156Driving and operatingTurn key briefly to position 3 and
release: an automatic procedure
operates the starter with a short delay
until the engine is running, see
Automatic Starter Control.
Manual transmission: during an
Autostop, the engine can be started
by depressing the clutch pedal
3 157.
Automatic transmission: during an
Autostop, the engine can be started
by releasing the brake pedal 3 157.
Vehicles with power button
Manual transmission: operate clutch
and brake pedal.
Automatic transmission: operate
brake pedal and move selector lever
to P or N.
Do not operate accelerator pedal.
Press Engine Start/Stop briefly: an
automatic procedure operates the
starter with a short delay until the engine is running, see automatic
starter control.
To switch off the engine when vehicle is stationary, press
Engine Start/Stop briefly. Automatic
transmission: apply the parking brake
and engage P.
To start the engine during an
Autostop:
● Manual transmission: during an Autostop, the engine can be
started by depressing the clutch
pedal 3 157.
● Automatic transmission: during an Autostop, the engine can be
started by releasing the brake pedal 3 157.Emergency engine shut off during
driving
If the engine needs to be switched offduring driving in case of emergency,
press Engine Start/Stop for longer
than 2 seconds or press twice briefly within 5 seconds.9 Danger
Switching off the engine during
driving may cause loss of power
support for brake and steering
systems. Assistance systems and
airbag systems are disabled.
Lighting and brake lights will
extinguish. Therefore power down the engine and ignition while
driving only when required in case of emergency.
Driving and operating157Starting the vehicle at lowtemperatures
Starting the engine without additional
heaters is possible down to -25 °С for diesel engines and -30 °C for petrol
engines. Required is an engine oil
with the correct viscosity, the correct fuel, performed services and a
sufficiently charged vehicle battery.
With temperatures below -30 °C the
automatic transmission requires a
warming phase of approx. 5 minutes.
The selector lever must be in position
P .
Automatic starter control This function controls the engine
starting procedure. The driver does
not need to hold the key in position 3
or to hold Engine Start/Stop pressed.
Once applied, the system will go on
starting automatically until the engine
is running. Because of the checking procedure, the engine starts running
after a short delay.Possible reasons for a non-starting
engine:
● clutch pedal not operated (manual transmission)
● brake pedal not operated or selector lever not in P or N
(automatic transmission)
● timeout occurred
Turbo engine warm-up
Upon start-up, engine available
torque may be limited for a short time,
especially when the engine
temperature is cold. The limitation is
to allow the lubrication system to fully
protect the engine.
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. The ignition stays on.
The engine switches on automatically
when certain conditions apply or
restart is activated by a driver.
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.
158Driving and operatingDeactivation
Deactivate the stop-start system
manually by pressing D. The
deactivation is indicated when the
LED in the button illuminates.
Autostop
Vehicles with manual transmission
Depending on the engine, two
versions of an Autostop are available. See engine data to identify the engine
identifier code for your vehicle
3 280.
Conventional Autostop
An Autostop can be activated at a
speed lower than 5 km/h.Activate a conventional Autostop as
follows:
● Depress the clutch pedal.
● Set the lever in neutral.
● Release the clutch pedal.
Early Autostop
An Autostop can be activated at a
speed lower than 14 km/h.
Early Autostop is inhibited if the
incline is greater than 5%.
Activate an early Autostop as follows: ● Depress the brake pedal sufficiently.
● Depress the clutch pedal.
The engine will be switched off while
the ignition stays on.
Early Autostop is inhibited when the
turn lights are on, trailer hitch is
connected, the steering wheel is
moved beyond a certain point or the
inclines is greater than 5%.Vehicles with automatic transmission
If the vehicle is at a standstill with
depressed brake pedal, Autostop is
activated automatically.Indication
An Autostop is indicated by the
needle at the AUTOSTOP position in
the tachometer.
After restart, the idle speed is
indicated.
During an Autostop, the heating and
brake performance will be
maintained.
Conditions for an Autostop
The stop-start system checks if each
of the following conditions is fulfilled:
● The stop-start system is not manually deactivated.
● The bonnet is fully closed.
Driving and operating159● The driver's door is closed or thedriver's seat belt is fastened.
