2012 MERCEDES-BENZ S-Class ignition

Display messagesPossible causes/consequences and M SolutionsThe red F (USA only)/ ! (Canada only) indicator lamp
flashes, the yellow F (USA only)/ ! (Canada only) warning
lamp lights up and a warning tone sounds.
The electric parking brake is malfunctioning and the braking effect
is restricted.
While the vehicle is in motion:XRelease the electric parking brake handle.
While the vehicle is stationary:
XSwitch off the ignition and turn it back on.XRelease the electric parking brake.
If the display message continues to be displayed:
XShift the transmission to P.XUse the folding wheel chock (Y page 474) from the vehicle tool
kit to secure the vehicle against rolling away.XConsult a qualified specialist workshop.F (USA
only) ! (Canada
only)
Parking Brake See
Oper. ManualThe yellow F (USA only)/ ! (Canada only) warning lamp
lights up. Additionally, the red F (USA only)/ ! (Canada
only) indicator lamp may light up.
The electric parking brake is malfunctioning.
To release:XPull the electric parking brake handle.
or
XPull away carefully.XVisit a qualified specialist workshop.
To apply:
XSwitch off the ignition.XPull the electric parking brake lever for at least ten seconds,
until the display message disappears.
If the display message continues to be displayed:
XShift the transmission to P.XUse the folding wheel chock (Y page 474) from the vehicle tool
kit to secure the vehicle against rolling away.XConsult a qualified specialist workshop.Display messages393On-board computer and displaysZ

Display messagesPossible causes/consequences and M SolutionsThe red F (USA only)/ ! (Canada only) indicator lamp lights
up.
The power supply for the electric parking brake was interrupted.XPull the electric parking brake handle.
or
XPull away carefully.
or
XPull the electric parking brake handle until the display message
disappears.The red F (USA only)/ ! (Canada only) indicator lamp
flashes and the yellow F (USA only)/ ! (Canada only)
warning lamp lights up.
The electric parking brake is malfunctioning.XSwitch off the ignition and turn it back on.XEngage or release the electric parking brake.
or
XPull away carefully.XVisit a qualified specialist workshop.The yellow F (USA only)/ ! (Canada only) warning lamp
lights up. The red F (USA only)/ ! (Canada only) indicator
lamp flashes for approximately 10 seconds after the electric
parking brake has been applied or released. It then goes out or
remains lit.
The electric parking brake is malfunctioning, e.g. because of
overvoltage or undervoltage.XPull away carefully.XVisit a qualified specialist workshop.
If there is overvoltage or undervoltage:
XRemove the cause for the overvoltage or undervoltage, e.g. by
charging the battery or restarting the engine.XSwitch the ignition off and on, and then engage or release the
electric parking brake.
If this does not release the electric parking brake:
XDo not drive on.XConsult a qualified specialist workshop.394Display messagesOn-board computer and displays

Display messagesPossible causes/consequences and M SolutionsThe yellow F (USA only)/ ! (Canada only) warning lamp
lights up. The red F (USA only)/ ! (Canada only) indicator
lamp flashes for approximately 10 seconds after the electric
parking brake has been applied or released. It then goes out or
remains lit.
The electric parking brake has overheated.XAllow the vehicle to cool down. Do not engage or release the
electric parking brake during this time.XUse the folding wheel chock (Y page 474) from the vehicle tool
kit to secure the vehicle against rolling away.XWhen the vehicle has cooled down: switch the ignition off and
on again, then engage or release the electric parking brake.F (USA
only) ! (Canada
only)
Parking Brake
InoperativeThe yellow F (USA only)/ ! (Canada only) warning lamp
lights up. The red F (USA only)/ ! (Canada only) indicator
lamp flashes for approximately 10 seconds after the electric
parking brake has been applied or released. It then goes out or
remains lit.
The electric parking brake is malfunctioning.XSwitch the ignition off and on, and then engage the electric
parking brake.
If it is not possible to engage the electric parking brake:
XShift the transmission to P.XUse the folding wheel chock (Y page 474) from the vehicle tool
kit to secure the vehicle against rolling away.XConsult a qualified specialist workshop.F (USA
only) ! (Canada
only)
Turn On the
Ignition to
Release the
Parking BrakeThe red F (USA only)/ ! (Canada only) indicator lamp lights
up.
You attempted to release the electric parking brake while the
ignition was switched off.XSmartKey: turn the SmartKey to position 1 in the ignition lock.XKEYLESS-GO: switch on the ignition.Display messages395On-board computer and displaysZ

Display messagesPossible causes/consequences and M SolutionsFront Passenger
Airbag Enabled
See Oper. ManualThe front-passenger air bag is 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 42 (Y page 50) indicator lamp and the
multifunction display and check the following:
Seat unoccupied and ignition switched on:
R the 42 indicator lamp must light up and remain lit.
When the indicator lamp is on, OCS (Y page 50) has deactivated
the front-passenger air bag.
R the Front Passenger Airbag Enabled See Oper. Manual
or Front Passenger Airbag Disabled See Oper. 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 the conditions are not fulfilled, the system is not operating
correctly.
XVisit a qualified specialist workshop immediately.Display messages399On-board computer and displaysZ

