2012 MERCEDES-BENZ CLS warning

EngineProblemPossible 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
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.
8
The yellow reserve fuel
warning lamp flashes
while the vehicle is in
motion. In addition, the
yellow Check Engine
warning lamp ;
may light up.The fuel system pressure is too low. The fuel filler cap is not closed
correctly or the fuel system is leaking.XObserve the additional display messages in the multifunction
display.XCheck that the fuel filler cap is correctly closed.XIf the fuel filler cap is not correctly closed: close the fuel filler
cap.XIf the fuel filler cap is closed: visit a qualified specialist
workshop.8
The yellow reserve fuel
warning lamp lights up
while the engine is
running.The fuel level has dropped into the reserve range.XRefuel at the nearest gas station.248Warning and indicator lamps in the instrument clusterOn-board computer and displays

ProblemPossible causes/consequences and M Solutions?
The red coolant
warning lamp lights up
while the engine is
running and the coolant
temperature gauge is
at the start of the scale.The temperature sensor for the coolant temperature gauge is
defective.
The coolant temperature is no longer being monitored. There is a
risk of engine damage if the coolant temperature is too high.XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions. Do not continue
driving under any circumstances.XEngage the parking brake.XConsult a qualified specialist workshop.Warning and indicator lamps in the instrument cluster249On-board computer and displaysZ

ProblemPossible causes/consequences and M Solutions?
The red coolant
warning lamp comes on
while the engine is
running.The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator
may be blocked or the electric engine radiator fan may be
malfunctioning.
The coolant is too hot and the engine is no longer being cooled
sufficiently.XObserve the additional display messages in the multifunction
display.XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.XAllow the engine and coolant to cool.XCheck the coolant level and add coolant (Y page 282). Observe
the warning notes.XIf you need to add coolant more often than usual, have the
engine coolant system checked.XMake sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.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 red coolant
warning lamp comes on
while the engine is
running. A warning tone
also sounds.The coolant temperature has exceeded 248 ‡ (120 †). The
airflow to the engine radiator may be blocked or the coolant level
may be too low.
The engine is not being cooled sufficiently and may be damaged.XObserve the additional display messages in the multifunction
display.XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.XAllow the engine and coolant to cool.XCheck the coolant level and add coolant (Y page 282). Observe
the warning notes.XIf you need to add coolant more often than usual, have the
engine coolant system checked.XMake sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.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.250Warning and indicator lamps in the instrument clusterOn-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 exceeds 248 ‡(120 †) do not continue driving. The engine will
otherwise be damaged.
Driving systems
ProblemPossible causes/consequences and M Solutions·
The red distance
warning lamp lights up
while the vehicle is in
motion. A warning tone
also sounds.GRisk of accident
The warning is issued if you approach a stationary vehicle or a
vehicle driving ahead of you at too high a speed.
XBe prepared to brake immediately.XPay careful attention to the traffic situation. You may have to
brake or take evasive action.
More information about DISTRONIC PLUS ( Y page 157) and
PRE-SAFE ®
Brake ( Y page 67).
Warning and indicator lamps in the instrument cluster251On-board computer and displaysZ

TiresProblemPossible causes/consequences and M Solutionsh
USA only:
The yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) is lit.
Canada only:
The yellow tire pressure
monitor warning lamp
(pressure loss) is lit.GRisk of accident
The tire pressure monitor has detected a loss of pressure in at
least one of the tires.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XObserve the additional display messages in the multifunction
display.XCheck the tire pressure. If necessary, correct the tire pressure
( Y page 322).XIf necessary, change a wheel ( Y page 338).h
USA only:
The yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) flashes for
60 seconds and then
remains lit.The tire pressure monitor is faulty.XObserve the additional display messages in the multifunction
display.XVisit a qualified specialist workshop.GWARNING
Each tire, including the spare (if provided), should be checked at least every two weeks when
cold and inflated to the pressure recommended by the vehicle manufacturer on the Tire and
Loading Information placard on the driver's door B-pillar or, if available, the tire pressure label
on the inside of the fuel filler flap. If your vehicle has tires of a different size than the size indicated
on the Tire and Loading Information placard or the tire pressure label, you should determine the
proper tire pressure for those tires.
As an added safety feature, your vehicle has been equipped with a tire pressure monitoring
system (TPMS) that illuminates a low tire pressure telltale when one or more of your tires are
significantly underinflated. Accordingly, when the low tire pressure telltale illuminates, you should
stop and check your tires as soon as possible, and inflate them to the proper pressure. Driving
on a significantly underinflated tire causes the tire to overheat and can lead to tire failure.
Underinflation also reduces fuel efficiency and tire tread life, and may affect the vehicle's handling
and stopping ability. Please note that the TPMS is not a substitute for proper tire maintenance,
and it is the driver's responsibility to maintain correct tire pressure, even if underinflation has
not reached the level to trigger illumination of the TPMS low tire pressure telltale.
USA only:
Your vehicle has also been equipped with a TPMS malfunction indicator to indicate when the
system is not operating properly. The TPMS malfunction indicator is combined with the low tire
pressure telltale. When the system detects a malfunction, the telltale will flash for approximately
1 minute and then remain continuously illuminated. This sequence will continue upon subsequent
252Warning and indicator lamps in the instrument clusterOn-board computer and displays

