2014 MERCEDES-BENZ C-CLASS SALOON engine

Display messages
Possible causes/consequences and
M
MSolutions The yellow
!warning lamp lights up. If you manually apply or
release the electric parking brake, the red !indicator lamp
flashes.
The electric parking brake is malfunctioning. It is not possible to
apply the electric parking brake manually.
X Vehicles with manual transmission: switch off the ignition.
The electric parking brake is applied automatically.
X Vehicles with automatic transmission: shift the transmission
to P, as the electric parking brake is not applied automatically.
X Visit a qualified specialist workshop.
If it is not possible to release the electric parking brake manually: X Release the electric parking brake automatically (Y page 209).!
Parking Parking
brake
brakeinop‐
inop‐
erative
erative The yellow
!warning lamp lights up. The red !indicator
lamp flashes for about ten 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 over- voltage or undervoltage.
X Rectify the cause of the overvoltage or undervoltage, e.g. by
charging the battery or restarting the engine.
X Apply or release the electric parking brake.
If the electric parking brake still cannot be applied or released: X Switch off the ignition and turn it back on.
X Apply or release the electric parking brake.
If the electric parking brake still cannot be released: X Consult a qualified specialist workshop.
If it is still not possible to apply the electric parking brake: X Visit a qualified specialist workshop. The yellow
!warning lamp lights up and the red !indicator
lamp flashes.
It is not possible to apply the electric parking brake manually.
X Vehicles with manual transmission: engage first gear.
X Vehicles with automatic transmission: shift the transmission
to P.
X Visit a qualified specialist workshop. Display
messages
321On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions !
Turn on the igni‐ Turn on the igni‐
tion to release tion to release
the parking brake the parking brake The red
!indicator lamp lights up.
You attempted to release the electric parking brake while the igni-
tion was switched off.
X Switch the ignition on. J
Check brake fluid Check brake fluid
level level There is insufficient brake fluid in the brake fluid reservoir.
In addition, the red Jwarning lamp lights up in the instrument
cluster and a warning tone sounds.
G WARNING
Braking efficiency may be impaired.
There is a risk of an accident. X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away (Y page 207).
X Consult a qualified specialist workshop.
X Do not top up the brake fluid. This does not correct the fault. #
Check brake pad Check brake pad
wear wear The brake pads/linings have reached their wear limit.
X Visit a qualified specialist workshop. Collision Preven‐
Collision Preven‐
tion Assist Plus tion Assist Plus
currently unavail‐ currently unavail‐
able See Owner's able See Owner's
Manual Manual COLLISION PREVENTION ASSIST PLUS is temporarily inoperative.
Possible causes:
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation
R the system is outside the operating temperature range
R the on-board voltage is too low
Once the causes listed above no longer apply, the display message goes out.
COLLISION PREVENTION ASSIST PLUS is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 207).
X Restart the engine. 322
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions Collision Preven‐
Collision Preven‐
tion Assist Plus tion Assist Plus
inoperative inoperative COLLISION PREVENTION ASSIST PLUS is temporarily inoperative
due to a malfunction. Adaptive Brake Assist may also have failed.
X Visit a qualified specialist workshop. PRE-SAFE inopera‐
PRE-SAFE inopera‐
tive See Owner's tive See Owner's
Manual Manual
Important functions of PRE-SAFE
®
have failed. All other occupant
safety systems, e.g. airbags, remain available.
X Visit a qualified specialist workshop immediately. PRE-SAFE
PRE-SAFE
Functions
Functions
currently limited
currently limited
See Owner's Manual See Owner's Manual PRE
‑SAFE ®
PLUS or PRE ‑SAFE®
Brake is temporarily inoperative.
Possible causes:
R the 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 sta-
tions or other sources of electromagnetic radiation
R the system is outside the operating temperature range
R the on-board voltage is too low
Once the causes listed above no longer apply, the display message
goes out.
PRE ‑SAFE ®
PLUS and PRE ‑SAFE®
Brake are operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 207).
