or

Briefly step on the accelerator pedal.
Your vehicle starts off and adapts its speed
to the vehicle in front of you.
Driving
If no vehicle is driving ahead of you, DIS-
TRONIC Plus functions like cruise control
(
page 380).
When DISTRONIC Plus detects that the ve-
hicle in front of you is driving more slowly,
it brakes the vehicle in order to keep the
distance specified by you.
When DISTRONIC Plus detects that the ve-
hicle in front of you is driving faster, the ve-
hicle accelerates up to the set speed.Stopping
When DISTRONIC Plus detects that the ve-
hicle in front of you is stopping, the vehicle
brakes until it also stops.
Warning!
G
When you step on the brake pedal, you
switch off DISTRONIC Plus except when the
vehicle is at a standstill. DISTRONIC Plus will
no longer brake your vehicle. You are always
responsible for maintaining a distance from
other vehicles, observing road speeds and
braking well in advance.Warning!
G
DISTRONIC Plus’s braking effect is canceled
and the vehicle can start to roll if

DISTRONIC Plus is switched off using
the DISTRONIC Plus lever


you accelerate


the system or the power supply is mal-
functioning, e.g. due to battery failure


the electrical components in the engine
compartment or the fuses have been
manipulated


the battery is disconnected
Warning!
G
Never get out of the vehicle while DISTRON-
IC Plus is switched on!
DISTRONIC Plus must never be operated or
switched off by passengers or from outside
the vehicle.
DISTRONIC Plus is not a substitute for the
electric parking brake and may not be used
for parking.
When you get out of the vehicle or switch off
the engine, deactivate DISTRONIC Plus and
secure the vehicle from rolling away by en-
gaging the electric parking brake.

393 Controls in detail
Driving systems
Once DISTRONIC Plus has stopped your
vehicle and it is at a standstill, it remains
stationary; the brake pedal does not need
to be depressed.
Setting the current speed
Accelerate or decelerate to the desired
speed.

Briefly lift the DISTRONIC Plus lever in
the direction of arrow1 or depress in
the direction of arrow2.
DISTRONIC Plus is activated and the
current speed is set.

Remove your foot from the accelerator
pedal.Setting a higher speed
You can increase the set speed in two stag-
es.
Adjustment in 1 mph (Canada: 1 km/h)
increments

Briefly lift the DISTRONIC Plus lever to
the resistance point in direction of
arrow1 (
page 381).

Release the DISTRONIC Plus lever.
The vehicle speed increases in incre-
ments of 1 mph (Canada: 1 km / h).
Adjustment in 5 mph
(Canada: 10 km/h) increments
i
After a short while, your vehicle is secured in
place by the electric parking brake so that the
operating brake can be relieved of load.
i
Depending on the following distance set us-
ing the distance setting switch on the DISTRON-
IC Plus lever, your vehicle will stop approx.
13.1 ft. (4 m) away from the vehicle in front of
you.
i
If you do not take your foot off of the accel-
erator completely, the following message will ap-
pear in the multifunction display:
DISTRONIC PLUS passive
The distance to a slower moving vehicle in front
of you will not be set. Your vehicle speed will
then be determined only by the accelerator ped-
al position.
i
The set speed value is increased in 1 mph
(Canada: 1 km/h) increments each time you lift
the DISTRONIC Plus lever to the resistance
point.
Warning!
G
You can increase the vehicle speed in 5 mph
(Canada 10 km/h) increments. When using
this feature, keep in mind that it may take a
brief moment until the vehicle has reached
the set speed.
Increase the vehicle speed to a value that
the prevailing road conditions permit. Other-
wise, sudden and unexpected acceleration
of the vehicle could cause an accident
and/or serious injury to you and others.i
The set value is increased in 5 mph
(Canada: 10 km/h) increments each time you lift
the DISTRONIC Plus lever past the resistance
point.


394 Controls in detailDriving systems
Briefly lift the DISTRONIC Plus lever
past the resistance point in direction of
arrow1 (
page 381).

Release the DISTRONIC Plus lever.
The vehicle speed increases in incre-
ments of 5 mph (Canada: 10 km / h).
Setting a lower speed
You can reduce the speed in two stages.
Adjustment in 1 mph (Canada: 1 km/h)
increments

Briefly press the DISTRONIC Plus lever
down to the resistance point in direc-
tion of arrow2 (
page 381).

Release the DISTRONIC Plus lever.
The vehicle speed decreases in incre-
ments of 1 mph (Canada: 1 km/h).
Adjustment in 5 mph
(Canada: 10 km/h) increments

Briefly press the DISTRONIC Plus lever
down past the resistance point in
direction of arrow2 (
page 381).

