Page 137 of 261

Driving and operating135Idle speed control
To increase the idle speed press the
switch. After a few seconds the
function will be activated.
The function will be deactivated
when:
● The clutch pedal is depressed.
● The accelerator pedal is depressed.
● MTA is not in N (neutral).
● Vehicle speed is above 0 mph. ● Control indicator A, W or C
illuminate in the instrument
cluster.
To increase or decrease the fast idle
speed rate, consult a workshop.
Notice
When the fast idle function is
activated, the stop-start system is
automatically deactivated.
Stop-start system 3 135.
Overrun cut-off
The fuel supply is automatically cut off
during overrun, i.e. when the vehicle
is driven with a gear engaged but accelerator pedal is released.
Depending on driving conditions, the
overrun cut-off may be deactivated.
Stop-start system The stop-start system helps to save
fuel and to reduce the exhaust
emissions. When conditions allow, it
switches off the engine as soon as the
vehicle is at a low speed or at a
standstill, e.g. at a traffic light or in a
traffic jam.It restarts the engine automatically as
soon as the clutch pedal is depressed (manual transmission) or the brake
pedal is released (manual
transmission automated).
A vehicle battery sensor ensures that
an Autostop is only performed if the vehicle battery is sufficiently charged
for a restart.
Activation
The stop-start system is available as
soon as the engine is started, the
vehicle starts-off and the conditions
as stated below in this section are
fulfilled.
If the below conditions are not
fulfilled, an Autostop is prohibited and
control indicator \ illuminates in the
instrument cluster 3 99.
Page 138 of 261

136Driving and operatingDeactivation
Deactivate the stop-start system
manually by pressing Î.
Deactivation is indicated when the
LED in the button illuminates.
To reactivate, press Î again; LED
extinguishes in the button. The
system is reactivated automatically
the next time the ignition is switched
on.
Notice
When the fast idle function is
activated, the stop-start system is
automatically deactivated and
cannot be reactivated by pressing
Î . LED in button illuminates to
indicate deactivation and a
corresponding message may
appear in the Driver Information Centre 3 101.
Idle speed control 3 135.
AutostopManual transmission
If the vehicle is at low speed or
standstill, activate an Autostop as
follows:
● depress the clutch pedal
● move the selector lever to neutral
● release the clutch pedal
Control indicator Ï may flash if the
clutch is not released sufficiently.Manual transmission automated
If the vehicle is at a standstill, activate an Autostop as follows:
● selector lever in position N (or
A/M )
● depress brake pedal firmly
● do not accelerate
The engine will be switched off while
the ignition stays on if the required conditions are fulfilled.
An Autostop is indicated when Ï
illuminates green in the instrument
cluster 3 99.
During an Autostop, the heating
performance, power steering and
brake performance will be
maintained. Brake assist, however, is
not available 3 155.
Notice
If you exit the vehicle while the
engine is in an Autostop, a warning
chime will sound as a reminder that
the engine is on standby and has not been switched off.
Page 139 of 261

