2003 MERCEDES-BENZ SL500 Bra Js

171 Controls in detail
Driving systems
Distronic*
When activated, the Distronic adaptive
cruise control system increases the driving
convenience afforded by the cruise control
during travel on expressways and other
major roads.

If the Distronic distance sensor detects
a slower moving vehicle directly ahead,
your vehicle speed will be reduced so
that you follow that vehicle at a preset
distance.


If there is no vehicle directly ahead of
you, Distronic will function in the same
way as cruise control (
page 168).
Warning!
G
Distronic adaptive cruise control is no sub-
stitute for active driving involvement. It does
not react to stationary objects, nor recog-
nize or predict the curvature and lane layout
or the movement of vehicles ahead. Distron-
ic 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 road, weather and traffic con-
ditions and to provide the steering, braking
and other driving inputs necessary to retain
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 responsibili-
ty for the vehicle speed and the distance to
the vehicle ahead, including most impor-
tantly brake operation to assure safe stop-
ping distance, always rests with the driver.
Distronic cannot take street and traffic con-
ditions into account.
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.iFor operation in the USA only: This de-
vice complies with Part 15 of the
FCC Rules. Operation is subject to the
following two conditions:

This device may not cause harmful
interference, and


this device must accept any inter-
ference received, including interfer-
ence that may cause undesired
operation.
Any unauthorized modification to this
device could void the user’s authority
to operate the equipment.

173 Controls in detail
Driving systems
Distronic displays in the speedometer
dial
If Distronic detects a vehicle directly
ahead, the DTR indicator lamp
E
in the
speedometer dial lights up white.
If the distance to the vehicle ahead is too
small for the DTR to be able to maintain the
preset distance, the DTR warning lamp
E
in the speedometer lights up red.
If Distronic calculates that there is a dan-
ger of collision


the DTR warning lamp
E
in the
speedometer lights up red


an intermittent warning sounds

Immediately brake the vehicle to avoid
a collision.
Under no circumstances should the
driver await the intermittent warning
sound before braking. See warning
note to the right. The intermittent warning sound ceases
and the red DTR warning lamp
E

goes out when the necessary distance
to the vehicle ahead is again estab-
lished.
1Red DTR warning lamp
E
Warning!
G
An intermittent warning sounds and the
DTR warning lamp (red) in the speedometer
dial is illuminated if the Distronic system cal-
culates that the distance to the vehicle
ahead and your vehicle’s current speed indi-
cate 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 vehicle in front of you.
The warning sound is intended as a final cau-
tion that you have not interceded with your
own braking inputs to avoid a potentially
dangerous situation. Do not wait for the op-
eration 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 be-
ing avoided.
Tailgating increases the risk of an accident.

174 Controls in detailDriving systems
Distronic menu in the control system
In the Distronic menu you can read the cur-
rent settings for Distronic. What appears in
the left display field depends on whether
the Distronic is turned on or off.
Press button
è
or
ÿ
repeatedly
until you see one of the following dis-
plays.Distronic deactivated
When Distronic is deactivated you will see
the standard display in the left display
field.
1Vehicle ahead, if detected
2Actual distance to vehicle ahead
3Should-be distance to vehicle ahead
4Your vehicle
5Symbol for activated distance warning
function
Warning!
G
The Distronic brakes your vehicle with a
maximum of 6.5 ft/s
2 (2 m/s
2). This corre-
sponds to about 20% of the maximum decel-
eration ability of your vehicle.
Distronic brakes the vehicle in an effort to
restore the preset distance or to maintain
the speed. The brake pedal is automatically
applied as this happens which results in the
brake pedal moving.
Keep driver’s foot area clear at all times, in-
cluding the area under the brake pedal. Ob-
jects stored in this area may impair pedal
movement which could interfere with the
braking ability of the Distronic system.
Do not place your foot under the brake pedal
– your foot could become caught.

