2012 MERCEDES-BENZ GLK-Class check engine

an authorized Mercedes-Benz Center for
this purpose.
! To prevent ESP ®
from intervening, the
ignition must be switched off (SmartKey in
position 0 or 1) if:
R the parking brake is being tested on a
brake dynamometer.
R the vehicle is being towed with only one
axle raised (not permitted for vehicles
with 4MATIC).
The brake system could otherwise be
damaged.
Refueling
Important safety notes
GWARNING
Gasoline is highly flammable and poisonous.
It burns violently and can cause serious
personal injury.
Never allow sparks, flames or smoking
materials near gasoline.
Turn off the engine before refueling.
Whenever you are around gasoline, avoid
inhaling fumes and any skin or clothing
contact.
Direct skin contact with fuels and the
inhalation of fuel vapors are damaging to your
health.
GWARNING
Overfilling of the fuel tank may create
pressure in the system which could cause a
gas discharge. This could cause the gasoline
to spray back out when removing the fuel
pump nozzle, which could cause personal
injury.
! Do not use diesel to refuel vehicles with a
gasoline engine. Even small amounts of the
wrong fuel result in damage to the fuel
system and engine.
! Do not switch on the ignition if you
accidentally refuel with the wrong fuel.
Otherwise, the fuel will enter the fuel lines.
Notify a qualified specialist workshop and
have the fuel tank and fuel lines drained
completely.
Gasoline
Fuel grade
! You should only refuel with unleaded
premium-grade gasoline as this avoids
damaging the catalytic converter.
If engine running problems are apparent,
have the cause checked immediately and
repaired. Excess unburned fuel can
otherwise enter the catalytic converter,
leading to overheating and possibly
causing a fire.
! Use a filter when refueling from a fuel can.
Otherwise, the fuel lines and/or injection
system could be blocked by particles from
the fuel can.
i Only refuel with premium-grade unleaded
gasoline with a specified minimum octane
number of 91 (average value of 96 RON/
86 MON).
You will usually find information about the
fuel grade on the pump. If you cannot find
the label on the pump, ask the staff for
assistance.
You can find more information under "Fuel"
( Y page 304), or by contacting an
authorized Mercedes-Benz Service Center
or visiting http://www.mbusa.com (USA
only).
Refueling
Fuel filler flap
The fuel filler flap is unlocked or locked
automatically when you open or close the
vehicle with the SmartKey or using KEYLESS-
GO.
The position of the fuel filler cap is displayed
in the instrument cluster 8. The arrow
Refueling141Driving and parkingZ

next to the filling pump indicates the side of
the vehicle.:To open the fuel filler flap;To insert the fuel filler cap=Tire pressure table?Fuel type
Opening
XSwitch off the engine.XRemove the SmartKey from the ignition
lock.
KEYLESS-GO: open the driver’s door. This
switches the ignition to position 0, which
corresponds to having removed the
SmartKey. The driver’s door can be closed
again.XPress the fuel filler flap in the direction of
arrow :.
The fuel filler flap opens slightly.XOpen the fuel filler flap.XTurn the fuel filler cap counter-clockwise
and remove it.XInsert the fuel filler cap into the holder
bracket on the inside of filler flap ;.XCompletely insert the pump nozzle into the
filler neck and refuel.XOnly fill the tank until the pump nozzle
switches off.
! Overfilling the fuel tank could damage the
fuel system.
ClosingXReplace the fuel filler cap and turn it
clockwise. The fuel filler cap audibly
engages.XClose the fuel filler flap.
i If you drive with the fuel filler cap open,
reserve fuel warning lamp 8 flashes. In
addition, the ; Check Engine warning
lamp may light up. A message appears in
the multifunction display ( Y page 194).
For further information on warning and
indicator lamps in the instrument cluster,
see ( Y page 206).
i Close the fuel filler flap before locking the
vehicle. A locking pin otherwise prevents
the fuel filler flap from closing after the
vehicle has been locked.
142RefuelingDriving and parking

