check engine MERCEDES-BENZ GLC SUV 2015 Workshop Manual

G
WARNING
If engine oil comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Make sure that engine oil does not spill out
over the filler neck. Allow the engine to cool
down and thoroughly clean the components
that have come into contact with engine oil
before you start the engine. H
Environmental note
When topping up the oil, take care not to spill
any. If oil enters the soil or waterways, it is
harmful to the environment.
! Only use engine oils and oil filters that
have been approved for vehicles with a ser-
vice system. You can obtain a list of the
engine oils and oil filters tested and
approved in accordance with the
Mercedes-Benz Specifications for Service
Products at any Mercedes-Benz Service
Centre.
Damage to the engine or exhaust system is caused by the following:
R using engine oils and oil filters that have
not been specifically approved for the
service system
R changing the engine oil and oil filter after
missing the change interval required by
the service system
R using engine oil additives
! Do not add too much oil. Topping up with
too much engine oil can result in damage to
the engine or to the catalytic converter.
Have excess engine oil siphoned off. Example
X Turn cap :anti-clockwise and remove it.
X Top up the engine oil.
If the oil level is at or below the MIN mark on
the oil dipstick, top up with 1.0 lof engine
oil.
X Replace cap :on the filler neck and turn
clockwise.
Make sure that the cap locks securely into place.
X Check the oil level again with the oil dip-
stick (Y page 416).
For further information on engine oil, see
(Y page 485). Other service products
Checking the coolant level G
WARNING
Certain components in the engine compart-
ment could be very hot, e.g. the engine, the
radiator and parts of the exhaust system.
There is a risk of injury when accessing the
engine compartment.
As far as possible, allow the engine to cool
down and only touch the components descri- bed in the following. G
WARNING
The cooling system is pressurised, particu-
larly when the engine is warm. If you open the cap, you could be scalded if hot coolant
sprays out. There is a risk of injury. Engine compartment
417Maintenance and care
Z

Let the engine cool down before you open the
cap. Wear gloves and eye protection. Open
the cap slowly to release the pressure. X
Park the vehicle on a level surface.
Only check the coolant level if the vehicle is
on a level surface and the engine has
cooled down.
X Turn the key to position 2in the ignition
lock (Y page 187).
or
X On vehicles with KEYLESS-GO, press the
Start/Stop button twice (Y page 187).
X Check the coolant temperature display in
the instrument cluster (Y page 313).
The coolant temperature must be below
70 †.
X Turn the key to position 0(Y page 187).
or
X On vehicles with KEYLESS-GO, pull the
Start/Stop button from the ignition lock
(Y page 187).
X Slowly turn cap :half a turn anti-clock-
wise to allow excess pressure to escape.
X Turn cap :further anti-clockwise and
remove it.
If the coolant is at the level of marker bar =
in the filler neck when cold, there is enough
coolant in coolant expansion tank ;.
If the coolant level is approximately 1.5 cm above marker bar =in the filler neck when
warm, there is enough coolant in coolant
expansion tank ;. X
If necessary, top up with coolant that has
been tested and approved by Mercedes-
Benz.
X Replace cap :and turn it clockwise as far
as it will go.
Further information on coolant (Y page 487).
Topping up the windscreen washer sys- tem G
WARNING
Certain components in the engine compart-
ment could be very hot, e.g. the engine, the
radiator and parts of the exhaust system.
There is a risk of injury when accessing the
engine compartment.
As far as possible, allow the engine to cool
down and only touch the components descri- bed in the following. G
WARNING
If windscreen washer concentrate comes into contact with hot components of the engine or
the exhaust system, it can ignite. There is a
risk of fire and injury.
Make sure the windscreen washer concen-
trate does not come into contact with the filler neck. X
To open: pull cap:upwards by the tab
and open.
X Top up with the premixed washer fluid.
X To close: press cap :onto the filler neck
until it engages. 418
Engine compartmentMaintenance and care

