brake MERCEDES-BENZ M-CLASS 2007 Service Manual

258 Controls in detailDriving systemsSetting a lower speed
You can reduce the set speed in two ways.
Adjustment in 1 mph (Canada: 1 km/h)
increments
Briefly press the cruise control lever
down to the resistance point in direc-
tion of arrow2 (
page 255).

Release the cruise control 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 cruise control lever
down past the resistance point in direc-
tion of arrow2 (
page 255).

Release the cruise control lever.
The vehicle set speed decreases in
increments of 5 mph
(Canada: 10 km/h).
i
When you use the cruise control 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 cruise control lever down to the resis-
tance 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 speed value is decreased in 5 mph
(Canada: 10 km/h) increments each time you
press the cruise control lever down past the
resistance point.
i
The new speed is set and the vehicle will
decelerate. Keep in mind that it may take a brief
moment until the vehicle has reached the set
speed.
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259 Controls in detail
Driving systems
Setting to last stored speed
(“Resume” function)
Briefly pull the cruise control lever in
direction of arrow4 (
page 255).
The Distronic resumes to the last set
speed.

Remove your foot from the accelerator
pedal.
The last set speed or, if no speed is stored,
the current set speed appears in the
multifunction display for approximately
5seconds.Deactivating Distronic
There are several ways to deactivate the
Distronic system:

Step on the brake pedal.
or

Briefly tip the cruise control lever in
direction of arrow3 (
page 256).
Distronic will be deactivated. The last set
speed will be stored in memory.
Warning!
G
The set speed stored in memory should only
be set again if prevailing road conditions
permit. Possible acceleration or decelera-
tion differences arising from returning to the
preset speed could cause an accident
and/or serious injury to you and others.
i
The following message appears in the multi-
function display for approximately 5 seconds:
DISTRONIC Off
.
The last stored set speed is deleted when the
engine is turned off.
i
The Distronic switches off automatically
when


you step on the brake pedal


you depress the parking brake pedal
In this case, the Distronic speed segments in the
speedometer (
page 253) will go out.


the vehicle speed falls below 20 mph
(30 km/h)


the ESP
® is in operation


the ESP
® is switched off with the ESP
®
switch (
page 99)


the ESP
® has switched off due to a
malfunction (
page 419)


you set the automatic transmission toN
while driving
The Distronic speed segments in the
speedometer (
page 253) will go out and an
acoustic warning will sound.
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260 Controls in detailDriving systems
Setting the following distance in
Distronic
You can set the specified following
distance for Distronic by varying the time
setting between 1.0 and 2.0 seconds. Us-
ing this time setting and the current speed
of your vehicle, Distronic calculates and
sets the required following distance to the
preceding vehicle. The set distance will be
shown in the multifunction display
(page 255).
The distance setting switch for the time
setting is located on the cruise control le-
ver on the left-hand side of the steering
column.1Distance setting switch
2To decrease distance
3To increase distance
Increasing distance
Increasing the distance setting tells
Distronic to maintain a greater following
distance to the preceding vehicle.

Turn distance setting switch1 in
direction of arrow3.
Warning!
G
Distronic switches off and releases the
brakes when the vehicle decelerates below
the minimum speed of 20 mph (30 km/h)
by operation of the system. At that time the
driver must apply the brakes in order to
reduce vehicle speed further or bring it to a
stop.!
Setting the automatic transmission toN
while driving cancels the Distronic. However, 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 the Distronic. After a brief accelera-
tion (e.g. for passing), the Distronic will resume
the last set speed.
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.
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261 Controls in detail
Driving systems
Decreasing distance
Decreasing the distance setting tells
Distronic to maintain a smaller following
distance to the preceding vehicle.
Turn distance setting switch1 in
direction of arrow2.
Driving with Distronic
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. Braking
will deactivate the Distronic system.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 408).
Warning!
G
Distronic works to maintain the speed se-
lected by the driver unless a moving obsta-
cle proceeding directly ahead of it in the
same travel direction is detected (e.g. fol-
lowing another vehicle ahead of you at your
set distance).
This means that:

Your vehicle can pass another vehicle
after you have changed lanes.


While in a sharp turn or if the preceding
vehicle is in a sharp turn, Distronic could
lose sight of the preceding vehicle. Your
vehicle could then accelerate to the
previously selected speed.
Distronic regulates only the distance be-
tween your vehicle and those directly ahead
of it, but does not register stationary objects
in the road, e.g.:


a stopped vehicle in a traffic jam


a disabled vehicle


an oncoming vehicle
The driver must always be alert, observe all
traffic and intercede as required by means
of steering or braking the vehicle.
Warning!
G
Distronic should not be used in snowy or icy
road conditions.
i
If the message
DISTRONIC available
again
appears during driving the dirt (e.g.
slush) has dissolved; Distronic works again, if
you reactivate it (
page 256).
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262 Controls in detailDriving systemsTurns 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.Lane changing
Distronic has not yet detected the vehicle
changing lanes. There will be insufficient
distance to the lane-changing vehicle.
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263 Controls in detail
Driving systems
Narrow vehicles
Because of their narrow profile, the vehi-
cles traveling near the outer edges of the
lane have not yet been detected by
Distronic. There will be insufficient
distance to the vehicles ahead.
Distance warning function*
When Distronic* is deactivated, this
function will continue to warn you when
recognizing a stationary obstacle or a
slower vehicle moving in your vehicle’s
path and the danger of a collision exists:

The distance warning lampl in the
instrument cluster comes on.


