2015 MERCEDES-BENZ GL-Class Pre safe

If the restraint system control unit detects a
high accident severity, additional compo-
nents of the restraint system are activated
independently of one another in certain fron- tal collision situations:
R Front air bags and driver's knee bag
R Windowbag, if the system determines that
it can offer additional protection to that
provided by the seat belt
Depending on the person occupying the front-
passenger seat, the front-passenger air bag is activated or deactivated. The front-passenger front air bag can only be deployed in an acci-
dent if the PASSENGER AIR BAG OFF indica-
tor lamp is off. Observe the information on the
PASSENGER AIR BAG OFF indicator lamp
(Y page 45).
Your vehicle has two-stage front air bags.
During the first deployment stage, the front
air bag fills with propellant gas which reduces
the risk of injury. The second stage is then
triggered within milliseconds, filling the front
air bag with the maximum amount of propel-
lant gas.
The deployment thresholds for the Emer-
gency Tensioning Devices and air bags are
calculated on the basis of the vehicle decel-
eration or acceleration occurring at various
points in the vehicle. This process is pre-emp- tive in nature. The air bag must be deployed
on time, at the start of the collision.
The rate of vehicle deceleration or accelera-
tion and the direction of the force are essen-
tially determined by:
R distribution of the force during the impact
R collision angle
R deformation characteristics of the vehicle
R characteristics of the object with which the
vehicle has collided
Factors which can only be seen and measured
after the collision has occurred do not play a
decisive role in the deployment of an airbag,
nor do they provide an indication of air bag
deployment. The vehicle may be considerably deformed
without an air bag being deployed. This is the
case if only relatively easily deformable parts
have been hit and a high rate of deceleration
has not been reached. Conversely, an air bag may be deployed even though the vehicle suf-
fers only minor deformation. This is the case
if, for example, very rigid vehicle parts such as
the longitudinal body members are hit in an
accident and the rate of deceleration is suffi-
cient.
If the restraint system control unit detects a
side impact or an overturn situation, the rel-
evant restraint system components are acti-
vated independently of one another depend-
ing on the apparent type of accident. If addi-
tional protection for the vehicle occupants is determined in this situation, the belt tension-
ers are also triggered.
R Side impact air bags on the side of the col-
lision, regardless of Emergency Tensioning
Device and use of the seat belt on the driv-
er's side and the outer seats on the second row
The sidebag on the front-passenger side
deploys under the following conditions:
- the OCS system detects that the front-
passenger seat is occupied or
- the belt tongue has engaged in the belt
buckle of the front-passenger seat.
R Window curtain air bag on the side of the
collision, regardless of seat belt use and
whether front-passenger seat is occupied
R Windowbags on the driver's and front-
passenger sides in certain overturn situa-
tions if the system determines that they
can offer additional protection to that pro-
vided by the seat belt
i Not all air bags are deployed in an acci-
dent. The various air bag systems work
independently of each other. Occupant safety
59Safety Z

How the air bag system works is deter-
mined by the severity of the accident detec- ted, especially the vehicle deceleration or
acceleration, and the apparent type of acci- dent:
R frontal collision
R side impact
R rollover PRE-SAFE
®
(anticipatory occupant
protection system)
Introduction In certain hazardous situations, PRE-SAFE
®
takes pre-emptive measures to protect the
vehicle occupants.
Important safety notes !
Make sure that there are no objects in the
footwell or behind the seats. There is a dan- ger that the seats and/or objects could be
damaged when PRE-SAFE ®
is activated.
Although your vehicle is equipped with PRE-
SAFE ®
, the possibility of injury in the event of
an accident cannot be ruled out. Always
adapt your driving style to suit the prevailing
road and weather conditions and maintain a
safe distance from the vehicle in front. Drive
carefully.
