sensor MERCEDES-BENZ GL-Class 2014 X166 User Guide

Problem Possible causes/consequences and
M
MSolutions The PASSENGER AIR
BAG OFF indicator
lamp does not light up
and/or stays on.
The front-passenger
seat is:
R unoccupied
R occupied with the
weight of a child up
to twelve months old
in a child restraint
system The OCS is malfunctioning.
X
Make sure there is nothing between the seat cushion and the
child seat.
X Make sure that the backrest and base of the child restraint
system are resting securely on the front-passenger seat. If
necessary, adjust the position of the front-passenger seat.
X When installing the child restraint system, make sure that the
seat belt is tight. Do not pull the seat belt tight with the front-
passenger seat adjustment. This could result in the seat belt
being pulled too tightly.
X Check the installation of the child restraint system.
X Make sure that no objects are applying additional weight onto
the seat.
X If the PASSENGER AIR BAG OFF indicator lamp remains off, have
the OCS system checked as soon as possible at a qualified
specialist workshop. Do not transport a child on the front-
passenger seat until the OCS has been repaired.
X Observe the additional display messages in the multifunction
display (Y page 301). PRE-SAFE
®
(anticipatory occupant
protection system)
Introduction PRE-SAFE
®
takes preemptive measures to
protect occupants in certain hazardous
situations.
Important safety notes !
Make sure that there are no objects in the
footwell or behind the seats when resetting
the seats. There is a risk that the seats
and/or the objects could be damaged.
Despite your vehicle being equipped with the
PRE-SAFE ®
system, the possibility of
personal injuries occurring as a result of an
accident cannot be eliminated.
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
physical limits are exceeded and the
vehicle understeers or oversteers severely.
R on vehicles with DISTRONIC PLUS: if
BAS PLUS brakes hard 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
detected:
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. On vehicles with a
panorama roof with power tilt/sliding
panel, they are closed completely. 54
Occupant safetySafety

The pulsating brake pedal can be an
indication of hazardous road conditions, and
functions 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 258).
At speeds below 20 mph (30 km/h), the front
wheels lock cyclically during braking. The
digging-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
situations. 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"
section (Y page 67). 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"
section (Y page 67).
BAS PLUS is only available in vehicles
equipped 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
situation and be ready to brake. Terminate the
intervention in a non-critical driving situation. G
WARNING
BAS PLUS does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering 68
Driving safety systemsSafety

As a result, BAS PLUS may not intervene in all
critical situations. There is a risk of an
accident.
Always pay careful attention to the traffic
situation and be ready to brake.
In the event of snowfall or heavy rain, the
recognition can be impaired.
Recognition by the radar sensor system is
also impaired in the event of:
R dirt on the sensors or anything else
covering 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
vehicle, have the configuration and operation
of the radar sensors checked at a qualified
specialist workshop. This also applies to
collisions 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
possible 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
traffic situation.
BAS PLUS provides braking assistance in
hazardous 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
stationary objects. Examples of stationary
objects are stopped or parked vehicles.
i
If BAS PLUS demands particularly high
braking force, preventative passenger
protection measures (PRE-SAFE ®
) are
activated 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
function 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 256), BAS
PLUS is likewise deactivated. COLLISION PREVENTION ASSIST
General notes COLLISION PREVENTION ASSIST consists of
Adaptive Brake Assist and the distance
warning function, which are described in the
following.
Distance warning function
Important safety notes
i
Observe the "Important safety notes"
section ( Ypage 67). 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 Driving safety systems
69Safety
Z

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
situation 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
situation and do not rely solely on the distance
warning function.
Function
X To activate/deactivate: activate or
deactivate the distance warning function in
the on-board computer (Y page 281).
If the distance warning function is not
activated, the æsymbol appears in the
assistance 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 ·distance 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
conditions may also cause the system to
display a warning.
With the help of the radar sensor system, the
distance warning function can detect
obstacles that are in the path of your vehicle
for an extended period of time.
From a speed of around 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
covering 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
PREVENTION ASSIST system has been
serviced
Observe the notes in the section on
breaking-in (Y page 166).
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 low speeds where there is no
visible damage to the front of the vehicle. 70
Driving safety systemsSafety

