2015 MERCEDES-BENZ GLK-Class ECU

R
When you couple up a trailer, check at reg-
ular 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 driv-
ing 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. Thenincrease the pressure on the brake pedal.
R If the automatic transmission repeatedly
shifts between gears on uphill or downhill
gradients, shift to a lower gear using the
left-hand steering wheel paddle shifter.
A lower gear and lower speed reduce the
risk of engine failure.
R When driving downhill, shift to a lower gear
to utilize 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 dra-
matically while the air-conditioning system
is switched on, switch off the air-condition-
ing system.
Coolant heat can additionally be dissipated
by opening the windows and by setting the
blower fan and the interior temperature to
maximum.
R When overtaking, pay particular attention
to the extended length of your vehicle/
trailer combination.
Due to the length of the vehicle/trailer
combination, you require additional road
space in relation to the vehicle you are
overtaking, before you can change back to
the original lane. Decoupling a trailer
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 overrun brake is engaged.
! Do not disconnect a trailer with an
engaged overrun brake. Otherwise, your
vehicle could be damaged by the rebound- ing of the overrun brake.
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 Apply the trailer's parking brake.
X Remove the trailer cable and decouple the
trailer. Permissible trailer loads and drawbar
loads
Weight specifications The gross trailer weight is calculated by add-
ing the weight of the trailer to the weight of
the load and equipment on the trailer.
You will find installing dimensions and loads
under "Technical data" (Y
page 381).
Loading a trailer R
When loading the trailer, make sure that
neither the permissible gross weight of the
trailer nor the gross vehicle weight is
exceeded. The permissible gross vehicle
weight is indicated on the identification
plate on the B-pillar on the driver's side of
the vehicle.
You can find the maximum permissible val-
ues on the type plates of your vehicle and
the trailer. When calculating how much
weight the vehicle and trailer may carry, 216
Towing a trailerDriving and parking

pay attention to the respective lowest val-
ues.
R The trailer drawbar load on the ball coupling
must be added to the rear axle load to avoid
exceeding the permissible gross axle
weight. The permissible gross vehicle
weight is indicated on the identification
plate on the B-pillar on the driver's side of
the vehicle.
i Mercedes-Benz recommends a trailer
load where the trailer drawbar noseweight
accounts for 8% to 15% of the trailer's per-
missible gross weight.
i The weight of other accessories, passen-
gers and loads reduces:
R the permissible trailer load
R the permissible noseweight that your
vehicle can tow
Checking the vehicle and trailer weight R
To ensure compliance of the weight of the
towing vehicle and the trailer with the max-
imum permissible values, have the vehicle/ trailer combination (towing vehicle includ-
ing driver, passenger, load and fully laden
trailer) weighed on a calibrated weigh-
bridge.
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 cou-
pling 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 max-
imum 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
217Driving and parking Z

Display messages
Possible causes/consequences and
0050
0050Solutions 0027(USA
only)004D
(Canada
only)
Check Brake Fluid Check Brake Fluid
Level 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 168).
X Consult a qualified specialist workshop.
X Do not add brake fluid. This does not correct the malfunction. 0026
Check Brake Pad Check Brake Pad
Wear Wear The brake pads/linings have reached their wear limit.
X Visit a qualified specialist workshop. 0053
Inoperative
Inoperative One or more main features of the mbrace system are malfunc-
tioning.
X Have the mbrace system checked immediately at a qualified
specialist workshop. PRE-SAFE PRE-SAFE
Inoperative See Inoperative See
Operator's Manual 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. 238
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
0050
0050Solutions PRE-SAFE
PRE-SAFE
Functions Cur‐ Functions Cur‐
rently rently
Limited
Limited See
See
Operator's Manual
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 trim 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 sta-
tions 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 mes-
sage 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 168).
X Clean the sensors in the radiator grill and the bumper
(Y page 309).
X Restart the engine. PRE-SAFE PRE-SAFE
Functions Limited Functions Limited
See See
Operator's
Operator's Man‐
Man‐
ual
ual 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 SRS Malfunction
Service required Service required There is a malfunction in the SRS (Supplemental Restraint Sys-
tem). The
0075warning lamp also lights up in the instrument clus-
ter.
G WARNING
The air bags or Emergency Tensioning Devices may either be trig- gered 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 43). Display
messages
239On-board computer and displays Z

