ECU MERCEDES-BENZ E-Class CABRIOLET 2017 A207 Repair Manual

Important safety notes
GWARNING
If wheels and tires of th ewrong siz eare used,
th ewhee lbrakes or suspension component s
may be damaged. Ther eis aris kof an acci-
dent.
Always replace wheels and tires wit hthose
that fulfill th especification sof th eoriginal
part .
When replacing wheels, mak esur eto use th e
correct:
Rdesignation
Rmodel
When replacing tires ,mak esur eto use th e
correct:
Rdesignation
Rmanufacturer
Rmodel
GWARNIN G
A flat tire severely impairs th edriving ,steer -
ing and braking characteristics of th evehicle.
Ther eis aris kof accident.
Tires without run-flat characteristics :
Rdo notdriv ewit h a flat tire.
Rimmediately replace th eflat tire wit hyour
emergenc yspar ewhee lor spar ewheel, or
consult aqualified specialist workshop.
Tires wit hrun-flat characteristics :
Rpay attention to theinformation and warn -
ing notice son MOExtended tires (tire swit h
run-flat characteristics).
Accessories that are no tapprove dfor your vehi-
cle by Mercedes-Ben zor are no tbein gused cor-
rectl ycan impair th eoperating safety.
Before purchasing and usin gnon-approve d
accessories, visit aqualified specialist work-
sho pand ask about :
Rsuitability
Rlegal stipulation s
Rfactory recommendation sFurther information regarding wheels and tires
can be foun
dunder "Wheel/tire combinations"
(
Ypage 307).
You can ask for information regarding permitte d
wheel-tire combination sat an authorize d
Mercedes-Ben zCenter.
Information on tire pressur ecan be found:
Ron th eTir eand Loading Information placard
on th eB-pillar on th edriver' sside
(
Ypage 294)
Rin th etire pressur etable in th efuel filler flap
(Ypage 142)
Runder "Tir epressure" (Ypage 288)
Operation
Information on driving
Checkth etire pressur ewhen th evehicl eis
heavily laden and adjust prio rto atrip.
While driving ,pay attention to vibrations, noises
and unusual handlin gcharacteristics ,e.g. pull-
ing to on eside .This may indicat ethat th e
wheels or tires are damaged. If you suspec tthat
a tire is defective, reduce your spee dimmedi-
ately. Stop th evehicl eas soo nas possible to
chec kth ewheels and tires for damage. Hidden
tire damag ecould also be causing th eunusual
handlin gcharacteristics .If you fin dno sign sof
damage, hav eth etires and wheels checke dat a
qualified specialist workshop.
When parking your vehicle, mak esur ethat th e
tires do no tget deformed by th ecur bor other
obstacles. If they canno tbe avoided, driv eove r
obstacles suc has curbs slowly and at an obtuse
angle. Otherwise, you may damag eth ewheels
or tires .
Regular checking of wheels and tires
GWARNIN G
Damaged tires can caus etire inflation pres-
sur eloss .As aresult ,you could lose control of
your vehicle. Ther eis aris kof accident.
Chec kth etires regularly for sign sof damag e
and replace any damaged tires immediately.
Operation285
Wheels and tires
Z

Important notes on tire pressure
GWARNING
If th etire pressur edrops repeatedly, th e
wheel, valv eor tire may be damaged. Tir e
pressur ethat is to olow may result in atire
blow-out .Ther eis aris kof an accident.
RChec kth etire for foreign objects .
RCheckwhether th ewhee lis losing air or th e
valv eis leaking .
If you are unable to rectify th edamage, con-
tac t a qualified specialist workshop.
GWARNIN G
If you fit unsuitable accessories onto tire
valves, th etire valves may be overloaded and
malfunction ,whic hcan caus etire pressur e
loss .Due to their design ,retrofitte dtire pres-
sur emonitors keep th etire valv eopen .This
can also result in tire pressur eloss .Ther eis a
ris kof an accident.
