Page 65 of 261

erty. Only mount child restraint systems to the
upper retaining straps.◀
Retaining strap guide WARNING
If the upper retaining strap is incorrectly
used for the child restraint system, the protec‐
tive effect can be reduced. There is a risk of in‐
jury. Make sure that the upper retaining strap is
not guided across sharp edges and without
twisting to the upper retaining strap.◀1Direction of travel2Upper retaining strap3Head restraint4Rear window shelf5Mounting point6Hook for upper retaining strap
Attaching the upper retaining strap to
the mounting point
1.Lift the cover over the mounting point.2.Guide the upper retaining strap over the
head restraint.3.Attach the hook of the retaining strap to
the anchor.4.Tighten the retaining strap by pulling it
down.Locking the doors and
windows in the rear
Rear doors
Push the locking lever on the rear doors down.
The door can now be opened from the outside
only.
Safety switch for the rear Press button on the driver's door.
The LED lights up if the safety func‐
tion is switched on.
This locks various functions so that they can‐
not be operated from the rear. Safety switch,
refer to page 47.
Seite 65Transporting children safelyControls65
Online Edition for Part no. 01 40 2 969 305 - II/16
Page 66 of 261

DrivingVehicle features and options
This chapter describes all standard, country-
specific and optional features offered with the
series. It also describes features that are not
necessarily available in your car, e. g., due to
the selected options or country versions. This
also applies to safety-related functions and
systems. The respectively applicable country
provisions must be observed when using the
respective features and systems.
Start/Stop button The concept Pressing the Start/Stop button
switches the ignition on or off
and starts the engine.
The engine starts with the brake
pedal pressed when you press
the Start/Stop button.
Ignition on Press the Start/Stop button, and do not press
on the brake pedal at the same time.
All vehicle systems are ready for operation.
Most of the indicator and warning lights in the
instrument cluster light up for a varied length
of time.
To save battery power when the engine is off,
switch off the ignition and any unnecessary
electronic systems/power consumers.
Ignition offPress the Start/Stop button again without
stepping on the brake.
All indicator lights in the instrument cluster go
out.To save battery power when the engine is off,
switch off the ignition and any unnecessary
electronic systems/power consumers.
Information
When switching off the ignition, the selector
lever position P is selected automatically if the
selector lever position D or R is selected.
The ignition is switched off automatically in the
following situations while the vehicle is station‐
ary and the engine is off:▷When locking the vehicle, and when the
low beams are activated.▷Shortly before the battery is discharged
completely, so that the engine can still be
started.▷When opening or closing the driver door, if
the driver's safety belt is unbuckled and
the low beams are turned off.▷While the driver's safety belt is unbuckled
with driver's door open and low beams off.
The low beams switch to parking lights after
approx. 15 minutes of no use.
Radio ready state
Activate radio-ready state: when the engine is
running: press the Start/Stop button.
Some electronic systems/power consumers
remain ready for operation.
The radio-ready state is switched off automati‐
cally in the following situations:
▷After approx. 8 minutes.▷When the vehicle is locked using the cen‐
tral locking system.▷Shortly before the battery is discharged
completely, so that the engine can still be
started.Seite 66ControlsDriving66
Online Edition for Part no. 01 40 2 969 305 - II/16
Page 67 of 261