vehicle start-ups as long as the malfunction exists. When the malfunction indicator is illuminated,
the system may not be able to detect or signal low tire pressure as intended.
TPMS malfunctions may occur for a variety of reasons, including the installation of incompatible
replacement or alternate tires or wheels on the vehicle that prevent the TPMS from functioning
properly. Always check the TPMS malfunction telltale after replacing one or more tires or wheels
on your vehicle to ensure that the replacement or alternate tires and wheels allow the TPMS to
continue to function properly.Warning and indicator lamps in the instrument cluster253On-board computer and displaysZ

Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment of your vehicle available at the
time of publication of the Operator's
Manual. Country-specific differences are
possible. Please note that your vehicle may
not be equipped with all features
described. This also applies to safety-
related systems and functions.
i Please read the information on qualified
specialist workshops ( Y page 22).
Loading guidelines
GWARNING
Always fasten items being carried as securely
as possible. Use cargo tie-down rings and
fastening materials appropriate for the weight
and size of the load.
In an accident, during hard braking or sudden
maneuvers, loose items will be thrown around
inside the vehicle. This can cause injury to
vehicle occupants unless the items are
securely fastened in the vehicle.
To help avoid personal injury during a collision
or sudden maneuver, exercise care when
transporting cargo. Do not pile luggage or
cargo higher than the seat backrests.
The trunk is the preferred place to carry
objects.
Never drive a vehicle with the trunk open.
Deadly carbon monoxide (CO) gases may
enter vehicle interior resulting in
unconsciousness and death.
The handling characteristics of a laden
vehicle are dependent on the distribution of
the load within the vehicle. For this reason,
you should observe the following notes when
transporting a load:
R when transporting a load, never exceed the
maximum permissible gross vehicle weight
or the gross axle weight rating of the
vehicle (including occupants). The values
are specified on the vehicle identification
plate on the B-pillar of the driver's door.
R position heavy loads as far forwards as
possible and as low down in the trunk as
possible.
R the load must not protrude above the upper
edge of the seat backrests.
R always place the load against the rear or
front seat backrests. Make sure that the
seat backrests are securely locked into
place.
R always place the load behind unoccupied
seats if possible.
R secure the load with sufficiently strong and
wear-resistant tie down. pad sharp edges
for protection.
Stowage areas
Stowage compartments
Important safety notes
GWARNING
To help avoid personal injury during a collision
or sudden maneuver, exercise care when
storing objects in the vehicle. Put luggage or
cargo in the trunk if possible.
Do not pile luggage or cargo higher than the
seat backrests.
Keep compartment lids closed. This will help
to prevent stored objects from being thrown
about and injuring vehicle occupants during
R braking
R vehicle maneuvers
R an accident
Stowage compartments in the front
Glove box
i The glove box can be ventilated
( Y page 128).
256Stowage areasStowing and features

XTo open: pull handle : upwards.
The armrest folds out.
Stowage compartment under the front
seats
XTo open: pull handle : up and fold
cover ; forwards.
Stowage compartments in the rear
Stowage compartment in the rear seat
armrest
! Do not sit or lean your bodyweight on the
armrests when they are folded out as you
could damage them.
! Close the cover of the stowage
compartment before folding the rear seat
armrest back into the seat backrest.
XTo open: fold down seat armrest ;.XFold cover : of the armrest upwards.
Stowage pockets
GWARNING
Storage bags are intended for storing light-
weight items only.
Heavy objects, objects with sharp edges or
fragile objects may not be transported in the
storage bag. In an accident, during hard
braking, or sudden maneuvers, they could be
thrown around inside the vehicle and cause
injury to vehicle occupants.
Storage bags cannot protect transported
goods in the event of an accident.
Storage bags are located in the rear
compartment on the driver's and front-
passenger seat backrests.
Parcel nets
GWARNING
Parcel nets are intended for storing light-
weight items only, such as road maps, mail,
etc.
Heavy objects, objects with sharp edges, or
fragile objects may not be transported in the
parcel nets. In an accident, during hard
braking, or sudden maneuvers, they could be
thrown around inside the vehicle and cause
injury to vehicle occupants.
Parcel nets cannot protect transported goods
in the event of an accident.
258Stowage areasStowing and features