Only screw th estandard valv ecap or other
valv ecap sapprove dby Mercedes-Ben zfor
your vehicl eonto th etire valve.
Use asuitable pressur egauge to chec kth etire
pressure. The outer appearanc eof atire does
no tpermit any reliable conclusio nabout th etire
pressure. On vehicles equipped wit hth eelec -
tronic tire pressur emonitor, th etire pressur e
can be checke din th eon-board computer.
The tire temperature and pressur eincreas e
when th evehicl eis in motion .This is dependen t
on th edriving spee dand th eload.
Therefore, you should only correc ttire pres-
sures when th etires are cold.
The tires are cold:
Rif th evehicl ehas been parked wit hth etires
out of direct sunligh tfor at least three hour s
and
Rif th evehicl ehas no tbeen driven further than
1 mile (1. 6km)
The tire temperature changes depending on th e
outside temperature, th evehicl espee dand th e
tire l
oad. If th etire temperature changes by
18 ‡(10 †), th etire pressur echanges by
approximately 10 kP a(0. 1bar/1.5 psi) .Tak e
this int oaccoun twhen checkin gth epressur eof
warm tires .Only correc tth etire pressur eif it is to
olow for th ecurren toperating conditions. If
you chec kth etire pressur ewhen th etires are
warm ,th eresulting value will be higher than if
th etires were cold. This is normal. Do no t
reduce th etire pressur eto th evalue specifie d
for cold tires .The tire pressur ewould otherwise
be to olow.
Observ eth erecommended tire pressures for
cold tires :
Ron theTir eand Loading Information placard
on th eB-pillar on th edriver' sside
Rin th etire pressur etable on th efuel filler flap
(Ypage 142)
Underinflated or overinflated tires
Underinflated tires
GWARNIN G
Tires wit hpressur ethat is to olow can over-
heat and burs tas aconsequence .In addition ,
they also suffer from excessiv eand/o rirreg-
ular wear ,whic hcan severely impair th ebrak -
ing properties and th edriving characteristics .
Ther eis aris kof an accident.
Avoid tire pressures that are to olow in all th e
tires ,includin gth espar ewheel.
Underinflated tires may:
Roverheat, leadin gto tire defects
Radversely affec thandlin g
Rwear excessively and/o runevenly
Rhav ean adverse effec ton fuel consumption
Overinflated tires
GWARNIN G
Tires wit hexcessively high pressur ecan burs t
because they are damaged mor eeasil yby
road debris, pothole setc. In addition ,they
also suffer from irregular wear ,whic hcan
severely impair th ebraking properties and th e
driving characteristics .Ther eis aris kof an
accident.
Avoid tire pressures that are to ohigh in all th e
tires ,includin gth espar ewheel.
290Tire pressure
Wheels and tires

Overinflated tires may:
Rincrease the braking distance
Radversely affect handling
Rwear excessively and/or unevenly
Rhave an adverse effect on ride comfort
Rbe more susceptible to damage
Maximum tire pressures
:Example: maximum permissible tire pres-
sure
Never exceed the maximum permissible tire
inflation pressure. Always observe the recom-
mended tire pressure for your vehicle when
adjusting the tire pressure (
Ypage 288).
iThe actual values for tires are vehicle-spe-
cific and may deviate from the values in the
illustration.
Checking the tire pressures
Important safety notes
Observe the notes on tire pressure
(Ypage 288).
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
Rin the tire pressure table in the fuel filler flap
(Ypage 142)
Rin the "Tire pressure" section
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 to the
recommended value on the Tire and Loading
Information placard or the tire pressure table (
Ypage 288).
XIf the tire pressure is too low, increase the tire
pressure to the recommended value.
XIf the tire pressure is too high, release air. To
do so, press down the metal pin in the valve,
using the tip of a pen for example. Then check
the tire pressure again using the tire pressure
checker.
XScrew the valve cap onto the valve.
XRepeat these steps for the other tires.