The radio-ready state remains active if, for ex‐
ample, the ignition is automatically switched
off for the following reasons:▷Opening or closing the driver's door.▷Unfastening of the driver's safety belt.▷When automatically switching from low
beams to parking lights.
If the engine is switched off and the ignition is
switched on, the system automatically
switches to the radio-ready state if the lights
are turned off or, if correspondingly equipped,
the daytime running lights are activated.
Starting the engine
Information DANGER
If the exhaust pipe is blocked or ventila‐
tion is insufficient, harmful exhaust gases can
enter into the vehicle. The exhaust gases con‐
tain carbon monoxide, an odorless and color‐
less but highly toxic gas. In enclosed areas, ex‐
haust gases can also accumulate outside of
the vehicle. There is danger to life. Keep the
exhaust pipe free and ensure sufficient ventila‐
tion.◀
WARNING
An unsecured vehicle can begin to move
and possibly roll away. There is risk of an acci‐
dent. Before exiting, secure the vehicle against
rolling.
In order to ensure that the vehicle is secured
against rolling away, observe the following:
▷Set the parking brake.▷On uphill grades or on a downhill slope,
turn the front wheels in the direction of the
curb.▷On uphill grades or on a downhill slope,
also secure the vehicle, e.g., with a wheel
chock.◀ATTENTION
In the case of repeated starting attempts
or repeated starting in quick succession, the
fuel is not burned or is inadequately burned.
The catalytic converter can overheat. There is
a risk of damage to property. Avoid repeated
starting in quick succession.◀
Steptronic transmission
Starting the engine1.Depress the brake pedal.2.Press the Start/Stop button.
The ignition is activated automatically for a
certain time and is stopped as soon as the en‐
gine starts.
Engine stop
Information WARNING
Unattended children or animals can
cause the vehicle to move and endanger them‐
selves and traffic, e.g., due to the following ac‐
tions:
▷Pressing the Start/Stop button.▷Releasing the parking brake.▷Opening and closing the doors or win‐
dows.▷Engaging selector lever position N.▷Using vehicle equipment.
There is risk of accidents or injuries. Do not
leave children or animals unattended in the ve‐
hicle. Take the remote control with you when
exiting and lock the vehicle.◀
WARNING
An unsecured vehicle can begin to move
and possibly roll away. There is risk of an acci‐
dent. Before exiting, secure the vehicle against
rolling.
Seite 67DrivingControls67
Online Edition for Part no. 01 40 2 969 305 - II/16
Page 68 of 261

In order to ensure that the vehicle is secured
against rolling away, observe the following:▷Set the parking brake.▷On uphill grades or on a downhill slope,
turn the front wheels in the direction of the
curb.▷On uphill grades or on a downhill slope,
also secure the vehicle, e.g., with a wheel
chock.◀
Before driving into a car wash
So that the vehicle can roll into a car wash ob‐
serve instructions for going into an automatic
car wash, refer to page 239.
Steptronic transmission
Switching off the engine
1.Engage selector lever position P with the
vehicle stopped.2.Press the Start/Stop button.
The engine is switched off.
The radio-ready state is switched on.3.Set the parking brake.
Auto Start/Stop function
The concept The Auto Start/Stop function helps save fuel.
The system switches off the engine during a
stop, for example, in traffic congestion or at
traffic lights. The ignition remains switched on.
The engine starts automatically for driving off.
Information After every start of the engine using the Start/
Stop button, the Auto Start/Stop function is in
the last selected state. When the Auto Start/
Stop function is active, it is available when the
vehicle is traveling faster than about 3 mph,
approx. 5 km/h.
Engine stop
The engine is switched off automatically dur‐
ing a stop under the following conditions:
Steptronic transmission:▷The selector lever is in selector lever posi‐
tion D.▷The brake pedal remains pressed while the
vehicle is stationary or the vehicle is held
by Automatic Hold.▷The driver's safety belt is buckled or the
driver's door is closed.
The air flow from the air conditioner is reduced
when the engine is switched off.
Displays in the instrument cluster The display indicates that the
Auto Start/Stop function is
ready for an Automatic engine
start.
The display indicates that the conditions for an automatic en‐
gine stop have not been met.
Functional limitations The engine is not switched off automatically in
the following situations:
▷External temperature too low.▷The external temperature is high and auto‐
matic climate control is running.▷The car's interior has not yet been heated
or cooled to the required level.▷The engine is not yet at operating temper‐
ature.▷The wheels are at a sharp angle or the
steering wheel is being turned.▷After driving in reverse.▷Fogging of the windows when the auto‐
matic climate control is switched on.Seite 68ControlsDriving68
Online Edition for Part no. 01 40 2 969 305 - II/16
Page 69 of 261

