2012 MERCEDES-BENZ GLK SUV check engine light

Interior lighting control
General notes In order to prevent the vehicle's battery from
discharging, the interior lighting functions are
automatically deactivated after some time
except for when the key is in position 2in the
ignition lock.
Automatic interior lighting control X
To activate/deactivate: press the|
button.
When the automatic interior lighting con-
trol is activated, the button is flush with the
overhead control panel.
The interior lighting automatically switches
on if you:
R unlock the vehicle
R open a door
R remove the key from the ignition lock
The interior lighting is activated for a short
time when the key is removed from the igni-
tion lock. You can activate this delayed
switch-off using the on-board computer
(Y page 241).
Manual interior lighting control X
To switch the front interior lighting on/
off: press the cbutton.
X To switch the rear interior lighting on/
off: press the ubutton.
X To switch the reading lamps on/off:
press the pbutton. Crash-responsive emergency lighting
The interior lighting is activated automatically
if the vehicle is involved in an accident.
X To switch off the crash-responsive
emergency lighting: press the hazard
warning lamp button.
or
X Lock and then unlock the vehicle using the
key. Replacing bulbs
Important safety notes
Xenon bulbs G
DANGER
Xenon bulbs are under high voltage. If you
touch the electrical contacts of a xenon bulb,
you could suffer an electric shock and be seri-
ously or even fatally injured. For this reason,
do not remove the cover of xenon bulbs.
Do not change the xenon bulbs yourself, but
have them replaced at a qualified workshop.
If your vehicle is equipped with xenon bulbs,
you can recognise this by the following: the
cone of light from the xenon bulbs moves
from the top to the bottom and back again
when you start the engine. For this to be
observed, the lights must be switched on
before starting the engine.
Bulbs and lamps are an important aspect of
vehicle safety. You must therefore make sure
that these function correctly at all times.
Have the headlamp setting checked regularly.
Other bulbs G
WARNING
Bulbs and lamps can be very hot. You should
therefore allow them to cool down before you
change them. Otherwise, you could be burned
if you touch them. 118
Replacing bulbsLights and windscreen wipers

R
Always keep the engine running and in gear
when driving on a downhill gradient. Acti-
vate DSR (Y page 213).
R Drive slowly and evenly, if necessary at
walking pace.
R Ensure that the wheels are in contact with
the ground at all times.
R Drive with extreme care on unknown off-
road routes where visibility is poor. For
safety reasons, get out of the vehicle first
and survey the off-road route.
R Check the depth of water before fording
rivers and streams.
R Look out for obstacles such as rocks, holes,
tree stumps and furrows.
R Always keep the side windows and the pan-
orama sliding sunroof closed during the
journey.
R Do not stray from marked routes or paths.
i Information about retrofitting special all-
terrain tyres is available from any qualified
specialist workshop.
Checklist before driving off-road X
Engine oil level: check the engine oil and
top it up if necessary.
X Tyre-change tool kit: check that the jack
is working and make sure you have the
wheelbrace, a robust tow cable and a fold-
ing spade in the vehicle.
X Wheels and tyres: check the tyre tread
depth and tyre pressure.
X Check for damage and remove any foreign
objects, e.g. small stones, from the
wheels/tyres.
X Replace any missing valve caps.
X Replace dented or damaged wheels.
Checklist after driving off-road Driving over rough terrain places greater
demands on your vehicle than driving on nor-
mal 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.
X Deactivate DSR ( Ypage 213).
X Clean the headlamps and rear lights and
check for damage.
X Clean the front and rear licence plates.
X Clean the wheels/tyres with a water jet and
remove any foreign objects.
X Clean the wheels, wheel arches and the
vehicle underside with a water jet; check
for any foreign objects and damage.
X Check whether twigs or other parts of
plants have become trapped. These
increase the risk of fire and can damage
fuel pipes, brake hoses or the rubber bel-
lows of the axle joints and propeller shafts.
X After the trip, examine without fail the
entire undercarriage, wheels, tyres, brakes,
bodywork structure, steering, chassis and
exhaust system for damage.
X After driving for extended periods across
sand, mud, gravel, water or in similarly dirty
conditions, have the brake discs, wheels,
brake pads/linings and axle joints checked
and cleaned.
X If you detect strong vibrations after off-road
travel, check for foreign objects in the
wheels and drive train and remove them if
necessary. Foreign objects can disturb the
balance and cause vibrations. Driving tips
171Driving and parking Z