Tire pressure monitor
General notes
If a tire pressure monitor is installed, the vehi-
cle's wheels have sensors that monitor the tire
pressures in all four tires. The tire pressure mon-
itor warns you if the pressure drops in one or
more of the tires. The tire pressure monitor only
functions if the corresponding sensors are
installed in all wheels.
Information on tire pressures is displayed in the
multifunction display. After a few minutes of
driving, the current tire pressure of each tire is
shown in the Service
menu of the multifunction
display, see illustration (example).
For information on the message display, refer to
the "Checking the tire pressure electronically"
section (
Ypage 293).
Tire pressure291
Wheels and tires
Z

Important safety notes
GWARNING
Eac htire, includin gth espar e(if provided),
should be checke dat least once amonth
when cold and inflated to th epressur erec -
ommended by th evehicl emanufacturer on
th eTir eand Loading Information placard on
th edriver' sdoor B-pillar or th etire pressur e
label on th einside of th efuel filler flap .If your
vehicl ehas tires of adifferen tsiz ethan th e
siz eindicated on th eTir eand Loading Infor -
mation placard or th etire pressur elabel, you
should determine th eproper tire pressur efor
those tires .
As an added safet yfeature, your vehicl ehas
been equipped wit h atire pressur emonitoring
system (TPMS) that illuminate s alow tire pres-
sur etelltale when on eor mor eof your tires
are significantly underinflated. Accordingly,
when th elow tire pressur etelltale illuminates,
you should stop and chec kyour tires as soo n
as possible ,and inflat ethem to th eproper
pressure. Drivin gon asignificantly underin-
flated tire causes th etire to overheat and can
lead to tire failure. Underinflation also
reduce sfuel efficiency and tire tread life ,and
may affec tth evehicle's handlin gand stop-
pin gability.
Pleas enote that th eTPM Sis no t asubstitut e
for proper tire maintenance ,a
nd it is th edriv -
er' sresponsibilit yto maintai ncorrec ttire
pressure, eve nif underinflation has no t
reached th elevel to trigge rillumination of th e
TPM Slow tire pressur etelltale.
Your vehicl ehas also been equipped wit h a
TPM Smalfunction indicator to indicat eif th e
system is no toperating properly. The TPM S
malfunction indicator is combined wit hth e
low tire pressur etelltale. When th esystem
detects amalfunction ,th ewarning lamp will
flas hfor approximately aminute and then
remain continuously illuminated. This
sequenc ewill be repeated every time th evehi-
cle is started as lon gas th emalfunction
exists.
When th emalfunction indicator is illuminated,
th esystem may no tbe able to detec tor signal
low tire pressur eas intended. TPM Smalfunc -
tion smay occur for avariet yof reasons,
includin gth einstallation of incompatible
replacemen tor alternate tires or wheels on
th evehicl ethat preven tth eTPM Sfrom func-
tioning properly. Always chec kth eTPM Smal-
function telltale after replacing on eor mor e
tires or wheels on your vehicl eto ensur ethat
th ereplacemen tor alternate tires and wheels
allow th eTPM Sto continue to function prop-
erly.
It is th edriver' sresponsibilit yto set th etire
pressur eto that recommended for cold tires
whic his suitable for th eoperating situation
(
Ypage 288). Not ethat th ecorrec ttire pressur e
for th ecurren toperating situation must first be
taught-in to th etire pressur emonitor. If there is
a substantial loss of pressure, th ewarning
threshold for th ewarning message is aligned to
th ereferenc evalue staught-in .Restart th etire
pressur emonitor after adjusting th epressur eof
th ecold tires (
Ypage 293). The curren tpres-
sures are saved as ne wreferenc evalues. As a
result , awarning message will appear if th etire
pre ssur
ed
rops significantly.
The tire pressur emonitor does no twarn you of
an incorrectl yset tire pressure. Observ eth e
note son th erecommended tire pressur e
(
Ypage 288).
The tire pressur emonitor is no table to warn you
of asudde nloss of pressure, e.g. if th etire is
penetrated by aforeign object. In th eevent of a
sudde nloss of pressure, brin gth evehicl eto a
halt by braking carefully. Avoid abrup tsteering
movements.