● The vehicle battery is sufficiently charged and in good condition.
● The engine is warmed up.
● The engine coolant temperature is not too high.
● The engine exhaust temperature is not too high, e.g. after driving
with high engine load.
● The ambient temperature is above -5 °C.
● The brake vacuum is sufficient.
● Between the last restart and a new Autostop must be about10 seconds.
● The self-cleaning function of the exhaust filter is not active.
● The vehicle was driven at least at
walking speed since the last
Autostop.
Otherwise an Autostop will be
inhibited.
The stop-start system will be
deactivated on inclines of 12% or
more.Certain settings of the climate control
system may inhibit an Autostop. See
Climate control chapter for more
details 3 141.
Immediately after motorway driving
an Autostop may be inhibited.
New vehicle running-in 3 152.
Vehicle battery discharge protection
To ensure reliable engine restarts,
several vehicle battery discharge
protection features are implemented
as part of the stop-start system.
Power saving measures
During an Autostop, several electrical
features e.g. auxiliary electric heater
or heated rear window are disabled or switched to a power saving mode.
The fan speed of the climate control
system is reduced to save power.
Restart of the engine by the driverVehicles with manual transmission
Depending on the engine, two
versions of a restart are available.
See engine data to identify the engine
identifier code for your vehicle
3 280.Conventional restart
Depress the clutch pedal to restart the
engine. For engines with late restart,
this is only possible without
depressing the brake pedal.
Late restart ● Depress the brake pedal.
● Depress the clutch pedal.
● Select first gear.
● Release the brake pedal to restart the engine.Vehicles with automatic transmission:Release the brake pedal or move
selector lever out of D into N or P to
restart the engine.
Restart of the engine by the stop-
start system
On vehicles with manual transmission
which are in a conventional Autostop,
the selector lever must be in neutral
to enable an automatic restart.
On vehicles with manual transmission
which are in an early Autostop, an
automatic restart is possible, when
not in neutral if the brake pedal and
the clutch pedal are depressed.
Driving and operating169Interruption of power supplyIn the event of an interruption of
power supply, the selector lever
cannot be moved out of the P
position. The ignition key cannot be
removed from the ignition switch.
If the vehicle battery is discharged,
start the vehicle using jump leads
3 263.
If the vehicle battery is not the cause
of the fault, release the selector lever.
1. Apply the parking brake.
2. Release the selector lever trim from the centre console. Poke
with a finger into the leather
socket below the selector lever
and push the trim upwards.
Rotate trim to the left.
3. Insert a small stick (e.g. a pen or screw driver) into the opening
near the selector lever. Push
down the stick vertically and move
the selector lever out of P. If this
position is engaged again, the
selector lever will be locked again.
Have the cause of the power
supply interruption remedied by a
workshop.
4. Mount the selector lever trim onto
the centre console and refit.
Manual transmission
To engage reverse, depress the
clutch pedal and then press the
release button on the selector lever
and engage the gear.
If the gear does not engage, set the
lever to neutral, release the clutch
pedal and depress again; then repeat
gear selection.
Do not slip the clutch unnecessarily.
When operating, depress the clutch
pedal completely. Do not use the
pedal as a foot rest.
170Driving and operatingWhen clutch slip is detected for a
specific time, the engine power will be
reduced. A warning is displayed in the Driver Information Centre. Release
the clutch.Caution
It is not advisable to drive with the hand resting on the selector lever.
Gear shift indication 3 111.
Stop-start system 3 157.
Brakes
The brake system comprises two
independent brake circuits.
If a brake circuit fails, the vehicle can
still be braked using the other brake
circuit. However, braking effect is
achieved only when the brake pedal
is depressed firmly. Considerably
more force is needed for this. The
braking distance is extended. Seek
the assistance of a workshop before
continuing the journey.
When the engine is not running, the
support of the brake servo unit
disappears once the brake pedal has been depressed once or twice.
Braking effect is not reduced, but
braking requires significantly greater
force. It is especially important to bear this in mind when being towed.
Control indicator R 3 110.
