brake MERCEDES-BENZ CLS 2012 Repair Manual

Assistance menu
Introduction
In the DriveAssist. menu you can:
R show the distance display
R activate/deactivate ESP ®
R activate/deactivate PRE-SAFE ®
Brake
R activate/deactivate ATTENTION ASSIST
R activate/deactivate Blind Spot Assist or
Active Blind Spot Assist
R activate/deactivate Lane Keeping Assist or
Active Lane Keeping Assist
Showing the distance display
This function is only available with
DISTRONIC PLUS.
XPress the = or ; button on the
steering wheel to select the DriveAssist
menu.XPress the 9 or : button to select
Distance Display .XPress a.
The DISTRONIC PLUS distance display
( Y page 163) appears in the multifunction
display.Deactivating/activating ESP ®GWARNING
Under no circumstances should you
deactivate ESP ®
when the ÷ ESP®
warning lamp in the instrument cluster
flashes. Proceed as follows:
R when driving off, apply as little throttle as
possible.
R while driving, ease up on the accelerator
pedal.
R adapt your speed to suit the prevailing road
and weather conditions.
Failure to observe these guidelines could
cause the vehicle to skid. ESP ®
cannot
prevent accidents resulting from excessive
speed.
This function is not available in AMG vehicles.
For activating or deactivating ESP ®
on AMG
vehicles, see ( Y page 65).
Further information about ESP ®
(Y page 63).
XStart the engine.XPress = or ; on the steering wheel
to select the DriveAssist. menu.XPress the 9 or : button to select
ESP .XPress the a button.XTo deactivate: press a again.
The å warning lamp in the instrument
cluster comes on.GWARNING
When the å ESP®
OFF warning lamp is lit,
ESP ®
is deactivated.
If the ÷ ESP®
warning lamp and the
å ESP®
OFF warning lamp remain lit,
ESP ®
is not available due to a malfunction.
When ESP ®
is deactivated or not operational,
vehicle stability in standard driving
maneuvers is reduced.
Adapt your speed and driving to the prevailing
road conditions and to the non-operating
status of the ESP ®
.
206Menus and submenusOn-board computer and displays

XTo activate: press a again.
The å warning lamp in the instrument
cluster goes out.
Activating/deactivating PRE-SAFE ®
Brake
PRE-SAFE ®
Brake is only available in vehicles
with DISTRONIC PLUS.
XPress the = or ; button on the
steering wheel to select the DriveAssist
menu.XPress 9 or : to select PRE-SAFE
Brake .XPress a.
The current selection is displayed.XTo activate/deactivate: press a
again.
When PRE-SAFE ®
Brake ( Y page 67) is
activated, the multifunction display shows
the Ä symbol as long as the HOLD
function is not activated ( Y page 166).
Vehicles with Active Parking Assist: if
PARKTRONIC is activated and you are driving
at a speed under 22 mph (35 km/h), the j
Active Parking Assist symbol will be displayed
instead of the Ä symbol.
Activating/deactivating ATTENTION
ASSIST
XPress the = or ; button on the
steering wheel to select the DriveAssist
menu.XPress the 9 or : button to select
Attention Asst. .XPress a.
The current selection is displayed.XTo activate/deactivate: press a
again.
When ATTENTION ASSIST ( Y page 180) is
activated, the À symbol appears in the
multifunction display when the ignition is on.
Activating/deactivating Blind Spot
Assist
You can use the Blind Spot Asst. function
to activate or deactivate Blind Spot Assist
( Y page 184) or Active Blind Spot Assist
( Y page 188).
XPress = or ; on the steering wheel
to select the DriveAssist menu.XPress 9 or : to select Blind Spot
Asst. .XPress a.
The current selection is displayed.XTo activate/deactivate: press a
again.
Activating/deactivating Lane Keeping
Assist
You can use the Lane Keep. Asst. function
to activate/deactivate Lane Keeping Assist
( Y page 186) or Active Lane Keeping Assist
( Y page 191).
XPress the = or ; button on the
steering wheel to select the DriveAssist
menu.XPress the 9 or : button to select
Lane Keep. Asst. .XPress a.
If the function is activated, the road
markings are shown in red in the
multifunction display.XTo activate/deactivate: press a
again.
If Lane Keeping Assist or Active Lane keeping
Assist is activated, the multifunction display
shows the à symbol when the ignition is
switched on.
Menus and submenus207On-board computer and displaysZ

