MERCEDES-BENZ S-CLASS SEDAN 2012 Owners Manual

Display messagesPossible causes/consequences and M SolutionsPRE-SAFE
Functions
Currently Limited
See Operator's
ManualGRisk of accident
PRE-SAFE ®
Brake is temporarily inoperative. Possible causes are:
R the DISTRONIC PLUS cover in the radiator grill is dirty.
R function is impaired due to heavy rain or snow.
R the sensors in the bumpers are dirty.
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 the system is outside the operating temperature range.
R the on-board voltage is too low.
If the display message does not disappear:
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XApply the electric parking brake.XClean the DISTRONIC PLUS cover in the radiator grill
( Y page 470).XClean the bumpers ( Y page 470).XRestart the engine.
If the system detects that the sensors are fully operational, the
display message disappears.
PRE-SAFE ®
Brake is operational again.
PRE-SAFE
Function Limited
See Oper. 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 SRS
Malfunction
Service Required  
or  Front Right SRS
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.Display messages399On-board computer and displaysZ

Display messagesPossible causes/consequences and M Solutions6
Rear Left SRS
Malfunction
Service Required  
or  Rear Right SRS
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
Rear Center SRS
Malfunction
Service RequiredGRisk of injury
SRS has malfunctioned at the rear center. 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 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.
400Display messagesOn-board computer and displays

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.XApply the parking brake.XSwitch the ignition off.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 54) 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 54) 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 messages401On-board computer and displaysZ

GWARNING
If the 42 indicator lamp remains off even after performing the above corrective
steps, do not have any children twelve 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.XApply the parking brake.XSwitch the ignition off.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 54) 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 54) 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.
402Display messagesOn-board computer and displays

Lights
i Display messages about LEDs:
This display message will only appear if all LEDs have failed.Display messagesPossible causes/consequences and M Solutionsb
Check Left
Cornering
Light or Check
Right Cornering
LightThe left or right-hand cornering light is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 286).
or
XVisit a qualified specialist workshop.b
Check Left Low
Beam or Check Right
Low BeamThe left or right-hand low-beam headlamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 286).
or
XVisit a qualified specialist workshop.b
Check Rear Left
Turn
Signal or Check
Rear Right Turn
SignalThe rear left-hand or rear right-hand turn signal is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 286).
or
XVisit a qualified specialist workshop.b
Check Front Left
Turn
Signal or Check
Front Right Turn
SignalThe front left-hand or front right-hand turn signal is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 286).
or
XVisit a qualified specialist workshop.b
Check Left Mirror
Turn
Signal or Check
Right Mirror Turn
SignalThe turn signal in the left-hand or right-hand exterior mirror is
defective.XCheck whether you are permitted to change the bulb yourself
( Y page 286).
or
XVisit a qualified specialist workshop.Display messages403On-board computer and displaysZ

Display messagesPossible causes/consequences and M Solutionsb
Check Center Brake
LampThe high-mounted brake lamp is faulty.XCheck whether you are permitted to change the bulb yourself
( Y page 286).
or
XVisit a qualified specialist workshop.b
Check Left Tail
and Brake
Lamp or Check Right
Tail and Brake LampThe left or right-hand tail lamp/brake lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 286).
or
XVisit a qualified specialist workshop.b
Check Left High
Beam or Check Right
High BeamThe left or right-hand high beam is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 286).
or
XVisit a qualified specialist workshop.b
Check Left License
Plate Lamp or Check
Right License
Plate LampThe left or right-hand license plate lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 286).
or
XVisit a qualified specialist workshop.b
Check Left Fog
Lamp or Check Right
Fog LampThe left-hand or right-hand front fog lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 286).
or
XVisit a qualified specialist workshop.b
Check Rear Left
Fog Lamp or Check
Rear Right Fog LampThe left-hand or right-hand rear fog lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 286).
or
XVisit a qualified specialist workshop.b
Check Front Left
Parking
Lamp or Check Front
Right Parking LampThe front left or front right parking or standing lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 286).
or
XVisit a qualified specialist workshop.404Display messagesOn-board computer and displays

Display messagesPossible causes/consequences and M Solutionsb
Check Left Reverse
Lamp or Check Right
Reverse LampThe left or right-hand backup lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 286).
or
XVisit a qualified specialist workshop.b
Check Front Left
Sidemarker
Lamp or Check Front
Right Sidemarker
LampThe left or right front side marker lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 286).
or
XVisit a qualified specialist workshop.b
Check Rear Left
Sidemarker
Lamp or Check Rear
Right Sidemarker
LampThe rear left or right side marker lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 286).
or
XVisit a qualified specialist workshop.b
Check Left Daytime
Running
Light or Check
Right Daytime
Running LightThe left or right-hand daytime running lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 286).
or
XVisit a qualified specialist workshop.b
Active Headlamps
InoperativeThe active light function is defective.XVisit a qualified specialist workshop.b
Malfunction See
Oper. ManualThe exterior lighting is defective.XVisit a qualified specialist workshop.b
AUTO Lamp Function
InoperativeThe light sensor is defective.XVisit a qualified specialist workshop.
USA only:
XSwitch off the daytime running lamps in the on-board computer
( Y page 387).XSwitch the lights on and off using the light switch.Display messages405On-board computer and displaysZ