▷Vehicle battery is heavily discharged.▷At higher elevations.▷The engine compartment lid is unlocked.▷HDC Hill Descent Control is activated.▷The parking assistant is activated.▷Stop-and-go traffic.▷Selector lever in selector lever position N,
M/S or R.▷Use of fuel with high ethanol content.
Starting the engine
The engine starts automatically under the fol‐
lowing conditions:
▷Steptronic transmission: by releasing the
brake pedal.
When Automatic Hold is activated: press
the accelerator pedal.
After the engine starts, accelerate as usual.
Safety mode
After the engine switches off automatically, it
will not start again automatically if any one of
the following conditions are met:
▷The driver's safety belt is unbuckled and
the driver's door is open.▷The hood was unlocked.
Some indicator lights light up for a varied
length of time.
The engine can only be started via the Start/
Stop button.
Functional limitations
Even if driving off was not intended, the deacti‐
vated engine starts up automatically in the fol‐
lowing situations:
▷Excessive warming of the car's interior
when the cooling function is switched on.▷The steering wheel is turned.▷Fogging of the windows when the auto‐
matic climate control is switched on.▷Vehicle battery is heavily discharged.▷Excessive cooling of the car's interior when
the heating is switched on.
Activating/deactivating the system
manually
Using the button
Press button.
▷LED comes on: Auto Start/Stop function is
deactivated.
The engine is started during an automatic
engine stop.
The engine can only be stopped or started
via the Start/Stop button.▷LED goes out: Auto Start/Stop function is
activated.
Switching off the vehicle during an
automatic engine stop
During an automatic engine stop, the vehicle
can be switched off permanently, e.g., when
leaving it.
Steptronic transmission:
1.Press the Start/Stop button. The ignition is
switched off. The Auto Start/Stop function
is deactivated.
Selector lever position P is engaged auto‐
matically.2.Set the parking brake.
Engine start as usual via Start/Stop button.
Seite 69DrivingControls69
Online Edition for Part no. 01 40 2 969 305 - II/16
Page 70 of 261

Automatic deactivation
In certain situations, the Auto Start/Stop func‐
tion is deactivated automatically for safety rea‐
sons, as it is detected that no driver is present.
Malfunction
The Auto Start/Stop function no longer
switches off the engine automatically. A Check Control message is displayed. It is possible to
continue driving. Have the system checked by
a dealer’s service center or another qualified
service center or repair shop.
Parking brake
The concept The parking brake is used to prevent the vehi‐
cle from rolling when it is parked.
Information WARNING
An unsecured vehicle can begin to move
and possibly roll away. There is risk of an acci‐
dent. Before exiting, secure the vehicle against
rolling.
In order to ensure that the vehicle is secured
against rolling away, observe the following:▷Set the parking brake.▷On uphill grades or on a downhill slope,
turn the front wheels in the direction of the
curb.▷On uphill grades or on a downhill slope,
also secure the vehicle, e.g., with a wheel
chock.◀
WARNING
Unattended children or animals can
cause the vehicle to move and endanger them‐
selves and traffic, e.g., due to the following ac‐
tions:
▷Pressing the Start/Stop button.▷Releasing the parking brake.▷Opening and closing the doors or win‐
dows.▷Engaging selector lever position N.▷Using vehicle equipment.
There is risk of accidents or injuries. Do not
leave children or animals unattended in the ve‐
hicle. Take the remote control with you when
exiting and lock the vehicle.◀
Overview
Parking brake
Setting Pull the switch.
The LED lights up.
The indicator lamp lights up red. The
parking brake is set.
While driving
Use as emergency brake while driving:
Pull the switch and hold it. The vehicle brakes
hard while the switch is being pulled.
The indicator lamp lights up red, a sig‐
nal sounds and the brake lights light
up.
A Check Control message is displayed.
If the vehicle is slowed down to a speed of ap‐
prox. 2 mph/3 km/h the parking brake is set.
Seite 70ControlsDriving70
Online Edition for Part no. 01 40 2 969 305 - II/16
Page 71 of 261

