2008 MERCEDES-BENZ SL55AMG ESP

215 Controls in detail
Driving systems
1Setting current or higher speed
2Setting current or lower speed
3Canceling the cruise control
4Activating the cruise control or resum-
ing to last set speedActivating cruise control
You can activate the cruise control when
the vehicle speed is above
20 mph (30 km/h).
In the following cases you cannot activate
the cruise control:

when you brake

when you have set the parking brake

when the gear selector lever is set to
position P, R, or N

when the ESP® is switched off
Setting current speed
Accelerate or decelerate to the desired
speed.
Briefly lift the cruise control lever in
direction of arrow1 or depress in
direction of arrow2.
The current speed is set.
Remove your foot from the accelerator
pedal.
The cruise control is activated.
The currently set speed appears in the
status indicator of the multifunction
display:

USA only:
CRUISE XXX MPH

Canada only:
Ñ
XXX Km/h
Warning!G
The cruise control brakes automatically so
that the set speed is not exceeded.
Keep in mind that the cruise control is a con-
venience system designed to assist the driv-
er during vehicle operation. The driver is and
must always remain responsible for the ve-
hicle’s speed and for safe brake operation.
iThe vehicle speed displayed in the speedom-
eter can briefly vary from the speed setting for
the cruise control system.
iOn uphill grades, the cruise control may not
be able to maintain the set speed. Once the
grade eases, the set speed will be resumed.
On downhill grades, the cruise control maintains
the set speed by braking with the vehicle’s brake
system. In addition, on longer downhill grades
the automatic transmission will downshift auto-
matically.

216 Controls in detail
Driving systems
Canceling the cruise control
There are several ways to cancel the cruise
control:
Step on the brake pedal.
The cruise control is canceled. The last
set speed is stored for later use.
or
Briefly push the cruise control lever in
direction of arrow3.
The cruise control is canceled. The last
set speed is stored for later use.
iThe last stored speed is canceled when you
turn off the engine.
iThe cruise control switches off auto-
matically when

you step on the brake pedal

you depress the parking brake pedal
The cruise control also switches off auto-
matically when

the vehicle speed is below
20 mph (30 km/h) (
page 214)

the ESP® is in operation or switched off with
the ESP® switch (page 93)

you move the gear selector lever to
positionN while driving
An acoustic warning sounds and the message
CC Off appears in the multifunction display for
approximately 5 seconds.
!Moving the gear selector lever to positionN
while driving cancels the cruise control.
However, the gear selector lever should not be
moved to positionN while driving except to
coast when the vehicle is in danger of skidding
(e.g. on icy roads).
iDepressing the accelerator pedal does not
deactivate the cruise control. After brief acceler-
ation (e.g. for passing), the cruise control will re-
sume the last speed set.

218 Controls in detail
Driving systems
Distronic*
When activated, the Distronic adaptive
cruise control system increases the driving
convenience afforded by the cruise control
while traveling on expressways and other
major roadways.

If the Distronic distance sensor detects
a slower moving vehicle directly ahead,
your vehicle’s speed will be reduced so
that you follow that vehicle at the pre-
set following distance.

If there is no vehicle directly ahead of
you, Distronic will function in the same
way as standard cruise control
(
page 214).
Warning!G
Distronic adaptive cruise control is not a
substitute for active driving involvement. It
does not react to pedestrians or stationary
objects, recognize or predict the lane curva-
ture nor the movement of preceding
vehicles.
Distronic can only apply a maximum of 20%
of the vehicle’s braking power.
It is the driver’s responsibility at all times to
be attentive to the road, weather and traffic
conditions. In addition, the driver must pro-
vide the steering, braking and other driving
inputs necessary to remain in control of the
vehicle.
Warning!G
Distronic is a convenience system. Its speed
adjustment reduction capability is intended
to make cruise control more effective and
usable when traffic speeds vary. It is not
however, intended to, nor does it, replace
the need for extreme care.
The responsibility for the vehicle’s speed,
distance to the preceding vehicle and, most
importantly, brake operation to assure a
safe stopping distance, always remains with
the driver.
Warning!G
Distronic requires familiarity with its opera-
tional characteristics. We strongly recom-
mend that you review the following
information carefully before operating the
system.
Warning!G
Distronic cannot take street and traffic con-
ditions into account. Only use Distronic if
the road, weather and traffic conditions
make it advisable to travel at a constant
speed.