R
Observe the warnings for off-road driving
(Y page 170).
R Drive slowly.
R Accelerate gently and make sure that the
wheels are gripping.
R Avoid high engine speeds, except when
driving on sandy and muddy routes with
high driving resistance.
R Select a shift range appropriate to the gra-
dient.
R Before tackling steep downhill gradients,
select shift range 1.
Maximum gradient-climbing capability On good road surfaces, 70% of the maximum
gradient-climbing capability is available.
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 recognises this and brakes the
wheels accordingly. The rear wheel torque
is increased and it is easier to pull away.
Hilltops When driving up an uphill gradient, slightly
reduce pressure on the accelerator immedi-
ately before reaching the brow of the hill.
Make use of the vehicle's own impetus to
travel over the brow.
This style of driving prevents:
R the vehicle from lifting off the ground on the
brow of a hill
R the vehicle from travelling 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. Oth-
erwise, the vehicle could slip sideways, tip
and overturn. 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.
i Off-road ABS is activated when the off-
road drive program is selected.
At speeds below 30 km/h, the front wheels
lock cyclically during braking. The digging-
in effect achieved in the process reduces
the stopping distance when driving off-
road. The steerability of the vehicle is con-
siderably reduced if the wheels lock. 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. You must
select a low gear in good time on long and
steep downhill gradients, especially if the
vehicle is laden or towing a trailer. On vehicles
with automatic transmission, select shift
range
1,2or 3. By doing so, you will make
use of the braking effect of the engine. This
relieves the load on the brake system and
prevents the brakes from overheating and
wearing too quickly. G
WARNING
Do not change down for additional engine
braking on a slippery road surface. This could
cause the drive wheels to lose their grip and
the vehicle could skid.
Use cruise control only if road and traffic con-
ditions make it appropriate to maintain a
steady speed for a prolonged period. You can
store any road speed above 30 km/h. Driving systems
173Driving and parking Z

SPEEDTRONIC
Important safety notes G
WARNING
Never depress the brake pedal continuously
while the vehicle is in motion, e.g. never cause
the brakes to rub by applying constant slight
pedal pressure. This causes the brake system
to overheat, increases the braking distance
and can lead to the brakes failing completely. G
WARNING
Do not change down for additional engine
braking on a slippery road surface. This could
cause the drive wheels to lose their grip and
the vehicle could skid. G
WARNING
SPEEDTRONIC is only an aid designed to
assist driving. You are responsible for the
vehicle's speed and for braking in good time.
SPEEDTRONIC brakes automatically so that
you do not exceed the set speed. On long and
steep downhill gradients, especially if the
vehicle is laden or towing a trailer, you must
shift to a lower gear in good time or select
shift range 1,2or 3on vehicles with auto-
matic transmission. By doing so, you will
make use of the braking effect of the engine.
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.
You can set a variable or permanent limit
speed:
R variable for speed limits, e.g. in built-up
areas
R permanent for long-term speed restric-
tions, e.g. when driving with winter tyres
fitted (Y page 178)
i The speed indicated in the speedometer
may differ slightly from the limit speed
stored. Variable SPEEDTRONIC General notes
With the cruise control lever, you can operate
cruise control or DISTRONIC PLUS and vari-
able SPEEDTRONIC.
The LIM indicator lamp on the cruise control
lever indicates which system you have selec-
ted:
R LIM indicator lamp off: cruise control or
DISTRONIC PLUS is selected.
R LIM indicator lamp on: variable SPEED-
TRONIC is selected.
You can use the cruise control lever to limit
the speed to any speed above 30 km/hw hile
the engine is running. :
To store the current speed or a higher
speed
; LIM indicator lamp
= To store the current speed and call up the
last stored speed
? To store the current speed or a lower
speed
A To switch between cruise control and var-
iable SPEEDTRONIC
B To deactivate variable SPEEDTRONIC
Selecting variable SPEEDTRONIC
X Check whether LIM indicator lamp ;is on.
If it is on, variable SPEEDTRONIC is already
selected. 176
Driving systemsDriving and parking