Adaptive Brake Assist
i
Observe the "Important safety notes"
section (Y page 67). G
WARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic
situations.
In such cases, Adaptive Brake Assist may:
R intervene unnecessarily
R not intervene
There is a risk of an accident.
Always pay careful attention to the traffic
situation and be ready to brake. Terminate the
intervention in a non-critical driving situation. G
WARNING
Adaptive Brake Assist does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R to stationary obstacles
R when cornering
As a result, Adaptive Brake Assist may not
intervene in all critical conditions. There is a
risk of an accident.
Always pay careful attention to the traffic
situation and be ready to brake.
Due to the nature of the system, particularly
complicated but non-critical driving
conditions may also cause Brake Assist to
intervene.
Adaptive Brake Assist aids you in braking
during hazardous situations at speeds above
4 mph (7 km/h) and uses the radar sensor
system to evaluate the traffic situation.
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.
Should you approach an obstacle and
Adaptive Brake Assist has detected a risk of
collision, Adaptive Brake Assist calculates the braking force necessary to avoid a rear-end
collision. Should you apply the brakes
vigorously, Adaptive Brake Assist will
automatically increase the braking force to a
level suitable for the traffic conditions.
X
Keep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will work normally again if:
R you release the brake pedal.
R there is no longer any danger of a collision.
R no obstacle is detected in front of your
vehicle.
Adaptive Brake Assist is then deactivated.
Vehicles with PRE-SAFE ®
:if adaptive Brake
Assist requires particularly high brake
pressure, preventive passenger protection
measures (PRE-SAFE ®
) are deployed
simultaneously.
Up to vehicle speeds of around 155 mph
(250 km/h), adaptive Brake Assist is capable
of reacting to moving objects that have
already been recognized as such at least once
over the period of observation. Adaptive
Brake Assist does not react to stationary
obstacles.
If Adaptive Brake Assist is not available due
to a malfunction in the radar sensor system,
the brake system remains available with full
brake boosting effect and BAS.
In particular, the detection of obstacles can
be impaired if there is:
R dirt on the sensors or anything else
covering 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 Driving safety systems
71Safety Z

R
a vehicle traveling in front on a different line
relative to the center of your vehicle
R new vehicles or after the COLLISION
PREVENTION ASSIST system has been
serviced
Observe the notes in the section on
breaking-in (Y page 166).
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 low speeds where there is no
visible damage to the front of the vehicle. ESP
®
(Electronic Stability Program)
General notes i
Observe the "Important safety notes"
section (Y page 67).
ESP ®
monitors driving stability and traction,
i.e. power transmission between the tires and
the road surface.
If ESP ®
detects that the vehicle is deviating
from the direction desired by the driver, one
or more wheels are braked to stabilize the
vehicle. The engine output is also modified to
keep the vehicle on the desired course within
physical limits. ESP ®
assists the driver when
pulling away on wet or slippery roads. ESP ®
can also stabilize the vehicle during braking.
4ETS (Electronic Traction System) 4ETS traction control is part of ESP
®
.
Traction control brakes the drive wheels
individually if they spin. This enables you to
pull away and accelerate on slippery surfaces,
for example if the road surface is slippery on
one side. In addition, more drive torque is
transferred to the wheel or wheels with
traction.
Traction control remains active, even if you
deactivate ESP ®
.
In appropriate driving situations, activate the
off-road program (Y page 258). Off-road 4ETS (Electronic Traction
System) A 4ETS system specifically suited to off-road
terrain is activated automatically once the off-
road program is activated (Y
page 258).
Important safety notes G
WARNING
If ESP ®
is malfunctioning, ESP ®
is unable to
stabilize the vehicle. Additionally, further
driving safety systems are deactivated. This
increases the risk of skidding and an accident.
Drive on carefully. Have ESP ®
checked at a
qualified specialist workshop.
! Only operate the vehicle for a maximum
of ten seconds on a brake test
dynamometer. Switch off the ignition.
Application of the brakes by ESP ®
may
otherwise destroy the brake system.
! A function or performance test should
only be carried out on a two-axle
dynamometer. Before you operate the
vehicle on such a dynamometer, please
consult a qualified workshop. You could
otherwise damage the drive train or the
brake system.
ESP ®
is deactivated if the åwarning lamp
in the instrument cluster lights up
continuously when the engine is running.
If the ÷ warning lamp and the å
warning lamp are lit continuously, ESP ®
is not
available due to a malfunction.
Observe the information on warning lamps
(Y page 329) and display messages which
may be shown in the instrument cluster
(Y page 291).
i Only use wheels with the recommended
tire sizes. Only then will ESP ®
function
properly. 72
Driving safety systemsSafety