219 Controls in detail
Driving systems
Warning!G
Use of Distronic can be dangerous on slip-
pery roads. Rapid changes in tire traction
can result in wheel spin and loss of control.
Distronic does not act upon adverse sight
distance conditions. Do not use Distronic
during conditions of fog, heavy rain, snow or
sleet.
Warning!G
Distronic cannot take weather conditions
into account. Switch off Distronic or do not
switch it on if:

roads are slippery or covered with snow
or ice
The wheels could lose traction while
braking or accelerating and the vehicle
could skid.

the sensor is dirty or visibility is dimin-
ished due to snow, rain or fog for exam-
ple
The distance control system functional-
ity could be impaired.
Always pay attention to surrounding traffic
conditions even while Distronic is switched
on. Otherwise, you may not be able to recog-
nize dangerous situations until it is too late.
This could cause an accident in which you
and/or others could be injured.
Warning!G
Close attention to road and traffic condi-
tions is imperative at all times, regardless of
whether or not Distronic is activated.
Use of Distronic can be dangerous on wind-
ing roads or in heavy traffic because condi-
tions do not allow safe driving at a constant
speed.
Distronic will not react to stationary objects
on the roadway (e.g. a stopped vehicle in a
traffic jam or a disabled vehicle). Distronic
will also not respond to oncoming vehicles.


221 Controls in detail
Driving systems
If Distronic detects a vehicle directly
ahead, the Distronic indicator lamp E
in the speedometer dial comes on white.
If Distronic calculates that there is a dan-
ger of collision:

The distance warning lamp E in the
speedometer comes on red.

An intermittent warning sounds.
Immediately apply the brake to avoid a
collision.
Under no circumstances should the
driver await the intermittent warning
sound before braking. See the follow-
ing warning note.
The intermittent warning sound ceases
and the red distance warning
lampE goes out when the neces-
sary distance to the vehicle ahead is
established again.
Warning!G
An intermittent warning sounds and the
distance warning lamp (red) E in the
speedometer dial is illuminated if the
Distronic system calculates that the
distance to the vehicle ahead and your
vehicle’s current speed indicate that
Distronic will not be capable of slowing the
vehicle sufficiently to maintain the preset
following distance, which creates a danger
of a collision.
Immediately brake the vehicle to increase
the distance to the preceding vehicle. The
warning sound is intended as a final caution
that you have not interceded with your own
braking inputs to avoid a potentially danger-
ous situation. Do not wait for the operation
of the warning signal to intercede with your
own braking, as that will result in potentially
dangerous emergency braking which will
not always result in an impact being
avoided.
Tailgating increases the risk of an accident.
Warning!G
Distronic brakes your vehicle with a maxi-
mum deceleration of 6.5 ft/s2 (2 m/s2). This
corresponds to about 20% of the maximum
deceleration ability of your vehicle.
Distronic brakes the vehicle in an effort to
restore the preset distance or to maintain
the set speed.

223 Controls in detail
Driving systems
Cruise control lever
The Distronic system is operated by means
of the cruise control lever.
The cruise control lever is the uppermost
lever found on the left-hand side of the
steering column.
1Setting current or higher speed
2Setting current or lower speed
3Deactivate Distronic
4Activating Distronic or resuming at last
set speedActivating Distronic
You can activate Distronic when the vehi-
cle speed is between 20 mph (30 km/h)
and 110 mph (180 km/h).
When Distronic is activated, the left multi-
function display will show a message such
as
DTR 55 MPH.
If Distronic is not activated after the cruise
control lever is pulled, the left multifunc-
tion display will show the message
DTR --- MPH.
In the following cases you cannot activate
Distronic:

up to 2 minutes after starting the
engine

when you brake

when you have set the parking brake

when the gear selector lever is set to
positionP, R, or N.

when the ESP® is switched off1White Distronic indicator lamp E
2Set speed
iThe vehicle speed displayed in the speedom-
eter can briefly vary from the speed setting for
the Distronic.

225 Controls in detail
Driving systems
Setting to last stored speed
(“Resume” function)
Briefly pull the cruise control lever in
direction of arrow4 (
page 223).
Distronic resumes the last stored
speed or, if no speed is stored, it will
set and store the current speed.
Remove your foot from the accelerator
pedal.Deactivating Distronic
There are several ways to deactivate the
Distronic system:
Step on the brake pedal.
or
Briefly push the cruise control lever in
direction of arrow3 (
page 223).
Distronic will be deactivated. The last set
speed will be stored into memory.
The following message appears in the mul-
tifunction display for approximately
5 seconds:
DTR Off
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 caused an accident
and/or serious injury to you and others.
iThe last stored set speed is deleted when
the engine is turned off.
iDistronic deactivates automatically when

you depress the parking brake pedal

the vehicle speed is below
20 mph (30 km/h) (
page 223)

the ESP® is in operation or switched off with
the ESP® switch (page 93)

you move the gear selector lever into
positionN
An acoustic warning sounds and the
message
DTR Off appears in the multifunc-
tion display for approximately 5 seconds.
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.

227 Controls in detail
Driving systems
Driving with Distronic
This section describes a number of driving
situations where special precaution is
required on the part of the driver.
Be prepared to brake in such situations.
This 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
Oper. Manual
appears in the multifunction
display.
For cleaning and care of the Distronic sen-
sor, see “Cleaning the Distronic* system
sensor cover” (
page 336).
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 pre-
viously set 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.
iIf the message DISTRONIC Currently
Unavailable See Oper. Manual
disappears
from the multifunction display during driving, the
dirt (e.g. slush) has dissolved. Distronic is avail-
able again if you reactivate it (
page 223).