Function PRE-SAFE
®
intervenes:
R in emergency braking situations, e.g. when
BAS is activated
R in critical driving situations, e.g. when phys-
ical limits are exceeded and the vehicle
understeers or oversteers severely
R on vehicles with the Active Driving Assis-
tance package: if BAS PLUS intervenes
powerfully or the radar sensor system
detects an imminent danger of collision in
certain situations PRE-SAFE
®
takes the following measures
depending on the hazardous situation detec-
ted:
R the front seat belts are pre-tensioned.
R if the vehicle skids, the sliding sunroof and
the side windows are closed so that only a
small gap remains. The panorama roof with power tilt/sliding panel is completely
closed.
R vehicles with the memory function: the
front-passenger seat is adjusted if it is in an
unfavorable position.
R vehicles with a multicontour seat: the air
pressure in the side bolsters of the seat
backrest is increased.
If the hazardous situation passes without
resulting in an accident, PRE-SAFE ®
slackens
the belt pre-tensioning. On vehicles with mul-
ticontour seats, the air pressure in the side
bolsters is reduced again. All settings made
by PRE-SAFE ®
can then be reversed.
If the seat belt pre-tensioning is not reduced:
X Move the seat backrest or seat back
slightly when the vehicle is stationary.
The seat belt pre-tensioning is reduced and
the locking mechanism is released.
The seat-belt adjustment is an integral part of
the PRE-SAFE ®
convenience function. Infor-
mation about the convenience function can
be found under "Belt adjustment"
(Y page 49). Automatic measures after an acci-
dent
Immediately after an accident, the following
measures are implemented, depending on
the type and severity of the impact:
R by activating the hazard warning lamps
R the emergency lighting is activated
R the vehicle doors are unlocked
R the front side windows are lowered 60
Occupant safetySafety

portion of the seat belt. The seat belt cannot
be immediately refastened. There is an
increased risk of injury, possibly even fatal.
Stop the vehicle immediately, paying atten-
tion to road and traffic conditions. Reactivate the special seat belt retractor and secure the
child restraint system properly.
All seat belts in the vehicle, except the driv-
er's seat belt, are equipped with a special seat belt retractor. When activated, the special
seat belt retractor ensures that the seat belt
cannot slacken once the child seat is secured.
Installing a child restraint system:
X Make sure you observe the child restraint
system manufacturer's installation instruc-
tions.
X Pull the seat belt smoothly from the belt
outlet.
X Engage seat belt tongue in belt buckle.
Activating the special seat belt retractor:
X Pull the seat belt out fully and let the inertia
reel retract it again.
While the seat belt is retracting, you should hear a ratcheting sound. The special seat
belt retractor is enabled.
X Push the child restraint system down so
that the seat belt is tight and does not
loosen.
Removing a child restraint system/deactivat-
ing the special seat belt retractor:
X Make sure you observe the child restraint
system manufacturer's installation instruc- tions.
X Press the belt buckle release button, hold
the belt tongue and guide it back towards
the belt outlet.
The special seat belt retractor is deactiva-
ted. Child restraint system
The use of seat belts and child restraint sys-
tems is required by law in:
R all 50 states
R the U.S. territories
R the District of Columbia
R all Canadian provinces
If you install a rearward-facing child restraint
system on the center rear seat, the rear arm
rest must be folded back as far as possible.
You can obtain further information about the correct child restraint system from any
authorized Mercedes-Benz Center. G
WARNING
If the child restraint system is installed incor- rectly on a suitable seat, it cannot protect as
intended. The child cannot then be restrained in the event of an accident, heavy braking or
sudden changes of direction. There is an
increased risk of injury, possibly even fatal.
Make sure that you observe the child restraint
system manufacturer's installation instruc-
tions and the notes on use. Please ensure,
that the base of the child restraint system is
always resting completely on the seat cush-
ion. Never place objects, e.g. cushions, under or behind the child restraint system. Only use
child restraint systems with the original cover
designed for them. Only replace damaged
covers with genuine covers. G
WARNING
If the child restraint system is installed incor- rectly or is not secured, it can come loose in
the event of an accident, heavy braking or a
sudden change in direction. The child
restraint system could be thrown about, strik- ing vehicle occupants. There is an increased
risk of injury, possibly even fatal.
