2013 MERCEDES-BENZ GLK-CLASS SUV ECU

i
This also applies if you have activated
cruise control.
This will use the braking
effect of the engine,
so that less braking will be required to
maintain the speed, This relieves the load on
the brake system and prevents the brakes
from overheating and wearing too quickly. If
you need additional braking, depress the
brake pedal repeatedly rather than
continuously.
Driving tips R
Maintain a greater distance from the
vehicle in front than when

driving without a
trailer.
R Avoid braking abruptly. If possible, brake
gently at first to allow the trailer to run on.
Then, increase the braking force rapidly.
R The values given for gradient-climbing
capabilities from a standstill refer to sea
level. When driving in mountainous areas,
note that the power output of the engine
and, consequently, the vehicle's gradient-
climbing capability, decreases with
increasing altitude.
If the trailer swings from side to side:
X Do not accelerate.
X Do not counter-steer.
X Brake if necessary. Installing the ball coupling
G
WARNING
If the ball coupling is not installed and secured
correctly the trailer
may come

loose. There is
a risk of an accident.
Install and secure the ball coupling as
described in the ball coupling installation
instructions. Make sure that the ball coupling
is installed and secured correctly before every
journey.
! Mercedes-Benz recommends that you
only use ball couplings that have been tested and approved by Mercedes-Benz.
This helps to avoid damage to the vehicle.
Cover cap
X
Pull protective cap 0043 in the direction of
the
arrow, out of ball coupling recess 0044.
X Store protective cap 0043 in a safe place.
X Observe the manufacturer's installation
instructions. G
WARNING
If the ball coupling is not installed and secured
correctly it can become detached while the
vehicle is in motion and fall onto the road.
There is a risk of an accident and injury.
Install and secure the ball coupling as
described in the ball coupling installation
instructions. Make sure that the

ball coupling
is installed and secured correctly before every
journey. Coupling up a trailer
Observe the maximum permissible trailer
dimensions (width and length).
Most U.S. states and all Canadian provinces
require by law:
R safety chains between the towing vehicle
and the trailer. The chains

should be cross-
wound under the trailer drawbar. They must
be fastened to the vehicle's trailer
coupling, not to the bumper or the axle. 210
Towing a trailer
Driving and parking

Leave enough play in the chains to make
tight cornering possible.
R a separate brake system for certain types
of trailer.
R a safety switch for braked trailers. Check
the specific legal requirements applicable
to your state.
If the trailer detaches from the towing
vehicle, the safety switch applies the
trailer's brakes.
! Do not connect the trailer's
brake system
(if featured) to the hydraulic brake system
of the towing vehicle, as the latter is
equipped with an anti-lock brake system.
Doing so will result in a loss of function of
the brake systems of both the vehicle and
the trailer.
i The vehicle's wiring harness features a
connection to the brake indicator lamp.
X Make sure that the automatic transmission
is set to position P.
X Apply the vehicle's parking brake.
X Close all doors and the tailgate.
X Couple up the trailer.
X Establish all electrical connections. Towing a trailer
There are numerous legal requirements
concerning the towing of a

trailer, e.g. speed
restrictions. Make sure that your car/trailer
combination complies with the local
regulations:
R in your place of residence
R in the location to which you are driving
The police and local authorities can provide
reliable information.
Observe the following when towing a trailer:
R To gain driving experience and to become
accustomed to the new handling characteristics, you should practice the
following in a traffic-free location:
-
cornering
- stopping
- backing up
R Before driving, check:
-the trailer tow hitch
- the safety switch for braked trailers
- the safety chains
- electrical connections
- the lights
- the wheels
R Adjust the exterior mirrors to provide an
unobstructed view of the rear

section of the
trailer.
R If the trailer has electronically controlled
brakes, pull away carefully. Brake manually
using the brake controller and check
whether the brakes function correctly.
R Secure any objects on the trailer to prevent
the cargo from slipping when the vehicle is
in motion.
R When you couple up a trailer, check at
regular intervals that the load is firmly
secured. If the trailer is equipped with
trailer lights and brakes, check the trailer
to ensure that these 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, has a decreased
gradient climbing capability and a longer
braking distance.
It is more susceptible to side winds and
requires more careful steering.
R If possible, avoid abrupt braking. Depress
the brake pedal moderately at first, so that
the trailer can activate its own brakes. Then
increase the pressure on the brake pedal.
R If the automatic transmission continues to
shift back and forth between two gears Towing a trailer
211
Driving and parking Z