X Restart the engine. PRE-SAFE PRE-SAFE
Functions
Functions
limited See Own‐
limited See Own‐
er's Manual er's Manual PRE
‑SAFE ®
PLUS or PRE‑ SAFE®
Brake is unavailable due to a mal-
function. BAS PLUS might also be deactivated.
X Visit a qualified specialist workshop. Display
messages
323On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions Radar sensors
Radar sensors
dirty See Owner's dirty See Owner's
Manual Manual At least one of the following driving systems or driving safety sys-
tems is temporarily restricted or inoperative:
R PRE-SAFE ®
PLUS
R PRE-SAFE ®
Brake
R COLLISION PREVENTION ASSIST PLUS
R Active Lane Keeping Assist
R Active Blind Spot Assist
R DISTRONIC PLUS
Possible causes:
R the sensors in the radiator trim and/or in the bumpers are dirty
R the function of the driving system and/or driving safety system
is impaired due to heavy rain or snow
A warning tone also sounds.
Once the causes listed above no longer apply, the display message
goes out. All driving systems/driving safety systems are operative again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 207).
X Switch off the engine.
X Clean the sensors (Y page 401) in the following locations:
R in the radiator trim
R in the front bumper
R in the rear bumper, particularly in the middle of the rear
bumper
X Restart the engine.
The display message disappears. ü ü If this symbol appears in the multifunction display, a seat belt
tongue has been inserted into a rear seat belt buckle.
Further information on the status indicator for the rear seat belts
(Y page 50). 324
Display
messagesOn-board computer and displays

Engine
Display messages
Possible causes/consequences and
M
MSolutions +
Top Top
up
upcoolant
coolant See
See
Owner’s Manual
Owner’s Manual The coolant level is too low.
! Avoid making long journeys with too little coolant in the engine
cooling system. The engine will otherwise be damaged.
X Top up the coolant, observing the warning notes before doing so
(Y page 393).
X If the coolant needs topping up more often than usual, have the
engine coolant system checked at a qualified specialist work-
shop. ? ? The fan motor is faulty.
X If the coolant temperature is below 120 †, you can continue
driving to the nearest qualified specialist workshop.
X Avoid putting the engine under heavy load as you do so, e.g.
driving in mountainous terrain and stop-start traffic. ?
Coolant Stop vehi‐ Coolant Stop vehi‐
cle Switch engine cle Switch engine
off off The coolant is too hot.
A warning tone also sounds.
G WARNING
Never drive with an overheated engine. Driving when your engine is overheated can cause some fluids which may have leaked into
the engine compartment to catch fire.
In addition, steam from an overheated engine can cause serious
burns, which can occur just by opening the bonnet.
There is a risk of injury.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Secure the vehicle to prevent it from rolling away (Y page 207).
X Wait until the engine has cooled down.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.
X Do not start the engine again until the display message goes out
and the coolant temperature is below 120 †. The engine may
otherwise be damaged.
X Pay attention to the coolant temperature display.
X If the temperature increases again, visit a qualified specialist
workshop immediately.
Under normal operating conditions and with the specified coolant level, the coolant temperature may rise to 120 †. Display messages
333On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions #
See Owner's Manual See Owner's Manual The battery is not being charged.
A warning tone also sounds.
Possible causes:
R faulty alternator
R defective power electronics (hybrid vehicles)
R torn poly-V-belt
R a malfunction in the electronics
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
! Do not continue driving. The engine could otherwise overheat.
X Secure the vehicle to prevent it from rolling away (Y page 207).
X Consult a qualified specialist workshop. #
Stop vehicle See Stop vehicle See
Owner's Manual Owner's Manual The battery is no longer being charged and the battery charge level
is too low.
A warning tone also sounds.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Secure the vehicle to prevent it from rolling away (Y page 207).
X Observe the instructions in the #See Owner's Manual See Owner's Manual
display message.
X Consult a qualified specialist workshop. #
Start engine See Start engine See
Owner's Manual Owner's Manual The engine is off and the battery charge level is too low.