Indicator and warning display
:
Yellow indicator lamp/red warning lamp
If Blind Spot Assist is switched on, indicator
lamp :in the exterior mirrors lights up yel-
low up to a speed of 30 km/h. At speeds
above 30 km/h, the indicator lamp goes out
and Blind Spot Assist is operational.
If a vehicle is detected within the monitoring
range of Blind Spot Assist at speeds above
30 km/h, warning lamp :on the corre-
sponding side lights up red. This warning
always occurs when a vehicle enters the blind
spot monitoring range from behind or from
the side. When you overtake a vehicle, the
warning only occurs if the difference in speed
is less than 12 km/h.
The yellow indicator lamp goes out if reverse
gear is engaged. Blind Spot Assist is then
deactivated.
The brightness of the indicator/warning
lamps is adjusted automatically according to
the ambient light. G
WARNING
Blind Spot Assist is not active at speeds below
30 km/h. The indicator lamps in the exterior
mirrors are yellow. Vehicles in the monitoring
range are then not indicated.
Always pay attention to traffic conditions and
your surroundings. Otherwise, you may fail to
recognise dangers in time, cause an accident
and injure yourself and others. Collision warning
If a vehicle is detected in the monitoring range
of Blind Spot Assist and you switch on the
corresponding turn signal, a double warning
tone sounds. Red warning lamp
:flashes. If
the turn signal remains on, detected vehicles
are indicated by the flashing of red warning
lamp :. There are no further warning tones.
Activating on Blind Spot Assist
X Make sure that the radar sensor system
(Y page 242) and Blind Spot Assist
(Y page 237) are activated in the on-board
computer.
X Turn the key to position 2in the ignition
lock.
Warning lamps :in the exterior mirrors
light up red for approximately
1.5 seconds and then turn yellow.
Towing a trailer
If you attach a trailer, make sure that you have
correctly established the electrical connec-
tion. This can be accomplished by checking
the trailer lighting. Blind Spot Assist is then
deactivated. The indicator lamp lights up yel-
low in the exterior mirrors and the Blind
Blind
Spot Assist currently unavailable Spot Assist currently unavailable
See Owner's Manual See Owner's Manual message appears in
the multifunction display.
i You can deactivate the indicator lamps in
the exterior mirrors.
To do so, deactivate Blind Spot Assist if:
R the key is in position 2in the ignition
lock.
R the engine is not running.
R the electrical connection to the trailer
has been established.
Lane Keeping Assist Important safety notes
G
WARNING
Lane Keeping Assist does not keep your vehi-
cle in its lane. It is only an aid and may detect Driving systems
205Driving and parking
Z

Towing a trailer
If you attach a trailer, make sure that you have
correctly established the electrical connec-
tion. This can be accomplished by checking
the trailer lighting.
Off-road driving systems
4MATIC (permanent all-wheel drive)
G
WARNING
4MATIC cannot reduce the risk of an accident
if you drive too fast.
If a drive wheel spins due to insufficient grip:
R only depress the accelerator pedal as far as
necessary when pulling away.
R accelerate less when driving.
R adapt your driving style to suit road and
traffic conditions.
! Never tow the vehicle with one axle
raised. This may damage the transfer case.
Damage of this sort is not covered by the
Mercedes-Benz implied warranty. All
wheels must remain either on the ground
or be fully raised. Observe the instructions
for towing the vehicle with all wheels in full
contact with the ground.
4MATIC ensures that all four wheels are per-
manently driven. Together with ESP ®
and
ETS, it improves the traction of your vehicle
whenever a drive wheel spins due to insuffi-
cient grip.
i In wintry driving conditions, the maximum
effect of 4MATIC can only be achieved if
you use winter tyres (M+S tyres), with snow
chains if necessary.
! When testing the parking brake, operate
the vehicle only briefly (for a maximum of
ten seconds) on a brake test dynamometer.
When doing this, turn the key to position
0 or 1in the ignition. Failure to do this can
cause damage to the drive train or the
brake system. !
A function or performance test should
only be carried out on a twin-axle dyna-
mometer. Before you operate the vehicle
on such a dynamometer, please consult a
qualified workshop. You could otherwise
damage the drive train or the brake system.
For information about "Driving off-road", see
(Y page 170). DSR (Downhill Speed Regulation)
Important safety notes i
DSR (Downhill Speed Regulation) is only
available for vehicles with the Off-Road
Engineering package.
DSR is an aid to assist you when driving down-
hill. It keeps the speed of travel at the speed
selected on the on-board computer. The
steeper the downhill gradient, the greater the
DSR braking effect on the vehicle. When driv-
ing on flat stretches of road or on an uphill
gradient, the DSR braking effect is minimal or
non-existent. G
WARNING
DSR is only an aid designed to assist you when
driving downhill. You are responsible for keep-
ing control of the vehicle and for assessing
whether the downhill gradient can be man-
aged.
When activating DSR the vehicle may brake
suddenly due to DSR intervening. This is
dependent on the downhill gradient and the
difference between the current speed and the
speed set. DSR may not always be able to
keep to the set speed, depending on road sur-
face and tyre conditions. You could lose con-
trol of the vehicle and cause an accident.
Select a set speed suitable for the prevailing
conditions and when necessary, apply the
brakes manually.
DSR controls the vehicle’s speed when it is
activated and the transmission is in position
D, Ror N. By accelerating or braking, you can Off-road driving systems
213Driving and parking Z

