ECU MERCEDES-BENZ CLS 2014 Repair Manual

XFirst, remove the jumper cablesfrom earth pointand negative terminal!,then from
positiveclampand positiveterminal$.Begineachtime at the contacts on your own
vehicle first.
XClose coverof positiveclampafterremoving the jumper cables.
XHave the battery checkedataqualified specialist workshop.
iJump-startingisnot considered to beanormal operatingcondition.
iJumper cables and further information regardingjump-starting can be obtained at any
qualified specialist workshop.
Towing and tow-starting
Importantsafetynotes
GWARNING
Functionsrelevant to safety are restricted or
no longer available if:
Rthe engineisnot running.
Rthe brake system or the power steering is
malfunctioning.
Rthereisamalfunction in the voltage supply
or the vehicle's electrical system.
If your vehicle is being towed, much more
forcemay be necessary to steer or brake.
There isarisk of an accident.
In such cases, useatow bar. Beforetowing,
make sure that the steering moves freely.
GWARNING
If the weight of the vehicle to be towed or tow-
started is greater than the permissible gross
weight of your vehicle:
Rthe towingeye could detach itself
Rthe vehicle/trailer combination could
rollover.
There isarisk of an accident.
When towingortow-starting another vehicle,
its weight should not be greater than the
permissible gross weight of your vehicle.
Information on your vehicle's gross vehicle
weight ratingcan be found on the vehicle
identification plate (Ypage 372).
!If DISTRONIC PLUS or the HOLD function
is activated, the vehicle brakes
automatically in certain situations. To
preventdamage to thevehicle,deactivate
DISTRONICPLUS and the HOLD function in
the following or other similar situations:
Rwhen towing the vehicle
Rin the car wash
!Only secure the tow rope or tow bar at the
towing eyes. Otherwise,the vehicle could
be damaged.
!Do not use the towing eye for recovery,
this could damage the vehicle.Ifindoubt,
recover the vehicle withacrane.
!When towing, pullawayslowly and
smoothly.Ifthe tractive power is too high,
the vehicles could be damaged.
!Do not tow with sling-type equipment.
This could damage the vehicle.
!When towing vehicles with KEYLESS-GO,
use the key instead of the Start/Stop
button. Otherwise, the automatic
transmission may shift to positionPwhen
the driver's or front-passenger door are
opened, which could lead to damage to the
transmission.
!The vehicle can be towedamaximum of
30 miles (50km). The towing speed of
30 mph (50 km/h) must not be exceeded.
If the vehicle has to be towed more than
30 miles(50km), the entire vehicle must be
raised and transported.
328Towing and tow-starting
Breakdown assistance

XTurn the SmartKey to position2in the
ignition lock.
XShift the automatic transmission to
positionN.
As soon as the vehicle is loaded:
XPrevent the vehicle from rolling away by
applying the parking brake.
XShift the automatic transmission to
positionP.
XTurn the SmartKey to position0in the
ignition lock and remove the SmartKey
from the ignition lock.
XSecure the vehicle.
Notes on 4MATIC vehicles
!Vehicles with 4MATICmust not be towed
with either the frontorthe rear axle raised,
as doing so will damage the transmission.
If the vehicle has transmission damage or
damage to the front or rear axle, have it
transported onatransporter or trailer.
In the event of damage to the electrical
system
If the battery is defective, the automatic
transmission will be locked in positionP.To
shift the automatic transmission to position
N,you must provide power to the vehicle's
electrical system in the same way as when
jump-starting (Ypage 326).
Have the vehicle transported onatransporter
or trailer.
Tow-starting (emergency engine
starting)
!Vehicles with automatic transmission
must not be started by tow-starting. This
could otherwise damage the transmission.
You can find information on "Jump-starting"
at (Ypage 326).
Fuses
Important safety notes
GWARNING
If you manipulate or bridgeafaulty fuse or if
you replace it withafuse withahigher
amperage, the electric cables could be
overloaded. This could result inafire. There
isarisk of an accident and injury.
Always replace faulty fuses with the specified
new fuses having the correct amperage.
!Only use fuses that have been approved
for Mercedes-Benzvehicles and which
have the correct fuse ratingfor the system
concerned. Otherwise, componentsor
systems could be damaged.
The fuses in your vehicle serve to close down
faulty circuits. Ifafuse blows,all the
componentsonthecircuit and their functions
stop operating.
Blown fusesmust be replacedwith fuses of
the same rating, which you can recognize by
the color and value. The fuse ratings are listed
in the fuse allocation chart.
Ifanewly inserted fuse also blows, have the
cause traced and rectified ataqualified
specialist workshop, e.g. an authorized
Mercedes-BenzCenter.
Beforechangingafuse
XSecure the vehicle against rolling away
(Ypage 167).
XSwitchoff all electrical consumers.
XTurn the SmartKey to position0in the
ignition lock and remove it (Ypage 147).
or
XOn vehicles with KEYLESS-GO, make sure
the ignition is switched off (Ypage 147).
All indicator lamps in the instrument cluster
must be off.
Fuses331
Breakdown assistance
Z

