Page 236 of 309
234Vehicle careWiper blade replacement
Lift the wiper arm until it stays in the
raised position, press button to
disengage the wiper blade and
remove.
Attach the wiper blade slightly angled
to the wiper arm and push until it
engages.
Lower wiper arm carefully.
Wiper blade on the rear window
Lift wiper arm. Disengage wiper blade as shown in illustration and remove.
Attach the wiper blade slightly angled
to the wiper arm and push until it
engages.
Lower wiper arm carefully.
Bulb replacement
Switch off the ignition and switch off
the relevant switch or close the doors.
Only hold a new bulb at the base. Do not touch the bulb glass with bare
hands.
Use only the same bulb type for
replacement.
Replace headlight bulbs from within
the engine compartment.
Bulb check
After a bulb replacement switch on
the ignition, operate and check the
lights.
Halogen headlights Halogen headlights with separate
bulbs for low beam and high beam.
Page 247 of 309
Vehicle care245Electrical system
Fuses Data on the replacement fuse must
match the data on the defective fuse.
There are three fuse boxes in the
vehicle:
● engine compartment
● instrument panel
● load compartment
Before replacing a fuse, turn off the
respective switch and the ignition.
A blown fuse can be recognized by its melted wire. Do not replace the fuse
until the cause of the fault has been
remedied.
Some functions are protected by
several fuses.
Fuses may also be inserted without existence of a function.
Fuse extractor
A fuse extractor may be located in the
fuse box in the engine compartment.Place the fuse extractor on the
various types of fuse from the top or
side, and withdraw fuse.
Page 251 of 309

Vehicle care249No.Circuit1–2Climate control system, fan3Power seat driver side4Cigarette lighter/Power outlet
front5–6Power window front7ABS8Heated steering wheel9Body control module10Power window rear11Sunroof12Body control module13Seat heating (only on vehicles
without alarm horn)14Exterior mirror15Body control module16Body control moduleNo.Circuit17Body control module18Body control module19Data link connector20Airbag system21Climate control system22Central locking system, tailgate23Electronic key system24Power seat memory function25Airbag system steering wheel26Ignition switch/Steering column
lock27Body control module28USB socket29–30Selector lever31Rear window wiper32Transmission control moduleNo.Circuit33Anti-theft alarm system/Power
sounder34Parking assist/Side blind spot
alert/Infotainment system/USB
socket35OnStar36Info display/Instrument cluster/ CD player37Infotainment system, radio
After having changed defective fuses,
close the fuse box cover and press
until it engages.
Vehicles with power connector: 1. Apply the cover on the right side.
Page 253 of 309
Vehicle care251No.Circuit1–2DC/AC Inverter3Trailer module4Power seat passenger side5–6Distance warning module7–8–9Rear seat heating (on vehicles
without alarm horn)10Service11–12Front seat heating (on vehicles
with alarm horn)13Rear seat heating (on vehicles
with alarm horn)14Ignition15Seat ventilationNo.Circuit16Trailer outlet17Trailer outlet18–19–20–21Electrical rear seat folding22Power tailgate
After having changed defective fuses,
close the fuse box cover and press
until it engages.
Additional fuses are located near the
vehicle battery.
No.Circuit1Fuel pump2Engine control module3Power supply
Page 256 of 309

254Vehicle careTyre pressureCheck the pressure of cold tyres at
least every 14 days and before any
long journey. Do not forget the spare
wheel.
This also applies to vehicles with tyre
pressure monitoring system.
Unscrew the valve cap.
Tyre pressure 3 292.
The tyre pressure information label
on the left door frame indicates the
original equipment tyres and the
correspondent tyre pressures.
The tyre pressure data refers to cold
tyres. It applies to summer and winter tyres.
Always inflate the spare tyre to the
pressure specified for full load.
The ECO tyre pressure serves to
achieve the smallest amount of fuel
consumption possible.
Incorrect tyre pressures will impair
safety, vehicle handling, comfort and
fuel economy and will increase tyre
wear.
Tyre pressures differ depending on
various options.
For the correct tyre pressure value,
follow the procedure below:
● Identify the engine identifier code. Engine data 3 284.
● Identify the respective tyre. ● The tyre pressure tables show all
possible tyre combinations
3 292.
For the tyres approved for your
vehicle, refer to the EEC Certificate of Conformity provided with your vehicle
or other national registration
documents.The driver is responsible for correct
adjustment of tyre pressure.9 Warning
If the pressure is too low, this can
result in considerable tyre warm-
up and internal damage, leading to tread separation and even to tyre
blow-out at high speeds.
9 Warning
For specific tyres the
recommended tyre pressure as
shown in the tyre pressure table may exceed the maximum tyre
pressure as indicated on the tyre.
Never exceed the maximum tyre
pressure as indicated on the tyre.
If the tyre pressure must be reduced
or increased on a vehicle with tyre
pressure monitoring system, switch
off ignition.
Page 258 of 309