You should therefore adapt your driving style
to the different handling characteristics. Have
the brake system checked at a qualified
specialist workshop.
Observe information regarding indicator and
warning lamps ( Ypage 327) as well as
display messages (Y page 293). ADAPTIVE BRAKE
ADAPTIVE BRAKE enhances braking safety
and offers increased braking comfort. In
addition to the braking function, ADAPTIVE
BRAKE also has the HOLD function
(Y page 216) and hill start assist
(Y page 171). PRE-SAFE
®
Brake
General information i
Observe the "Important safety notes"
section (Y page 67).
PRE-SAFE ®
Brake is only available in vehicles
with DISTRONIC PLUS.
For PRE-SAFE ®
Brake to assist you when
driving, the radar sensor system must be
operational.
With the help of the radar sensor system,
PRE-SAFE ®
Brake can detect obstacles that
are in front of your vehicle for an extended
period of time.
PRE-SAFE ®
Brake can help you to minimize
the risk of a collision with a vehicle ahead, and
reduce the effects of such a collision. If PRE-
SAFE ®
Brake has detected a risk of collision,
you will be warned visually and acoustically
as well as by automatic braking. PRE-SAFE ®
Brake cannot prevent a collision without your
intervention. Important safety notes G
WARNING
PRE-SAFE ®
Brake will initially brake your
vehicle by a partial application of the brakes
if a danger of collision is detected. There may
be a collision unless you also brake.
Automatic emergency braking cannot prevent
a collision. There is a risk of an accident.
Always apply the brakes yourself and try to
take evasive action. G
WARNING
PRE-SAFE ®
Brake cannot always clearly
identify objects and complex traffic
conditions.
In these cases, PRE-SAFE ®
Brake may:
R give an unnecessary warning and then
brake the vehicle
R not give a warning or intervene
There is a risk of an accident.
Always pay particular attention to the traffic
situation and be ready to brake, especially if
PRE-SAFE ®
Brake warns you. Terminate the
intervention in a non-critical driving situation.
In order to maintain the appropriate distance
to the vehicle in front and thus prevent a
collision, you must apply the brakes yourself. G
WARNING
PRE-SAFE ®
Brake does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering
As a result, PRE-SAFE ®
Brake may neither
give warnings nor intervene in all critical
situations. There is a risk of an accident.
Always pay careful attention to the traffic
situation and be ready to brake.
In the event of snowfall or heavy rain, the
recognition can be impaired. Driving safety systems
75Safety Z

Recognition by the radar sensor system is
also impaired in the event of:
R dirt on the sensors or anything else
covering 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
vehicle, have the configuration and operation
of the radar sensors checked at a qualified
specialist workshop. This also applies to
collisions at low speeds where there is no
visible damage to the front of the vehicle.
Function X
To activate/deactivate: activate or
deactivate PRE-SAFE ®
Brake in the on-
board computer (Y page 281).
If the PRE-SAFE ®
Brake is not activated, the
æ symbol appears in the multifunction
display.
Starting at a speed of around 4 mph
(7 km/h), this function warns you if you
rapidly approach a vehicle in front. An
intermittent warning tone will then sound and
the · distance warning lamp will light up
in the instrument cluster.
X Brake immediately to defuse the situation.
or
X Take evasive action provided it is safe to do
so.
PRE-SAFE ®
Brake can also brake the vehicle
automatically under the following conditions:
R the driver and front-passenger have their
seat belts fastened
and
R the vehicle speed is between
approximately 4 mph (7 km/h) and
124 mph (200 km/h) At speeds of up to approximately 40 mph
(70 km/h) PRE-SAFE ®
Brake can also detect
stationary objects. Examples of stationary
objects are stopped or parked vehicles.
i If there is an increased risk of collision,
preventive passenger protection measures
(PRE-SAFE ®
) are activated.
If the risk of collision with the vehicle in front
remains and you do not brake, take evasive
action or accelerate significantly, the vehicle
may perform automatic emergency braking,
up to the point of full brake application.
Automatic emergency braking is not
performed until immediately prior to an
imminent accident.
You can prevent the intervention of the PRE-
SAFE ®
Brake at any time by:
R depressing the accelerator pedal further.
R activating kickdown.
R releasing the brake pedal.
The braking action of PRE-SAFE ®
Brake is
ended automatically if:
R you maneuver to avoid the obstacle.
R there is no longer any danger of a collision.
R there is no longer an obstacle detected in
front of your vehicle.
If you have activated DSR (Y page 256), PRE-
SAFE ®
Brake is deactivated. STEER CONTROL
General information STEER CONTROL helps you by transmitting a
noticeable steering force to the steering
wheel in the direction required for vehicle
stabilization.
This steering assistance is provided in
particular if:
R both right wheels or both left wheels are on
a wet or slippery road surface when you
brake.
R the vehicle starts to skid. 76
Driving safety systemsSafety