GWARNING
If the 42 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 Oper. ManualThe front-passenger air bag is 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 42 (Y page 50) indicator lamp and the
multifunction display and check the following:
Seat unoccupied and ignition switched on:
R the 42 indicator lamp must light up and remain lit.
When the indicator lamp is on, OCS (Y page 50) has deactivated
the front-passenger air bag.
R the Front Passenger Airbag Enabled See Oper. Manual
or Front Passenger Airbag Disabled See Oper. 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 fulfilled, the front-passenger seat can be
occupied again. Whether the 42 indicator lamp
remains lit or goes out depends on how OCS classifies the
occupant.
If the conditions are not fulfilled, the system is not operating
correctly.
XVisit a qualified specialist workshop immediately.GWARNING
If the 42 indicator lamp remains lit with an adult occupant on the front-passenger
seat even after performing the above corrective steps, do not have any passenger use the front-
passenger seat until the system has been repaired.
400Display messagesOn-board computer and displays

SmartKeyDisplay messagesPossible causes/consequences and M SolutionsÂ
Key Does Not
Belong to VehicleYou have put the wrong SmartKey in the ignition lock.XUse the correct SmartKey.Â
Take Your Key From
IgnitionThe SmartKey is in the ignition lock.XRemove the SmartKey.Â
Obtain a New KeyThe SmartKey needs to be replaced.XVisit a qualified specialist workshop.Â
Replace Key BatteryThe batteries of the KEYLESS-GO key are discharged.XChange the batteries ( Y page 82).Â
Don't Forget Your
KeyThe display message is shown for a maximum of 60 seconds and
is only a reminder.
You have opened the driver's door with the engine switched off.
The KEYLESS-GO key is not in the ignition lock.XRemember to take the KEYLESS-GO key with you when you
leave the vehicle.Â
Key Not Detected
(Red display message)The KEYLESS-GO key is not in the vehicle.
A warning tone also sounds.
If the engine is switched off, you can no longer lock the vehicle
centrally or start the engine.XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XEngage the electric parking brake.XLocate the KEYLESS-GO key.The KEYLESS-GO key is not detected while the engine is running
because there is interference from a strong source of radio waves.
A warning tone also sounds.XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XEngage the electric parking brake.XOperate the vehicle with the SmartKey in the ignition lock.Display messages419On-board computer and displaysZ

Display messagesPossible causes/consequences and M SolutionsÂ
Key Not Detected
(White display
message)The KEYLESS-GO key cannot be detected at present.XChange the location of the key with the KEYLESS-GO functions
in the vehicle.
If the KEYLESS-GO key is still not detected:
XOperate the vehicle with the SmartKey in the ignition lock.Â
Key Detected In
VehicleThe KEYLESS-GO key has been detected inside the vehicle during
locking.XRemove the KEYLESS-GO key from the vehicle.Â
Remove 'Start'
Button and Insert
KeyKEYLESS-GO is temporarily malfunctioning or is defective.XInsert the SmartKey into the ignition lock and turn it to the
desired position.XVisit a qualified specialist workshop.Â
Close Doors to
Lock VehicleAt least one door is open. A warning tone also sounds.XClose all doors and lock the vehicle again.
Warning and indicator lamps in the instrument cluster
Seat belt
ProblemPossible causes/consequences and M Solutions7
After starting the
engine, the red seat
belt warning lamp lights
up for six seconds.The seat belt warning lamp reminds the driver and front passenger
to fasten their seat belts.XFasten your seat belt ( Y page 57).7
After starting the
engine, the red seat
belt warning lamp lights
up. In addition, a
warning tone sounds
for up to six seconds.GRisk of injury
The driver's seat belt is not fastened.
XFasten your seat belt ( Y page 57).
The warning tone ceases.420Warning and indicator lamps in the instrument clusterOn-board computer and displays

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.
Engine
ProblemPossible causes/consequences and M Solutions;
The yellow Check
Engine warning lamp
lights up while the
engine is running.There may be a malfunction, for example:
R in the engine management
R in the fuel injection system
R in the exhaust system
R in the ignition system (for vehicles with a gasoline engine)
R in the fuel system
The emission limit values may be exceeded and the engine may
be running in emergency mode.XHave the vehicle checked as soon as possible at a qualified
specialist workshop.
i In some states, you are required by law to immediately visit a
qualified specialist workshop as soon as the yellow Check
Engine warning lamp lights up. If in doubt, check whether such
legal regulations apply in the state/province in which you are
currently driving.
Vehicles with a diesel engine: the fuel tank has been run dry
( Y page 320).XStart the engine three to four times after refueling.
If the yellow Check Engine warning lamp goes out, emergency
running mode is canceled. The vehicle need not be checked.Warning and indicator lamps in the instrument cluster427On-board computer and displaysZ