
available from the police and local
authorities.
Observe the following when towing a trailer:
R
Practice driving around bends, stopping
and backing up at a place where there is no
traffic. This enables you to gain experience
and get used to the new handling
characteristics.
R Before driving, check:
-that the trailer tow hitch and ball
coupling are secure
- that the safety switch for a braked trailer
is functioning properly
- that the safety chains are secure and not
damaged
- that the electrical connections are
secure
- that the lights are working
- that the wheels are in good order and the
tire pressure is correct
R Adjust the exterior mirrors to provide an
unobstructed view of the rear sectio nofthe
trailer.
R If the trailer has electronically controlled
brakes, pull the vehicle/trailer
combination away carefully. Brake
manually using the brake controller and
check that the brakes are working.
R Secure the load on the trailer according to
the applicable specifications and current
standards on securing loads
(Y page 234).
R When driving with a trailer, check at regular
intervals that the load is secured and that
the brakes and lights are working.
R Bear in mind that the handling will be less
stable when towing a trailer than when
driving without one. Avoid sudden steering
movements.
R The vehicle/trailer combination is heavier,
accelerates more slowly and has a
decreased gradient climbing capability and
a longer braking distance.
It is more susceptible to crosswinds and
requires cautious steering. R
If possible, do not brake suddenly, but
rather moderately at first so that the trailer
can activate its brakes. Then increase the
force on the brake pedal.
R If the automatic transmission repeatedly
shifts between gears when driving on
inclines, restrict the shift range. Select shift
range 4,3,2or 1.
Driving in a low gear and at a low speed
reduces the risk of damaging the engine.
R When driving on a downhill gradient, shift
to a low gear and take advantage of the
engine's braking effect.
Avoid continuous brake application as this
may overheat the vehicle brakes and, if
installed, the trailer brakes.
R If the coolant temperature increases
dramatically while the air-conditioning
system is switched on, switch off the air-
conditioning system.
Coolant heat can also be dissipated by
switching the airflow and the temperature
of the heater/air conditioning to the
maximum level. Open the windows if
necessary.
R When overtaking, pay particular attention
to the extended length of your vehicle/
trailer combination.
Due to the length of your vehicle/trailer
combination you need an additional
distance before you can return to your
original lane. Uncoupling
atrailer G
WARNING
If you uncouple a trailer with the overrun
brake engaged, you could trap your hand
between the vehicle and the trailer drawbar.
There is a risk of injury.
Do not uncouple a trailer if the overru nbrake
is engaged.
! Do not disconnect a trailer with an
engaged overru nbrake. Otherwise, your 172
Towing
atrailerDriving an d parking

Useful information
This Operator's Manual describes all models
as well as standard and optional equipment
of your vehicle that were available at the time
of going to print. Country-specific variations
are possible. Note that your vehicle may not
be equipped with all of the described
functions. This also applies to systems and
functions relevant to safety.
Read the information on qualified specialist
workshops (Y page 26). Important safety notes
G
WARNING
If you are driving and reach through the
steering wheel to operate the adjustment
knob, you could lose control of the vehicle.
There is a risk of an accident and injury.
Only operate the adjustment knobs when the
vehicle is stationary. Do not reach through the
steering wheel when driving. G
WARNING
If you operate information systems and
communication equipment integrated in the
vehicle while driving, you will be distracted
from traffic conditions. You could also lose
control of the vehicle. There is a risk of an
accident.
Only operate the equipment when the traffic
situatio npermits .Ifyou are not sure that this
is possible, park the vehicle paying attention
to traffic conditions and operate the
equipment when the vehicle is stationary. G
WARNING
If the instrument cluster has failed or
malfunctioned, you may not recognize
function restrictions in systems relevant to
safety. The operating safety of your vehicle
may be impaired. There is a risk of an
accident. Drive on carefully. Have the vehicle checked
at a qualified specialist workshop
immediately.
If uncertainties regarding the operating safety
of the vehicle arise when continuing the
journey, stop the vehicle, paying attention to
road and traffic conditions.
You must observe the legal requirements for
the country in which you are currently driving
when operating COMAND. Instrument cluster
Overview
0005
Instrument cluster on vehicles without
steering wheel buttons
0006 Instrument cluster in vehicles with
steering-wheel buttons
0026 000E/000F adjustment button, 0004menu
button, 0007reset button, 0012service button
(engine oil level check)
You will find a full overview of the instrument
cluster in the "At a glance" section
(Y page 33).
The display in the instrument cluster is
activated when you:
R open the driver's door
R turn the key to position 2in the ignition lock 176
Instrument clusterOn-board computer and displays

