ECU MERCEDES-BENZ CLA 2014 Service Manual

Display messagesPossible causes/consequences and
Solutions
ToDeselectPorN,
Depress Brake and
Start Engine
You have attempted to shift the transmissionto positionRorD
without starting the engine.
XStart the engine.
XDepress the brake pedal.
iIt is only possible to shift the transmission from positionPto
the desired position if you depress the brake pedal. Only then
can the parking lock be deactivated. If you do not depress the
brake pedal, you can move the DIRECT SELECT lever but the
parking lock remains engaged.
iAt transmission fluid temperatures below4 ‡ (20 †) you
can only shift out of positionPinto another transmission
position when the engine is running.
Apply Brake to
Shift from 'P'
You have attempted to move the transmission selector lever to
positionR,NorDwithout depressing the brake pedal.
XDepress the brake pedal.
Transmission Not
in P
Risk of Vehicle
Rolling Away
The driver's door is open and the transmission is in positionR,N
orD.
Awarning tone also sounds.
XShift the transmission to positionP.
XSecure the vehicle against rolling away (Ypage 153).
Service Required
DoNotShiftGears
Visit Dealer
You cannotchange the transmission position due to a malfunction.
Awarning tone also sounds.
If transmission positionDis selected:
XDrive to a qualified specialist workshop without shifting the
transmission from positionD.
If transmission positionR,NorPis selected:
XNotify a qualified specialist workshop or breakdown service.
Only Sift to 'P'
when Vehicle
is Stationary
The vehicle is moving.
XPull overand stop the vehicle safely as soonas possible, paying
attention to road and traffic conditions.
XShift the transmission to positionP.
Reversing Not
Possible Service
Required
The automatic transmission is malfunctioning. You cannot back
up.
XVisit a qualified specialist workshop.
Display messages237
On-board computer and displays
Z

Display messagesPossible causes/consequences and
Solutions
Transmission
malfunction
The automatictransmission is malfunctioning.
XVisitaqualified specialist workshop.
Transmission
Malfunction Stop
The automatic transmission is malfunctioning.
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 153).
XConsult a qualified specialist workshop.
StopVehicleShift
to P Leave Engine
Running
The automatic transmission has overheated.
XDrive on carefully.
The automatic transmission is available again when the display
message goes out.
If the display message continues to be displayed:
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 153).
XWait until the automatic transmission has cooled down and the
display message has disappeared.
Trans. Oil
Overheated Drive
on with Care
AMG vehicles: the transmission oil has overheated.
Manual drive programMand the temporarily active manual drive
program are no longer available. The engine power output is
reduced.
XAllow the vehicle to cool down.
4matic Currently
Unavailable
4MATIC (permanentall-wheeldrive) has overheated. The vehicle
is only drivenby the frontwheels.
XDrive on.
The airflow cools 4MATIC more quickly.
When the display message goes out, 4MATIC is available again
and the vehicle is driven by all four wheels.
4matic Inoperative4MATIC is malfunctioning. The vehicle is only driven by the front
wheels.
XVisit a qualified specialist workshop.
The trunk lid is open.
XClose the trunk lid.
238Display messages
On-board computer and displays

ProblemPossible causes/consequences and
Solutions

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 front passenger has not fastened their seat belt.
XFasten your seat belt (Ypage 50).
The warning lamp goes out.
There are objects on the front-passenger seat.
XRemove the objects from the front-passenger seat and stow
them in a secure place.
The warning lamp goes out.

The red seat belt
warning lamp flashes
and an intermittent
audible warning
sounds.
The driver or front passenger has not fastened their seat belt. In
addition, you are driving faster than 15 mph (25 km/h)or you have
briefly driven faster than 15 mph (25 km/h).
XFasten your seat belt (Ypage 50).
The warning lamp goes out and the intermittentwarning tone
ceases.
There are objects on thefront-passengerseat. In addition, you are
driving faster than 15 mph (25 km/h) or you have briefly driven
faster than 15 mph (25 km/h).
XRemove the objects from the front-passenger seat and stow
them in a secure place.
The warning lamp goes out and the intermittentwarning tone
ceases.
Warning and indicator lamps in the instrument cluster241
On-board computer and displays
Z

Safety systems
ProblemPossible causes/consequences and
Solutions
(USA only)
(Canada only)
The red brake system
warning lamp comes on
while the engine is
running. A warning tone
also sounds.
There is not enough brake fluid in the brake fluid reservoir.
GWARNING
The braking effect may be impaired.
There is a risk of an accident.
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
XSecure the vehicle against rolling away (Ypage 153).
XDo not add brake fluid. Adding more will not remedy the
malfunction.
XConsult a qualified specialist workshop.
XObserve the additional display messages in the multifunction
display.

