
Drive on carefully. Have ABS checked imme-
diately at a qualified specialist workshop.
If ABS is malfunctioning, other systems will also
fail, including driving safety systems. Observe
the information relating to the !warning
lamp (
Ypage 196).
ABS regulates brake pressure in such a way that the wheels do not lock when you brake. This
allows you to continue steering the vehicle when
braking.
ABS works from a speed of about 5 mph
(8 km/h), regardless of road-surface conditions. ABS works on slippery surfaces, even when you
only brake gently.
The yellow !warning lamp in the instrument
cluster lights up when the ignition is switched
on. The lamp goes out when the engine starts
running.
Braking
If ABS intervenes when braking, you will feel a
pulsating in the brake pedal.
The pulsating brake pedal can be an indication
of hazardous road conditions and functions as a
reminder to take extra care while driving.
XIf ABS intervenes: continue to depress the
brake pedal with force until the braking sit-
uation is over.
XTo make a full brake application: depress
the brake pedal with full force.
ASR (acceleration skid control)
General notes
Important safety notes
Observe the important safety guidelines for the
driving safety system (Ypage 54).
ASR can neither reduce the risk of an accident
nor suspend the laws of physics if the driver
does not pay attention when pulling away or
accelerating. ASR is only an aid. Always adapt
your driving style to suit the prevailing road and
weather conditions.
If you activate or deactivate the all-wheel drive
in a vehicle with this option, ASR will be deacti- vated for the duration of the activation/deacti-
vation process. Vehicles without steering wheel buttons: if ASR
is malfunctioning, the
:indicator lamp lights
up while the engine is running and the engine
power may be reduced (
Ypage 196).
ASR significantly improves traction, i.e. the
transmission of power from the tires to the road surface, and thus increases the vehicle's driving
stability. If the driving wheels start to spin, ASR
brakes individual drive wheels and limits the
engine torque. ASR thus significantly assists you
when pulling away and accelerating, especially
on wet or slippery roads.
If traction on the road surface is not sufficient,
even ASR will not allow you to pull awa
y without
difficulty. The type of tires and total weight of the
vehicle as well as the gradient of the road also
play a crucial role.
If ASR intervenes, the dwarning lamp in the
instrument cluster flashes.
Activating/deactivating ASR
GWARNING
If deactivated, ASR will not attempt to stabi-
lize the vehicle during pulling away and accel- eration. There is an increased risk of skidding
and of an accident.
Only deactivate ASR in the situations descri-
bed in the following.
!If you deactivate ASR, ESP®will still inter-
vene to stabilize the vehicle. Frequent braking
automatically triggered by ESP
®can damage
the brake system.
For this reason, deactivate ASR only briefly
and when absolutely necessary.
When ESP®is intervening and the dwarning
lamp in the instrument cluster is flashing, leave
Driving safet ysystem s55
Safety
Z

ASR on. In this case, only depress the acceler-
ator pedal as far as required when pulling away.
XPress theàbutton.
If ASR is deactivated, the dwarning lamp
in the instrument cluster lights up.
ASR is automatically activated when the engine
is started.
It may be best to deactivate ASR briefly in the
following situations:
Rwhen using snow chains
Rin deep snow
Ron sand or gravel
If you deactivate ASR:
Rengine torque is not limited and the drive
wheels are able to spin. The spinning wheels
will then achieve a cutting effect for better
traction.
Rtraction control remains active through brake
intervention. If a drive wheel attains its tire
traction limit because one side of the road is
slippery, for example, that wheel is braked.
The traction is then increased in this situation.
Ractive brake intervention by ESP®to increase
driving stability remains active. The d
warning lamp in the instrument cluster
flashes when ESP
®is intervening.
BAS (Brake Assist System)
GWARNING
If BAS is malfunctioning, the braking distance
in an emergency braking situation is
increased. There is a risk of an accident.
In an emergency braking situation, depress
the brake pedal with full force. ABS prevents
the wheels from locking.