Vehicle
Activating/deactivating the automatic
door locking feature
If you select the Auto. Door Locks
function, the vehicle is centrally locked above
a speed of around 9 mph (15 km/h).
i For further information on the automatic
locking feature, see ( Y page 80).
XPress the = or ; button on the
steering wheel to select the Settings
menu.XPress the : or 9 button to select the
Vehicle submenu.XPress the a button to confirm.XPress the : or 9 button to select the
Auto. Door Locks function.
When the Auto. Door Locks function is
activated, the vehicle doors are displayed
in red in the multifunction display.XPress the a button to save the setting.
Activating/deactivating the acoustic
locking confirmation
If you activate the Acoustic Lock function,
an audible signal sounds when the vehicle is
locked or unlocked. When unlocking, the
signal sounds once. When locking, it sounds
three times.
XPress the = or ; button on the
steering wheel to select the Settings
menu.XPress the : or 9 button to select the
Vehicle submenu.XPress the a button to confirm.XPress the : or 9 button to select the
Acoustic Lock function.
If the Acoustic Lock function is activated,
the & symbol in the multifunction
display lights up red.XPress the a button to save the setting.Activating/deactivating the radar sensor
system
The following systems are switched off when
the radar sensor system is deactivated:
R DISTRONIC PLUS ( Y page 157)
R BAS PLUS ( Y page 62)
R PRE-SAFE ®
Brake ( Y page 67)
R Blind Spot Assist ( Y page 184)
R Active Blind Spot Assist ( Y page 188)
i USA 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.
i Canada only:
This device complies with RSS-210 of
Industry Canada. Operation is subject to
the following two conditions:
1. This device may not cause harmful
interference, and
2. this device must accept any interference
received, including interference that may
cause undesired operation.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.XPress the = or ; button on the
steering wheel to select the Settings
menu.XPress the : or 9 button to select the
Vehicle submenu.XPress the a button to confirm.XPress the 9 or : button to select
Radar Sensor (See Oper. Manual): .
You will see the selected setting: Enabled
or Disabled .XPress the a button to save the setting.Menus and submenus211On-board computer and displaysZ

Safety systemsDisplay messagesPossible causes/consequences and M Solutions!÷
Currently
Unavailable See
Operator's ManualGRisk of accident
ABS (Anti-lock Braking System), ESP ®
(Electronic Stability
Program), BAS (Brake Assist), PRE-SAFE ®
, the HOLD function and
hill start assist are temporarily unavailable.
BAS PLUS and PRE-SAFE ®
Brake may also have failed.
In addition, the ÷, å and ! warning lamps light up in
the instrument cluster.
The self-diagnosis function might not be complete, for example.
ATTENTION ASSIST is deactivated.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
XCarefully drive a suitable distance making slight steering
movements at a speed above 12 mph (20 km/h).
If the display message disappears, the functions mentioned
above are available again.
If the display message continues to be displayed:
XDrive on carefully.XVisit a qualified specialist workshop.GRisk of accident
ABS, ESP ®
, BAS, PRE-SAFE ®
, the HOLD function and hill start
assist are temporarily unavailable.
BAS PLUS and PRE-SAFE ®
Brake may also have failed.
In addition, the ÷, å and ! warning lamps light up in
the instrument cluster.
For example, the on-board voltage may be insufficient.
ATTENTION ASSIST is deactivated.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
XDrive on carefully.
If the display message disappears, the functions mentioned
above are available again.
If the display message continues to be displayed:
XDrive on carefully.XVisit a qualified specialist workshop.Display messages217On-board computer and displaysZ