ASSYST PLUS service interval display after
the service work has been carried out. You
can also obtain further information on main-
tenance work, for example.
Special service requirements The prescribed service interval is based on
normal operation of the vehicle. Service work
will need to be performed more often if the
vehicle is operated under arduous conditions
or increased loads, for example:
R regular city driving with frequent intermedi-
ate stops
R if the vehicle is primarily used to travel
short distances
R for frequent operation in mountainous ter-
rain or on poor road surfaces
R if the engine is often left idling for long peri-
ods
In these or similar operating conditions, have,
for example, the air filter, engine oil and oil
filter changed more frequently. The tyres
must be checked more frequently if the vehi-
cle is operated under increased loads. Fur-
ther information can be obtained at a quali-
fied specialist workshop, e.g. a Mercedes-
Benz Service Centre.
Driving abroad An extensive Mercedes-Benz Service network
is also available in other countries. You can
obtain further information from any
Mercedes-Benz Service Centre. Care
General notes
H
Environmental note
Dispose of empty packaging and cleaning
cloths in an environmentally responsible man- ner. !
For cleaning your vehicle, do not use any
of the following:
R dry, rough or hard cloths
R abrasive cleaning agents
R solvents
R cleaning agents containing solvents
Do not scrub.
Do not touch the surfaces or protective
films with hard objects, e.g. a ring or ice
scraper. You could otherwise scratch or
damage the surfaces and protective film.
! Do not park up the vehicle for an extended
period straight after cleaning it, particularly after having cleaned the wheels with wheel
cleaner. Wheel cleaners could cause
increased corrosion of the brake discs and brake pads/linings. For this reason, you
should drive for a few minutes after clean-
ing. Braking heats the brake discs and the
brake pads/linings, thus drying them. The
vehicle can then be parked up.
Regular care of your vehicle is a condition for
retaining the quality in the long term.
Use care products and cleaning agents rec-
ommended and approved by Mercedes-Benz. Washing the vehicle and cleaning the
paintwork
Automatic car wash G
WARNING
Braking efficiency is reduced after the vehicle has been washed. There is a risk of an acci-
dent.
After washing the vehicle, brake carefully
while paying attention to the traffic conditions in order to restore full braking efficiency.
! When DISTRONIC PLUS or the HOLD
function is activated, the vehicle brakes
automatically in certain situations. 420
CareMaintenance and care

R
Make sure that the positive terminal of a
connected battery does not come into con-
tact with vehicle parts.
R Never place metal objects or tools on a bat-
tery.
R It is important that you observe the descri-
bed order of the battery terminals when
connecting and disconnecting a battery.
R When jump-starting, make sure that the
battery poles with identical polarity are
connected.
R It is particularly important to observe the
described order when connecting and dis-
connecting the jump leads.
R Never connect or disconnect the battery
terminals while the engine is running. G
WARNING
Battery acid is caustic. There is a risk of injury. Avoid contact with the skin, eyes or clothing.
Do not breathe in any battery gases. Do not
lean over the battery. Keep the batteries out
of the reach of children. Immediately rinse off
battery acid thoroughly with plenty of clean
water and seek medical attention at once.
All vehicles: H
Environmental note Batteries contain pollutants.
It is illegal to dispose of them with the household rubbish.
They must be collected sep-
arately and disposed of in anenvironmentally responsible
recycling system. Dispose of batteries in an
environmentally responsible
manner. Take discharged
batteries to a qualified spe-
cialist workshop or to a col-
lection point for used batter-
ies.
! Have the battery checked regularly at a
qualified specialist workshop. Observe the service intervals in the Service
Booklet or contact a qualified specialist
workshop for more information.
! Always have work on the batteries carried
out at a qualified specialist workshop.
Should it, in exceptional circumstances, be absolutely necessary to disconnect the 12-
volt battery yourself, please observe the
following:
R secure the vehicle to prevent it from roll-
ing away.
R switch off the engine and remove the
key. Make sure the ignition is switched
off. Check that all the indicator lamps in
the instrument cluster are off. Otherwise,
you may damage electronic components such as the alternator, for example.
R first, disconnect the negative terminal
clamp, followed by the positive terminal
clamp. Never swap the terminal clamps.
The vehicle electronics may otherwise be
damaged.
R the transmission is locked in position P
after disconnecting the battery. The vehi-
cle is secured against rolling away. You
can then no longer move the vehicle.
The batteries and the covers of the positive
terminal clamps must always be fitted
securely during operation.
Comply with safety precautions and take pro-
tective measures when handling batteries. Risk of explosion
Fire, naked flames and smoking
are prohibited when handling the
battery. Avoid creating sparks.
Electrolyte or battery acid is corro-
sive. Avoid contact with the skin,
eyes or clothing.
Wear suitable protective clothing,
in particular gloves, an apron and a face mask. Battery (vehicle)
439Breakdown assistance Z