Driving and operating137Conditions for an Autostop
The stop-start system checks if each
of the following conditions is fulfilled,
otherwise an Autostop will be
inhibited and control indicator \ will
illuminate in the instrument cluster.
● the stop-start system is not manually deactivated
● the bonnet is fully closed
● the vehicle battery is sufficiently charged and in good condition
● the engine is warmed up
● the engine coolant temperature is
not too high
● the ambient temperature is not too low
● the defrosting function is not activated
● the climate control system does not inhibit an Autostop
● the rear air conditioning system is
not activated
● the brake vacuum is sufficient● the self-cleaning function of the diesel particle filter is not active
3 141
● the vehicle has moved since the last Autostop
Otherwise an Autostop will be
inhibited.
An Autostop may become
unavailable as the ambient
temperature approaches freezing
point.
Certain settings of the climate control
system may also inhibit an Autostop.
See "Climate control" chapter for
further information 3 115.
Immediately after motorway driving
an Autostop may be inhibited.
New vehicle running-in 3 133.
Vehicle battery discharge protection
To ensure reliable engine restarts, several vehicle battery discharge
protection features are implemented
as part of the stop-start system.Restart of the engine by the driverManual transmission
With the selector lever in neutral,
depress the clutch pedal to restart the
engine.
Notice
If any gear is selected, the clutch
pedal must be fully depressed to
restart the engine.
If the engine does not restart first
time, depress clutch pedal fully again.Manual transmission automated
With the selector lever in position N
(or A/M ) and the parking brake
released, release the brake pedal to
restart the engine.
Engaging reverse gear or depressing the accelerator pedal may also restart the engine.
The green control indicator Ï will
extinguish in the instrument cluster
when the engine is restarted. If
certain conditions are not fulfilled, a
restart will not take place; start using
the ignition key.
Starting the engine 3 134.
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138Driving and operatingBus
The engine is restarted automatically
when operating the power sliding
door switch on the instrument panel
during an Autostop.
Sliding door 3 27.
Restart of the engine by the stop-
start system
If one of the following conditionsoccurs during an Autostop, the
engine may be restarted
automatically by the stop-start
system. Control indicator Ï will flash
green in the instrument cluster during
an automatic engine restart.
● the vehicle battery is discharged
● the ambient temperature is too low
● the defrosting function is activated
● the brake vacuum is not sufficient
● the brake pedal is operated repeatedly
● the vehicle starts to moveAn automatic engine restart may not
be possible if a door or the bonnet is
open.
If an electrical accessory, e.g. a
portable CD player, is connected to
the power outlet, a brief power drop during restart might be noticeable.
If the Infotainment system is active,
audio sound may briefly be reduced
or interrupted during the restart.
Fault
If control indicator Ï illuminates
yellow, or the LED illuminates in
deactivation button Î without first
being pressed to deactivate the
system, there is a fault in the stop-
start system 3 99. A corresponding
message also appears in the Driver
Information Centre 3 101.
Seek the assistance of a workshop.
Warning chimes 3 102.Parking9 Warning
● Do not park the vehicle on an
easily ignitable surface. The
high temperature of the
exhaust system could ignite the
surface.
● Always apply parking brake without pressing release
button. Apply as firmly as
possible on a downhill slope or
uphill slope. Depress brake
pedal at the same time to
reduce operating force.
● Switch off the engine.
● If the vehicle is on a level surface or uphill slope, engage
first gear. On an uphill slope,
turn the front wheels away from
the kerb.
If the vehicle is on a downhill
slope, engage reverse gear.
Turn the front wheels towards the kerb.
Page 141 of 261

Driving and operating139● Close the windows.
● Turn the ignition key to position
0 and remove it. Turn the
steering wheel until the
steering wheel lock is felt to
engage.
Lock the vehicle 3 22 and activate the
anti-theft locking system 3 32 and
anti-theft alarm system 3 32.
Air suspension
Operates automatically when the
vehicle is driven. The air suspension
system constantly adjusts the ride
height according to the vehicle load.
Caution
To ensure safe operation of the air
suspension system, do not exceed the maximum permissible gross
vehicle weight rating. Refer to
identification plate 3 223 or the
vehicle documents.
For further information on the air
suspension system, refer to the
operating instructions supplied.
Master switchCaution
The air suspension system must
be switched off when the vehicle is being towed, jump‐started, raised
off the ground or transported.
Do not switch off the air
suspension system when driving.
Jump starting 3 212, Towing the
vehicle 3 214.
The master switch is located on the
door pillar.
Switch on to enable operation and
adjustment of the air suspension
system.
Switch off to put the vehicle into
service mode.
Remote control
When increased ground clearance or improved vehicle access is required,the suspension can be raised or
lowered using the remote control.
Page 142 of 261