Display messagesPossible causes/consequences and M Solutions!÷
Inoperative See
Operator's ManualGRisk of accident
ABS, ESP ®
, BAS, PRE-SAFE ®
, the HOLD function and hill start
assist are not available due to a malfunction.
BAS PLUS and PRE-SAFE ®
Brake may also have failed.
The $ (USA only)/ J (Canada only), ÷, å and !
warning lamps in the instrument cluster also light up.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
ATTENTION ASSIST is deactivated.
XDrive on carefully.XVisit a qualified specialist workshop immediately.÷
Inoperative See
Operator's ManualGRisk of accident
ESP ®
, BAS, PRE-SAFE ®
, the HOLD function and hill start assist are
not available due to a malfunction.
BAS PLUS and PRE-SAFE ®
Brake may also have failed.
In addition, the ÷ and å warning lamps light up in the
instrument cluster.
ATTENTION ASSIST is deactivated.
The brake system continues to function normally, but without the
functions listed above.
XDrive on carefully.XVisit a qualified specialist workshop.T !
÷
Inoperative See
Operator's ManualGRisk of accident
EBD (electronic brake force distribution), ABS, ESP ®
, BAS, PRE-
SAFE ®
, the HOLD function and hill start assist are not available
due to a malfunction.
BAS PLUS and PRE-SAFE ®
Brake may also have failed.
In addition, the ÷, å and ! warning lamps light up in
the instrument cluster and a warning tone sounds.
ATTENTION ASSIST is deactivated.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
XDrive on carefully.XVisit a qualified specialist workshop immediately.218Display messagesOn-board computer and displays

Display messagesPossible causes/consequences and M Solutions#
Check Brake Pad
WearThe brake pads/linings have reached their wear limit.XVisit a qualified specialist workshop.$ (USA
only) J (Canada
only)
Release Parking
BrakeYou are driving with the parking brake applied. A warning tone also
sounds.XRelease the parking brake$ (USA
only) J (Canada
only)
Check Brake Fluid
LevelGRisk of accident
There is not enough brake fluid in the brake fluid reservoir.
Additionally, the red $ (USA only)/ J (Canada only)
warning lamp lights up in the instrument cluster and a warning
tone sounds.
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.XEngage the parking brake.XConsult a qualified specialist workshop.XDo not add brake fluid. This will not correct the malfunction.GWARNING
Driving with the message Check Brake Fluid Level displayed can result in an accident. Have
your brake system checked immediately.
Do not add brake fluid before checking the brake system. Overfilling the brake fluid reservoir can
result in spilling brake fluid on hot engine parts and the brake fluid catching fire. You can be
seriously burned.
Display messages219On-board computer and displaysZ

Display messagesPossible causes/consequences and M SolutionsG
Tele Aid
InoperativeUSA only: one or more of the main functions in the mbrace system
are malfunctioning.
Canada only: one or more of the main functions of the TELEAID
system are malfunctioning.XUSA only: have the mbrace system checked at a qualified
specialist workshop.XCanada only: have the TELEAID system checked at a qualified
specialist workshop.PRE-SAFE
Inoperative See
Operator's ManualGRisk of injury
Important functions of PRE-SAFE ®
have failed. All other occupant
safety systems, e.g. air bags, remain available.
XVisit a qualified specialist workshop immediately.PRE-SAFE
Function Currently
Limited See Oper.
ManualGRisk of accident
PRE-SAFE ®
Brake is temporarily inoperative if:
R the DISTRONIC PLUS cover in the radiator grill is dirty.
R the sensors in the bumpers are dirty.
R its function is impaired due to heavy rain or snow.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio
stations or other sources of electromagnetic radiation.
R AMG vehicles only: you deactivate ESP ®
.
R the system is outside the operating temperature range.
R the on-board voltage is too low.
PRE-SAFE ®
Brake is operational again and the display message
disappears if:
R the dirt (e.g. slush) drops away while the vehicle is in motion.
R the system detects that the sensors are fully available again.
R AMG vehicles only: you reactivate ESP ®
.
R the system is within the operating temperature range.
If the display message continues to be displayed:
XClean the DISTRONIC PLUS cover in the radiator grill
( Y page 289).XClean the bumpers ( Y page 289).XRestart the engine.XWait until the battery is sufficiently charged.220Display messagesOn-board computer and displays

