
244 Driving instructions
Te ch n ica l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index
Aquaplaning
Depending on the depth of the water layer on the road, 
aquaplaning may occur, even at low speeds and with 
new tires. Reduce vehicle speed, avoid track grooves in 
the road and apply brakes cautiously in the rain.
Tire traction
The safe speed on a wet, snow covered or icy road is 
always lower than on a dry road.
You should pay particular attention to the condition of 
the road whenever the outside temperatures are close to 
the freezing point.We recommend M+S rated radial-ply tires for the winter 
season for all four wheels to insure normal balanced 
handling characteristics. On packed snow, they can 
reduce your stopping distance as compared with 
summer tires. Stopping distance, however, is still 
considerably greater than when the road is not snow or 
ice covered.
Wa r n i n g !
If ice has formed on the road, tire traction will be 
substantially reduced. Under such weather 
conditions, drive, steer and brake with extreme 
caution. 

257 Driving systems
Te ch n ica l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index •For a more precise setting the speed can be 
increased in increments of 1 mph (Canada: 1 km/h) 
by brief ly pulling the control lever in direction (4).
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 will be determined only by the 
accelerator pedal position.Invalid attempts to activate
The multifunction display will show “–––” during 
invalid attempts to activate Distronic:
•below a speed of approx. 25 mph 
(Canada: 30 km/h),
•while the electronic stability program (ESP) is 
switched off – ESP warning lampv in 
speedometer dial is illuminated, see page 114, 
•by moving the distronic control lever in “RESUME” 
direction (4) when no speed is stored in memory,
•during the initialization and self-test phase after the 
engine is started – this can take up to 2 minutes,
•while depressing the service brake pedal,
•while the parking brake is set – check ;warning 
lamp (Canada: !) in instrument cluster, see 
page 114,
•with the gear selector lever in position “P”, “R” 
or “N” – check gear range indicator display in 
instrument cluster, see page 114.
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 u nder the brake pedal – you r 
foot could become caught. 

258 Driving systems
Te ch n ica l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index
Deactivation of Distronic
Briefly move the distronic control lever in “OFF” 
direction (3) – the stored speed remains in the memory 
until the electronic key in the starter switch is turned to 
position 1 or 0.
Distronic is also deactivated if:
•the service brake pedal is depressed,
•the parking brake is activated,
•the vehicle decelerates to less than approximately 
25 mph (Canada: 30 km/h), e.g. while maintaining 
the distance to the vehicle ahead.•the gear selector lever is moved to position “N”,
•the electronic stability program (ESP) is active,
•the electronic stability program (ESP) is switched off 
manually,
•Model CL 55 AMG only:
the vehicle speed exceeds approximately 160 mph 
(260 km/h).
Note:
A signal sounds and the message “DTR OFF” appears 
for 5 seconds in the multifunction display everytime 
Distronic is deactivated.
Wa r n i n g !
The Distronic switches off and releases the brakes 
when the vehicle decelerates below the minimum 
speed of 25 mph  (Canada: 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. 

259 Driving systems
Te ch n ica l
data Instruments 
and controlsOperationDrivingInstrument 
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  th e distance sensor detects a slower veh ic le 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 you r foot under th e brake pedal – you r 
foot could become caught. 

260 Driving systems
Te ch n ica l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index
The distance warning sound continues until the driver 
activates the brake pedal, or the preset distance is 
obtained. As soon as t he preset d ista nce is obta ined , th e 
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. 

263 Driving systems
Te ch n ica l
data Instruments 
and controlsOperationDrivingInstrument 
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. 

264 Driving systems
Te ch n ica l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index
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 dri ver reaction, w ill not always be able to avoi d 
a collision. 

268 Driving systems
Te ch n ica l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index
Brake assist system (BAS)
The BAS is designed to maximize the vehicle’s braking 
capability during emergency braking maneuvers by 
having maximum power boost applied to the brakes 
more quickly in emergency braking conditions than 
might otherwise be afforded solely by the driver’s 
braking style. This can help reduce braking distances 
over what ordinary driving and braking style might do. 
The BAS complements the antilock brake system (ABS).Applying the brakes very quickly results in maximum 
BA S  a ssistance.
To receive the benefit of the system you must apply 
continuous full braking power during the stopping 
sequence. Do not reduce brake pedal pressure.
Once the brake pedal is released, the BAS is deactivated.
If the BAS warning message is displayed, a malfunction 
has been detected in the system. The brake system 
functions in the usual manner, but without BAS.
With the ABS malfunctioning, the BAS is also switched 
off.
If a BAS warning message is displayed, have the BAS 
checked at your authorized Mercedes-Benz Center as 
soon as possible.
Wa r n i n g !
BAS cannot prevent the natural laws of physics 
from acting on the vehicle, nor can it increase 
braking efficiency beyond that afforded by the 
condition of the vehicle brakes and tires or the 
traction afforded. The BAS cannot prevent 
accidents, including those resulting from excessive 
speed in turns, following another vehicle too 
closely, or aquaplaning. Only a safe, attentive, and 
skillful driver can prevent accidents. The 
capabilities of a BAS equipped vehicle must never 
be exploited in a reckless or dangerous manner 
which could jeopardize the user’s safety or the 
safety of others.