The fuses are located in various fuse boxes:
RFuse box in the engine compartment on the
left-hand side of the vehicle, when viewed
in the direction of travel
Rfuse box in the trunk on the right-hand side,
when viewed in the direction of travel
the fuse allocation chart is located in the
vehicle tool kit in the stowage compartment
under the trunk floor (Ypage 320).
Fuse box in the engine compartment
GWARNING
When the hood is open and the windshield
wipers are set in motion,you can be injured
by the wiper linkage. There isarisk of injury.
Always switch off the windshield wipers and
the ignition before opening the hood.
!Make sure that no moisture can enter the
fuse box when the cover is open.
!When closing the cover, make sure that it
is lying correctly on the fuse box. Moisture
seeping in or dirt could otherwise impair
the operation of the fuses.
XMake sure that the windshield wipers are
turned off.
XOpen the hood.
XUseadry cloth to remove any moisture
from the fuse box.
XTo open:remove linesfrom the guides.
XMove linesaside. Route the lines behind
connection$to do this.
XOpen clamp.
XRemove the fuse box cover forwards.
XTo close:check whether the rubber seal is
lying correctly in the cover.
XInsert the cover at the rear of the fuse box
into the retainer.
XFold down cover and close clamps.
XSecure linesin the guides.
XClose the hood.
Fuse box in the trunk
!Make sure that no moisture can enter the
fuse box when the cover is open.
!When closing the cover, make sure that it
is lying correctly on the fuse box. Moisture
seeping in or dirt could otherwise impair
the operation of the fuses.
XOpen the trunk lid.
XTo open:release coverat the top right
and left-hand sides withaflat object.
XOpen coverdownwards in the direction
of the arrow.
332Fuses
Breakdown assistance

when adjustingthetirepressure
(Ypage 338).
iThe actual values for tires are vehicle-
specific and may deviatefromthe values in
the illustration.
Checking the tire pressures
Important safety notes
Observe the notes on tire pressure
(Ypage 338).
Information on air pressure for the tires on
your vehicle can be found:
Ron the vehicle's Tire and Loading
Information placard on the B-pillar
(Ypage 345)
Ron the tire pressure label on the fuel filler
flap (Ypage 165)
Rin the "Tire pressure" section
Runder "Tire pressure" (Ypage 338)
Checking tire pressures manually
To determine and set the correct tire
pressure, proceed as follows:
XRemove the valve cap of the tire that is to
be checked.
XPress the tire pressure gauge securely onto
the valve.
XRead the tire pressure and compare it with
the recommended value on the Tire and
Loading Information placard (Ypage 338).
XIf the tire pressure is too low, increase it to
the recommended value.
XIf the tire pressure is too high, release air
by pressing down the metal pin in the valve.
Use the tip ofapen, for example. Then,
check the tire pressure again using the tire
pressure gauge.
XScrew the valve cap onto the valve.
XRepeatthese steps for the other tires.
Tire pressureloss warning system
(Canada only)
General notes
While the vehicle is in motion, the tire
pressure loss warning system monitors the
set tire pressure using the rotational speed of
the wheels. This enables the system to detect
significant pressure loss inatire. If the speed
of rotation ofawheel changes asaresult of
aloss of pressure,acorresponding warning
message will appearinthe multifunction
display.
You can recognizethe tire pressure loss
warning by theRun Flat Indicator
Active Press 'OK' to Restartmessage
which appears in theServ.menu of the
multifunction display. Further information on
the message displaycan be found under
"Restarting the tire pressure loss warning
system" section (Ypage 342).
Important safety notes
The tire pressure warning system does not
warn you of an incorrectly set tire pressure.
Observe the notes on the recommended tire
pressure (Ypage 338).
The tire pressure loss warning does not
replace the need to regularly check the tire
pressure. An even loss of pressure on several
tires at the same time cannot be detected by
the tire pressure loss warning system.
The tire pressure monitor is not able to warn
you ofasudden loss of pressure, e.g. if the
tire is penetrated byaforeign object.Inthe
event ofasudden loss of pressure, bring the
vehicle toahalt by braking carefully. Avoid
abrupt steering maneuvers.
The function of the tire pressure loss warning
system is limited or delayed if:
Rsnow chains are mounted on your vehicle's
tires.
Rroad conditionsare wintry.
Ryou are driving on sand or gravel.
Check341
Wheels and tires
Z

