ECU MERCEDES-BENZ CLS 2014 Service Manual

Safety
Seat belts
ProblemPossible causes/consequences andSolutions

After startingthe
engine, the red seat
belt warning lamp lights
up for6seconds.
The seat belt warning lamp reminds the driver and frontpassenger
to fasten their seat belts.
XFastenyour seat belt (Ypage 56).

After starting the
engine, the red seat
belt warning lamp lights
up. In addition, a
warning tonesounds
for up to six seconds.
The driver's seat belt is not fastened.
XFasten your seat belt (Ypage 56).
The warning toneceases.

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 56).
The warning lamp goes out.
There are objectsonthe front-passenger seat.
XRemove the objectsfrom the front-passenger seat and stow
them inasecure 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. You
are driving faster than 15 mph (25 km/h) or have briefly driven
faster than 15 mph (25 km/h).
XFasten your seat belt (Ypage 56).
The warning lamp goes out and the intermittentwarning tone
ceases.
Thereare objectsonthefront-passenger seat.You are driving
faster than 15 mph (25 km/h) or have briefly driven faster than
15 mph (25 km/h).
XRemove the objectsfrom the front-passenger seat and stow
them inasecure place.
The warning lamp goes out and the intermittentwarning tone
ceases.
Indicator and warning lamps in theinstrumentcluster265
On-boar dc omputer and displays
Z

Safety systems
ProblemPossible causes/consequences andSolutions
(USA only)

(Canada only)
The red brake system
warning lamp comes on
while the engine is
running.Awarning tone
also sounds.
GWARNING
The brake boosting effect is malfunctioning and the braking
characteristics may be affected.
There isarisk 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 167).
XConsultaqualified specialist workshop.
XObserve the additional display messages in the multifunction
display.
(USA only)

(Canada only)
The red brake system
warning lamp comes on
while the engine is
running.Awarning tone
also sounds.
There is not enough brake fluid in the brake fluid reservoir.
GWARNING
The braking effect may be impaired.
There isarisk 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 167).
XDo not add brake fluid. Adding more will not remedy the
malfunction.
XConsultaqualified specialist workshop.
XObserve the additional display messages in the multifunction
display.
266Indicator and warning lampsinthe instrument cluster
On-board computer and displays

Engine
ProblemPossible causes/consequences andSolutions
\n
The yellow Check
Enginewarning lamp
lightsupwhile the
engineisrunning.
Theremay beamalfunction, for example:
Rin theenginemanagement
Rin thefuel injection system
Rin theexhaust system
Rin theignition system
Rin thefuel system
The emission limit values may be exceeded and theenginemay
be runninginemergencymode.
XHavethevehicle checked as soon as possible ataqualified
specialist workshop.
iIn somestates, you must immediately visitaqualified
specialist workshopassoon as theyellow CheckEngine warning
lamp lights up.This is due to the legal requirements in effect in
these states. 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 vehicle is in
motion.
In addition, the\n
Check Enginewarning
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.
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:visitaqualified specialist
workshop.

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.
XSecure the vehicle against rolling away (Ypage 167).
XConsultaqualified specialist workshop.
Indicator and warning lampsinthe instrument cluster273
On-board computer and displays
Z

ProblemPossible causes/consequences andSolutions

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 167).
XLeave the vehicle and keepasafe distance from the vehicle until
the engine has cooled down.
XCheck the coolant level and add coolant, observing the warning
notes (Ypage 308).
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 couldbedamaged.
XDrive to the nearest qualified specialist workshop.
XAvoid subjecting the engine to heavy loads, e.g. driving in
mountainousterrain, and stop-and-go traffic.

The red coolant
warning lamp comes on
while the engine is
running.Awarning 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 cooledsufficiently 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
catchfire.
Steam from the overheated engine can also cause serious burns
which can occur just by opening the hood.
There isarisk 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 167).
274Indicator and warning lampsinthe instrument cluster
On-board computer and displays

Tires
ProblemPossible causes/consequencesandSolutions

The yellow tire pressure
monitor warninglamp
(pressure loss/
malfunction) is lit.
The tire pressure monitor hasdetectedalossofpressure in at
leastone of the tires.
GWARNING
With tire pressures which aretoo low, there isarisk 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 steeringand braking, may
be greatly impaired.
There isarisk of an accident.
XStop the vehicle without making any sudden steeringorbraking
maneuvers. Pay attention to the traffic conditions as you do so.
XSecure the vehicle against rolling away (Ypage 167).
XObserve the additional display messages in the multifunction
display.
XCheck the tires and, if necessary, follow the instructions for a
flat tire (Ypage 321).
XCheck the tire pressure (Ypage 342).
XIf necessary, correctthe 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 isarisk of an accident.
XObserve the additional display messages in the multifunction
display.
XVisitaqualified specialist workshop.
276Indicator and warning lampsinthe instrument cluster
On-board computer and displays

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 notethat your vehicle may
not be equipped with all features
described. This also applies to safety-
related systemsand functions.
iRead the information on qualified
specialist workshops: (Ypage 26).
Stowage areas
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 isarisk of injury,
particularly in the eventofsudden braking or
asuddenchange in direction.
Always store objectssothat they cannot be
flung around. Secure objects, luggageor
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
arisk of poisoning.
Always switch off the engine before opening
the trunk lid. Never drive with the trunk lid
open.
The handling characteristics ofaladen
vehicle are dependent on the distribution of
the load within the vehicle. For this reason,
you should observe the following notes when
transportingaload:
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 strongand
wear-resistant tie-downs. pad sharp edges
for protection.
Stowage space
Important safety notes
GWARNING
If you do not correctly store objectsinthe
vehicle interior, they can slip or be flung
around, thus strikingvehicle occupants.
There isarisk of injury, especially when
braking or abruptly changing directions.
278Stowage areas
Stowage and features