accelerate. This could lead to accidents and
injury.
Rolling with the engine switched offGWARNING
There is no power assistance for the steering
and the brake when the engine is not running.
Steering and braking requires significantly
more effort and you could lose control of the
vehicle and cause an accident as a result.
Do not turn off the engine while the vehicle is
in motion.
Exhaust check
GWARNING
Inhalation of exhaust gas is hazardous to your
health. All exhaust gas contains carbon
monoxide (CO), and inhaling it can cause
unconsciousness and possible death.
Do not run the engine in confined areas (such
as a garage) which are not properly ventilated.
If you think that exhaust gas fumes are
entering the vehicle while driving, have the
cause determined and corrected
immediately. If you must drive under these
conditions, drive only with at least one
window fully open at all times.
Certain engine systems are designed to keep
the level of poisonous components in exhaust
fumes within legal limits.
These systems only work at peak efficiency
when they are maintained exactly in
accordance with the manufacturer's
specifications. For this reason, all work on the
engine must be carried out only by qualified
and authorized Mercedes-Benz technicians.
The engine settings must not be changed in
any circumstances. Furthermore, all specific
service work must be carried out at regular
intervals and in accordance with the
Mercedes-Benz service requirements. Details
can be found in the Service Booklet.
Brakes
Important safety notesGWARNING
On slippery road surfaces, never downshift in
order to obtain braking action. This could
result in drive wheel slip and reduced vehicle
control. Your vehicle's ABS will not prevent
this type of loss of control.
GWARNING
Make sure that you do not endanger other
road users when you apply the brakes.
Downhill gradients
! On long and steep gradients, you must
reduce the load on the brakes by shifting
early to a lower gear. This allows you to take
advantage of the engine braking effect and
helps avoid overheating and excessive
wear of the brakes.
When you take advantage of the engine
braking effect, a drive wheel may not turn
for some time, e.g. on a slippery road
surface. This could cause damage to the
drive train. This type of damage is not
covered by the Mercedes-Benz warranty.
Heavy and light loads
GWARNING
Depressing the brake pedal constantly results
in excessive and premature wear to the brake
pads.
It may also cause the brakes to overheat,
seriously impairing their effectiveness. It may
then not be possible to stop the vehicle in
sufficient time to avoid an accident.
If the brakes have been subjected to a heavy
load, do not stop the vehicle immediately, but
drive on for a short while. This allows the
airflow to cool the brakes more quickly.
146Driving tipsDriving and parking

Wet roadsGWARNING
After driving in heavy rain for some time
without applying the brakes or through water
deep enough to wet brake components, the
first braking action may be somewhat
reduced. You have to depress the brake pedal
more firmly. Maintain a safe distance from
vehicles in front.
After driving on a wet road or having the
vehicle washed, brake firmly while paying
attention to the traffic conditions. This will
warm up the brake discs, thereby drying them
more quickly and protecting them against
corrosion.
Limited braking performance on salt-
treated roads
GWARNING
The layer of salt on the brake discs and the
brake pads/linings may cause a delay in the
braking effect, resulting in a significantly
longer braking distance, which could lead to
an accident.
To avoid this danger, you should:
R occasionally brake carefully, without
putting other road users at risk, when you
are driving on salted roads. This helps to
remove any salt that may have started to
build up on the brake discs and the brake
pads/linings.
R maintain a greater distance to the vehicle
ahead and drive with particular care.
R carefully apply the brakes at the end of a
trip and immediately after commencing a
new trip, so that salt residues are removed
from the brake discs.
Servicing the brakes
! If the red brake warning lamp lights up in
the instrument cluster and you hear a
warning tone while the engine is running,
the brake fluid level may be too low.
Observe additional warning messages in
the multifunction display.
The brake fluid level may be too low due to
brake pad wear or leaking brake lines.
Have the brake system checked
immediately. This work should be carried
out at an authorized Mercedes-Benz
Center.
All checks and maintenance work on the
brake system must be carried out at a
qualified specialist workshop. This work
should be carried out at an authorized
Mercedes-Benz Center.
Have the brake pads replaced and the brake
fluid renewed at a qualified specialist
workshop, e.g. an authorized Mercedes-Benz
Center.GWARNING
If brake pads or brake fluid other than those
recommended are used, the braking
properties of the vehicle can be degraded to
an extent that safe braking is substantially
impaired. This could result in an accident.
! Vehicles with 4MATIC: function or
performance tests may only be carried out
on a 2-axle dynamometer. If you are
planning to have the vehicle tested on such
a dynamometer, contact an authorized
Mercedes-Benz Center to obtain further
information first. Otherwise, you could
damage the drive train or the brake system.
! As the ESP ®
system operates
automatically, the engine and the ignition
must be switched off (SmartKey in position
0 or 1 in the ignition lock) when:
R testing the parking brake on a brake
dynamometer.
R you intend to have the vehicle towed with
the front or rear axle raised (not
permitted for vehicles with 4MATIC).
Braking maneuvers triggered automatically
by ESP ®
may seriously damage the brake
system.
Driving tips147Driving and parkingZ