100 kilopascals (kPa)are the equivalent of
1bar.
DOT (Department of Transportation)
DOT marked tires fulfill the requirements of
the United States Department of
Transportation.
Normal occupant weight
The numberofoccupants for which the
vehicleisdesigned multipliedby
68 kilograms (150 lb).
Uniform Tire Quality GradingStandards
Auniform standard to grade the quality of
tireswithregards to treadquality,tire traction
and temperaturecharacteristics. Ratingsare
determinedbytire manufacturersusing U.S.
government testing procedures. The ratings
aremoldedinto the sidewall of the tire.
Recommendedtire pressure
The recommendedtire pressure appliesto
the tiresmounted at the factory.
The Tire and Loading Informationplacard
containsthe recommendedtirepressures for
cold tires onafully loaded vehicle and for the
maximum permissible vehicle speed.
The tirepressure table containsthe
recommendedpressures for cold tires for
various operating conditions, i.e. differing
load and speed conditions.
Increased vehicle weight duetooptional
equipment
This is the combined weight of all standard
and optional equipmentavailablefor the
vehicle, regardless of whetheritisactually
installed on the vehicle or not.
Rim
This is the part of the wheel on which the tire
is mounted.
GAWR (Gross Axle Weight Rating)
The GAWR is the maximum gross axle weight
rating. The actual load on an axle must never
exceed the gross axle weight rating. The
gross axle weight rating can be found on the
vehicle identification plate on the B-pillar on
the driver's side.
Speed rating
The speed rating is part of the tire
identification. It specifies the speed range for
which the tire is approved.
GVW (Gross Vehicle Weight)
The gross vehicle weight includes the weight
of the vehicle including fuel, tools, the spare
wheel, accessories installed, occupants,
luggage and the drawbarnoseweight, if
applicable. The gross vehicle weight must not
exceed the gross vehicle weight rating GVWR
as specified on the vehicle identification plate
on the B-pillar on the driver's side.
GVWR (Gross Vehicle Weight Rating)
The GVWR is the maximum permissible gross
weight ofafully loaded vehicle (the weight of
the vehicle including all accessories,
occupants, fuel, luggage and the drawbar
noseweight, if applicable). The gross vehicle
weight rating is specified on the vehicle
identification plate on the B-pillar on the
driver's side.
Maximumloaded vehicle weight
The maximum weight is thesum of:
Rthecurbweight of thevehicle
Rtheweight of theaccessories
Rtheload limit
Rtheweight of thefactory installedoptional
equipment
Kilopascal (kPa)
Metric unit for tirepressure. 6.9kPa
correspondsto1psi. Another unit for tire
pressure is bar. Thereare 100kilopascals
(kPa) to1bar.
Load index
In addition to theload-bearing index,theload
index may also be imprinted on thesidewall
of thetire. This specifiesthe load-bearing
capacity more precisely.
All about wheels and tires355
Wheels and tires
Z