accounts for 8% to 15% of the trailer's
permissible gross weight.
i The weight of other accessories,
passengers and loads reduces:
R the permissible trailer load
R the permissible noseweight that your
vehicle can tow
Checking the vehicle and trailer
weightR
To ensure compliance of the weight of the
towing vehicle and the trailer with the
maximum permissible values, have the
vehicle/trailer combination (towing vehicle
including driver, passenger, load and fully
laden trailer) weighed on a calibrated
weighbridge.
R Check the gross axle weight rating of the
front and

rear axles, the gross weight of the
trailer and trailer drawbar load. Removing the ball coupling
X Observe the manufacturer's installation
instructions.
X Press the protective cap into the ball
coupling recess.
X Make sure that the protective cap is firmly
in place. Storing the ball coupling
G
WARNING
Do not carry the ball coupling in the vehicle
interior if it is not secured.
Otherwise, you and others could

be injured by
the ball coupling being thrown around if you:
R brake sharply
R change direction suddenly
R are involved in an accident
X Observe the manufacturer's installation
instructions. Trailer power supply
The trailer socket of your

vehicle is equipped
at the factory with a permanent power supply.
The permanent power supply is supplied via
trailer socket pin 4.
! You can connect accessories with a
maximum power consumption of 240 W to
the permanent power supply.
You must not charge a trailer battery using
the power supply.
The trailer's permanent power supply is
switched off in the event of low vehicle supply
voltage and after six hours at the latest.
A qualified specialist workshop can provide
more information about installing the trailer
electrics. Towing a trailer
213
Driving and parking Z

Display messages Possible causes/consequences and
0050 Solutions0027(USA
only)004D(Canada
only)
Check Brake Fluid
Level There is not enough brake fluid in the brake fluid reservoir.
In addition, the 0027 (USA only)/004D (Canada only) warning
lamp lights up in the instrument cluster and a warning tone
sounds.
G WARNING
The braking effect may be impaired.
There is a risk of an accident.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic
conditions. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away ( Y page 160).
X Consult a qualified specialist workshop.
X Do not add brake fluid. This does not correct the malfunction. 0026
Check Brake Pad
Wear The brake pads/linings have reached their wear limit.
X
Visit a qualified specialist workshop. 0053
mbrace Inoperative One or more main features of the mbrace system are
malfunctioning.
X
Have the mbrace system checked immediately at a qualified
specialist workshop. PRE-SAFE
Inoperative See
Operator's Manual
Important functions of PRE-SAFE
®
have failed. All other
occupant
safety systems, e.g. air bags, remain available.
X Visit a qualified specialist workshop immediately.234
Display messages
On-board computer and displays

Display messages Possible causes/consequences and
0050 SolutionsPRE-SAFE
Functions
Currently Limited
See Operator's
Manual
PRE-SAFE
®
Brake is temporarily inoperative. Possible causes are:
R function is impaired due to heavy rain or snow.
R the sensors in the radiator grill and the bumper are dirty.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio
stations or other sources of electromagnetic radiation.
R the system is outside the operating temperature range.
R the on-board voltage is too low.
When the causes stated above no longer apply, the display
message disappears.
PRE-SAFE ®
Brake is operational again.
If the display message does not disappear:
X Pull over and stop
the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Y page 160).
X Clean the sensors in the radiator grill and the bumper
(Y page 307).
X Restart the engine. PRE-SAFE
Functions Limited
See Operator's
Manual
PRE-SAFE
®
Brake is inoperative due to a malfunction. BAS PLUS
or the distance warning signal may also have failed.
X Visit a qualified specialist workshop. 0075
SRS Malfunction
Service Required There is a malfunction in the SRS (Supplemental Restraint
System). The 0075 warning lamp also lights up in the instrument
cluster.
G WARNING
The air bags or Emergency Tensioning Devices may either be
triggered unintentionally or, in the event of an accident, may not
be triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop.
For further information about SRS, see (Y page 41). Display messages
235
On-board computer and displays Z