If your brake system is subject only to
moderate loads, you should test the
functionality of your brakes at regular
intervals by pressing firmly on the brake pedal
at high speeds. This improves the grip of the
brake pads.GWARNING
Make sure that you do not endanger other
road users when you apply the brakes.
You can find a description of Brake Assist
(BAS) on ( Y page 62).
Parking brake
If you drive on wet roads or dirt-covered
surfaces, road salt and/or dirt could get into
the parking brake.
In order to prevent corrosion and a reduction
in the braking power of the parking brake,
observe the following:
R Gently depress the parking brake from time
to time before beginning the journey.
R Drive a distance of approximately 110 yds
(100 m) with a maximum speed of 12 mph
(20 km/h).
GWARNING
While performing this procedure please
assure that the vehicle is stopped before
applying the parking brake. Otherwise the
rear wheels could lock up. You could lose
control of the vehicle and cause an accident.
In addition, the vehicle's brake lights do not
light up when the parking brake is engaged.
Make sure not to endanger any other road
users when you engage the parking brake.
Driving on wet roads
Hydroplaning
If water has accumulated to a certain depth
on the road surface, there is a danger of
hydroplaning occurring, even if:
R you drive at low speeds.
R the tires have adequate tread depth.
For this reason, in the event of heavy rain or
in conditions in which hydroplaning can occur
you must drive in the following manner:
R reduce your speed
R avoid ruts
R brake carefully
Driving on flooded roads
! Do not drive through flooded areas.
Check the depth of any water before driving
through it. Drive slowly through standing
water. Otherwise, water may enter the
vehicle interior or the engine compartment.
This can damage the electronic
components in the engine or the automatic
transmission. Water can also be drawn in
by the engine's air suction nozzles and this
can cause engine damage.
Do not allow water to enter the passenger
compartment or the engine compartment. If
you have to drive through a stretch of
standing water, please be aware the
following:
R the depth of the water must not exceed
12 inches (30 cm) for calm water
R you should drive no faster than at walking
pace.
Winter driving
General notes
GWARNING
If the vehicle becomes trapped in snow,
ensure that snow is kept away from the
exhaust pipe and from around the vehicle as
148Driving tipsDriving and parking

long as the engine is running. Otherwise,
poisonous carbon monoxide (CO) may enter
the vehicle, resulting in loss of consciousness
and even death.
To assure sufficient fresh air ventilation, open
a window slightly on the side of the vehicle
not facing the wind.
At the onset of winter, have your vehicle
winterproofed at a qualified specialist
workshop, e.g. at an authorized Mercedes-
Benz Center.
Observe the notes in the "Winter operation"
section ( Y page 272).
Driving with summer tires
Observe the notes in the "Winter operation"
section ( Y page 272).
Slippery road surfaces
GWARNING
The outside temperature indicator is not
designed to serve as an ice-warning device
and is therefore unsuitable for that purpose.
Indicated temperatures just above the
freezing point do not guarantee that the road
surface is free of ice. The road may still be icy,
especially in wooded areas or on bridges.
GWARNING
On slippery road surfaces, never downshift in
order to obtain braking action. This could
result in drive wheel slip and reduced vehicle
control. Your vehicle's ABS will not prevent
this type of loss of control.
Drive particularly carefully on slippery road
surfaces. Avoid sudden acceleration, steering
and braking maneuvers. Do not use cruise
control.
If the vehicle threatens to skid or cannot be
stopped when moving at low speed:
XShift the transmission to position N.i
For more information on driving with
snow chains, see ( Y page 272).GWARNING
Make sure that you do not endanger other
road users when you apply the brakes.
Off-road driving
Important safety notes
GWARNING
Grains of sand, particles of dirt and other
abrasive materials can enter the brake
system. This can lead to excessive wear and
unpredictable braking efficiency.
After the brakes have been exposed to dirty
conditions, have them checked and cleaned
at a qualified specialist workshop, e.g. an
authorized Mercedes-Benz Center.
Otherwise, there is a risk that braking power
may be insufficient in the event of an
emergency, or that the braking effect may be
unpredictable.
GWARNING
Do not reduce the tire inflation pressure
before driving through sand. However, if you
do so, remember to correct the tire inflation
pressure before continuing your trip. Driving
with reduced tire inflation pressure increases
the risk of losing control of the vehicle and
rolling over.
General notes
Read this section carefully before driving your
vehicle off-road. Practice by driving over more
gentle off-road terrain first.
Familiarize yourself with the characteristics
of your vehicle and the gear shift operation
before driving through difficult terrain.
Driving tips149Driving and parkingZ