Curbweight
The weight ofavehicle with standard
equipment includingthemaximum capacity
of fuel, oil and coolant.Italso includes the air-
conditioningsystem and optional equipment
if these are installed in the vehicle, but does
not include passengers or luggage.
Maximumload rating
The maximum tireload is the maximum
permissible weight in kilograms or lbs for
whichatireisapproved.
Maximumpermissible tirepressure
Maximum permissible tirepressure for one
tire.
Maximumload on one tire
Maximum load on one tire. This is calculated
by dividingthe maximum axle load of one axle
by two.
PSI (pounds per squareinch)
Astandardunitofmeasure for tire pressure.
Aspect ratio
Relationship between tire height and tire
width in percent.
Tirepressure
This is pressure inside the tire applying an
outward forcetoeach square inch of the tire's
surface. The tire pressure is specified in
pounds per square inch (psi), in kilopascal
(kPa) or in bar. The tire pressure should only
be corrected when the tires are cold.
Cold tirepressure
The tires are cold:
Rif the vehicle has been parked without
direct sunlight on the tires for at least three
hours and
Rif the vehicle has been driven for less than
1mile (1.6 km).
Tread
The part of the tire that comes intocontact
with the road.
Bead
The tire bead ensures that the tire sits
securely on the wheel. There are several steel
wires in the bead to preventthe tire from
comingloose from the wheel rim.
Sidewall
The part of the tire between the tread and the
bead.
Weight of optional extras
The combined weight of those optional extras
that weigh more than the replaced standard
parts and more than 2.3 kilograms (5 lbs).
These optional extras, such as high-
performance brakes, level control,aroof rack
orahigh-performancebattery, are not
included in the curb weight and the weight of
the accessories.
TIN (Tire Identification Number)
This isaunique identifier which can be used
byatire manufacturer to identify tires, for
example foraproduct recall, and thus identify
the purchasers. The TIN is made up of the
manufacturer's identity code, tire size, tire
type code and the manufacturing date.
Load bearing index
The load bearing index (also load index) is a
code that contains the maximum load bearing
capacity ofatire.
Traction
Traction is the result of friction between the
tires and the road surface.
Treadwear indicators
Narrow bars (tread wear bars) that are
distributed over the tire tread. If the tire tread
is level with the bars, the wear limit ofin
(1.6 mm) has been reached.
356All about wheels and tires
Wheels and tires

to the tiresorchassiscomponents.
Components damagedinthiswaymayfail
unexpectedly.There isarisk of an accident.
Do not use power washers with circular jet
nozzles to clean the vehicle. Have damaged
tires or chassis components replaced
immediately.
Mountingawheel
Preparing the vehicle
XStop the vehicle on solid, non-slippery and
levelground.
XApply the parking brake.
XBring the front wheels into the straight-
ahead position.
XShift the transmission to positionP.
XVehicles with AIRMATIC:make sure that
"normal" levelisselected(Ypage 189).
XSwitch off theengine.
XVehicles without KEYLESS-GO:remove
theSmartKey from theignition lock.
XVehicles with KEYLESS-GO:open the
driver'sdoor.
The on-board electronics nowhave status
0.This is the same as the SmartKey having
been removed.
XVehicles with KEYLESS-GO:remove the
Start/Stop button from the ignition lock
(Ypage 147).
XIf included in the vehicle equipment,
remove the tire-change tool kit from the
vehicle (Ypage 320).
XSecure the vehicle to prevent it from rolling
away.
Securing the vehicle to prevent it from
rolling away
If your vehicle is equipped withawheel chock,
it can be found in the tire-change tool kit
(Ypage 320).
The folding wheel chock is an additional
safety measure to prevent the vehicle from
rolling away,for example when changing a
wheel.
XFold both plates upwards.
XFold out lower plate.
XGuidethe lugs on the lower plate fully into
the openings in base plate$.
Securing the vehicle on level ground
XOn level ground:place chocksorother
suitable items under the front and rear of
the wheel that is diagonallyopposite the
wheel you wish to change.
358Changingawheel
Wheels and tires