Vehicles without steering wheel buttons: if the
BAS driving safety system is malfunctioning,
the : warning lamp lights up while the
engine is running (
Ypage 196).
BAS operates in emergency braking situations.
If you depress the brake quickly, BAS automat-
ically increases the brake pressure, thereby
reducing the stopping distance.
The brakes will function as usual once you
release the brake pedal. BAS is deactivated.
EBD (electronic brake force distribu-
tion)
GWARNING
If EBD is malfunctioning, the rear wheels can
lock, e.g. under full braking. This increases the
risk of skidding and an accident.
You should therefore adapt your driving style
to the different handling characteristics. Have
the brake system checked at a qualified spe-
cialist workshop.
EBD monitors and controls the brake pressure
to the rear wheels. This enables EBD to improve
handling during braking.
Observe the information on warning and indica-
tor lamps (
Ypage 196).
ESP®(Electronic Stability Program)
Important safety notes
GWARNING
If ESP
®is malfunctioning it will not provide
any vehicle stabilization. There is an increased
risk of skidding or of an accident.
Exercise caution when continuing to drive.
Have ESP
®checked at a qualified specialist
workshop.
!Do not run the vehicle on a roller dynamom-
eter (e.g. for performance tests). If you must
operate the vehicle on a roller dynamometer,
please consult a qualified specialist workshop
in advance. You could otherwise damage the
drive train or the brake system.
If you activate or deactivate the all-wheel drive
in a vehicle with this option, ESP
®will be deac-
tivated for the duration of the activation/deac-
tivation process.
If ESP
®is malfunctioning, the hindicator
lamp lights up while the engine is running and
the engine power may be reduced
(
Ypage 195).
iOnly use wheels with the recommended tire
sizes. Only then will ESP®function properly.
56Driving safety systems
Safety

the battery main switch. You could otherwise
damage components of the electrical system.
You can use the battery isolating switch to dis-
connect the power supply to all your vehicle's
consumers. This will prevent uncontrolled bat-
tery discharge caused by off-load current con-
sumption.
If your vehicle is equipped with an auxiliary bat-
tery in the engine compartment, you will need to
disconnect both batteries. Only then is the elec- trical system fully disconnected from the power
supply.
iOnly switch the vehicle to de-energized
using the battery main switch if:
Rthe vehicle is stationary for a lengthy period
Rit is absolutely necessary
After the power supply has been activated,
you will need to reset the side windows
(
Ypage 73).
Switching off the power supply
Battery main switch to the left of the center con-
sole
XRemove the key from the ignition lock and
wait for at least five minutes.
XPress button ;in the direction of the arrow
and hold.
XPull connector :from the ground pin.
XPush connector :as far to the side as pos-
sible so that it cannot make contact with the
ground pin.
All starter battery consumers are disconnec-
ted from the power supply.
Switching on the power supply
XInsert the key into the ignition lock.
XPress connector :onto ground pin ;until
you feel it engage and the lock inhibitor is
released.
Connector :must be in full contact with
ground pin ;.
All consumers are reconnected to the DC
power supply.
Key positions
gTo insert and remove the key, lock the steer-
ing wheel
1To unlock the steering wheel, power supply
for some consumers (e.g. the radio)
2To switch on the ignition. Power supply for
all consumers, preglow and drive position
3To start the engine
On vehicles with a battery main switch, you must
first switch on the power supply (
Ypage 118).
iTo unlock the steering, move the steering
wheel slightly while turning the key to position
1 .
Driving119
Dr iving an d parking
Z

Cruise controlisdeactivated automatically
when:
Ryou apply the brakes
Ryouapply the parking brake and the c
indicator lamp inthe instrument cluster lights
up
Ryou are driving slower than 20 mph (30 km/h)
Ryou shift the automat ictransmission to neu-
tral position Nwhile the vehicle is inmotion
RESP®or ASR intervenes
Rthere isa malfunction inthe ESP®, ASR or ABS
system
Problems with cruise control
ProblemPossible causes/consequences and MSolutions
On vehicleswit h steering
wheel buttons, the
speed cannot beset
when cruise control is
activated.The displ ay shows a high-priority message. Thus a change in speed is
not possible.