Display messagesPossible causes/consequences and M SolutionsPRE-SAFE
Functions Limited
See Operator's
ManualGRisk of accident
PRE-SAFE ®
Brake is defective. BAS PLUS or the distance warning
signal may also have failed.
XVisit a qualified specialist workshop.6
SRS Malfunction
Service RequiredGRisk of injury
There is a malfunction in the SRS (Supplemental Restraint
System). The 6 warning lamp also lights up in the instrument
cluster.
XVisit a qualified specialist workshop.6
Front Left
Malfunction
Service Required or
Front Right
Malfunction
Service RequiredGRisk of injury
SRS has malfunctioned at the front on the left or right. The 6
warning lamp also lights up in the instrument cluster.
XVisit a qualified specialist workshop.6
Rear Left
Malfunction
Service Required or
Rear Right
Malfunction
Service RequiredGRisk of injury
SRS has malfunctioned at the rear on the left or right. The 6
warning lamp also lights up in the instrument cluster.
XVisit a qualified specialist workshop.6
Left Side Curtain
Airbag Malfunction
Service Required or
Right Side Curtain
Airbag Malfunction
Service RequiredGRisk of injury
There is a malfunction in the left-hand and/or right-hand window
curtain air bag. The 6 warning lamp also lights up in the
instrument cluster.
XVisit a qualified specialist workshop.GWARNING
In the event a malfunction of the SRS is indicated as outlined above, the SRS may not be
operational.
For your safety, we strongly recommend that you contact an authorized Mercedes-Benz Center
immediately to have the system checked. Otherwise the SRS may not be activated when needed
in an accident, which could result in serious or fatal injury, or it might deploy unexpectedly and
unnecessarily which could also result in injury.
Display messages221On-board computer and displaysZ

Display messagesPossible causes/consequences and M SolutionsFront Passenger
Airbag Enabled
See Operator's
ManualThe front-passenger air bag and front-passenger knee bag are
enabled during the journey, even though:
R a child, a small adult or an object weighing less than the
system's weight threshold is located on the front-passenger
seat.
R the front-passenger seat is unoccupied.
The system may detect objects or forces applying additional
weight on the seat.XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XEngage the parking brake.XSwitch off the ignition.XOpen the front-passenger door.XRemove the child and the child restraint system from the front-
passenger seat.XIf necessary, secure the child in a child restraint system on a
suitable rear seat.XMake sure that there are no objects on the seat adding to the
weight.
The system may otherwise detect the additional weight and
interpret the seat occupant's weight as greater than it actually
is.XKeep the seat unoccupied, close the front-passenger door and
switch on the ignition.
Observe the 45(Y page 43) indicator lamp and the
multifunction display and check the following:
Seat unoccupied and ignition switched on:
R the 45 indicator lamp must light up and remain lit. When
the indicator lamp is on, OCS ( Y page 43) has deactivated the
front-passenger air bag and front-passenger knee bag.
R the Front Passenger Airbag Enabled See Operator's
Manual or Front Passenger Airbag Disabled See
Operator's Manual display messages must not appear in the
multifunction display. Wait for a period of at least 60 seconds
until the necessary system checks have been completed and to
make sure that the display messages do not appear in the
multifunction display.
If these conditions are met, the front-passenger seat can be
occupied again. Whether the 45 indicator lamp remains lit
or goes out depends on how OCS classifies the occupant.
If the conditions are not met, the system is not operating correctly.
222Display messagesOn-board computer and displays

Display messagesPossible causes/consequences and M SolutionsXVisit a qualified specialist workshop immediately.GWARNING
If the 45 indicator lamp remains off even after performing the above corrective steps, do
not have any children 12 years old and under and other small individuals use the front-passenger
seat until the system has been repaired.
Display messagesPossible causes/consequences and M SolutionsFront Passenger
Airbag Disabled
See Operator's
ManualThe front-passenger air bag and the front-passenger knee bag are
deactivated during the journey even though an adult or a person
larger than a certain size is occupying the front-passenger seat. If
additional forces are applied to the seat, the system may interpret
the occupant's weight as lower than it actually is.XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XEngage the parking brake.XSwitch off the ignition.XHave the occupant get out of the vehicle.XKeep the seat unoccupied, close the front-passenger door and
switch on the ignition.
Observe the 45(Y page 43) indicator lamp and the
multifunction display and check the following:
Seat unoccupied and ignition switched on:
R the 45 indicator lamp must light up and remain lit. When
the indicator lamp is on, OCS ( Y page 43) has deactivated the
front-passenger air bag and front-passenger knee bag.
R the Front Passenger Airbag Enabled See Operator's
Manual or Front Passenger Airbag Disabled See
Operator's Manual display messages must not appear in the
multifunction display. Wait for a period of at least 60 seconds
until the necessary system checks have been completed and to
make sure that the display messages do not appear in the
multifunction display.
If these conditions are met, the front-passenger seat can be
occupied again. Whether the 45 indicator lamp remains lit
or goes out depends on how OCS classifies the occupant.
If the conditions are not met, the system is not operating correctly.
XVisit a qualified specialist workshop immediately.Display messages223On-board computer and displaysZ