Display messages
Possible causes/consequences and
0050
0050Solutions Front Passenger
Front Passenger
Airbag Disabled Airbag Disabled
See See
Operator's
Operator's Man‐
Man‐
ual
ual The front-passenger air bag is deactivated 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 inter-
pret 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 168).
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 AIR BAG OFF indicator lamp in the
center console and the multifunction display and check the fol-
lowing:
Seat unoccupied and ignition switched on:
R the PASSENGER AIR BAG 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 49).
R the Front Passenger Airbag Enabled See Operator's Front Passenger Airbag Enabled See Operator's
Manual
Manual orFront Passenger Airbag Disabled See Oper‐
Front Passenger Airbag Disabled See Oper‐
ator's Manual
ator'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 sys-
tem checks have been completed.
X Make sure that the display messages do not appear in the mul-
tifunction display.
If these conditions are fulfilled, the front-passenger seat can be
occupied again. Whether the PASSENGER AIR BAG 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 cor-
rectly.
X Visit a qualified specialist workshop immediately. Display
messages
241On-board computer and displays Z

Display messages
Possible causes/consequences and
0050
0050Solutions For further information about the Occupant Classification System,
see (Y page 49). Front Passenger
Front Passenger
Airbag Enabled Airbag Enabled
See See
Operator's
Operator's Man‐
Man‐
ual
ual 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 sys-
tem'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 168).
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 AIR BAG OFF indicator lamp in the
center console and the multifunction display and check the fol-
lowing:
Seat unoccupied and ignition switched on:
R the PASSENGER AIR BAG OFF indicator lamp must light up and
remain lit. If the indicator lamp is on, OCS (Occupant Classifi-
cation System) has disabled the front-passenger air bag
(Y page 49).
R the Front Passenger Airbag Enabled See Operator's Front Passenger Airbag Enabled See Operator's
Manual
Manual orFront Passenger Airbag Disabled See Oper‐
Front Passenger Airbag Disabled See Oper‐
ator's Manual
ator's Manual display messages must not be shown in the
multifunction display. 242
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
0050
0050Solutions 00AC
Coolant Stop vehi‐ Coolant Stop vehi‐
cle Switch engine cle Switch engine
off 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 168).
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 †). Other-
wise, 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 †). 248
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
0050
0050Solutions 003D The battery is not being charged.
A warning tone also sounds.
Possible causes are:
R a defective alternator
R a torn poly-V-belt
R a malfunction in the electronics
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 168).
X Open the hood.
X Check whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do not continue driving. The engine could otherwise overheat.
X Consult a qualified specialist workshop.
If the poly-V-belt is not damaged: X Visit a qualified specialist workshop. 00B2
Check Engine Oil Check Engine Oil
At Next Refueling At Next Refueling The engine oil level has dropped to the minimum level.
A warning tone also sounds.
X Check the oil level when next refueling, at the latest
(Y page 301).
X If necessary, add engine oil (Y page 302).
X Have the engine checked at a qualified specialist workshop if
engine oil needs to be added more often than usual.
! Avoid long journeys with too little engine oil. The engine will
otherwise be damaged.
Information on approved engine oils can be obtained from any
qualified specialist workshop or on the Internet at http://
bevo.mercedes-benz.co m.00B6
Reserve fuel level Reserve fuel level The fuel level has dropped into the reserve range.
X Refuel at the nearest gas station. 00A8 There is only a very small amount of fuel in the fuel tank.
X Refuel at the nearest gas station without fail. Display messages
249On-board computer and displays Z