Always install child restraint systems prop-
erly, even if they are not being used. Make
sure that you observe the child restraint sys-
tem manufacturer's installation instructions. 62
Children in the vehicleSafety

G
WARNING
If the child restraint system is subjected to
direct sunlight, parts may get very hot. Chil-
dren may burn themselves on these parts,
particularly on the metal parts of the child
restraint system. There is a risk of injury.
If you leave the vehicle, taking the child with
you, always ensure that the child restraint
system is not exposed to direct sunlight. Pro- tect it with a blanket, for example. If the child
restraint system has been exposed to direct
sunlight, let it cool down before securing the
child in it. Never leave children unattended in the vehicle.
Child-proof locks for the rear doors You secure each door individually with the
child-proof locks on the rear doors. A door
secured with a child-proof lock cannot be
opened from inside the vehicle. When the
vehicle is unlocked, the door can be opened
from the outside.
X To activate: press the child-proof lock
lever up in the direction of arrow 0043.
X Make sure that the child-proof locks are
working properly.
X To deactivate: press the child-proof lock
lever down in the direction of arrow 0044.Override feature for the rear side win-
dows
X
To activate/deactivate: press button0043.
If indicator lamp 0044is lit, operation of the
rear side windows is disabled. Operation is
only possible using the switches in the driv- er's door. If indicator lamp 0044is off, oper-
ation is possible using the switches in the
rear compartment. Pets in the vehicle
G
WARNING
If you leave animals unattended or unsecured in the vehicle, they could press buttons or
switches, for example.
As a result, they could:
R activate vehicle equipment and become
trapped, for example
R activate or deactivate systems, thereby
endangering other road users
Unsecured animals could also be flung around
the vehicle in the event of an accident or sud- den steering or braking, thereby injuring vehi-
cle occupants. There is a risk of an accident
and injury.
Never leave animals unattended in the vehi-
cle. Always secure animals properly during
the journey, e.g. use a suitable animal trans-
port box. Pets in the vehicle
67Safety Z

Driving safety systems
Overview of driving safety systems
In this section, you will find information about the following driving safety systems:
R ABS (Anti-lock BrakingSystem)
(Y page 68)
R BAS (Brake Assist System) (Y page 69)
R BAS PLUS (Brake Assist System Plus)
(Y page 69)
R COLLISION PREVENTION ASSIST (distance
warning function and adaptive Brake
Assist) (Y page 70)
R ESP ®
(E lectronic StabilityProgram)
(Y page 73)
R EBD (Electronic Brake forceDistribution)
(Y page 75)
R ADAPTIVE BRAKE (Y page 76)
R PRE-SAFE ®
Brake (Y page 76)
R STEER CONTROL (Y page 77)Important safety notes
If you fail to adapt your driving style or
become distracted, the driving safety sys-
tems can neither reduce the risk of accident
nor override the laws of physics. Driving
safety systems are merely aids designed to
assist driving. You are responsible for the dis-
tance to the vehicle in front, for vehicle speed and for braking in good time. Always adapt
your driving style to suit the prevailing road
and weather conditions and maintain a safe
distance from the vehicle in front. Drive care-
fully.
i The driving safety systems described only
work as effectively as possible when there
is adequate contact between the tires and
the road surface. Please pay special atten- tion to the notes on tires, recommended
minimum tire tread depths, etc.
(Y page 406).
In wintry driving conditions, always use
winter tires (M+S tires) and if necessary, snow chains. Only in this way will the driv-
ing safety systems described in this section
work as effectively as possible. ABS (Anti-lock Braking System)
General information ABS regulates brake pressure in such a way
that the wheels do not lock when you brake.