Display messages Possible causes/consequences and
0050 SolutionsFront Passenger
Airbag Disabled
See Operator's
Manual The front-passenger air bag is disabled during the journey, even
though:
R
an adult
or
R a person larger than a certain size is occupying the front-
passenger seat
If additional forces are applied to the seat, the system may
interpret the occupant's weight as lower than it actually is.
G WARNING
The front-passenger air bag does not deploy during an accident.
There is an increased risk of injury.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Y page 160).
X Switch the ignition off.
X Have the occupant get out of the vehicle.
X Keep the seat unoccupied, close the front-passenger door and
switch on the ignition.
X Observe the PASSENGER AIRBAG OFF indicator lamp in the
center console and the multifunction display and check the
following:
Seat unoccupied and ignition switched on:
R the PASSENGER AIRBAG OFF indicator lamp must light up and
remain lit. If
the indicator
lamp is on, OCS has disabled the front-
passenger air bag ( Y page 47).
R the Front Passenger Airbag Enabled See Operator's
Manual or Front Passenger Airbag Disabled See
Operator's Manual display messages must not be shown in
the multifunction display.
X Wait for a period of at least 60 seconds until the necessary
system checks have been completed.
X Make sure that the display messages do not appear in the
multifunction display.
If these conditions are fulfilled, the front-passenger seat can be
occupied again. Whether the PASSENGER AIRBAG OFF indicator
lamp remains lit or goes out depends on how OCS classifies the
occupant.
If the conditions are not fulfilled, the system is not operating
correctly.
X Visit a qualified specialist workshop immediately. Display messages
237
On-board computer and displays Z

Display messages Possible causes/consequences and
0050 SolutionsFor further information about the Occupant Classification System,
see (
Y page 47). Front Passenger
Airbag Enabled
See Operator's
Manual The front-passenger air bag is enabled during the journey, even
though:
R
a child, a small adult or an object weighing less than the
system's weight threshold is located on the front-passenger
seat
or
R the front-passenger seat is unoccupied
The system may detect objects or forces applying additional
weight on the seat.
G WARNING
The air bag may deploy unintentionally.
There is an increased risk of injury.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Y page 160).
X Switch the ignition off.
X Open the front-passenger door.
X Remove the child and the child restraint system from the front-
passenger seat.
X Make sure that there are no objects on the seat adding to the
weight.
The system may otherwise detect the additional weight and
interpret the seat occupant's weight as greater than it actually
is.
X Keep the seat unoccupied, close the front-passenger door and
switch on the ignition.
X Observe the PASSENGER AIRBAG OFF indicator lamp in the
center console and the multifunction display and check the
following:
Seat unoccupied and ignition switched on:
R the PASSENGER AIRBAG OFF indicator lamp must light up and
remain lit. If the indicator lamp is on, OCS (Occupant
Classification System) has
disabled the
front-passenger air bag
(Y page 47).
R the Front Passenger Airbag Enabled See Operator's
Manual or Front Passenger Airbag Disabled See
Operator's Manual display messages must not be shown in
the multifunction display.238
Display messages
On-board computer and displays

Display messages Possible causes/consequences and
0050 Solutions00AC
Coolant Too Hot
Stop Vehicle Turn
Engine Off The coolant is too hot.
A warning tone also sounds.
G WARNING
Do not drive when your engine is overheated. This can cause some
fluids which may have leaked into the engine compartment to
catch fire.
Steam from the overheated engine can also cause serious burns
which can occur just by opening the hood.
There is a risk of injury.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Y page 160).
X Wait until the engine has cooled down.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
X Do not start the engine again until the display message goes out
and the coolant temperature is below 248 ‡ (120 †).
Otherwise, the engine could be damaged.
X Pay attention to the coolant temperature display.
X If the temperature increases again, visit a qualified specialist
workshop immediately.
Under normal operating
conditions and with the specified coolant
level, the coolant temperature may rise to 248 ‡ (120 †). 244
Display messages
On-board computer and displays