The yellow ABS warning
lamp is lit while the
engine is running.
ABS (Anti-lock Braking System) is deactivated due to a
malfunction. Therefore, BAS (Brake Assist), COLLISION
PREVENTION ASSIST, COLLISION PREVENTION ASSIST PLUS,
ESP®(Electronic Stability Program), the HOLD function and hill
start assist, for example, are also deactivated.
ATTENTION ASSIST is deactivated.
GWARNING
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
The steerability and braking characteristics may be severely
affected. The braking distance in an emergency braking situation
can increase.
If ESP®is not operational, ESP®is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
XObserve the additional display messages in the multifunction
display.
XDrive on carefully.
XVisit a qualified specialist workshop.
If the ABS control unit is faulty, there is also a possibility that other
systems, such as the navigation system or the automatic
transmission, will not be available.
242Warning and indicator lamps in the instrument cluster
On-board computer and displays

Engine
ProblemPossible causes/consequences and
Solutions

The yellow Check
Engine warning lamp
lights up while the
engine is running.
There may be a malfunction, for example:
Rin the engine management
Rin the fuel injection system
Rin the exhaust system
Rin the ignition system
Rin the fuel system
The emission limit values may be exceeded and the enginemay
be running in emergency mode.
XHave the vehicle checked as soon as possible at a qualified
specialist workshop.
iIn some states, you must immediately visit a qualified
specialist workshop as soon as the yellow CheckEngine warning
lamp lights up.This depends on the locally applicable legal
requirements. If in doubt, check whether such legal regulations
apply in the state in which you are currently driving.


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.


The yellow reserve fuel
warning lamp flashes
while the engine is
running.
The fuel system pressure is too low. The fuel filler cap is not closed
correctly or the fuel system is leaking.
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.
\r
The red coolant
warning lamp lights up
while the engine is
running and the coolant
temperature gage is at
the start of the scale.
The temperature sensor for the coolant temperature gage 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.
XSecure the vehicle against rolling away (Ypage 153).
XConsult a qualified specialist workshop.
248Warning and indicator lamps in the instrument cluster
On-board computer and displays

ProblemPossible causes/consequences and
Solutions
\r
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.
XSecure the vehicle against rolling away (Ypage 153).
XLeave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
XCheck the coolant level and add coolant (Ypage 283). 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.
XDo not start the engine again until the coolant temperature is
under 248‡(120 †). Otherwise, the engine could be damaged.
XDrive to the nearest qualified specialist workshop.
XAvoid subjecting the engine to heavy loads, e.g. driving in
mountainous terrain, and stop-and-go traffic.
\r
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.
GWARNING
The engine is not being cooled sufficiently and may be damaged.
Do not drive whenyour engine is overheated. This can cause some
fluids which may have leaked into the engine compartment to
catch fire.
Vapor from the overheated engine can also cause serious burns
which can occur just by opening the hood.
There is a risk of injury.
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.
XSecure the vehicle against rolling away (Ypage 153).
Warning and indicator lamps in the instrument cluster249
On-board computer and displays
Z

Tires
ProblemPossible causes/consequences and
Solutions

The yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) is lit.
The tire pressure monitor has detected a loss of pressure in at
leastone of the tires.
GWARNING
With tire pressures which aretoo low, there is a risk of the
following hazards:
Rthey may burst, especially as the load and vehicle speed
increase.
Rthey may wear excessively and/or unevenly, which may greatly
impair tire traction.
Rthe driving characteristics, as well as steering and braking, may
be greatly impaired.
There is a risk of an accident.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.
XSecure the vehicle against rolling away (Ypage 153).
XObserve the additional display messages in the multifunction
display.
XCheck the tires and, if necessary, follow the instructions for a
flat tire (Ypage 295).
XCheck the tire pressure (Ypage 320).
XIf necessary, correct the tire pressure.

The yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) flashes for
approximately one
minute and then
remains lit.
The tire pressure monitor is faulty.
GWARNING
The system is possibly unable to recognize or register low tire
pressure.
There is a risk of an accident.
XObserve the additional display messages in the multifunction
display.
XVisit a qualified specialist workshop.
Warning and indicator lamps in the instrument cluster251
On-board computer and displays
Z

Useful information
iThis 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.
iRead the information on qualified
specialist workshops: (Ypage 25).
Loading guidelines
GWARNING
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,
particularly in the eventofsudden braking or
a suddenchange in direction.
Always store objects so that they cannot be
flung around. Secure objects, luggage or
loads against slipping or tipping before the
journey.
GWARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Exhaust
gases can enter the vehicle interior if the
trunk lid is open when the engine is running,
especially if the vehicle is in motion. There is
a risk of poisoning.
Always switch off the engine before opening
the trunk lid. Never drive with the trunk lid
open.
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:
RNever 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.
RThe trunk is the preferred place to carry
objects.
RPosition heavy loads as far forwards as
possible and as low down in the trunk as
possible.
RThe load must not protrude above the
upper edge of the seat backrests.
RAlways place the load against the rear or
front seat backrests. Make sure that the
seat backrests are securely locked into
place.
RAlways place the load behind unoccupied
seats if possible.
RUse the cargo tie down rings and the parcel
nets to transport loads and luggage.
RUse cargo tie-down rings and fastening
materials appropriate for the weight and
size of the load.
RSecure the load with sufficiently strong and
wear-resistant tie-downs. pad sharp edges
for protection.
Stowage areas
Stowage space
Important safety notes
GWARNING
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
braking or abruptly changing directions.
254Stowage areas
Stowage and features

RAlways store objects so thatthey cannot be
flung around in these or in similar
situations.
RAlways make sure that objects do not
protrude from stowage compartments,
parcel nets or stowage nets.
RClose lockable stowage compartments
while driving.
RStow and secure objects that are heavy,
hard, pointy, sharp-edged, fragile or too
large in the trunk.
Observe the loading guidelines (Ypage 254).
Stowage compartments in the front
Glove box
XTo open:pull handleand open glove box
flap.
XTo close:fold glove box flapupwards
until it engages.
iThere is a pen holder at the top of the
glove box flap.
Eyeglasses compartment
XTo open:press marking.
Make sure that the eyeglasses compartment
is always closed while the vehicle is in motion.
Stowage compartment in the center
console
XTo open:press the marking on cover.
iDepending on the vehicle equipment,
there may be an ashtray in the center
console instead of a storage compartment.
Stowage areas255
Stowage and features
Z

Stowage compartment in front of the
armrest (vehicles with automatic
transmission)
XTo open:press the marking on cover.
iYou can remove the non-slip mat and the
insert for cleaning. When removing the
insert you will have to overcome some
slight resistance.
Stowage compartment under the armrest
XTo open:on vehicles with moveable
armrests, make sure that the armrest is in
the rearmost position.
XPress buttonand fold the armrest up.
iDepending on the vehicle's equipment, a
USB connection and an AUX IN connection
or a Media Interface are installed in the
stowage compartment. A Media Interface
is a universal interface for portable audio
equipment, e.g. for an iPod®or MP3 player
(see the separate Audio or COMAND
Operating Instructions).
Stowage compartment under the driver's
seat and front-passenger seat
GWARNING
If you exceed the maximum load for the
stowage compartment, the cover may not be
able to restrain the items. Items may be
thrown out of the stowage compartment and
hit vehicle occupants. There is a risk of injury,
particularly in the event of sudden braking or
a sudden change in direction.
Never exceed the maximum permissible load
for the stowage compartment. Stow and
secure heavy objects in the trunk.
The maximum permissible load of the
stowage compartment is 2.6 lbs (1.5 kg).
XTo open:pull handleup and fold
coverforwards.
Stowage space in the rear
Stowage compartment in the rear center
console
256Stowage areas
Stowage and features