This allows you to continue steering the vehi- cle when braking.
The 0025 ABS warning lamp in the instrument
cluster lights up when the ignition is switched on. It goes out when the engine is running.
Important safety notes i
Observe the "Important safety notes" sec-
tion (Y page 68). G
WARNING
If ABS is faulty, the wheels could lock when
braking. The steerability and braking charac-
teristics may be severely impaired. Addition-
ally, further driving safety systems are deac-
tivated. There is an increased danger of skid- ding and accidents.
Drive on carefully. Have ABS checked imme-
diately at a qualified specialist workshop.
When ABS is malfunctioning, other systems,
including driving safety systems, will also
become inoperative. Observe the information on the ABS warning lamp (Y page 328) and
display messages which may be shown in the
instrument cluster (Y page 293).
ABS works from a speed of about 5 mph
(8 km/ h), regardless of road-surface condi-
tions. ABS works on slippery surfaces, even
when you only brake gently. 68
Driving safety systemsSafety

Braking
X
If ABS intervenes: continue to depress the
brake pedal vigorously until the braking sit- uation is over.
X To make a full brake application:
depress the brake pedal with full force.
If ABS intervenes when braking, you will feel a pulsing in the brake pedal.
The pulsating brake pedal can be an indica-
tion of hazardous road conditions, and func-
tions as a reminder to take extra care while
driving.
Off-road ABS An ABS system specifically suited to off-road
terrain is activated automatically once the off-
road program is activated (Y page 259).
At speeds below 20 mph (30 km/h), the front
wheels lock cyclically during braking. The dig-
ging-in effect achieved in the process reduces the stopping distance on off-road terrain. This
limits steering capability. BAS (Brake Assist System)
General information BAS operates in emergency braking situa-
tions. If you depress the brake pedal quickly,
BAS automatically boosts the braking force,
thus shortening the stopping distance.
Important safety notes i
Observe the "Important safety notes" sec-
tion (Y page 68). G
WARNING
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. Braking X
Keep the brake pedal firmly depressed until
the emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will function as usual once you
release the brake pedal. BAS is deactivated. BAS PLUS (Brake Assist System
PLUS)
General information i
Observe the "Important safety notes" sec-
tion (Y page 68).
BAS PLUS is only available in vehicles equip-
ped with DISTRONIC PLUS.
For BAS PLUS to assist you, the radar sensor system must be operational.
With the help of the radar sensor system, BAS
PLUS can detect obstacles that are in the
path of your vehicle for an extended period of
time.
If the radar sensor system is malfunctioning,
BAS PLUS will not be available. The brake
system is still available with complete brake
boosting effect and BAS.
BAS PLUS can help you to minimize the risk of a collision with a vehicle or reduce the effects
of such a collision. If BAS PLUS detects a
danger of collision, you are assisted when
braking.
Important safety notes G
WARNING
BAS PLUS cannot always clearly identify
objects and complex traffic situations.
In such cases, BAS PLUS may:
R intervene unnecessarily
R not intervene
There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake. Terminate the
intervention in a non-critical driving situation. Driving safety systems
69Safety Z

G
WARNING
BAS PLUS does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering
As a result, BAS PLUS may not intervene in all
critical situations. There is a risk of an acci-
dent.
Always pay careful attention to the traffic sit-
uation and be ready to brake.
In the event of snowfall or heavy rain, the rec-
ognition can be impaired.
Recognition by the radar sensor system is
also impaired in the event of:
R dirt on the sensors or anything else cover-
ing the sensors
R there is interference by other radar sources
R there are strong radar reflections, for
example in parking garages
R a narrow vehicle traveling in front, e.g. a
motorbike
R a vehicle traveling in front on a different line
relative to the center of your vehicle
Following damage to the front end of the vehi-
cle, have the configuration and operation of
the radar sensors checked at a qualified spe-
cialist workshop. This also applies to colli-
sions at low speeds where there is no visible
damage to the front of the vehicle.