Securing the vehicle on slight downhillgradients
XOn light downhill gradients:place
chocks or othersuitableitemsinfront of
the wheelsofthe front and rearaxle.
Raisingthe vehicle
GWARNING
If youdonot positionthe jack correctly at the
appropriate jackingpoint of the vehicle, the
jack could tip over with the vehicle raised.
There isarisk of injury.
Only position the jack at the appropriate
jackingpoint of the vehicle. The base of the
jack must be positioned vertically, directly
under the jackingpoint of the vehicle.
!The jack is designed exclusively for
jackingupthe vehicle at the jackingpoints.
Otherwise, your vehicle could be damaged.
The following must be observed when raising
the vehicle:
Rto raise the vehicle, only use the vehicle-
specific jack that has been tested and
approved by Mercedes-Benz. If used
incorrectly, the jack could tip over with the
vehicle raised.
Rthe jack is designed only to raise and hold
the vehicle forashort time whileawheel
is being changed. It is not suited for
performing maintenancework under the
vehicle.
Ravoid changing the wheel on uphill and
downhill slopes.
Rbefore raising the vehicle, secure it from
rolling away by applying the parking brake
and insertingwheel chocks. Never
disengage the parking brake while the
vehicle is raised.
Rthe jack must be placed onafirm, flat and
non-slip surface. Onaloose surface, a
large, load-bearing underlay must be used.
Onaslippery surface,anon-slip underlay
must be used, e.g. rubber mats.
Rdo not use wooden blocks or similar
objectsasajack underlay.Otherwise, the
jackwill not be able to achieveits load-
bearingcapacity due to the restricted
height.
Rmakesure that the distancebetween the
underside of the tires and the grounddoes
not exceed 1.2in(3cm).
Rnever place your hands and feet under the
raised vehicle.
Rnever lie under the raised vehicle.
Rnever start the engine when the vehicle is
raised.
Rnever open or closeadoor or the trunk lid
when the vehicle is raised.
Rmakesure that no persons are present in
the vehicle when the vehicle is raised.
XUsinglug wrench,loosen the boltson
the wheel you wish to change by about one
full turn. Do not unscrew the bolts
completely.
Changingawheel359
Wheels and tires
Z

GWARNING
If you tighten the wheelbolts or wheelnuts
when the vehicleisraised, the jack couldtip
over. There isarisk of injury.
Only tighten the wheelbolts or wheelnuts
when the vehicleisonthe ground.
Always pay attention to the instructions and
safety notes in the "Changingawheel"
section (Ypage357).
Only use wheelbolts that have been designed
for the wheeland the vehicle. For safety
reasons, Mercedes-Benz recommends that
you only use wheelbolts which have been
approved for Mercedes-Benz vehicles and the
respective wheel.
!AMG vehicle with ceramic brake
discs:during removaland repositioning of
the wheel, the wheelrim can strike the
ceramic-brake disc and damage it.
Therefore, take precautions and have a
second personassist you. Alternatively,
you can useasecond alignment bolt.
!To prevent damage to the paintwork, hold
the wheel securely against the wheel hub
while screwing in the first wheel bolt.
Positioningawheel (example: vehicle with anemergency spare wheel)
XCleanthe wheel and wheel hub contact
surfaces.
XSlide the wheel to be mounted onto the
alignment bolt and push it on.
XTighten the wheel bolts until they are
finger-tight.
XUnscrew the alignment bolt.
XTighten the last wheel bolt until it is finger-
tight.
XVehicles withacollapsible spare
wheel:inflate thecollapsible spare wheel
(Ypage 368).
Only then lower thevehicle.
Lowering thevehicle
GWARNING
The wheels could work loose if thewheel nuts
and boltsare not tightenedtothe specified
tightening torque. There isarisk of accident.
Have the tightening torque immediately
checked ataqualified specialist workshop
afterawheel is changed.
!Vehicles withacollapsible spare
wheel:before lowering thevehicle, inflate
thecollapsible spare wheel with thetire
inflationcompressor. The wheel rim could
otherwise be damaged.
Tighteningthe wheel nuts (example: vehicle withan emergencyspare wheel)
XTurn the crank of the jack counter-
clockwise until the vehicle is once again
standingfirmly on the ground.
XPlace the jack to one side.
XTighten the wheel bolts evenly in a
crosswise pattern in the sequence
indicated (to). The specified
tightening torque is96 lb-ft(130 Nm).
XTurn the jack back to its initial position.
Changingawheel361
Wheels and tires
Z