Checklist before driving off-road
! If the engine oil warning lamp lights up
while the vehicle is in motion, stop the
vehicle in a safe place as soon as possible.
Check the engine oil level. The engine oil
warning lamp warning must not be ignored.
Continuing the journey while the symbol is
displayed could lead to engine damage.
Checklist after driving off-road
GWARNING
If you notice sudden significant vibrations or
unusual handling performance or if you
suspect that damage has occurred to the
vehicle, you should activate the hazard
warning lamps, gently reduce speed and
carefully head for an area that is located at a
safe distance from the road.
Check the tires and the underside of the
vehicle for damage. If the vehicle seems
unsafe, have the vehicle towed away to the
nearest Mercedes-Benz Center or tire dealer
to be repaired.
Driving over rough terrain places greater
demands on your vehicle than driving on
normal roads. After driving off-road, check
the vehicle. This allows you to detect damage
promptly and reduce the risk of an accident
to yourself and other road users.
Driving on sand
GWARNING
Do not reduce the tire inflation pressure
before driving through sand. However, if you
do so, remember to correct the tire inflation
pressure before continuing your trip. Driving
with reduced tire inflation pressure increases
the risk of losing control of the vehicle and
rolling over.
Ruts and gravel roads
Observe the following rules when driving
along ruts in off-road terrain or on roads with
loose gravel:
! Check that the ruts are not too deep and
that your vehicle has sufficient clearance.
Otherwise, your vehicle could be damaged
or bottom out and get stuck.
Driving over obstacles
! Obstacles could damage the floor of the
vehicle or components of the chassis. Ask
passengers for guidance when driving over
large obstacles. The passenger should
always keep a safe distance from the
vehicle when doing so in order to avoid
injury as a result of unexpected vehicle
movements. After driving off-road or over
obstacles, check the vehicle for possible
damage, especially to the underbody and
the components of the chassis.
Observe the following rules when driving over
tree stumps, large stones and other
obstacles:
Traveling uphill
Approach/departure angle
Maximum gradient-climbing capability
i If the load on the front axle is reduced
when pulling away on a steep uphill slope,
the front wheels have a tendency to spin.
4ETS recognizes this and brakes the
wheels accordingly. The rear wheel torque
is increased, making it easier to drive off.
Brow of hill
When driving up an uphill gradient, slightly
reduce pressure on the accelerator
immediately before reaching the brow of the
hill. Use the vehicle's own impetus to drive
over the top of the hill.
150Driving tipsDriving and parking

This style of driving prevents:
R the vehicle from lifting off the ground on the
brow of a hill
R the vehicle from traveling too quickly down
the other side
Driving downhill
R Drive slowly.
R Do not drive at an angle down steep
inclines. Steer into the line of fall and drive
with the front wheels aligned straight.
Otherwise, the vehicle could slip sideways,
tip and rollover.
R Before tackling steep downhill gradients,
select shift range 1.
R Activate DSR. If this is not sufficient, brake
gently. When doing so, make sure that the
vehicle is facing in the direction of the line
of fall.
R Check that the brakes are working normally
after a long downhill stretch.
Driving systems
Cruise control
Important safety notes
Cruise control maintains a constant road
speed for you. It brakes automatically in order
to avoid exceeding the set speed. On long and
steep downhill gradients, especially if the
vehicle is laden or towing a trailer, you must
select shift range 1, 2 or 3 in good time. By
doing so, you will make use of the braking
effect of the engine, which relieves the load
on the brake system and prevents the brakes
from overheating and wearing too quickly.
Use cruise control only if road and traffic
conditions make it appropriate to maintain a
steady speed for a prolonged period. You can
set any road speed above 20 mph
(30 km/h).
GWARNING
The cruise control is a convenience system
designed to assist the driver during vehicle
operation. The driver is and must always
remain responsible for the vehicle's speed
and for safe brake operation.
Only use the cruise control if the road, traffic,
and weather conditions make it advisable to
travel at a constant speed.
R The use of the cruise control can be
dangerous on winding roads or in heavy
traffic because conditions do not allow safe
driving at a constant speed.
R The use of the cruise control can be
dangerous on slippery roads. Rapid
changes in tire traction can result in wheel
spin and loss of control.
R Deactivate the cruise control when driving
in fog.
The "Resume" function should only be
operated if the driver is fully aware of the
previously set speed and wishes to resume
this particular preset speed.
GWARNING
The cruise control brakes automatically so
that the set speed is not exceeded.
i Cruise control should not be activated
during off-road driving.
Cruise control lever
:To switch on or to increase the speed;To switch on or to reduce the speedDriving systems151Driving and parkingZ