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180Driving and operatingFill the tank completely at regular
intervals to prevent corrosion in the
tank.
Faults and remedies
If gas mode is not possible, check the following:
● Is there enough liquid gas present?
● Is there enough petrol present for
starting?
Due to extreme temperatures in
combination with the gas
composition, it may take slightly
longer before the system switches
from petrol to gas mode.
In extreme situations, the system may
also switch back to petrol mode if the
minimum requirements are not
fulfilled. If conditions allow, it might be possible to manually switch back to
liquid gas operation.
Seek the assistance of a workshop in
the event of all other faults.Caution
Repairs and adjustments may only be made by trained specialists in
order to maintain the safety and
warranty on the LPG system.
Liquid gas is given a particular odour
(odorised) so that any leaks can be
detected easily.
9 Warning
If you smell gas in the vehicle or in
the immediate vicinity, switch to petrol mode immediately. No
smoking. No naked flames or
ignition sources.
If the gas odour persists, do not start
the engine. Have the cause of the
fault remedied by a workshop.
When using underground car parks,
follow the instructions of the operator
and local laws.
Notice
In the event of an accident, switch off
the ignition and lights.
Refuelling9 Danger
Before refuelling, switch off
ignition and any external heaters
with combustion chambers.
Follow the operating and safety
instructions of the filling station
when refuelling.
Page 210 of 267
208Vehicle careNo.Circuit14Heated exterior mirror15–16Brake booster kit17Ignition, crank power supply18Engine control module19Fuel pump20–21Engine solenoids, engine
sensors22–23Injection system24Washer system25–26Engine sensors27Heater shut off valve28Engine control module29Engine control moduleNo.Circuit30Engine control module31High beam left, Xenon low
beam left32High beam right, Xenon low
beam right33Engine control module34Horn35Air condition compressor clutch36Front fog lights
Page 212 of 267
210Vehicle careNo.Circuit1–2–3Power windows4Voltage transformer5Body control module 16Body control module 27Body control module 38Body control module 49Body control module 510Body control module 611Body control module 712Body control module 813–14Tailgate15Airbag system16Data link connection17IgnitionNo.Circuit18Air conditioning system19Sunroof20Parking assist/Rain sensor/
Front camera21Brake switch22Audio system23Display24–25Auxiliary jack26Instrument panel27Seat heating, driver28–29–30Instrument panel/Seat heating/
FlexDock31Horn32Seat heating, passenger33Heated steering wheelNo.Circuit34–35Tyre repair kit36–37Rear wiper38Cigarette lighter39Power windows/Sunroof/Auto‐
matic transmission display40–
Page 215 of 267

Vehicle care213Tyre pressure 3 252.
The tyre pressure information label
on the right door frame indicates the original equipment tyres and thecorrespondent tyre pressures.
The tyre pressure data refers to cold
tyres. It applies to summer and winter
tyres.
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 3 244.
● Identify the respective tyre.
The tyre pressure tables show all
possible tyre combinations 3 252.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.
If the tyre pressure must be reduced
or increased, switch off ignition. After
adjusting tyre pressure switch on
ignition and select the relevant setting on the page Tyre load in the Driver
Information Centre 3 96.
Temperature dependency The tyre pressure depends on the
temperature of the tyre. During
driving, tyre temperature and
pressure increase. Tyre pressure
values provided on the tyre
information label and tyre pressure
chart are valid for cold tyres, which means at 20 °C.
The pressure increases by nearly
1.5 psi for a 10 °C temperature
increase. This must be considered
when warm tyres are checked.
The tyre pressure value displayed in
the Driver Information Centre shows
the real tyre pressure. A cooled down
tyre will show a decreased value,
which does not indicate an air leak.
Tyre pressure monitoringsystem
The tyre pressure monitoring system
checks the pressure of all four tyres
once a minute when vehicle speed
exceeds a certain limit.Caution
Tyre pressure monitoring system
warns only about low tyre pressure condition and does not replace
regular tyre maintenance by the
driver.
Page 217 of 267