Display messagesPossible causes/consequences and M Solutionsb
Please Switch Off
LightsThe lights are still switched on when you leave the vehicle. A
warning tone also sounds.XTurn the light switch to $ or c .
or
XIf the rear fog lamp is switched on: press the light switch in to
the stop.Adaptive High-beam
Assist InoperativeAdaptive Highbeam Assist is faulty.XVisit a qualified specialist workshop.
Engine
Display messagesPossible causes/consequences and M Solutions+
Check Coolant
Level See Oper.
ManualThe coolant level is too low.XAdd coolant, observing the warning notes when doing so
( Y page 463).XIf coolant needs to be added more often than usual, have the
engine coolant system checked at a qualified specialist
workshop.GWARNING
Do not spill antifreeze on hot engine parts. Antifreeze contains ethylene glycol which may burn
if it comes into contact with hot engine parts. You could be seriously burned.
! The coolant level is too low. Avoid making long journeys with too little coolant in the cooling
system. The engine will otherwise be damaged.
The display messages and the corresponding symbol that indicate that the coolant level is
too low must not be ignored.
Display messagesPossible causes/consequences and M Solutions?
Coolant Low Stop
Vehicle Turn
Engine OffThe coolant is too hot.XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.XMake sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.XWait until the display message disappears before restarting the
engine. Otherwise, the engine could be damaged.XPay attention to the coolant temperature display.XIf the temperature increases again, visit a qualified specialist
workshop immediately.406Display messagesOn-board computer and displays

GWARNING
Driving when your engine is overheated can cause some fluids which may have leaked into the
engine compartment to catch fire. You could be seriously burned.
Steam from an overheated engine can cause serious burns which can occur just by opening the
engine hood. Stay away from the engine if you see or hear steam coming from it.
Stop the vehicle in a safe location away from other traffic. Turn off the engine, get out of the
vehicle and do not stand near the vehicle until the engine has cooled down.
! If the coolant temperature is over 248 ‡ (120 †), do not continue driving. The engine will
otherwise be damaged.
Display messagesPossible causes/consequences and M Solutions?The engine fan is defective.XAt coolant temperatures under 248 ‡(120 †), drive to the next
qualified specialist workshop.XAvoid subjecting the engine to heavy loads, e.g. driving in
mountainous terrain, and stop-and-go traffic.#The battery is not being charged.
Possible causes are:
R a defective alternator
R a torn poly-V-belt
R a malfunction in the electronicsXPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.XOpen the hood.XCheck whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do not continue driving. The engine could otherwise overheat.
XConsult a qualified specialist workshop.
If the poly-V-belt is not damaged:
XVisit a qualified specialist workshop.Display messages407On-board computer and displaysZ

Display messagesPossible causes/consequences and M Solutions4
Check Engine Oil
At Next RefuelingVehicles with an oil dipstick: the oil level has dropped to the
minimum level.XCheck the oil level when next refueling, at the latest
( Y page 459).XIf necessary, add engine oil ( Y page 462).XHave the engine checked at a qualified specialist workshop if
engine oil needs to be added more often than usual.4
Check Engine Oil
Level (Add 1 quart)
(USA only) Check
Engine Oil Level
(Add 1 Liter)
(Canada only)Vehicles without an oil dipstick: the engine oil level is too low.XCheck the oil level ( Y page 459).XIf necessary, add engine oil ( Y page 459).XHave the engine checked at a qualified specialist workshop if
engine oil needs to be added more often than usual.
Information on approved engine oils can be obtained from any qualified specialist workshop
or on the Internet at http://www.mbusa.com (USA only).
! The oil level is too low. Avoid long journeys with too little engine oil. There is a risk of
engine damage.
The display messages and the corresponding symbol that indicate that the oil level is too
low must not be ignored.
Display messagesPossible causes/consequences and M Solutions4
Engine Oil Level
Low Stop Vehicle
Turn Engine OffVehicles without an oil dipstick: the engine oil level is too low.
There is a risk of engine damage.XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.XApply the parking brake.XAdd engine oil ( Y page 462) and check the oil level
( Y page 459).4
Engine Oil Level
Too HighVehicles without an oil dipstick: you have added too much engine
oil. There is a risk of damage to the engine or to the catalytic
converter.XHave the excess oil siphoned off at a qualified specialist
workshop. Observe the legal requirements.4
Engine Oil Level
Cannot Be MeasuredVehicles without an oil dipstick: the measuring system is
defective.XVisit a qualified specialist workshop.408Display messagesOn-board computer and displays