ECU MERCEDES-BENZ GLK-CLASS SUV 2014 Repair Manual

Recovering a vehicle that has become
stuck
! Pull away smoothly, slowly, and in a
straight line when pulling out a vehicle that
has become stuck. Excessive tractive
power could damage the vehicles.
If the drive wheels get trapped on loose or
muddy ground, recover the vehicle with the
utmost care, especially so if the vehicle is
laden.
Never attempt to recover a vehicle with a
trailer attached.
Pull out the vehicle backwards, if possible,
using the tracks it made when it became
stuck. Tow-starting (emergency engine
starting)
! Vehicles with automatic transmission
must not be started by tow-starting. This
could otherwise damage the transmission.
You can find information on "Jump-starting"
at (Y page 320). Fuses
Important safety notes
G
WARNING
If you manipulate or bridge a faulty fuse or if
you replace it with a fuse with a higher
amperage, the electric cables could be
overloaded. This could result in a fire. There
is a risk of an accident and injury.
Always replace faulty fuses with the specified
new fuses having the correct amperage.
! Only use fuses that have been approved
for Mercedes-Benz vehicles and which
have the correct fuse rating for the system
concerned. Otherwise, components or
systems could be damaged.
The fuses in your vehicle serve to close down
faulty circuits. If a fuse blows, all the components on the circuit and their functions
stop operating.
Blown fuses must be replaced with fuses of
the same rating, which you can recognize by
the color and value. The fuse ratings are listed
in the fuse allocation chart.
If a newly inserted fuse also blows, have the
cause traced and rectified at a qualified
specialist workshop, e.g. an authorized
Mercedes-Benz Center. Before changing a fuse
X Secure the vehicle against rolling away
(Y page 164).
X Switch off all electrical consumers.
X Turn the SmartKey to position 0in the
ignition lock and remove it (Y page 145).
or
X On vehicles with KEYLESS-GO, make sure
the ignition is switched off (Y page 145).
All indicator lamps in the instrument cluster
must be off.
The fuses are located in various fuse boxes:
R Fuse box on the driver's side of the
dashboard
R Fuse box in the engine compartment on the
left-hand side of the vehicle, when viewed
in the direction of travel
R Fuse box in the stowage well under the
cargo compartment floor on the right-hand
side of the vehicle, when viewed in the
direction of travel
The fuse allocation chart is located in the
vehicle tool kit in the stowage compartment
under the cargo compartment floor
(Y page 314). Dashboard fuse box
! Do not use a pointed object such as a
screwdriver to open the cover in the
dashboard. You could damage the
dashboard or the cover. Fuses
325Breakdown assistance Z

!
Make sure that no moisture can enter the
fuse box when the cover is open.
! When closing the cover, make sure that it
is lying correctly on the fuse box. Moisture
seeping in or dirt could otherwise impair
the operation of the fuses. X
To open: pull out cover :slightly at the
bottom in the direction of arrow =.
X Pull cover :outwards in the direction of
arrow ;and remove it.
X To close: clip in cover :on the front of
the dashboard.
X Fold cover :inwards until it engages. Fuse box in the engine compartment
G
WARNING
When the hood is open and the windshield
wipers are set in motion, you can be injured
by the wiper linkage. There is a risk of injury.
Always switch off the windshield wipers and
the ignition before opening the hood.
! Make sure that no moisture can enter the
fuse box when the cover is open.
! When closing the cover, make sure that it
is lying correctly on the fuse box. Moisture
seeping in or dirt could otherwise impair
the operation of the fuses.
X Make sure that the windshield wipers are
turned off.
X Open the hood. X
Use a dry cloth to remove any moisture
from the fuse box.
X To open: take lines ;from the guides.
X Open clamps :.
X Remove the fuse box cover forwards.
X To close: check whether the rubber seal is
lying correctly in the cover.
X Insert the cover at the rear of the fuse box
into the retainer.
X Fold down cover and close clamps :.
X Secure lines ;in the guides.
X Close the hood. Fuse box in the cargo compartment
! Make sure that no moisture can enter the
fuse box when the cover is open.
! When closing the cover, make sure that it
is lying correctly on the fuse box. Moisture
seeping in or dirt could otherwise impair
the operation of the fuses.
X Open the tailgate. 326
FusesBreakdown assistance