Releasing
With the ignition switched on:
Steptronic transmission: press the
switch while the brake is pressed or se‐
lector lever position P is set.
The LED and indicator lamp go out.
The parking brake is released.
Automatic release in cars with
Steptronic transmission
For automatic release, step on the accelerator
pedal.
The LED and indicator lamp go out.
The parking brake is automatically released
when you step on the accelerator:▷Engine on.▷Drive mode engaged.▷Driver buckled in and doors closed.
Automatic Hold
The concept This system assists the driver by automatically
setting and releasing the brake, such as when
moving in stop-and-go traffic.
The vehicle is automatically held in place when
it is stationary.
On inclines, the system prevents the vehicle
from rolling backward when driving off.
Overview
Automatic Hold
Safety information WARNING
An unsecured vehicle can begin to move
and possibly roll away. There is risk of an acci‐
dent. Before exiting, secure the vehicle against
rolling.
In order to ensure that the vehicle is secured
against rolling away, observe the following:▷Set the parking brake.▷On uphill grades or on a downhill slope,
turn the front wheels in the direction of the
curb.▷On uphill grades or on a downhill slope,
also secure the vehicle, e.g., with a wheel
chock.◀
Under the following conditions, Automatic
Hold is automatically deactivated and the park‐
ing brake is set:
▷The engine is switched off.▷A door is opened and driver's safety belt is
unbuckled while the vehicle is stationary.▷The moving vehicle is brought to a stand‐
still using the parking brake.
The indicator lamp switches from
green to red and the letters AUTO H go out.
Activating
This function can be activated when the driv‐
er's door is closed, the safety belt is fastened
and the engine is running.
Press button.
The LED and the letters AUTO H light
up.
The indicator lamp lights up.
Automatic Hold is activated.
Seite 71DrivingControls71
Online Edition for Part no. 01 40 2 969 305 - II/16
Page 72 of 261

DeactivatingPress button again.
The LED and the letters AUTO H go
out.
Automatic Hold is deactivated.
If the vehicle is being held by Automatic Hold,
press on the brake pedal to deactivate it.
When the parking brake is set manually, Auto‐
matic Hold is deactivated automatically.
Driving Automatic Hold is activated: the vehicle is au‐
tomatically secured against rolling after brak‐
ing to a standstill.
The indicator lamp lights up green.
Step on the accelerator pedal to drive
off.
The brake is released automatically.
The indicator lamp goes out.
ATTENTION
If the vehicle is stationary, Automatic
Hold engages the parking brake. It prevents
the vehicle from rolling in a vehicle wash.
There is a risk of damage to property. Deacti‐
vate Automatic Hold prior to entering the vehi‐
cle wash.◀
Parking The parking brake is automatically set if the
engine is switched off while the vehicle is be‐
ing held by Automatic Hold.
The indicator lamp changes from green
to red.
The parking brake is not set if the en‐
gine is switched off while the vehicle is coast‐
ing to a halt. Automatic Hold is deactivated.
Automatic Hold remains activated during the
engine stop brought about by the Auto Start/
Stop function.WARNING
Unattended children or animals can
cause the vehicle to move and endanger them‐
selves and traffic, e.g., due to the following ac‐
tions:▷Pressing the Start/Stop button.▷Releasing the parking brake.▷Opening and closing the doors or win‐
dows.▷Engaging selector lever position N.▷Using vehicle equipment.
There is risk of accidents or injuries. Do not
leave children or animals unattended in the ve‐
hicle. Take the remote control with you when
exiting and lock the vehicle.◀
Malfunction
In the event of a failure or malfunction of the
parking brake, secure the vehicle against roll‐
ing using a wheel chock, e.g., when leaving it.
After a power failure
Putting the parking brake into
operation
1.Switch on the ignition.2. Press the switch while stepping on
the brake pedal or selector lever position P
is set.
It may take several seconds for the brake to be
put into operation. Any sounds associated with
this are normal.
The indicator lamp in the instrument
cluster goes out as soon as the parking
brake is ready for operation.
Seite 72ControlsDriving72
Online Edition for Part no. 01 40 2 969 305 - II/16