When a connection is established, the
name of the other person and/or the call
duration appear in the display.
X To exit the telephone book: press the
0005 button.
Redialing The on-board computer saves the last names
or numbers dialed in the redial memory.
Using the steering wheel buttons
X Use the 0010or0007 buttons to select the
TEL menu.
The display shows the mobile phone
operational readiness symbol.
X Press the 0001button.
The display shows the most recently dialed
numbers or names in the redial memory.
X Press the 0001or0009 button to select the
desired name or number.
X To start dialing: press the0001button.
The on-board computer dials the
corresponding phone number. The
Dialing (Audio 20) message appears in
the display.
When a connection is established, the
name of the other person and/or the call
duration appear in the display.
Or
X To exit the redial memory: press the
0005 button. Display messages
Notes on displa
ymessages
Important safety notes G
WARNING
No informatio nwill be displayed if either the
instrumen tcluster or the display is
inoperative.
As a result, you will not be able to see warning
and indicator lamps or information about the
driving conditions, such as speed or outside temperature. Driving characteristics may be
impaired
.Adjust your driving style and vehicle
speed accordingly.
Contac taqualified specialist workshop
immediately. G
WARNING
If service work is not carried out correctly, the
operating safety of your vehicle may be
affected. This could cause you to lose control
of your vehicle and cause an accident.
Moreover, the safety systems may no longer
be able to protect you or others as they are
designed to do.
Always have service work carried out at a
qualified specialist workshop.
i If you turn the key to position 2in the
ignition, a display chec kis performed. All
warning/indicator lamps (except the turn
signal indicator lamps) and the display are
activated. Before starting the journey,
check that the warning and indicator lamps
are operating correctly.
Vehicles without steering wheel
buttons Warnings, malfunctions or additional
information may also be shown in the display.
The following tables show all the display
messages.
Awarning tone sounds with
certain display messages.
Vehicles with steering wheel buttons The on-board computer shows warnings,
malfunctions or additional informatio
ninthe
display. Awarning tone sounds with certain
display messages .Display messages of a high
priority are shown in red.
Please respond in accordance with the
display messages and follow the additional
notes in this Operator's Manual.
You can hide low-priority display messages by
pressing the 0010,0007,0001or0009 192
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
0004 Solutions
000A
Unavailable ASR and BA
Shave been deactivated due to undervoltage.
The battery may no tbe being charged.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
The braking distance can increase in emergency braking
situations. The driven wheels can spin when accelerating.
There is an increased risk of skidding and accidents.
X Drive on with care.
X Visit a qualified specialist workshop immediately. 0005
Brake wear Visit
workshop The brake pads/linings have reached their wear limit.
X Have the brake pads/linings replaced as soon as possible at a
qualified specialist workshop. 0008
Brake fluid Visit
workshop There is insufficient brake fluid in the fluid reservoir.
G WARNING
Braking performance can be impaired.
There is a risk of an accident.
X Stop the vehicle as soon as possible, paying attention to road
and traffic conditions.
X Check the brake fluid level in the brake fluid reservoir
(Y page 245).
If the brake fluid is below the MIN mark:
X Do not continue driving under any circumstances.
X Do not add brake fluid. This does not solve the problem.
X Consult a qualified specialist workshop.
If the brake fluid is above the MIN mark:
X Drive on with care.
X Visit a qualified specialist workshop immediately. Display messages
199On-board computer and displays Z

Display messages Possible causes/consequences and
0004 Solutions
Check tire(s)
0001 The pressure of one or more tires has dropped significantly. If the
tire pressure monitor has detected the affected wheel, the wheel
position is also displayed.
X
Stop the vehicle as soo naspossible, paying attention to road
and traffic conditions.
X Check the tires.
X Repairorc hange the wheel if necessary (Y page 302).
X Check the tire pressure and correct it if necessary
(Y page 281).
The display message disappears automatically after driving for
a few minutes with the corrected tire pressure. Warning Tire defect
0001 One or more tires is losing air rapidly.Ift
he tire pressure monitor
has detected the affected wheel, the wheel position is also
displayed.
X Stop the vehicle without making any sudden steering or braking
maneuvers, paying attention to the traffic conditions as you do
so.
X Repair or change the wheel (Y page 302).Vehicle
Display messages Possible causes/consequences and
0004 Solutions
0010
Battery/
Alternator Visit
workshop The battery is not being charged. Possible causes are a defective
alternator or a torn poly-V-belt.
X
Stop the vehicle as soon as possible, paying attention to road
and traffic conditions.
X Check the poly-V-belt.
X If the poly-V-belt is torn: do not continue driving. Consult a
qualified specialist workshop.
X If the poly-V-belt is not damaged: have the vehicle checked as
soon as possible by a qualified specialist workshop. 0001
Electrical Step The electrical step has retracted or extended only partially or not
at all.
X
Make sure there is sufficient free space for the electrical step.
X Open or close the sliding door again.
X If the electrical step still does not extend or retract fully, push
the step in manually (Y page 72). Before stepping out, remind
the passengers that the step is missing. 208
Display messagesOn-board computer and displays