The tire pressur emonitor has ayellow warning
lamp in th einstrumen tcluste rfor indicating
pressur eloss or amalfunction .Whether th e
warning lamp flashes or lights up indicates
whether atire pressur eis to olow or th etire
pressur emonitor is malfunctioning :
Rif thewarning lamp is lit continuously, th etire
pressur eon on eor mor etires is significantly
to olow. The tire pressur emonitor is no tmal-
functioning .
Rif thewarning lamp flashes for aroun d a
minute and then remain slit constantly, th e
tire pressur emonitor is malfunctioning .
292Tire pressure
Wheels and tires

You can find more tire pressure values for
various operating conditions in the tire pres-
sure table inside the fuel filler flap
(
Ypage 288).
XMake sure that the tire pressure is correct on
all four wheels.
XMake sure that the SmartKey is in position2
in the ignition lock.
XPress the =or; button on the steering
wheel to select the Servicemenu.
XPress the9or: button to select
Tire Pressure.
XPress the abutton.
The multifunction display shows the current
tire pressure for the individual tires or the
Tire pressures will be displayed
after driving a few minutesmessage.
XPress the :button.
The UseCurrentPressuresasNewRef‐erenceValuesmessage appears in the mul-
tifunction display.
If you wish to confirm the restart:
XPress the abutton.
The TirePress.MonitorRestartedmes-
sage appears in the multifunction display.
After driving for a few minutes, the system
checks whether the current tire pressures are within the specified range. The new tire pres-
sures are then accepted as reference values
and monitored.
If you wish to cancel the restart:
XPress the %button.
The tire pressure values stored at the last
restart will continue to be monitored.
Loading the vehicle
Instruction labels for tires and loads
GWARNING
Overloaded tires can overheat, causing a
blowout. Overloaded tires can also impair the steering and driving characteristics and lead
to brake failure. There is a risk of accident.
Observe the load rating of the tires. The load
rating must be at least half of the GAWR of
your vehicle. Never overload the tires by
exceeding the maximum load. Two instruction labels on your vehicle show the
maximum possible load.
(1) The Tire and Loading Information placard is on the B-pillar on the driver's side. The Tire
and Loading Information placard shows the
maximum permissible number of occu-
pants and the maximum permissible vehicle
load. It also contains details of the tire sizes
and corresponding pressures for tires
mounted at the factory.
(2) The vehicle identification plate is on the B- pillar on the driver's side. The vehicle iden-
tification plate informs you of the gross
vehicle weight rating. It is made up of the
vehicle weight, all vehicle occupants, the
fuel and the cargo. You can also find infor-
mation about the maximum gross axle
weight rating on the front and rear axle.
The maximum gross axle weight rating is
the maximum weight that can be carried by
one axle (front or rear axle). Never exceed
the maximum load or the maximum gross
axle weight rating for the front or rear axle.
:B-pillar, driver's side
Maximum permissible gross vehicle
weight rating
294Loading the vehicle
Wheels and tires

tire pressure
Pressure inside the tire applying an outward
force to every 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 tire pressure
The tires are cold:
Rif the vehicle has been parked with the tires
out of direct sunlight for at least three hours
and
Rif the vehicle has not been driven further than
1 mile (1.6 km)
Tread
The part of the tire that comes into contact with
the road.
Bead
The tire bead ensures that the tire sits securely
on the wheel. There are several steel wires in thebead to prevent the tire from coming loose 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 kg (5 lbs). These
optional extras, such as high-performance
brakes, level control, a roof rack or a high-per-
formance battery, are not included in the curb
weight and the weight of the accessories.
TIN (Tire Identification Number)
This is a unique identifier which can be used by
a tire manuf acturer to identify tires, for example
for a product recall, and thus identify the pur-
chasers. The TIN is made up of the manufactur- er'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 capa-
city of a tire.
Traction
Traction is the result of friction between the tires
and the road surface.