Release the DISTRONIC Plus lever.
The vehicle speed decreases in incre-
ments of 5 mph (Canada: 10 km/h).
i
The new speed is set and the vehicle will ac-
celerate. Keep in mind that it may take a brief
moment until the vehicle has reached the set
speed.
i
When you use the DISTRONIC Plus lever to
decelerate, the brake system will automatically
brake the vehicle if the engine’s braking power
does not brake the vehicle sufficiently.
i
The set value is decreased in 1 mph
(Canada: 1 km/h) increments each time you
press the DISTRONIC Plus lever down to the re-
sistance point.
Warning!
G
You can decrease the vehicle speed in
5 mph (Canada 10 km/h) increments. When
using this feature, keep in mind that it may
take a brief moment until the vehicle has
reached the set speed.
Decelerate the vehicle speed to a value that
the prevailing road conditions permit. Other-
wise, sudden and unexpected deceleration
of the vehicle could cause an accident
and/or serious injury to you and others.
i
The set value is decreased in 5 mph
(Canada: 10 km/h) increments each time you
press the DISTRONIC Plus lever down past the
resistance point.
i
The new speed is set and the vehicle will de-
celerate. Keep in mind that it may take a brief
moment until the vehicle has reached the set
speed.


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.

396 Controls in detailDriving systems
Setting the following distance in
DISTRONIC Plus
You can set the specified following dis-
tance for DISTRONIC Plus by varying the
time setting between 1.0 and 2.0 seconds.
Using this time setting and the current set
speed of your vehicle, DISTRONIC Plus cal-
culates and sets the required following dis-
tance to the vehicle ahead. The set
distance will be shown in the multifunction
display.The distance setting switch for the target
distance is located on the DISTRONIC Plus
lever.
1Distance setting switch for target dis-
tance
2To increase target distance
3To decrease target distance
Increasing distance
Increasing the distance setting causes
DISTRONIC Plus to maintain a greater fol-
lowing distance to the vehicle ahead.

Move distance setting switch 1 in di-
rection 2.
Warning!
G
DISTRONIC Plus switches off and releases
the brakes when the vehicle decelerates be-
low the minimum speed of 20 mph
(30 km / h) by operation of the system un-
less DISTRONIC Plus detects a vehicle di-
rectly ahead of you. At that time the driver
must apply the brakes in order to reduce ve-
hicle speed further or bring it to a stop.!
Setting the automatic transmission toN
while driving cancels the DISTRONIC Plus. How-
ever, the automatic transmission should not be
set toN while driving except to coast when the
vehicle is in danger of skidding (e.g. on icy
roads).
i
Depressing the accelerator pedal does not
deactivate DISTRONIC Plus. After brief accelera-
tion (e.g. for passing), DISTRONIC Plus will re-
sume the last speed set.
Warning!
G
It is up to the driver to exercise discretion to
select the appropriate setting given road
conditions, traffic, driver’s preferred driving
style and applicable laws and driving recom-
mendations for safe following distance.

397 Controls in detail
Driving systems
Decreasing distance
Decreasing the distance setting causes
DISTRONIC Plus to maintain a shorter fol-
lowing distance to the vehicle ahead.
Move distance setting switch 1 in di-
rection 3.
Distance warning function
When DISTRONIC Plus is deactivated, this
function will continue to warn you when
recognizing a slower vehicle moving in
your vehicle’s path or a stationary object in
your vehicle’s path and the danger of a col-
lision exists:


The distance warning lampl in the
instrument cluster comes on.


An intermittent warning sounds.
If these warnings are issued, you must
brake manually to maintain a safe distance
and avoid a collision with the vehicle or
stationary object ahead.When pressing the brake pedal, the warn-
ing sound stops. The warning sound also
stops when the distance to the vehicle
ahead is sufficient again without applying
the brake pedal. In this case the distance
warning lampl also goes out.Activating and deactivating
The distance warning function can be acti-
vated or deactivated using the instrument
cluster control system (
page 252).
After the function has been activated,
: appears on the left-hand side of the
multifunction display.
Driving with DISTRONIC Plus
This section describes a number of driving
situations where special precaution is re-
quired on the part of the driver. Be pre-
pared to brake in such situations which will
deactivate the DISTRONIC Plus system.
Warning!
G
If the DISTRONIC Plus warning lampl in
the instrument cluster comes on while driv-
ing and/or an intermittent warning sounds,
immediate attention on the part of the driver
is required. As required by the traffic situa-
tion, apply the brakes and navigate around a
possible obstacle. However, do not drive by
relying on the distance warning function, as
this will result in an emergency braking ap-
plication. Especially depending on road sur-
face conditions and driver reaction, this will
not always enable you to avoid a collision.
Warning!
G
DISTRONIC Plus works to maintain the
speed selected by the driver unless a mov-
ing obstacle proceeding directly ahead of it
in the same travel direction is detected (e.g.
following another vehicle ahead of you at a
distance set by DISTRONIC Plus).


399 Controls in detail
Driving systems
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.Offset driving
A vehicle traveling in your lane but offset
from your direct line of travel may not be
detected by DISTRONIC Plus. There will be
insufficient distance to the vehicle ahead.Lane changing
DISTRONIC Plus has not yet detected the
vehicle changing lanes. There will be insuf-
ficient distance to the lane-changing vehi-
cle.

400 Controls in detailDriving systemsNarrow vehicles
Because of their narrow profile, the vehi-
cles traveling near the outer edge of the
lane have not yet been detected by
DISTRONIC Plus. There will be insufficient
distance to the vehicles ahead.Obstacles 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.

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)