X Switch off electrical consumers that you do not need, such as
the rear window heating and interior lighting.
X Leave the engine running for a few minutes, or drive for a longer
distance.
The battery charges. 334
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions 4
Check eng. oil Check eng. oil
lev. when next lev. when next
refuelling refuelling The engine oil level has dropped to the minimum level.
A warning tone also sounds.
X Check the engine oil level when next refuelling, at the latest
(Y page 392).
X If necessary, top up the engine oil (Y page 392).
X Have the engine checked at a qualified specialist workshop if the
engine oil needs topping up more often than usual.
! Avoid long journeys when there is too little coolant in the cool-
ing system. Otherwise the engine will be damaged.
Information on approved engine oils can be obtained from any
qualified specialist workshop or on the Internet at http://
bevo.mercedes-benz.co m.4
Add Add
1
1litre
litre engine
engine
oil
oil when
when next
next refu‐
refu‐
elling
elling Display message only for AMG vehicles:
The engine oil level has dropped to the minimum level.
X Check the engine oil level when next refuelling, at the latest
(Y page 392).
X If necessary, top up the engine oil (Y page 392).
X Have the engine checked at a qualified specialist workshop if the
engine oil needs topping up more often than usual.
! Avoid long journeys when there is too little coolant in the cool-
ing system. Otherwise the engine will be damaged.
Information on approved engine oils can be obtained from any
qualified specialist workshop or on the Internet at http://
bevo.mercedes-benz.com. 4
Engine oil level Engine oil level
Stop vehicle Stop vehicle
Switch engine off Switch engine off The engine oil level is too low. There is a risk of engine damage.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Secure the vehicle to prevent it from rolling away (Y page 207).
X Check the engine oil level (Y page 392).
X If necessary, top up the engine oil (Y page 392).8
Reserve fuel level Reserve fuel level The fuel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated if the fuel level
drops into the reserve range.
X Refuel at the nearest filling station. C C There is very little fuel in the fuel tank.
The auxiliary heating cannot be operated.
X Refuel at the nearest filling station without fail. Display messages
335On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions ¸
Replace Replace
air
aircleaner
cleaner Vehicles with a diesel engine: the engine air filter is dirty and must
be replaced.
X Visit a qualified specialist workshop. !
Clean Clean
the
thefuel
fuel fil‐
fil‐
ter
ter Vehicles with a diesel engine: there is water in the fuel filter. The
water must be drained off.
X Visit a qualified specialist workshop. Refill AdBlue See Refill AdBlue See
Owner’s Manual Owner’s Manual
The AdBlue
®
level has fallen below the reserve range. A warning
tone also sounds.
X Refill AdBlue ®
as soon as possible (Y page 204).Refill AdBlue No
Refill AdBlue No
start in ... mi start in ... mi
The AdBlue
®
level is only sufficient for the indicated distance. A
warning tone also sounds.
X Refill AdBlue ®
immediately (Y page 204).
i If you drive the vehicle faster than 15 km/h the
Refill
Refill
AdBlue
AdBlue No
Nostart
start in
in...
... mi
mimessage goes out after approx-
imately one minute. Refill
Refill
AdBlue
AdBlueEng.
Eng.
start not possible
start not possible The AdBlue
®
tank is empty. A warning tone also sounds. You can
no longer start the engine.
X Add at least 3.5 l of AdBlue ®
(Y page 204).
X Turn the ignition on for approximately one minute.
The system requires approximately one minute after refilling to
detect the change in the AdBlue ®
level.
X Start the engine. Check AdBlue See
Check AdBlue See
Owner’s Manual Owner’s Manual
The AdBlue
®
system is malfunctioning. A warning tone also
sounds.
X Visit a qualified specialist workshop. Eng.
Eng.
start
start not
notpos‐
pos‐
sible
sible The AdBlue
®
system is malfunctioning. A warning tone also
sounds. You can no longer start the engine.
X Consult a qualified specialist workshop immediately. 336
Display
messagesOn-board computer and displays