XProceed as instructed by the message inthe display.
XDeactivate cruise control
COLLISION PREVENTION ASSIST
General notes
COLL ISION PREVENTION AS SISTcomprises the
dist ance warning function and adaptive Brake
Assist.
Distance warning function
Important safety notes
iNote the section on 'Important safety notes'
(Ypage 54).
GWAR NING
The distance warning function does not react:
Rto people or animals
Rto oncoming veh icles
Rto crossing traff ic
Rwhen cornering
The distance warning function may not give
warnings inall critical situations. There isa
risk of an acc ident.
Alwa ys pay careful attention to the traff icsit-
uation and beready to brake.
Alwa ys adapt your speed to suit the pre vailing
road and traff icconditions.
GWARNING
The distance warning function cannot always
clearly identify objects and co mplex traffic
situations.
In such cases, the distance warning function
may:
Rgive an unnecessary warning
Rnot give a warning
There isa risk of an accident.
Always pay careful attention to the traffic sit-
uation and donot rely solely on the distance
warning function.
Operation
The distance warning function can help you to
minimize the risk of a front-end collision with a
vehicle ahead or reduce the effects of such a
collision. If the distance warning function
detects that there is a risk of a collision, you will
be warned visually and acoustically. Without
your intervention, the distance warning function
cannot prevent a collision.
The distance warning function willissue a warn-
ing at speeds of around 20 mph (30 km/h)or
more if:
Ryou approach a vehicle ahead of you very
quickly. You will then hear an intermittent
warning tone and the red ·warning lamp
in the instrument cluster flashes.
Driving systems141
Driving and parking
Z

Always pay careful attention to the traffic sit-uation and be ready to brake.
Adaptive Brake Assist aids you when braking
during hazardous situations at speeds above
20 mph (30 km/h). With the help of Adaptive
Brake Assist, the distance warning signal can
detect obstacles that are in the path of your
vehicle for an extended period of time.
When you approach an obstacle and adaptive
Brake Assist detects that there is a risk of a col- lision, adaptive Brake Assist calculates the brak-
ing force necessary to avoid a collision. Should
you apply the brakes forcefully, adaptive Brake
Assist will automatically increase the braking
force to the calculated level.
XKeep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes function as usual again if:
Ryou release the brake pedal
Rthere is no longer any danger of a collision
Rno obstacle is detected in front of your vehicle
Adaptive Brake Assist is then deactivated.
Up to the maximum vehicle speed, adaptive
Brake Assist can react to moving obstacles that
have already been recognized as such at least
once over the period of observa tion. Ad
aptive
Brake Assist does not react to stationary obsta-
cles.
In particular, the detection of obstacles can be
impaired if:
Rdirt, ice or anything else covering the sensors
Rsnow or heavy rain
Rinterference from other radar sources
Rthere are strong radar reflections, for exam-
ple in parking garages
Ra narrow vehicle traveling in front, e.g. a
motorbike
Ra vehicle traveling in front on a different line
If adaptive Brake Assist is not available due to a
malfunction in the radar sensor system, the full
brake boosting effect with the help of BAS
remains available.
Following damage to the front end of the vehicle,
have the configuration and operation of the
radar sensor checked at a qualified specialist
workshop. This also applies to collisions at slow
speeds where there is no visible damage to the
front of the vehicle.
Lane Tracking package
Blind Spot Assist
General notes
Blind Spot Assist monitors the areas on either
side of the vehicle that are not visible to the
driver with two lateral, rear-facing radar sensors
in the bumper. It supports you from speeds of
approximately 20 mph (30 km/h). A warning
display in the exterior mirrors draws your atten-
tion to vehicles detected in the monitored area. If you then switch on the corresponding turn
signal to change lane, you will also receive an
optical and audible collision warning.