X
To unlock centrally: press button=.
If you do not open the vehicle within
approximately 40 seconds of unlocking:
R the vehicle is locked again.
R the theft deterrent locking system is
armed again.
X To lock centrally: press button:.
The SmartKey centrally locks/unlocks:
R the doors
R the tailgate
R the fuel filler flap
The turn signals flash once when unlocking
and three times when locking.
You can also set an audible signal to confirm
that the vehicle has been locked. The audible
signal can be activated and deactivated using
the on-board computer (Y page 285).
When it is dark, the surround lighting also
comes on if it is activated in the on-board
computer (Y page 284). KEYLESS-GO
General notes Bear in mind that the engine can be started
by any of the vehicle occupants if there is a
KEYLESS-GO key in the vehicle.
Locking/unlocking centrally You can start, lock or unlock the vehicle using
KEYLESS-GO. To do this, you only need carry
the SmartKey with you. You can combine the
functions of KEYLESS-GO with those of a
conventional SmartKey. Unlock the vehicle
by using KEYLESS-GO, for instance, and lock
it using the &button on the SmartKey.
When locking or unlocking with KEYLESS-GO,
the distance between the SmartKey and the
corresponding door handle must not be
greater than 3 ft (1 m). KEYLESS-GO checks whether a valid
SmartKey is in the vehicle by periodically
establishing a radio connection between the
vehicle and the SmartKey. This happens:
R
when the external door handles are
touched
R when starting the engine
R while the vehicle is in motion X
To unlock the vehicle: touch the inner
surface of the door handle.
X To lock the vehicle: touch sensor
surface :.
X Convenience closing feature: touch
recessed sensor surface ;for an
extended period.
Further information on the convenience
closing feature (Y page 95).
If you pull on the handle of the tailgate, only
the cargo compartment of the vehicle is
unlocked. Changing the settings of the locking
system
You can change the settings of the locking
system. This means that only the driver's door
and the fuel filler flap are unlocked when the
vehicle is unlocked. This is useful if you
frequently travel on your own.
X To change the setting: press and hold
down the %and& buttons
simultaneously for approximately six SmartKey
81Opening and closing Z

seconds until the battery check lamp
flashes twice (Y
page 83).
i If the setting of the locking system is
changed within the signal range of the
vehicle, pressing the &or% button:
R locks or
R unlocks the vehicle
The SmartKey now functions as follows:
X To unlock the driver's door: press the
% button once.
X To unlock centrally: press the%
button twice.
X To lock centrally: press the&button.
The KEYLESS-GO function is changed as
follows:
X To unlock the driver's door: touch the
inner surface of the door handle on the
driver's door.
X To unlock centrally: touch the inner
surface of the door handle on the front-
passenger door or the rear door.
X To lock centrally: touch the outer sensor
surface on one of the door handles
(Y page 81).
X To restore the factory settings: press
and hold down the %and& buttons
simultaneously for approximately six
seconds until the battery check lamp
flashes twice (Y page 83). Mechanical key
General notes If the vehicle can no longer be locked or
unlocked with the SmartKey, use the
mechanical key.
If you use the mechanical key to unlock and
open the driver's door, the anti-theft alarm
system will be triggered (Y page 77).There are several ways to turn off the alarm:
X
To deactivate the alarm with the
SmartKey: press the%or& button
on the SmartKey.
or
X Insert the SmartKey into the ignition lock.
or
X To deactivate the alarm with KEYLESS-
GO: press the Start/Stop button in the
ignition lock. The SmartKey must be in the
vehicle.
or
X Lock or unlock the vehicle using KEYLESS-
GO. The SmartKey must be outside the
vehicle.
If you unlock the vehicle using the mechanical
key, the fuel filler flap will not be unlocked
automatically.
X To unlock the fuel filler flap: insert the
SmartKey into the ignition lock.
Removing the mechanical key X
Push release catch :in the direction of
the arrow and at the same time remove
mechanical key ;from the SmartKey.
For further information about:
R unlocking the driver's door (Y page 88)
R unlocking the cargo compartment
(Y page 93)
R locking the vehicle (Y page 88)82
SmartKeyOpening and closing