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259 Driving systems
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cluster displayPractical hints Car care Index Driving with Distronic activated
With the electronic key in starter switch position 2, the
distance warning lamp l in the speedometer dial comes
on and goes out with the engine running.
If the distance sensor detects a slower vehicle moving in
front, your vehicle speed will be reduced by
deceleration and braking of up to 20% of the vehicle
braking capacity, so that you follow the vehicle ahead at
the preset distance, see page 265. Segments in the
speedometer illuminate to indicate the speed range from the speed of the vehicle in front up to your
vehicle’s selected speed. See also page 266 for notes on
the multifunction displays.
Wa r n i n g !
Distronic brakes (up to 20% of vehicle braking
power) the vehicle to restore the preset distance or
to maintain the speed. The brake pedal is
automatically retracted as this happens.Keep driver’s foot area clear at all times, including
the area under the brake pedal. Objects 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.
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The distance warning sound continues until the driver
activates the brake pedal, or the preset distance is
obtained. As soon as the preset distance is obtained, the
distance warning lamp goes out.Caution!
If the driver’s foot is not fully removed from the
accelerator pedal, the Distronic control system will be
overridden and it will not regulate the preset vehicle
speed and following distance. The vehicle speed and
following distance is determined only by the accelerator
pedal position.
Distronic works on steep uphill and downhill gradients
by downshifting gears and applying the brakes to
maintain the speed selected by the driver. The
transmission will upshift again once the gradient evens
out.
The speed can be increased (e.g. for passing) by using
the accelerator. After the accelerator is released, the
previously set speed will be resumed automatically.
Distronic is deactivated if a vehicle in front causes your
vehicle to slow down to less than approx. 25 mph
(Canada: 30 km/h). A signal sounds and the message
“DTR OFF” appears for 5 seconds in the multifunction
display.
Wa r n i n g !
A continuous warning sounds and the distance
warning lamp 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 vehicle in front of you. The warning
sound is intended as a final caution that you have
not interceded with your own braking inputs to
avoid a potentially dangerous 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 an impact being avoided.Tailgating increases the risk of an accident.
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261 Driving systems
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cluster displayPractical hints Car care Index Additional driving hints
Important!
When starting the engine, Distronic goes through an
initialization and self-test phase.
The most likely cause for a malfunctioning system is
caused by 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 – CLEAN SENSOR!” appears in
the multifunction display.
For cleaning and care of the Distronic sensor see
page 378.
The following are some sample situations which may
influence the functions of Distronic.
Wa r n i n g !
Distronic works to maintain the speed selected by
the driver unless a moving obstacle proceeding
directly ahead of it in the same travel direction is
detected (e.g. following another vehicle ahead at a
distance 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, then your
vehicle could accelerate to the previously
selected speed.Distronic regulates only the distance between your
vehicle and those directly ahead, but does not
register stationary objects in the roadway, e.g.:
• a stopped vehicle in a traffic jam.
• a disabled vehicle.
• an oncoming vehicle.
The driver must always be on the alert and observe
all traffic and intercede with steering and braking
inputs as necessary.Wa r n i n g !
Distronic should not be used in snowy or icy road
conditions.
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262 Driving systems
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Traveling through turns or bends in the roadway may
result in Distronic detecting a moving vehicle traveling
in front but not in your lane of travel, causing your
vehicle to brake late or unexpectedly. You must be
prepared to intercede with accelerator or brake
application as necessary.The Distronic system’s detection zone is relatively
narrow at the start and becomes broader as it senses
further from the vehicle. Thus, Distronic may not
recognize another vehicle coming into your path close
to the front of your vehicle. You must be prepared to
intercede with braking or steering as necessary.
A vehicle not traveling directly in front of you could
cause detection problems, the actual distance to that
vehicle really being much shorter.
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263 Driving systems
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cluster displayPractical hints Car care Index A vehicle changing lanes at close range is only
recognized when entering the area scanned by
Distronic. You must apply the service brakes to gain
sufficient distance to the vehicle ahead.A narrow vehicle (e.g. a motorcycle) is only recognized
when entering the area scanned by Distronic. You must
apply the service brakes to gain sufficient distance to
the vehicle ahead.
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264 Driving systems
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Distance notification function
Even if Distronic is deactivated, the distance to the
vehicle ahead continues to be measured, see page 266
for multifunction display.
The Distronic lamp in the speedometer dial illuminates
to advise the driver of a situation which under normal
braking conditions and dry surfaces should have been
addressed by the driver.
The distance notification function can be activated
separately, see page 265. It operates when driving at
speeds above approx. 25 mph (Canada: 30 km/h).
When recognizing a stationary obstacle or a slower
vehicle moving in the vehicle’s path and the danger of a
collision exists, the distance warning lamp in the
speedometer dial lights up and simultaneously a
continuous warning sounds.
Note:
Model CL 55 AMG only:
Distance notification function is deactivated if the
vehicle speed exceeds approximately 160 mph
(260 km/h).Important!
With the Distronic switched off, only the distance
notification function operates, meaning the vehicle does
not slow down.
Important!
Complex driving situations are not always fully
recognized by Distronic, which could result in wrong or
missing distance warnings.
See page 261 for additional driving hints.
Wa r n i n g !
If the distance warning lamp in the speedometer
dial lights up while driving and a continuous
warning sounds, immediate attention on the part of
the driver is required.As required by the traffic situation, apply the
service brakes and navigate around a possible
obstacle. However, do not drive by relying on the
distance notification function as that will result in
an emergency braking application which,
especially depending on road surface conditions
and driver reaction, will not always be able to avoid
a collision.
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265 Driving systems
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data Instruments
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cluster displayPractical hints Car care Index Distronic settings
1Switch – for distance notification function
2Thumbwheel – for setting distance
Distronic provides a safe following distance range to the
vehicle in front. The medium setting is noticeable by a
detent in the center position of the thumbwheel (2).
If you want to:
•Increase distance – turn thumbwheel (2)
towards¯.•Decrease distance – turn thumbwheel (2)
towards®.
To switch the distance notification function on or off:
To switch on – press upper half of switch (1).
The indicator lamp in the switch lights up.
To switch off – press lower half of the switch (1).
The indicator lamp in the switch goes out.
For distance notification function see page 264.
Notes:
With the distance notification function activated, you
will still be advised by a continuous audible warning if a
potential emergency braking circumstance has been
detected, even if Distronic has been deactivated.
The last selected notification function mode (on/off) will
be stored in memory, even when removing the
electronic key from the starter switch.
Wa r n i n 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 recommendations for
safe following distance.
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266 Driving systems
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Multifunction displays1Distronic is deactivated. The actual distance (5) and
the should-be distance (6) to the vehicle ahead (4)
are displayed.
2Distronic is activated. The display shows the
selected speed for approx. 5 seconds.
3Distronic is activated. The message “DTR OFF”
appears for approx. 5 seconds when Distronic is
being deactivated.
4Vehicle ahead.
Only appears if a vehicle is detected ahead.
5Actual distance to vehicle ahead.
6Should-be distance to vehicle ahead (as calculated
by Distronic).
7Own vehicle.
To call up Distronic display:
Press button è or ÿ on the multifunction
steering wheel repeatedly until the display (1 or 3)
appears.
4
5
67
P54.30-3759-27
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