Antilock brake system
Antilock brake system (ABS)
prevents the wheels from locking.ABS starts to regulate brake pressure as soon as a wheel shows a tendency to lock. The vehicle remains
steerable, even during hard braking.
ABS control is made apparent
through a pulse in the brake pedal
and the noise of the regulation
process.
For optimum braking, keep the brake
pedal fully depressed throughout the
braking process, despite the fact that
the pedal is pulsating. Do not reduce
the pressure on the pedal.
After starting off, the system performs
a self-test which may be audible.
Control indicator u 3 111.
Adaptive brake light During full braking, all three brake
lights flash for the duration of ABS
control.
172Driving and operatingReleasing
Switch on ignition. Keep foot brake
pedal depressed and then push
switch m. If control indicator m
extinguishes, electric parking brake is
released.
Drive away function
Vehicles with manual transmission:
Depressing the clutch pedal and then slightly releasing the clutch pedal and
slightly depressing the accelerator
pedal releases the electric parking
brake automatically. This is not
possible when switch m is pulled at
the same time.
Vehicles with automatic transmission: Engaging D and then depressing the
accelerator pedal releases the
electric parking brake automatically.
This is not possible when switch m is
pulled at the same time.
Dynamic braking when vehicle is
moving
When the vehicle is moving and the
switch m is kept pulled, the electric
parking brake system will decelerate the vehicle, but will not apply
statically.As soon as the switch m is released,
dynamic braking will be stopped.
Automatic applying
If the vehicle is equipped with
automatic transmission and adaptive cruise control is active, electric
parking brake is applied automatically when vehicle is stopped by the
system for more than 2 minutes.
Parking brake releases automatically
after moving off.
Functionality check
When the vehicle is not moving, the
electric parking brake might be
applied automatically. This is done to
check the system.
Fault
Failure mode of electric parking brake
is indicated by a control indicator j
and by a vehicle message which is
displayed in the Driver Information
Centre.
Vehicle messages 3 122.Control indicator m flashes: electric
parking brake is not fully applied or
released. When continuously
flashing, release electric parking
brake and retry applying.
Brake assist If brake pedal is depressed quickly
and forcefully, maximum brake force
is automatically applied.
Operation of brake assist might
become apparent by a pulse in the
brake pedal and a greater resistance
when depressing the brake pedal.
Maintain steady pressure on the
brake pedal as long as full braking is
required. Maximum brake force is
automatically reduced when brake
pedal is released.
Hill start assist The system helps prevent unintendedmovement when driving away on
inclines.
Driving and operating177Vehicle speed can be increased bydepressing the accelerator pedal.
When the accelerator pedal is
released, the previously stored speed
is resumed.
Cruise control remains activated
while gearshifting.
Increase speed
With cruise control active, hold thumb wheel turned to RES/+ or briefly turn
to RES/+ repeatedly: speed
increases continuously or in small
increments.
Alternatively accelerate to the desired speed and store by turning to SET/-.Reduce speed
With cruise control active, hold thumb
wheel turned to SET/- or briefly turn to
SET/- repeatedly: speed decreases
continuously or in small increments.
Deactivation of the functionality
Press y; control indicator m in
instrument cluster illuminates white.
On Uplevel display m changes to
white.
Cruise control is deactivated, but not
switched off. Last stored speed
remains in memory for later speed
resume.
Automatic deactivation: ● Vehicle speed is below approx. 30 km/h.
● Vehicle speed drops more than 25 km/h below the set speed.
● The brake pedal is depressed.
● The clutch pedal is depressed for
a few seconds.
● The selector lever is in N.
● Engine speed is in a very low range.● The Traction Control system orElectronic Stability Control is
operating.
● Parking brake is applied.
● Simultaneous pressing RES/+
and brake pedal deactivates
cruise control and will delete stored speed.
Resume stored speed
Turn thumb wheel to RES/+ at a
speed above 30 km/h. The stored
speed will be obtained.
Switching off the system
Press m, control indicator m in
instrument cluster extinguishes. The
stored speed is deleted.
Pressing L to activate the speed
limiter or switching off the ignition also switches off cruise control and
deletes the stored speed.
Speed limiter
The speed limiter prevents the
vehicle exceeding a preset maximum
speed.