recommended tire pressure for your vehicle
when adjusting the tire pressure
(Y page 334). :
Example: maximum permissible tire
pressure
i The actual values for tires are vehicle-
specific and may deviate from the values in
the illustration. Checking the tire pressures
Important safety notes Observe the "tire pressure information"
section (Y page 334).
Information on air pressure for the tires on
your vehicle can be found:
R on the vehicle's Tire and Loading
Information placard on the B-pillar
R on the tire pressure label on the fuel filler
flap
R in the "Tire pressure information" section
Checking tire pressures manually To determine and set the correct tire
pressure, proceed as follows:
X Remove the valve cap of the tire that is to
be checked.
X Press the tire pressure gauge securely onto
the valve.
X Read the tire pressure and compare it with
the recommended value on the Tire and
Loading Information placard on the
B-pillar on the driver's side of your vehicle. X
If necessary, increase the tire pressure to
the recommended value (Y page 334).
X If the tire pressure is too high, release air
by pressing down the metal pin in the valve
using the tip of a pen, for example. Then,
check the tire pressure again using the tire
pressure gauge.
X Screw the valve cap onto the valve.
X Repeat these steps for the other tires. Tire pressure loss warning system
(Canada only)
General notes While the vehicle is in motion, the tire
pressure loss warning system monitors the
set tire pressure using the rotational speed of
the wheels. This enables the system to detect
significant pressure loss in a tire. If the speed
of rotation of a wheel changes as a result of
a loss of pressure, a corresponding warning
message will appear in the multifunction
display.
You can recognize the tire pressure loss
warning by the
Run Flat Indicator Run Flat Indicator
Active Press 'OK' to Restart
Active Press 'OK' to Restart message
which appears in the Service
Servicemenu of the
multifunction display. Information on the
message display can be found in the
"Restarting the tire pressure loss warning
system" section (Y page 338).
Important safety notes The tire pressure warning system does not
warn you of an incorrectly set tire pressure.
Observe the notes on the recommended tire
pressure (Y
page 334).
The tire pressure loss warning does not
replace the need to regularly check the tire
pressure. An even loss of pressure on several
tires at the same time cannot be detected by
the tire pressure loss warning system.
The tire pressure monitor is not able to warn
you of a sudden loss of pressure, e.g. if the
tire is penetrated by a foreign object. In the Tire pressure
337Wheels and tires Z

Maximum load on one tire
Maximum load on one tire. This is calculated
by dividing the maximum axle load of one axle
by two. PSI (pounds per square inch)
A standard unit of measure for tire pressure. Aspect ratio
Relationship between tire height and tire
width in percent. Tire pressure
This is pressure inside the tire applying an
outward force to each square inch of the tire's
surface. The tire pressure is specified in
pounds per square inch (psi), in kilopascal
(kPa) or in bar. The tire pressure should only
be corrected when the tires are cold. Tire pressure of cold tires
The tires are cold:
R if the vehicle has been parked without
direct sunlight on the tires for at least three
hours and
R if the vehicle has not been driven further
than 1 mile (1.6 km) Tread
The part of the tire that comes into contact
with the road. Bead
The tire bead ensures that the tire sits
securely on the wheel. There are several steel
wires in the bead to prevent the tire from
coming loose from the wheel rim. Sidewall
The part of the tire between the tread and the
bead. Weight of optional extras
The combined weight of those optional extras
that weigh more than the replaced standard
parts and more than 2.3 kg (5 lbs). These
optional extras, such as high-performance
brakes, level control, a roof rack or a high-
performance battery, are not included in the
curb weight and the weight of the
accessories. TIN (Tire Identification Number)
This is a unique identifier which can be used
by a tire manufacturer to identify tires, for
example for a product recall, and thus identify
the purchasers. The TIN is made up of the
manufacturer's identity code, tire size, tire
type code and the manufacturing date. Load bearing index
The load bearing index (also load index) is a
code that contains the maximum load bearing
capacity of a tire. Traction
Traction is the result of friction between the
tires and the road surface. TWR (Tongue Weight Rating)
The TWR specifies the maximum permissible
weight that the ball coupling of the trailer tow
hitch can support. Definition of terms for tires and loading
353Wheels and tires Z

Storing wheels
Store wheels that are not being used in a cool,
dry and preferably dark place. Protect the
tires from oil, grease, gasoline and diesel. Cleaning the wheels
G
WARNING
The water jet from a circular jet nozzle (dirt
blasters) can cause invisible exterior damage
to the tires or chassis components.
Components damaged in this way may fail
unexpectedly. There is a risk of an accident.
Do not use power washers with circular jet
nozzles to clean the vehicle. Have damaged
tires or chassis components replaced
immediately. Mounting a wheel
Preparing the vehicle
X Stop the vehicle on solid, non-slippery and
level ground.
X Apply the parking brake.
X Bring the front wheels into the straight-
ahead position.
X Move the selector lever to position P.
X Switch off the engine.
X Vehicles without KEYLESS-GO: remove
the SmartKey from the ignition lock.
X Vehicles with KEYLESS-GO: open the
driver's door.
The on-board electronics have status 0,
which is the same as the SmartKey having
been removed.
X Vehicles with KEYLESS-GO: remove the
Start/Stop button from the ignition lock
(Y page 145).
X If included in the vehicle equipment,
remove the tire-change tool kit from the
vehicle. X
Secure the vehicle to prevent it from rolling
away. Securing the vehicle to prevent it
from rolling away
If your vehicle is equipped with a wheel chock,
it can be found in the tire-change tool kit
(Y
page 314).
The folding wheel chock is an additional
safety measure to prevent the vehicle from
rolling away, for example when changing a
wheel.
X Fold both plates upwards :.
X Fold out lower plate ;.
X Guide the lugs on the lower plate fully into
the openings in base plate =. Securing the vehicle on level ground
X
On level ground: place chocks or other
suitable items under the front and rear of
the wheel that is diagonally opposite the
wheel you wish to change. Mounting a wheel
355Wheels and tires Z