Treadwear indicators
Narrow bars (tread wear bars) that are distrib-
uted over the tire tread. If the tire tread is level
with the bars, the wear limit of áin (1.6 mm)
has been reached.
Occupant distribution
The distribution of occupants in a vehicle at their
designated seating positions.
Total load limit
Nominal load and luggage load plus 68 kg
(150 lbs) multiplied by the number of seats in
the vehicle.
Changing a wheel
Flat tire
The "Breakdown assistance" section
(Ypage 270 )contains information and notes on
how to deal with a flat tire. Information on driv-
ing with MOExtended tires in the event of a flat
tire can be found under "MOExtended tires (tires
with run-flat characteristics" (
Ypage 270).
Vehicle with emergency spare wheel: in the
event of a flat tire, the emergency spare wheel is
mounted as described under "Mounting a
wheel" (
Ypage 304).
Rotating the wheels
GWARNING
Interchanging the front and rear wheels may
severely impair the driving characteristics if
the wheels or tires have different dimensions. The wheel brakes or suspension components
may also be damaged. There is a risk of acci-
dent.
Rotate front and rear wheels only if the wheels and tires are of the same dimensions.
!On vehicles equipped with a tire pressure
monitor, electronic components are located
in the wheel.
Changing a wheel303
Wheels and tires
Z

Tire-mounting tools should not be used near
the valve. This could damage the electronic
components.
Only have tires changed at a qualified spe-
cialist workshop.
Always observe the instructions and safety
notes in the "Mounting a wheel" section
(
Ypage 304).
The wear patterns on the front and rear tires
differ, depending on the operating conditions.
Rotate the wheels before a clear wear pattern
has formed on the tires. Front tires typically
wear more on the shoulders and the rear tires in the center.
On vehicles that have the same size front and
rear wheels, you can rotate the wheels accord-
ing to the intervals in the tire manufacturer's
warranty book in your vehicle documents. If no
warranty book is available, the tires should be
rotated every 3,000 to 6,000 miles (5,000 to
10,000 km). Depending on tire wear, this may
be required earlier. Do not change the direction
of wheel rotation.
Clean the contact surfaces of the wheel and the
brake disc thoroughly every time a wheel is rota-
ted. Check the tire pressure and reactivate the
tire pressure monitor if necessary (
Ypage 293).
Direction of rotation
Tires with a specified direction of rotation have
additional benefits, e.g. if there is a risk of hydro-
planing. These advantages can only be gained if
the tires are installed corresponding to the
direction of rotation.
An arrow on the sidewall of the tire indicates its
correct direction of rotation.
Storing wheels
Store wheels that are not being used in a cool,
dry and preferably dark place. Protect the tires
from oil, grease, gasoline and diesel.
Mounting a wheel
Preparing the vehicle
XStop the vehicle on solid, non-slippery and
level ground.
XApply the parking brake.
XBring the front wheels into the straight-ahead
position.
XShift the transmission to position P.
XSwitch off the engine.
XRemove the SmartKey from the ignition lock.
or, on vehicles with KEYLESS‑ GO:
XOpen the driver's door.
The on-board electronics now have status 0.
This is the same as the SmartKey having been
removed.
XRemove the Start/Stop button from the igni-
tion lock (Ypage 128).
XIf included in the vehicle equipment, remove
the tire-change tool kit from the vehicle
(
Ypage 270).
XSafeguard the vehicle against rolling away.
Securing the vehicle to prevent it from
rolling away
If your vehicle is equipped with a wheel chock, it
can be found in the tire-change tool kit
(
Ypage 270).
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;.
XGuide the lugs on the lower plate fully into the
openings in base plate =.
304Changing a wheel
Wheels and tires

XPlace chocks or other suitable items under
the front and rear of the wheel that is diago-
nally opposite the wheel you wish to change.
Raising the vehicle
GWARNING
If you do not position the jack correctly at the
appropriate jacking point of the vehicle, the
jack could tip over with the vehicle raised.
There is a risk of injury.
