2014 MERCEDES-BENZ S-CLASS COUPE ECU

Display messages
Possible causes/consequences and
M
MSolutions Â
Key not detected Key not detected
(red display message) The 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.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle to prevent it from rolling away (Y page 178).
X Locate the key.
X Press aon the steering wheel to confirm the display mes-
sage. Because there is interference from a strong source of radio waves,
the key is not detected whilst the engine is running.
A warning tone also sounds.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle to prevent it from rolling away (Y page 178).
X Operate the vehicle with the key in the ignition lock if necessary. Â
Remove starting Remove starting
button, then button, then
insert key insert key The key is continually undetected.
The key detection function has a temporary malfunction or is
faulty. A warning tone also sounds.
X Insert the key into the ignition lock and turn it to the desired
position.
X Visit a qualified specialist workshop. Display
messages
299On-board computer and displays Z

Warning and indicator lamps in the instrument cluster
Safety
Seat belts Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ü
N
Only for certain countries: the red seat belt warning lamp lights up for
6 seconds after the engine starts.
The seat belt warning lamp reminds the driver and front passenger to fasten
their seat belts.
X Fasten your seat belt (Y page 46).ü
N
Only for certain countries: the red seat belt warning lamp lights up after the
engine starts. In addition, a warning tone sounds for up to 6 seconds.
The driver's seat belt is not fastened.
X Fasten your seat belt (Y page 46).
The warning tone ceases. ü
N
The red seat belt warning lamp lights up after the engine starts, as soon as
the driver's or the front-passenger door is closed.
The driver or passenger has not fastened their seat belt.
X Fasten your seat belt (Y page 46).
The warning lamp goes out.
There are objects on the front-passenger seat.
X Remove the objects from the front-passenger seat and stow them in a
secure place.
The warning lamp goes out. ü
N
The red seat belt warning lamp flashes and an intermittent audible warning
sounds.
The driver or passenger has not fastened their seat belt. At the same time, you are driving faster than 25 km/h or have briefly driven faster than 25 km/h.
X Fasten your seat belt (Y page 46).
The warning lamp goes out and the intermittent warning tone ceases.
There are objects on the front-passenger seat. At the same time, you are
driving faster than 25 km/h or have briefly driven faster than 25 km/h.
X Remove the objects from the front-passenger seat and stow them in a
secure place.
The warning lamp goes out and the intermittent warning tone ceases. 300
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Safety systems
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions J
N
The yellow brake system warning lamp lights up while the engine is running.
G WARNING
The brake system is malfunctioning and the braking characteristics may be
affected.
There is a risk of an accident. X If the multifunction display shows a display message, please observe this.
X Drive on carefully.
X Visit a qualified specialist workshop. J
N
The red brake system warning lamp is lit while the engine is running. A
warning tone also sounds.
G WARNING
The brake boosting effect is malfunctioning and the braking characteristics
may be affected.
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 circumstan-
ces.
X Secure the vehicle to prevent it from rolling away (Y page 178).
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction display. J
N
The red brake system warning lamp is lit while the engine is running. A
warning tone also sounds.
There is insufficient brake fluid in the brake fluid reservoir.
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 circumstan-
ces.
X Secure the vehicle against rolling away (Y page 178).
X Do not top up the brake fluid. Topping up will not rectify the fault.
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction display. Warning and indicator lamps in the instrument cluster
301On-board computer and displays Z

Engine
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ;
N
The yellow engine diagnostics warning lamp lights up while the engine is
running.
There may be a fault, 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.
X Have the vehicle checked as soon as possible at a qualified specialist work-
shop. 8
N
The yellow reserve fuel warning lamp is on while the engine is running.
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. ?
N
The red coolant warning lamp lights up while the engine is running and the
coolant temperature gauge is at the start of the bar display.
The temperature sensor for the coolant temperature gauge is faulty.
The coolant temperature is no longer being monitored. There is a risk of engine
damage if the coolant temperature is too high.
X Stop the vehicle immediately, paying attention to road and traffic condi-
tions, and switch off the engine. Do not continue driving under any circum-
stances.
X Secure the vehicle against rolling away (Y page 178).
X Consult a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
307On-board computer and displays Z

Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ?
N
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.
X Observe the additional display messages in the multifunction display.
X Stop the vehicle immediately, paying attention to road and traffic condi-
tions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 178).
X Leave the vehicle and keep a safe distance from the vehicle until the engine
has cooled down.
X Check the coolant level and top up the coolant, observing the warning notes
(Y page 340).
X If you have to top up the coolant frequently, have the engine cooling system
checked.
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 coolant temperature is below 125 †.
The engine may otherwise be damaged.
X Drive 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. ?
N
The red coolant warning lamp comes on while the engine is running. A
warning tone also sounds.
The coolant temperature has exceeded 124 †. The airflow to the engine radi- ator may be blocked or the coolant level may be too low.
G WARNING
The engine is not being cooled sufficiently and may be damaged.
Never drive with an overheated engine. Driving when your engine is overhea-
ted can cause some fluids which may have leaked into the engine compart-
ment 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 Observe the additional display messages in the multifunction display.
X Stop the vehicle immediately, paying attention to road and traffic condi-
tions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 178).308
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Tyres
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions h
N
The yellow tyre pressure monitor warning lamp (pressure loss/malfunction)
is lit.
The tyre pressure monitor has detected a loss of pressure in at least one of the
tyres.
G WARNING
Underinflated tyres pose the following risks:
R the tyres may burst, especially as the load and vehicle speed increase
R the tyres may wear excessively and/or unevenly, which may greatly impair
tyre traction
R the driving characteristics, as well as steering and braking, may be greatly
impaired
There is a risk of an accident.
X Stop the vehicle without making any sudden steering or braking manoeu-
vres. Pay attention to the traffic conditions as you do so.
X Secure the vehicle to prevent it from rolling away (Y page 178).
X Observe the additional display messages in the multifunction display.
X Check the tyres and, if necessary, follow the instructions for a flat tyre
(Y page 356).
X Check the tyre pressure (Y page 381).
X If necessary, correct the tyre pressure. h
N
The yellow tyre pressure monitor warning lamp (pressure loss/malfunction)
flashes for approximately one minute and then remains lit.
The tyre pressure monitor is faulty.
G WARNING
The system is possibly unable to detect or register low tyre pressure.
There is a risk of an accident.
X Observe the additional display messages in the multifunction display.
X Visit a qualified specialist workshop. 310
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Useful information
i This Owner's Manual describes all mod-
els, series and optional equipment for your
vehicle that were available at the time of
going to press. National variations are pos- sible. Note that your vehicle may not be
equipped with all of the functions descri-
bed. This is also the case for systems and
functions relevant to safety.
i Read the information on qualified special-
ist workshops: (Y page 25). Stowage areas
Loading guidelines
G
WARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Exhaust
gases can enter the vehicle interior if the boot
lid is open when the engine is running, espe-
cially if the vehicle is in motion. There is a risk of poisoning.
Always switch off the engine before opening
the boot lid. Never drive with the boot lid
open. G
WARNING
If objects, luggage or loads are not secured or not secured sufficiently, they could slip, tip
over or be flung around and thereby hit vehicle
occupants. There is a risk of injury, especially when braking or abruptly changing directions.
Always store objects so that they cannot be
flung around. Secure objects, luggage or
loads against slipping or tipping before the
journey. G
WARNING
The exhaust tail pipe and tail pipe trim can
become very hot. If you come into contact
with these parts of the vehicle, you could burn
yourself. There is a risk of injury. Always be particularly careful around the
exhaust tail pipe and the tail pipe trim. Allow
these components to cool down before touch-
ing them.
The handling characteristics of a laden vehi-
cle 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 never exceed the maximum permissible
gross vehicle weight or the permissible axle
loads for the vehicle (including occupants).
R the boot is the preferred place to carry
objects.
R position heavy loads as far forwards as pos-
sible and as low down in the boot as pos-
sible.
R the load must not protrude above the upper
edge of the seat backrests.
R always place the load behind unoccupied
seats if possible.
R secure the load with sufficiently strong and
wear-resistant lashing material. Pad sharp
edges for protection.
i Load restraints are available at any quali-
fied specialist workshop, e.g. a Mercedes-
Benz Service Centre. Stowage spaces
Important safety notes G
WARNING
If you do not correctly store objects in the
vehicle interior, they can slip or be flung
around, thus striking vehicle occupants.
There is a risk of injury, especially when brak- ing or abruptly changing directions.
R Always store objects so that they cannot be
flung around in these or in similar situa-
tions.
R Always make sure that objects do not pro-
trude from stowage compartments, lug-
gage nets or stowage nets. 314
Stowage areasStowing and features

R
Close lockable stowage compartments
while driving.
R Stow and secure objects that are heavy,
hard, pointy, sharp-edged, fragile or too
large in the boot.
Observe the loading guidelines (Y page 314).
Front stowage compartments Glove compartment
X
To open: pull handle :and open glove
compartment flap ;.
X To close: fold glove compartment flap ;
upwards until it engages.
The glove compartment can be cooled
(Y page 155).
The glove compartment contains a coin
holder, a pen holder, three credit card holders
and a holder for the COMAND remote control. The glove compartment can only be locked
and unlocked using the emergency key ele-
ment. X
To lock: insert the emergency key element
into the lock and turn it 90° clockwise to
position 2.
X To unlock: insert the emergency key ele-
ment into the lock and turn it 90° anti-
clockwise to position 1.
Spectacles compartment X
To open: press marking :.
The spectacles compartment opens down- wards.
X To close: press marking :again and the
spectacles compartment returns upwards
and engages.
Make sure that the spectacles compartment
is always closed while the vehicle is in motion.
Stowage compartments in the centre con-
sole X
To open: briefly press marking ;.
X To close: push stowage compartment :
in the direction of the arrow until it
engages. Stowage areas
315Stowing and features Z