Important safety notes
GWARNING
Blind Spot Assist does not react to:
Rvehicles overtaken too closely on the side,
placing them in the blind spot area
Rvehicles which approach with a large speed
differential and overtake your vehicle
As a result, Blind Spot Assist may not give
warnings in such situations. There is a risk of
an accident.
Always observe the traffic conditions care-
fully, and maintain a safe lateral distance.
Blind Spot Assist is only an aid. It may fail to
detect some vehicles and is no substitute for
attentive driving. Always ensure that there is
sufficient distance to the side for other road
users and obstacles.
iUSA only:
This device has been approved by the FCC as
a "Vehicular Radar System". The radar sensor
is intended for use in an automotive radar
system only. Removal, tampering, or altering
of the device will void any warranties, and is
not permitted by the FCC. Do not tamper with, alter, or use in any non-approved way.
Any unauthorized modification to this device
could void the user’s authority to operate the
equipment.
Driving systems143
Driving an d parking
Z

Lane Keeping Assist does not keep your vehicle
in its lane.
The system may be impaired or may not function
if:
Rif the vehicle is incorrectly loaded
(Ypage 213)
Rthere is poor visibility, e.g. due to insufficient
illumination of the road, or due to snow, rain,
fog or spray
Rthere is glare, e.g. from oncoming traffic, the
sun or reflection from other vehicles (e.g. if
the road surface is wet)
Rthe windshield is dirty, fogged up, damaged or
covered, for instance by a sticker, in the vicin-
ity of the camera
Rno, or several, unclear lane markings are pres-
ent for one lane, e.g. in a construction area
Rthe lane markings are worn away, dark or cov-
ered up, e.g. by dirt or snow
Rthe distance to the vehicle in front is too small
and the lane markings thus cannot be detec-
ted
Rthe lane markings change quickly, e.g. lanes
branch off, cross one another or merge
Rthe road is narrow and winding
Rthere are highly variable shade conditions on
the road
A warning may be given if a front wheel passes
over a lane marking. In addition, a warning tone
sounds and the Ãindicator lamp in the
instrument cluster flashes red.
Activating/deactivating Lane Keeping
Assist
Lane Keeping Assist is automatically activated
when you start the engine.
XTo deactivate: press thejbutton in the
center console (Ypage 37).
On vehicles without steering wheel but-
tons:
OFF
flashes briefly in the display and the Ã
indicator lamp in the instrument cluster
flashes yellow and then lights up continu-
ously.
On vehicles with steering wheel buttons:
The Lane
Keep.AssistDeactivatedmes-
sage appears in the display and the Ã
indicator lamp in the instrument cluster
flashes yellow and then lights up continu-
ously. Lane Keeping Assist is deactivated.
XTo activate:
press thejbutton in the
center console again (Ypage 37).
On vehicles without steering wheel but-
tons:
on
flashes briefly in the display and the Ã
indicator lamp in the instrument cluster goes
out. If a lane marking is detected, the Ã
indicator lamp lights up green.
On vehicles with steering wheel buttons:
The Lane Keep. Assist Activated
mes-
sage appears in the display and the Ã
indicator lamp in the instrument cluster goes
out. If a lane marking is detected, the Ã
indicator lamp lights up green.
Lane Keeping Assist is activated.
A Lane Keeping Assist warning is suppressed if:
Ra driving safety system intervenes, such as
ABS, BAS or ESP®.
Ryou have set the turn signal and a lane change is detected. In this case, the warnings are
suppressed for a certain period of time.
Ryou accelerate hard, e.g. kickdown on vehi-
cles with an automatic transmission.
Ryou brake hard.
Ryou steer actively, e.g. swerve to avoid an
obstacle or change lane quickly.
Ryou cut the corner on a sharp bend.
In order that you are warned only when neces-
sary and in good time if you cross the lane mark-
ing, the system recognizes certain conditions
and warns you accordingly.
Lane Keeping Assist warns you earlier if:
Ryou approach the outer lane marking on a
bend.
Rthe road has very wide lanes, e.g. a freeway.