Only position the jack at the appropriate jack-
ing point of the vehicle. The base of the jack
must be positioned vertically, directly under
the jacking point of the vehicle.
!The jack is designed exclusively for jacking
up the vehicle at the jacking points. Other-
wise, your vehicle could be damaged.
Observe the following when raising the vehicle:
RTo raise the vehicle, only use the vehicle-spe-
cific 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 for a short time while a wheel is being
changed. It must not be used for performing
maintenance work under the vehicle.
RAvoid changing the wheel on uphill and down-
hill slopes.
RBefore raising the vehicle, secure it from roll-
ing away by applying the parking brake and
inserting wheel chocks. Do not disengage the
parking brake while the vehicle is raised.
RThe jack must be placed on a firm, flat and
non-slip surface. On a loose surface, a large,
flat, load-bearing underlay must be used. On a
slippery surface, a non-slip underlay must be
used, e.g. rubber mats.
RDo not use wooden blocks or similar objects
as a jack underlay. Otherwise, the jack will not
be able to achieve its load-bearing capacity
due to the restricted height.
RMake sure that the distance between the
underside of the tires and the ground does not
exceed 1.2 in (3 cm).
RNever place your hands and feet under the
raised vehicle.
RDo not lie under the vehicle.
RDo not start the engine when the vehicle is
raised.
RDo not open or close a door or the trunk lid
when the vehicle is raised.
RMake sure that no persons are present in the
vehicle when the vehicle is raised.
XUsing lug wrench :, loosen the bolts on the
wheel you wish to change by about one full
turn. Do not unscrew the bolts completely.
The jacking points are located just behind the
front wheel housings and just in front of the rear
wheel housings (arrows).
Vehicles with AMG equipment: to protect the
vehicle body, the vehicle has covers next to the
jacking points on the outer sills.
Changing a wheel305
Wheels and tires
Z

Only use wheel bolts that have been designed
for the wheel and the vehicle. For safety rea-
sons, Mercedes-Benz recommends that you
only use wheel bolts which have been approved
for Mercedes-Benz vehicles and the respective
wheel.
!To prevent damage to the paintwork, hold
the wheel securely against the wheel hub
while screwing in the first wheel bolt.
XClean the wheel and wheel hub contact sur-
faces.
XSlide the wheel to be mounted onto the align-
ment 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.
Lowering the vehicle
GWARNING
The wheels could work loose if the wheel nuts and bolts are not tightened to the specified
tightening torque. There is a risk of accident.
Have the tightening torque immediately
checked at a qualified specialist workshop
after a wheel is changed.
XTurn the crank of the jack counter-clockwise
until the vehicle is once again standing firmly
on the ground.
XPlace the jack to one side.
XTighten the wheel bolts evenly in a crosswisepattern in the sequence indicated (: toA).
The specified tightening torque is 96 lb-ft
(130 Nm) .
XTurn the jack back to its initial position.
XStow the jack and the rest of the vehicle tools
in the trunk again.
XVehicles with AMG equipment: insert the
cover into the outer sill.
XCheck the tire pressure of the newly mounted
wheel and adjust it if necessary.
Observe the recommended tire pressure
(
Ypage 288).
All wheels mounted must be equipped with func-
tioning sensors.
Wheel and tire combinations
You can ask for information regarding permitted
wheel-tire combinations at an authorized
Mercedes-Benz Center.
!For safety reasons, Mercedes-Benz recom-
mends that you only use tires and wheels
which have been approved by Mercedes-Benz
specifically for your vehicle.
These tires have been specially adapted for
use with the control systems, such as ABS or
ESP
®, and are marked as follows:
RMO = Mercedes-Benz Original
RMOE = Mercedes-Benz Original Extended
(tires featuring run-flat characteristics)
RMO1 = Mercedes-Benz Original (only cer-
tain AMG tires)
Mercedes-Benz Original Extended tires may
only be used on wheels that have been spe-
cifically approved by Mercedes-Benz.
Wheel and tire combinations307
Wheels and tires
Z