An intermittent warning will sound if
necessary.
If these warnings are issued, you must
brake manually to maintain a safe distance
and avoid a collision with the preceding
vehicle.
When pressing the brake pedal, the warn-
ing sound ceases. The warning sound will
also cease when the distance to the
preceding vehicle is sufficient again with-
out applying the brakes. In this case, the
distance warning lamp will also go out.

Switch on the distance warning
function in the control system
(page 179).
Warning!
G
If the distance warning lampl in the in-
strument cluster comes on while driving
and/or an intermittent warning sounds,
immediate attention on the part of the driver
is required. As required by the traffic
situation, 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 application. This will not always
enable you to avoid a collision, especially
when traveling on varying road surface
conditions and with varying driver reaction.
Complex driving situations are not always
fully recognized by the distance warning
function. This could result in wrong or miss-
ing distance warnings.
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264 Controls in detailDriving systemsDownhill Speed Regulation (DSR)For more information, see “Off-road driv-
ing” (
page 333).
The DSR is an aid for driving downhill. DSR
regulates your vehicle’s speed when driv-
ing downhill to the value set in the control
system (page 179). The steeper the
downhill gradient is, the greater the brake
application. On flat road surfaces, DSR
brakes only slightly or not at all.
DSR regulates the vehicle’s speed in auto-
matic transmission positionsD, orR.
You can drive slower or faster than the set
speed at any time by braking the vehicle or
depressing the accelerator pedal.
Warning!
G
Downhill Speed Regulation is a convenience
system designed to assist the driver during
vehicle operation. The system must be set
to be appropriate for the topographical and
weather conditions encountered which can
change quickly. The driver is and must
remain at all times responsible for the vehi-
cle speed and for safe brake operation.
Depending on the programmed speed
(page 179), actual vehicle speed and gra-
dient, switching on the DSR while driving
can cause the vehicle to slow down rapidly
and you may hear a sound which is caused
by the activation of the vehicle’s brake sys-
tem through the DSR. Sudden and unex-
pected deceleration can result in loss of
vehicle control, causing an accident and/or
serious personal injury to you and others.
Do not switch on the DSR in a circumstance
where rapid deceleration could result in a
loss of vehicle control.
i
In addition, make use of the engine’s braking
effect by shifting the automatic transmission
into a lower gear.
i
Whenever DSR is switched on, DSR will use
the programmed default speed to regulate the
vehicle’s speed. The default speed programmed
at the factory is 4 mph (Canada: 6 km / h). The
default speed can be reprogrammed using the
control system (
page 179). The next time DSR
is switched on, DSR will use the newly pro-
grammed default speed to regulate the vehicle’s
speed.
Once DSR is switched on, you can adjust the set
speed using the cruise control lever
(
page 255). Keep in mind that adjusting the
set speed using the cruise control lever with DSR
switched on will not change the programmed
default speed. If DSR is switched off and then
switched on again, DSR will use the programmed
default speed.
Depending on the road surface and level of
downhill grade, the DSR may not be able to
maintain the set speed. To maintain the set
speed, apply the brakes if necessary.
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265 Controls in detail
Driving systems
Switching the Downhill Speed
Regulation on/off
The switch is located in the lower part of
the center console.
1DSR on/off
2Indicator lampSwitching Downhill Speed Regulation on

Press DSR switch1 (
page 265).
The indicator lamp2 comes on.
The message
DSR
and the set speed ap-
pear in the multifunction display.
For information on how to program the set
speed while driving, see “Adjusting Down-
hill Speed Regulation speed with DSR
switched on” (
page 266).
Warning!
G
If the accelerator pedal is depressed while
the Downhill Speed Regulation is activated,
the vehicle can drive faster than the pro-
grammed set speed. You should therefore
drive downhill with particular caution as it
could otherwise lead to an accident and/or
serious injury to you or others. Keep in mind
that as soon as you remove the foot from
the accelerator pedal with the DSR switched
on, the DSR will start regulating the vehicle’s
speed including use of brakes if required.
Depending on the programmed set speed,
actual vehicle speed and gradient, the DSR
can cause the vehicle to slow down rapidly.
Sudden and unexpected deceleration can
result in loss of vehicle control, causing an
accident and/or serious personal injury to
you and others.
i
The DSR can only be switched on if the vehi-
cle speed is below 18 mph (Canada: 30 km/h).
i
If the DSR is switched on at a speed above
18 mph (Canada: 30 km/h), the message
DSR
Max. speed 18 mph
(Canada:
30 km/h
) ap-
pears in the multifunction display.
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274 Controls in detailDriving systemsWhen the highway level is reached, indica-
tor lamp2 (
page 271) goes out. and
the following message appears in the mul-
tifunction display for 5 seconds:
Parktronic system*
i
The message can be cleared by pressing
theèÿk or buttonj on the
multifunction steering wheel.
i
The vehicle is lowered automatically to the
highway level if:


the vehicle speed is above 55 mph
(88 km/h)


the speed stays between 40 mph (64 km/h)
and 55 mph (88 km/h) for approximately
20 seconds
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,
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.
Warning!
G
Make sure no persons or animals are in the
area in which you are maneuvering. You
could otherwise injure them.

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275 Controls in detail
Driving systems
The Parktronic system is an electronic
parking aid and 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, orN
The 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 sur-
roundings of your vehicle with six sensors
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).
!
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.
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