Securing the vehicle on slight downhill gradients
X On light downhill gradients: place
chocks or other suitable items in front of
the wheels of the front and rear axle. Raising the vehicle
G
WARNING
If you do not position the jack correctly at the
appropriate jacking point of the vehicle, the
jack could tip over with the vehicle raised.
There is a risk of injury.
Only position the jack at the appropriate
jacking point of the vehicle. The base of the
jack must be positioned vertically, directly
under the jacking point of the vehicle.
The following must be observed when raising
the vehicle:
R to raise the vehicle, only use the vehicle-
specific jack that has been tested and
approved by Mercedes-Benz. If used
incorrectly, the jack could tip over with the
vehicle raised.
R the jack is designed only to raise and hold
the vehicle for a short time while a wheel
is being changed. It is not suited for
performing maintenance work under the
vehicle.
R avoid changing the wheel on uphill and
downhill slopes.
R before raising the vehicle, secure it from
rolling away by applying the parking brake
and inserting wheel chocks. Never disengage the parking brake while the
vehicle is raised.
R the jack must be placed on a firm, flat and
non-slip surface. On a loose surface, a
large, load-bearing underlay must be used.
On a slippery surface, a non-slip underlay
must be used, e.g. rubber mats.
R do not use wooden blocks or similar
objects as a jack underlay. Otherwise, the
jack will not be able to achieve its load-
bearing capacity due to the restricted
height.
R make sure that the distance between the
underside of the tires and the ground does
not exceed 1.2 inche s (3cm).
R never place your hands and feet under the
raised vehicle.
R never lie under the raised vehicle.
R never start the engine when the vehicle is
raised.
R never open or close a door or the tailgate
when the vehicle is raised.
R make sure that no persons are present in
the vehicle when the vehicle is raised.
! The jack is designed exclusively for
jacking up the vehicle at the jacking points.
Otherwise, your vehicle could be damaged. 356
Mounting a wheelWheels and tires

bolts to come loose. As a result, you could
lose a wheel while driving. There is a risk of
accident.
Never oil or grease wheel bolts. In the event
of damage to the threads, contact a qualified
specialist workshop immediately. Have the
damaged wheel bolts or hub threads
replaced/renewed. Do not continue driving. G
WARNING
If you tighten the wheel bolts or wheel nuts
when the vehicle is raised, the jack could tip
over. There is a risk of injury.
Only tighten the wheel bolts or wheel nuts
when the vehicle is on the ground.
Always pay attention to the instructions and
safety notes in the "Changing a wheel"
section (Y page 354).
Only use wheel bolts that have been designed
for the wheel and the vehicle. For safety
reasons, Mercedes-Benz recommends that
you only use wheel bolts which have been
approved for Mercedes-Benz vehicles and the
respective wheel. :
Wheel bolts for all wheels supplied by the
factory
; Wheel bolts for the collapsible spare
wheel
! Always use wheel bolts ;to mount the
collapsible spare wheel. Using other wheel
bolts to mount the collapsible spare wheel
could damage the brake system. Be sure to use the original-length wheel bolts
when re-mounting the original wheel after it
has been repaired.
!
To prevent damage to the paintwork, hold
the wheel securely against the wheel hub
while screwing in the first wheel bolt. X
Clean the wheel and wheel hub contact
surfaces.
X Place the new wheel on the wheel hub and
push it on.
X Tighten the wheel bolts until they are
finger-tight.
X Inflate the collapsible spare wheel
(Y page 362).
Only then lower the vehicle. Lowering the vehicle
G
WARNING
The wheels could work loose if the wheel nuts
and bolts are not tightened to the specified
tightening torque. There is a risk of accident.
Have the tightening torque immediately
checked at a qualified specialist workshop
after a wheel is changed.
! Inflate the collapsible spare wheel using
the tire inflation compressor before
lowering the vehicle. The wheel rim could
otherwise be damaged. 358
Mounting a wheelWheels and tires