140Driving and operatingCaution
Ensure there is adequate
clearance and that there are no
obstructions when adjusting the
suspension height.
The remote control unit is magnetic
and may be fixed to any metal part of the vehicle or stored in its holder.
With the engine running, press the appropriate button for two seconds to
adjust the suspension height.
Indicator light will flash intermittently
while height adjustment is in progress
and illuminates when complete.
If the ignition is switched on with
engine not running, the suspension
height can only be lowered.
Notice
Handle with care, protect from
moisture and high temperatures and
avoid unnecessary operation.
Pre-programmed settings
Adjusts the suspension height to one
of three pre-programmed positions.
l:lowered positionk:normal positionj:raised positionCaution
If an obstacle is detected while
raising or lowering, the
suspension height is returned to the normal position after a delay.
This does not guarantee damage- free operation. Ensuring sufficient
clearance and freedom from
obstacles is the responsibility of the driver.
Manual settings
Manual adjustment can only be
performed when the vehicle is
stationary.
Select by pressing h for
two seconds , then R to raise, or S to
lower.
To exit, press any of the pre-
programmed buttons.
Notice
Obstacle detection is not available
during manual adjustment.
When a certain low speed is
exceeded or when the ignition is
switched off, height adjustment is deactivated automatically and the
suspension height is returned to the
normal position.
Service modeWhen the vehicle is stationary, press
i for five seconds to put the vehicle
into service mode. The indicator light
will illuminate.
When service mode has been
activated, the air suspension master
switch must be turned off.
To exit service mode, press i again
for five seconds.
Fault
If a fault is detected, i will flash
intermittently. If service mode has been activated and there is a fault, h,
S and R will flash simultaneously.
Have the cause of the fault remedied
by a workshop.
Page 143 of 261

Driving and operating141Engine exhaust9Danger
Engine exhaust gases contain
poisonous carbon monoxide,
which is colourless and odourless and could be fatal if inhaled.
If exhaust gases enter the interior
of the vehicle, open the windows.
Have the cause of the fault
rectified by a workshop.
Avoid driving with an open load
compartment, otherwise exhaust
gases could enter the vehicle.
Diesel particle filter
The diesel particle filter system filters
harmful soot particles out of the
exhaust gases. The system includes
a self-cleaning function that runs
automatically during driving without
any notification.
The filter is cleaned by periodically
burning off the soot particles at high
temperature. This process takes
place automatically under set driving
conditions. Autostop is not available
and fuel consumption may be higher
during this period. The emission of
smells and smoke during this process is normal.
Under certain driving conditions, e.g.
short distances, the system cannot
clean itself automatically.
If cleaning of the filter is required and
if previous driving conditions did not
enable automatic cleaning, it will be
indicated by illumination of control
indicator A 3 96. Seek the
assistance of a workshop
immediately.Caution
If the cleaning process is
interrupted, there is a risk of
provoking severe engine damage.
Cleaning takes place quickest at high engine speeds and loads.
Catalytic converter
The catalytic converter reduces the
amount of harmful substances in the
exhaust gases.
Caution
Fuel grades other than those listed on page 3 167, 3 225 could
damage the catalytic converter or
electronic components.
Unburnt fuel will overheat and
damage the catalytic converter.
Therefore avoid excessive use of the starter, running the fuel tank
dry and starting the engine by
pushing or towing.
In the event of misfiring, uneven
engine running, a reduction in engine performance or other unusual
problems, have the cause of the fault
rectified by a workshop as soon as
possible. In an emergency, driving
can be continued for a short period,
keeping vehicle speed and engine
speed low.
If control indicator Z flashes, the
permitted emission limits may be
exceeded. Lift your foot off the
accelerator until Z stops flashing and
is steadily illuminated. Contact a
workshop immediately.
Page 144 of 261

142Driving and operatingMalfunction indicator light 3 96.
AdBlue
General information
The selective catalytic reduction
(BlueInjection) is a method to
substantially reduce the nitrogen
oxides in the exhaust emission. This
is achieved by injecting a Diesel
Exhaust Fluid (DEF) into the exhaust
system.
The designation of this fluid is
AdBlue ®
. It is a non-toxic, non-
flammable, colourless and odourless
fluid which consists of 32% urea and
68% water.9 Warning
Avoid contact of your eyes or skin
with AdBlue.
In case of eye or skin contact,
rinse off with water.
Caution
Avoid contact of the paintwork with AdBlue.
In case of contact, rinse off with water.
AdBlue freezes at a temperature of
approx. -11 °C. As the vehicle is
equipped with an AdBlue pre-heater,
the emissions reduction at low
temperatures is ensured. The AdBlue
pre-heater works automatically.
AdBlue gauge
In versions without AdBlue level
warnings in the Driver Information
Centre, an AdBlue gauge is present,
which shows the current AdBlue fluid
level remaining in the tank.
AdBlue gauge 3 90.
Level warnings
The AdBlue consumption is approx.
3.5 litres per 600 miles (810 mpg) and depends on the driving behaviour.
Version with level warnings in the
Driver Information Centre
If the AdBlue level falls below a
certain value, a level warning will be
displayed in the Driver Information
Centre 3 101.