Display messages Possible causes/consequences and
M
MSolutions J
Brake immediately Brake immediately With the Hold function activated, you have either:
R
opened the driver's door and released the seat belt or
R switched off the engine or
R opened the bonnet
A tone may also sound at regular intervals. If you attempt to lock
the vehicle, the tone becomes louder.
You cannot start the engine.
X Paying attention to the traffic situation, immediately depress the
brake pedal firmly and hold until the display message disap-
pears.
X Use the folding wheel chock (Y page 333), from the vehicle tool
kit to secure the vehicle against rolling away.
You can restart the engine. J
Check brake fluid Check brake fluid
level level There is insufficient brake fluid in the brake fluid reservoir.
In addition, the red
Jwarning lamp lights up in the instrument
cluster and a warning tone sounds.
G WARNING
The braking efficiency 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 ( Ypage 164).
X Consult a qualified specialist workshop.
X Do not top up the brake fluid. This does not correct the error. #
Check brake wear Check brake wear The brake pads/linings have reached their wear limit.
X
Visit a qualified specialist workshop. PRE-SAFE PRE-SAFE
inoperative inoperative
G
WARNING
Important functions of PRE-SAFE ®
have failed. All other occupant
safety systems, e.g. airbags, remain available.
This poses an increased risk of injury.
X Visit a qualified specialist workshop. ü If the symbol appears in the multifunction display, a seat belt
tongue has been inserted into a rear seat belt buckle.
Further information on the status indicator for the rear seat belts
(Y
page 53). Display
messages
249On-board computer and displays Z

Display messages Possible causes/consequences and
M
MSolutions J
Brake immediately Brake immediately A malfunction has occurred while the HOLD function or DIS-
TRONIC PLUS is active.
or
Vehicles with manual transmission: with the HOLD function acti-
vated, you have either:
R
opened the driver's door and released the seat belt or
R switched off the engine or
R opened the bonnet.
A tone may also sound at regular intervals. If you attempt to lock
the vehicle, the tone becomes louder.
You cannot start the engine.
X Paying attention to the traffic situation, immediately depress the
brake pedal firmly and hold until the display message disap-
pears.
X Use the folding wheel chock (Y page 333), from the vehicle tool
kit to secure the vehicle against rolling away.
You can restart the engine. J
Check brake fluid Check brake fluid
level level There is insufficient brake fluid in the brake fluid reservoir.
In addition, the red
Jwarning lamp lights up in the instrument
cluster and a warning tone sounds.
G WARNING
The braking efficiency 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 ( Ypage 164).
X Consult a qualified specialist workshop.
X Do not top up the brake fluid. This does not correct the error. #
Check brake wear Check brake wear The brake pads/linings have reached their wear limit.
X
Visit a qualified specialist workshop. PRE-SAFE PRE-SAFE
inoperative See inoperative See
Owner's Manual Owner's Manual
Important functions of PRE-SAFE
®
have failed. All other occupant
safety systems, e.g. airbags, remain available.
X Visit a qualified specialist workshop immediately. 254
Display
messagesOn-board computer and displays