256Vehicle careSelect the Tyre pressure page under
the Info Menu in the Driver
Information Centre 3 114.
System status and pressure warnings are displayed by a message
indicating the corresponding tyre in the Driver Information Centre.
The system considers the tyre
temperature for the warnings.
Temperature dependency 3 254.
A detected low tyre pressure
condition is indicated by the control
indicator w 3 112.
If w illuminates, stop as soon as
possible and inflate the tyres as
recommended 3 292.
If w flashes for 60-90 seconds then
illuminates continuously, there is a
fault in the system. Consult a
workshop.
After inflating, some driving may be
required to update the tyre pressure
values in the Driver Information
Centre. During this time w may
illuminate.
If w illuminates at lower temperatures
and extinguishes after driving, this
could be an indicator for approaching a low tyre pressure condition. Check
tyre pressure.
Vehicle messages 3 122.
If the tyre pressure must be reduced
or increased, switch off ignition.
Only mount wheels with pressure
sensors, otherwise the tyre pressure
will not be displayed and w
illuminates continuously.
A spare wheel or temporary spare
wheel is not equipped with pressure
sensors. The tyre pressure
monitoring system is not operational
for these tyres. Control indicator w
illuminates. For the further three
tyres, the system remains
operational.The use of commercially-available liquid tyre repair kits can impair the
function of the system. Factory-
approved repair kits can be used.
Operating electronic devices or being
close to facilities using similar wave
frequencies could disrupt the tyre
pressure monitoring system.
Each time the tyres are replaced, tyre pressure monitoring system sensors
must be dismounted and serviced.
For the screwed sensor, replace
valve core and sealing ring. For the
clipped sensor, replace complete
valve stem.
Vehicle loading status
Adjust tyre pressure to load condition according to the tyre information label
or tyre pressure chart 3 292, and
select the appropriate setting in the
menu Tyre Load in the Driver
Information Centre, Vehicle
Information Menu 3 114. This setting
is the reference for the tyre pressure
warnings.
Page 259 of 309

Vehicle care257The Tyre load menu only appears
when the vehicle is at a standstill and
the parking brake is applied. On
vehicles with automatic transmission
the selector lever must be in P.
Midlevel display:
Select the Tyre load page under the
Vehicle Information Menu ? in the
Driver Information Centre 3 114.
Select ● Light for comfort pressure up to
three people.
● Eco for Eco pressure up to three
people.
● Max for full loading.
Uplevel display:
Select the Tyre load page under the
Options Menu in the Driver
Information Centre 3 114.
Select ● Light for comfort pressure up to
three people.
● Eco for Eco pressure up to
three people.
● Max for full loading.
Tyre pressure sensor matching
process
Each tyre pressure sensor has a
unique identification code. The
identification code must be matched
to a new wheel position after rotating the wheels or exchanging the
complete wheel set and if one or more tyre pressure sensors were replaced.
The tyre pressure sensor matching
process should also be performed
after replacing a spare wheel with a
road wheel containing the tyre
pressure sensor.
The malfunction light w and the
warning message or code should go
off at the next ignition cycle. The
sensors are matched to the wheel
positions, using a relearn tool, in the following order: left side front wheel,
right side front wheel, right side rear
wheel and left side rear wheel. The
turn signal light at the current active
position is illuminated until sensor is
matched.
Consult a workshop for service. There are two minutes to match the first
wheel position, and five minutes
overall to match all four wheel
Page 260 of 309

258Vehicle carepositions. If it takes longer, the
matching process stops and must be
restarted.
The tyre pressure sensor matching
process is:
1. Apply the parking brake.
2. Turn the ignition on.
3. On vehicles with automatic transmission: set the selector
lever to P.
On vehicles with manual
transmission: select neutral.
4. Midlevel display: Use MENU on the turn signal
lever to select the Vehicle
Information Menu ? in the
Driver Information Centre.
Uplevel display:
Press p on the steering wheel to
open main menu page.
Select the Info page with Q or P.
Confirm with 9.
5. Select the tyre pressure menu. Midlevel display:
Uplevel display:
6. Midlevel display:Press SET/CLR to begin the
sensor matching process. A
message requesting acceptance
of the process should be
displayed.
Press SET/CLR again to confirm
the selection. The horn sounds
twice to indicate that the receiver
is in relearn mode.
Uplevel display:
Press 9 to begin the sensor
matching process. The horn
sounds twice to indicate that the receiver is in relearn mode.
7. Start with the left side front wheel.
8. Place the relearn tool against the tyre sidewall, near the valve stem.Then press the button to activate
the tyre pressure sensor. A horn
chirp confirms that the sensor
identification code has been
matched to this wheel position.
9. Proceed to the right side front wheel, and repeat the procedure
in Step 8.
10. Proceed to the right side rear wheel, and repeat the procedure
in Step 8.
11. Proceed to the left side rear wheel, and repeat the procedure
in Step 8. The horn sounds twice