175 Controls in detail
Driving systems
Distronic activated
When Distronic is activated the DTR sym-
bol and the set speed are seen in the left
display.
1Symbol for activated Distronic
2Set speedCruise 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.
1Set current or higher speed
2Set current or lower speed
3Deactivate Distronic
4Resume at previously set speedActivating Distronic
You can activate Distronic if


you are driving over 25 mph
(Canada: 40 km/h)


ESP is activated (
page 70)
When Distronic is activated the speedome-
ter display will show a message such as
DTR60mph
.
If Distronic is deactivated, the speedome-
ter display will show the message
DTR --- mph
.
In the following cases you cannot activate
Distronic:


up to two minutes after starting the en-
gine


when you brake


if you have set the parking brake


if the gear selector lever is in
positionP, R or N.

178 Controls in detailDriving systemsDeactivating Distronic
There are several ways to deactivate the
Distronic system:
Briefly tip the cruise control lever in the
direction of arrow3 (
page 175).
or

Step on the brake pedal.
Distronic will be deactivated. The last
speed set will be stored into memory.Distronic deactivates automatically when


you set the parking brake


you drive slower than 25 mph
(Canada: 40 km/h)


ESP is active (
page 70) or you deac-
tivate ESP


You move the transmission selector le-
ver into positionN.
A signal will sound. The
DTR off
mes-
sage appears in the speedometer dis-
play for approximately five seconds.Setting the following distance in
Distronic
You can set the specified following for Dis-
tronic by varying the time setting between
1.0 and 2.0 seconds. Using this time set-
ting and the current speed of your vehicle,
Distronic calculates and sets the required
following distance to the vehicle ahead.
The set distance will be shown in the
speedometer display field.
The thumbwheel for making the time set-
ting is located on the lower section of the
center console.
iThe last stored speed is deleted when
you turn off the engine.
Warning!
G
Distronic switches off and releases the
brakes when the vehicle decelerates below
the minimum speed of 25 mph ( 40 km / h)
by operation of the system. At that time the
driver must apply the brakes in order to re-
duce vehicle speed further or bring it to a
stop.
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.

179 Controls in detail
Driving systems
1Distance warning function on/off
switch
2Thumbwheel for setting distance
Increasing distance
Increasing the distance setting tells Dis-
tronic to maintain a greater following dis-
tance to the vehicle ahead.
Turn thumbwheel2 towards
¯
.Decreasing distance
Decreasing the distance setting tells Dis-
tronic to maintain a smaller following dis-
tance to the vehicle ahead.

Turn thumbwheel2 towards
®
.Distance warning function
When Distronic is deactivated, this func-
tion will continue to warn you if you are fol-
lowing too close to the vehicle ahead:


The DTR warning lamp
E
lights up
red.


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 vehicle
ahead.

180 Controls in detailDriving systems
Activating
Press switch1.
The indicator lamp on the switch lights
up. A loudspeaker symbol appears in
the speedometer display (
page 174).
Deactivating

Press switch1.
The indicator lamp on the switch goes
out. No loudspeaker symbol appears in
the speedometer display.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. This will
deactivate the Distronic system.
Warning!
G
If the DTR warning lamp (red)
E
in the
speedometer dial lights up while driving
and/or an intermittent warning sounds, im-
mediate attention on the part of the driver is
required.
As required by the traffic situation, apply the
brakes and navigate around a possible ob-
stacle. However, do not drive by relying on
the distance warning function, as this will re-
sult in an emergency braking application.
Especially depending on road surface condi-
tions and driver reaction, this will not always
enable you to avoid a collision.
iComplex driving situations are not al-
ways fully recognized by Distronic. This
could result in wrong or missing dis-
tance warnings.

181 Controls in detail
Driving systems
The most likely cause for a malfunctioning
system is a dirty sensor (located behind
the hood grill), especially at times of snow
and ice or heavy rain. In such a case, Dis-
tronic will switch off, and the message DISTRONIC - CLEAR SENSOR!
appears in
the multifunction display.
For cleaning and care of the Distronic sen-
sor, see “Cleaning the Distronic* system
sensor cover” (
page 246).Turns 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.
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 a dis-
tance set by Distronic). This means that:

Your vehicle can pass another vehicle
after you change lanes.


While in a sharp turn or if the vehicle in
front is in a sharp turn, Distronic could
lose sight of a vehicle traveling in front
of it. 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 on the alert, ob-
serve all traffic and intercede as required by
steering or braking the vehicle.Warning!
G
Distronic should not be used in snowy or icy
road conditions.