Rthe system recognizes solid lane markings.
Warnings are given later if:
Rthe road has narrow lanes.
Ryou cut the corner on a bend.
All-wheel drive
Important safety notes
!Never tow the vehicle with one axle raised.
This may damage the transfer case. Damage
of this sort is not covered by the Mercedes-
Benz Limited Warranty. All wheels must
146Driving systems
Driving and parking

Display messages on vehicles withsteering wheel buttons
Safet ysystems
Display messagesPossible causes/consequences an dMSolutions
ABS
Visit workshop
AB Shas bee ndeactivated due to amalfunction .ES P®,AS Rand BAS,
as well as cruise control, hav ealso bee ndeactivated as aresult .
GWARNING
The brake syste mcontinues to function normally, but without th e
function slisted above. The wheels could therefore loc kif you brake
hard, fo rexample.
Thi scauses steerability and braking to be greatly impaired. The brak-
in gdistanc ecan increase in emergency braking situations. The driven
wheels can spi nwhen accelerating.
If ES P
®is no toperational, ES P®will notstabilize th evehicle.
There is an increase dris kof skidding and accidents .
XDrive on withcare.
XVisit aqualified specialis tworkshop immediately.
ABS
Unavailable
AB Sis temporarily unavailable or is deactivated due to undervoltage.
ES P®,AS Rand BAS, as well as cruise control, are also unavailable as
a result .
The battery may no tbe bein gcharged.
GWARNING
The brake syste mcontinues to function normally, but without th e
function slisted above. The wheels could therefore loc kif you brake
hard, fo rexample.
Thi scauses steerability and braking to be greatly impaired. The brak-
in gdistanc ecan increase in emergency braking situations. The driven
wheels can spi nwhen accelerating.
If ES P
®is no toperational, ES P®will notstabilize th evehicle.
There is an increase dris kof skidding and accidents .
XDrive for ashort distanc eat aspeed of more than 13 mph
(20 km/h).
If th edisplay messag edisappears ,th efunction smentioned abov e
are available again .
If th edisplay messag econtinues to be displayed:
XDrive on wit hcare.
XVisit aqualified specialis tworkshop immediately.
Display messages18 1
On-board computer and displays
Z

ProblemPossible causes/consequences andMSolutions
d
The yellow
ASR/ESP®warn-
ing lamp is lit
while the engine
is running.
The all-wheel drive is activated/deactivated. When changing gear,
ASR and ESP®are deactivated.
After changing gear, ASR and ESP®are automatically reactivated.
Engage/disengage the all-wheel drive (
Ypage 147).
d The yellow
ASR/ESP®warn-
ing lamp flashes
slowly while the
vehicle is in
motion.
In vehicles with all-wheel drive the brake system is overheated.
GWARNING
The performance of 4ETS is reduced. The braking power output may
be lower.
There is a risk of an accident.
XDrive on carefully and adapt your driving style to suit the road and
traffic conditions.
XWhen the message is no longer displayed, 4ETS and normal braking
power are available again.
d The yellow
ASR/ESP®warn-
ing lamp is lit
while the engine
is running.
ASR is deactivated.
GWARNING
The driven wheels can spin when accelerating.
There is an increased risk of skidding and accidents.
XActivate ASR again. Exceptions (Ypage 55).
h !:b
The yellow ESP®, ABS
and ASR/BAS indicator
lamps and the red brake
system indicator lamp
are lit while the engine is
running.
EBD is malfunctioning or deactivated due to undervoltage or malfunc-
tion.
The battery may not be being charged.
GWARNING
The rear wheels could lock sooner than expected when you apply the
brakes. The braking distance can increase in emergency braking sit-
uations.
There is an increased risk of skidding and accidents.
XVehicles with steering wheel buttons: also observe the messages in
the display (Ypage 181).
XStop the vehicle as soon as possible, paying attention to road and
traffic conditions.
XDo not drive on.
XConsult a qualified specialist workshop.
196Indicator and warning lamps in the instrument cluster
On-board computer and displays