Vehicle care215A detected low tyre pressure
condition is indicated by the control
indicator w 3 94.
If w illuminates, stop as soon as
possible and inflate the tyres as
recommended 3 252.
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 3 103.
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 3 252, and
select the appropriate setting in themenu Tyre Load in the Driver
Information Centre, Vehicle
Information Menu ? 3 96. This
setting is the reference for the tyre
pressure warnings.
The menu Tyre Load only appears if
the vehicle is in a standstill and the
parking brake is applied. On vehicles
with automatic transmission the
selector lever must be in P.
Baselevel display and Midlevel
display:
Page 219 of 267

Vehicle care217Baselevel display and Midlevel
display:
Uplevel display:
6. Press SET/CLR to begin the
sensor matching process. A
message requesting acceptance
of the process should be
displayed.
7. Press SET/CLR again to confirm
the selection. The horn sounds
twice to indicate that the receiver
is in relearn mode.
8. Start with the left side front wheel.
9. 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.
10. Proceed to the right side front wheel, and repeat the procedure
in Step 9.
11. Proceed to the right side rear wheel, and repeat the procedure
in Step 9.
12. Proceed to the left side rear wheel, and repeat the procedure
in Step 9. The horn sounds twice
to indicate that the sensor
identification code has beenmatched to the left side rear
wheel, and the tyre pressure
sensor matching process is no
longer active.
13. Turn off the ignition.
14. Set all four tyres to the recommended air pressure level
as indicated on the tyre pressure
information label.
15. Ensure the tyre loading status is set according to the selected
pressure 3 96.
Tread depth Check tread depth at regular
intervals.
Tyres should be replaced for safety
reasons at a tread depth of 2-3 mm
(4 mm for winter tyres).
For safety reasons it is recommended
that the tread depth of the tyres on
one axle should not vary by more than 2 mm.
Page 220 of 267

218Vehicle care
The legally permissible minimum
tread depth (1.6 mm) has been
reached when the tread has worn
down as far as one of the tread wear
indicators (TWI). Their position is
indicated by markings on the
sidewall.
Tyres age, even if they are not used.
We recommend tyre replacement
every six years.
Changing tyre and wheel size
If tyres of a different size than those
fitted at the factory are used, it may be necessary to reprogramme the
speedometer as well as the nominal
tyre pressure and to make other
vehicle modifications.
After converting to a different tyre
size, have the label with tyre
pressures replaced.Caution
When converting to wheels with 14 inch diameter, the ground
clearance will be reduced. This
must be considered when passing
over obstacles.
9 Warning
Use of unsuitable tyres or wheels
may lead to accidents and will
invalidate the vehicle type
approval.
Wheel covers
Wheel covers and tyres that are
factory approved for the respective
vehicle and comply with all of the
relevant wheel and tyre combination requirements must be used.
If the wheel covers and tyres used are
not factory approved, the tyres must
not have a rim protection ridge.
Wheel covers must not impair brake
cooling.9 Warning
Use of unsuitable tyres or wheel
covers could lead to sudden
pressure loss and thereby
accidents.
Steel wheels: When using locking
wheel nuts don't attach wheel covers.
Tyre chains
Page 222 of 267
220Vehicle care
3. Remove the electrical connectioncable and air hose from the
stowage compartments on the
underside of the compressor.
4. Screw the compressor air hose to
the connection on the sealant
bottle.
5. Fit the sealant bottle into the retainer on the compressor.
Set the compressor near the tyre
in such a way that the sealant
bottle is upright.
6. Unscrew valve cap from defective
tyre.
7. Screw the filler hose to the tyre valve.
8. The switch on the compressor must be set to J.
9. Connect the compressor plug to
the power outlet or cigarette
lighter socket.
To avoid discharging the battery,
we recommend running the
engine.
10. Set the rocker switch on the compressor to I. The tyre is filled
with sealant.
11. The compressor pressure gauge briefly indicates up to six bar
whilst the sealant bottle is
emptying (approx. 30 seconds).
Then the pressure starts to drop.
12. All of the sealant is pumped into the tyre. Then the tyre is inflated.