RAlwaysstoreobjects so thatthey cannot be
flung around in these or in similar
situations.
RAlways make sure that objectsdonot
protrude from stowage compartments,
parcel nets or stowage nets.
RClose lockable stowage compartments
while driving.
RStow and secure objectsthat are heavy,
hard, pointy, sharp-edged, fragile or too
large in the trunk.
Observe the loading guidelines (Ypage 278).
Glove box
XTo open:pull handleand open glove box
flap.
XTo close:fold glove box flapupwards
until it engages.
iThe glove box can be ventilated
(Ypage 142).
The glove box can only be locked and
unlocked using the mechanical key.
XTo lock:insert the mechanical key into the
lock and turn it 90° clockwise to position
.
XTo unlock:insert the mechanical key into
the lock and turn it 90° counter-clockwise
to position
.
Eyeglassescompartment
There isacompartmenttostow eyeglasses
in the headliner on the driver's side.
XTo open:pull down eyeglasses
compartmentby the handle.
Stowage compartments in the front
center console
All models except AMG vehicles
XTo open:slide the cover forwards by
handlein the direction of the arrow until
it engages.
XTo close:briefly press the front of
handle.
Stowage areas279
Stowage and features
Z

AMG vehiclesXBriefly press trim.
iThe stowagetray can be removed.
Stowage compartmentunderthe
armrest
XTo open:pull handleup.
The armrestfolds out.
iDependingonthe vehicle's equipment, a
12Vsocket,aUSB socket,and an AUX IN
connection or Media Interface are installed
in the stowage compartment.AMedia
Interface isauniversal interface for mobile
audio equipment, e.g. for an iPod®or MP3
player (see the separate COMAND
OperatingInstructions).
Stowage compartment under the front
seats
GWARNING
If you exceed the maximum load for the
stowage compartment,the cover may not be
able to restrain the items. Itemsmay be
thrown out of the stowage compartment and
hit vehicle occupants. There isarisk of injury,
particularly in the event of sudden brakingor
asudden change in direction.
Never exceedthe maximum permissible load
for the stowage compartment.Stowand
secure heavy objects in the trunk.
The maximum permissible load of the
stowage compartment is 3.3 lbs (1.5 kg).
XTo open:pull handleup and fold
coverforwards.
iOn vehicles withafire extinguisher, the
fire extinguisher is located in the stowage
compartment under the driver's seat.
Stowage compartmentsinthe rear
center console
XTo open:slide coversandin the
direction of the arrow.
iThere isa12Vpower socket in the front
stowage compartment.
280Stowage areas
Stowage and features

backrest forwards, the respective front
seat moves forward slightly, when
necessary, in order to avoid contact.
XVehicles without memoryfunction:if
necessary,movethe driver's or front-
passengerseat forwards.
XOpen the trunk.
XPull right-hand or left-hand rear seat
backrest release handle.
The correspondingrear seat backrest is
released.
XFold rear seat backrestforwards.
XMove the driver's or front-passenger seat
back if necessary.
Folding the seat backrest back
!Make sure that the seat belt does not
become trapped when folding the rear seat
backrest back. Otherwise, it could be
damaged.
XMove the driver's or front-passenger seat
forward if necessary.
XFold rear seat backrestback until it
engages.
If the rear seat backrest is not engaged and
locked, this will be shown in the
multifunction display in the instrument
cluster.Awarning tone also sounds.
XMovethedriver'sorfront-passenger seat
back if necessary.
iYou should always engage therear seat
backrests if you do notneed the through-
loading feature. This will prevent
unauthorized access to the trunkfrom the
vehicle interior.
Securing cargo
Cargo tie-down rings
General notes
Observe the following notes on securing
loads:
RObserve the loading guidelines
(Ypage 278).
RSecure the load using the cargo tie-down
rings.
RDistribute the load on the cargo tie-down
rings evenly.
RDo not use elastic straps or netstosecure
aload, as these are only intended as an
anti-slip protection for light loads.
RDo not route tie-downs across sharp edges
or corners.
RPad sharp edges for protection.
282Stowage areas
Stowage and features

Trunk
There aresixcargo tiedown ringsin the
trunk.
Baghook
GWARNING
The bag hookscannotrestrain heavy objects
or items of luggage. Objects or items of
luggage could be flung around and thereby hit
vehicle occupantswhen braking or abruptly
changingdirections. There isarisk of injury.
Only hang light objects on the bag hooks.
Never hang hard, sharp-edged or fragile
objects on the bag hooks.
!The bag hook can bearamaximum load
of 6.6lbs (3kg) and should not be used to
secureaload.
XPull bag hookdown by tab.
Stowage well under the trunk floor
!Unhook the handle before again before
closing the trunklid and clip it in securely
to prevent the handle flap fromprotruding.
Otherwise, you coulddamage the handle.
The TIREFIT kit, the vehicletool kit, etc. are
located in the stowage compartment.
XTo open:pullhandleup.
XHook handleinto rain trough.
Roof carrier
Important safety notes
GWARNING
When you loadthe roof, the center of gravity
of the vehiclerises and the driving
characteristics change. If you exceed the
maximumroof load, the driving
characteristics, as well as steering and
braking, will be greatly impaired. There is a
risk of an accident.
Stowage areas283
Stowage and features
Z