Function To avoid a collision, BAS PLUS calculates the
brake force necessary if:
R you approach an obstacle, and
R BAS PLUS has detected a risk of collision
When driving at a speed under 20 mph
(30 km/h): if you depress the brake pedal,
BAS PLUS is activated. The increase in brake pressure will be carried out at the last possi-
ble moment. When driving at a speed above 20 mph
(30 km/h): if you depress the brake pedal
sharply, BAS PLUS automatically raises the
brake pressure to a value adapted to the traf-
fic situation.
BAS PLUS provides braking assistance in haz-
ardous situations with vehicles in front within a speed range between 4 mph (7 km/h) and
155 mph (250 km/h).
At speeds of up to approximately 40 mph
(70 km/h), BAS PLUS can also react to sta-
tionary objects. Examples of stationary
objects are stopped or parked vehicles.
i If BAS PLUS demands particularly high
braking force, preventative passenger pro-
tection measures (PRE-SAFE ®
) are activa-
ted simultaneously.
X Keep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
BAS PLUS is deactivated and the brakes func- tion as usual again, if:
R you release the brake pedal.
R there is no longer a risk of collision.
R no obstacle is detected in front of your
vehicle.
If you have activated DSR (Y page 258), BAS
PLUS is likewise deactivated. COLLISION PREVENTION ASSIST
General notes COLLISION PREVENTION ASSIST consists of
Adaptive Brake Assist and the distance warn-
ing function, which are described in the fol-
lowing.
Distance warning function Important safety notes
i Observe the "Important safety notes" sec-
tion (Y page 68). 70
Driving safety systemsSafety

G
WARNING
The distance warning function does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering
Thus, the distance warning function cannot
provide a warning in all critical situations.
There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation and be ready to brake. G
WARNING
The distance warning function cannot always
clearly identify objects and complex traffic
situations.
In such cases, the distance warning function
may:
R give an unnecessary warning
R not give a warning
There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation and do not rely solely on the distance
warning function.
Function X To activate/deactivate: activate or deac-
tivate the distance warning function in the
on-board computer (Y page 283).
If the distance warning function is not activa-
ted, the 00D4symbol appears in the assis-
tance graphics display.
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. The
distance warning function cannot prevent a
collision without your intervention.
Starting at a speed of around 4 mph (7 km/h),
the distance warning function warns you if
you rapidly approach a vehicle in front. An
intermittent warning tone will then sound, and the
00BAdistance warning lamp will light
up in the instrument cluster.
X Brake immediately in order to increase the
distance from the vehicle in front.
or
X Take evasive action, provided it is safe to do
so.
Due to the nature of the system, particularly
complicated but non-critical driving condi-
tions may also cause the system to display a
warning.
With the help of the radar sensor system, the
distance warning function can detect obsta-
cles that are in the path of your vehicle for an extended period of time.
Up to a speed of about 40 mph (70 km/h), the
distance warning function can also react to
stationary obstacles, such as stopped or
parked vehicles.
If you approach an obstacle and the distance
warning function detects a risk of a collision, the system will initially alert you both visually
and acoustically.
In particular, the detection of obstacles can
be impaired if:
R dirt on the sensors or anything else cover-
ing the sensors
R there is snow or heavy rain
R there is interference by other radar sources
R there are strong radar reflections, for
example in parking garages
R a narrow vehicle traveling in front, e.g. a
motorbike
R a vehicle traveling in front on a different line
relative to the center of your vehicle
R new vehicles or after the COLLISION PRE-
VENTION ASSIST system has been serv-
iced
Observe the notes in the section on break-
ing-in (Y page 166).
Following damage to the front end of the vehi- cle, have the configuration and operation of
the radar sensor checked at a qualified spe-
cialist workshop. This also applies to colli- Driving safety systems
71Safety Z