Problem Possible causes/consequences and
0004 Solutions
0008
The red brake
system indicator
lamp is lit while
the engine is
running. There is insufficient brake fluid in the expansion tank.
G WARNING
Braking performance can be impaired.
There is a risk of an accident.
X Vehicles with steering wheel buttons:a lso observe the
messages in the display (Y page 192).
X Stop the vehicle as soon as possible, paying attention to road
and traffic conditions.
X Check the brake fluid level in the expansion tank
(Y page 245).
X If the brake fluid is below the MIN mark: do not drive on!
X Do not add brake fluid. This does not solve the problem.
X Consult a qualified specialist workshop. 0008
When towing a
trailer: the red
brake system
indicator lamp is
lit while the
engine is
running.
Additionally, a
warning tone
sounds. G
WARNING
The brake force booster in the trailer is faulty.
The driving and braking characteristics of your vehicle could
change. There is a risk of the trailer overbraking and of you losing
control over the truck/trailer combination.
There is a risk of an accident.
X Vehicles with steering wheel buttons :also observe the
messages in the display (Y page 192).
X Stop the vehicle as soon as possible, paying attention to road
and traffic conditions.
X Do not drive on.
X Consult a qualified specialist workshop. 000A
The yellow ASR/
BAS indicator
lamp is lit while
the engine is
running. ASR has been deactivated due to a malfunction.
The engine power output may be reduced.
G WARNING
The drive nwheels can spin when accelerating.
There is an increased risk of skidding and accidents.
X Drive on with care.
X Consult a qualified specialist workshop as soon as possible. Indicator and warning lamps in the instrument cluster
211On-board computer and displays Z

Problem Possible causes/consequences and
0004 Solutions
0008
The red 0008
warning lamp
does not go out
approximately
4s econds after
the ignition is
switched on, or
it lights up again. The restraint systems have malfunctioned.
G WARNING
If SRS is malfunctioning, individual systems could be triggered
inadvertently or might not be triggered at all in the event of an
accident.
There is an increased risk of injury and accidents.
X Drive on with care.
X Visit a qualified specialist workshop immediately. 0010
The red battery
indicator lamp is
lit while the
engine is
running. The battery is not being charged. Possible causes are a defective
alternator or a torn poly-V-belt.
X
Stop the vehicle as soon as possible, paying attention to road
and traffic conditions.
X Check the poly-V-belt.
X If the poly-V-belt is torn: do not continue driving. Consult the
nearest qualified specialist workshop.
X If the poly-V-belt is not damaged: have the vehicle checked as
soon as possible by a qualified specialist workshop. 0010
The red battery
indicator lamp is
lit while the
engine is
running. The battery is faulty.
X
Stop the vehicle as soon as possible, paying attention to road
and traffic conditions.
X Do not continue driving under any circumstances.
X Consult a qualified specialist workshop. 0005
The yellow brake
pad wear
indicator lamp is
lit after the
engine is started
or while the
vehicle is in
motion. The brake pads/linings have reached their wear limit.
G WARNING
Braking performance can be impaired.
There is a risk of an accident.
X Have the brake pads/linings replaced as soon as possible at a
qualified specialist workshop. 001D
The yellow
engine oil level
warning lamp is
lit after the
engine is started
or while the
vehicle is in
motion. The oil level has dropped to the minimum level.
X
Check the engine for oil loss.
X If oil loss is detected: consult a qualified specialist workshop
immediately.
X If no oil loss is detected: chec kthe oil level and add engine oil
(Y page 243). 214
Indicator and warning lamps in the instrument clusterOn-board computer and displays

Problem Possible causes/consequences and
0004 Solutions
0013
The yellow air
filter indicator
lamp is lit while
the engine is
running. The service limit for the air filter has been reached. The air filter
is dirty.
X
Have the air filter element replaced as soon as possible at a
qualified specialist workshop. 000A
The yellow tire
pressure
monitor warning
lamp comes on. G
WARNING
The tire pressure monitor indicates a rapid or severe loss of
pressure in at least one tire.
X Stop the vehicle without making any extreme steering
maneuvers or braking suddenly. Pay attention to the traffic
conditions while doing so.
X Check the tires and correctt he tire pressure. If a tire continues
to lose pressure, it must be replaced. Replace damaged tires
immediately.
The warning light will go out after the flat tire has been rectified
and you have been driving for a few minutes.
X Vehicles with steering wheel buttons: also observe the
messages in the display (Y page 192).000A
US vehicles
only:
The yellow tire
pressure
monitor warning
lamp flashes for
60 seconds and
then remains lit. The tire pressure monitor has malfunctioned.
X
Have the tire pressure monitor and the wheels checked at a
qualified specialist workshop. 000E
The yellow water
separator
indicator lamp is
lit when the
ignition is
switched on. The water that has collected in the water separator of the fuel filter
has reached the maximum level.
X
Drain the water separator (Y page 247).218
Indicator and warning lamps in the instrument clusterOn-board computer and displays