Immediately rinse electrolyte or
acid splashes off with clean water.
Consult a doctor if necessary. Wear eye protection.
Keep children away.
Observe this Owner's Manual.
For safety reasons, Mercedes-Benz recom-
mends that you only use batteries which have been tested and approved for your vehicle by
Mercedes-Benz. These batteries provide
increased impact protection to prevent vehi-
cle occupants from suffering acid burns
should the battery be damaged in the event of
an accident.
In order for the battery to achieve the maxi-
mum possible service life, it must always be
sufficiently charged.
The vehicle battery, like other batteries, can
discharge over time if you do not use the
vehicle. In such cases, have the battery dis-
connected at a qualified specialist workshop. You can also charge the battery with a
charger recommended by Mercedes-Benz.
For more information, please contact a quali-
fied specialist workshop.
Have the battery charge checked more fre-
quently if you use the vehicle mainly for short
trips or if you leave it standing idle for a
lengthy period. Consult a qualified specialist
workshop if you wish to leave your vehicle
parked up for a long period of time.
When you park the vehicle, remove the key if you do not require any electrical consumers.
The vehicle will then use very little energy,
thus conserving battery power.
PLUG-IN HYBRID vehicles: if the battery
charge is sufficient, the high-voltage battery
can also supply the 12 V battery. This only
happens if the battery charge of the 12 V bat- tery requires this, e.g. after using electrical
consumers for an extended period with the
engine switched off. As the on-board voltage
is continuously monitored this can also be
performed when the engine is switched off.
The battery charge of the 12 V battery and the
on-board voltage are thereby kept stable for
longer. High-voltage battery - important
safety notes
Only PLUG-IN HYBRID vehicles are equipped
with a high-voltage battery. G
DANGER
The vehicle's high voltage electrical system is under high voltage. If you modify components
in the vehicle's high-voltage electrical system or touch damaged components, you may be
electrocuted. The components in the vehi-
cle's high-voltage electrical system may be
damaged in an accident, although the damage
is not visible. There is a risk of fatal injury.
Do not touch any high-voltage components
after an accident and never modify the vehi-
cle's high-voltage electrical system. Have the vehicle towed away after an accident and the vehicle's high-voltage electrical system
checked by a qualified specialist workshop. G
WARNING
In the event of a vehicle fire, the internal pres- sure of the high-voltage battery could exceeda critical value. In this case, flammable gas
escapes through a vent valve in the vehicle's
underbody. The gas can ignite. There is a risk
of injury.
Leave the danger area immediately. Secure
the danger area at a suitable distance, whilst
observing legal requirements. G
WARNING
If the housing of the high-voltage battery has
been damaged, electrolyte and gases may
leak out. These are poisonous and caustic.
There is a risk of injury. 440
Battery (vehicle)Breakdown assistance

Avoid contact with the skin, eyes or clothing.
Immediately rinse electrolyte splashes off
with water and seek medical attention
straight away.
! Exhaustive discharge caused by the vehi-
cle standing idle for lengthy periods can
damage the high-voltage battery. If the
vehicle is idle for lengthy periods leave the
high-voltage battery connected to a charg-
ing station.
Consult a Mercedes-Benz Service Centre if
you wish to leave your vehicle parked up for a
long period of time. Charging the 12 V battery
Vehicles with a lithium-ion battery:
! Only use battery chargers with a maxi-
mum charging voltage of 14.4 V.
All ot her vehicles G
WARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, naked flames, creating
sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting.
Do not lean over a battery. G
WARNING
Battery acid is caustic. There is a risk of injury. Avoid contact with the skin, eyes or clothing.
Do not breathe in any battery gases. Do not
lean over the battery. Keep the batteries out
of the reach of children. Immediately rinse off
battery acid thoroughly with plenty of clean
water and seek medical attention at once. G
WARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing the vehicle or charging the battery, gases can escape from the battery. There is a risk of
an explosion.
Allow the frozen battery to thaw out before
charging it or jump-starting.
! Only use battery chargers with a maxi-
mum charging voltage of 14.8 V.
All ve hicles:
! Only charge the battery using the jump-
start connection point.
The jump-starting connection point is in the
engine compartment (Y page 443).
X Open the bonnet.
X Connect the battery charger to the positive
terminal and earth point in the same order
as when connecting the donor battery in
the jump-starting procedure (Y page 443).
Keep away from fire and open flames. Do not lean over the battery. Never charge the bat-
tery if it is still fitted to the vehicle, unless you
use a battery charger which has been tested
and approved by Mercedes-Benz. A battery
charger unit specially adapted for Mercedes- Benz vehicles and tested and approved by
Mercedes-Benz is available as an accessory.
This device permits charging of the battery in
position. Contact a Mercedes-Benz Service
Centre for information and availability. Read
the battery charger's operating instructions
before charging the battery.
All vehicles except vehicles with a lith-
ium-ion battery: if the indicator/warning
lamps in the instrument cluster do not light up at low temperatures, it is very likely that the
discharged battery has frozen. In this case
you may neither jump-start the vehicle nor
charge the battery. The service life of a bat-
tery that has been thawed may be reduced.
The starting characteristics may be impaired,
especially at low temperatures. Have the
thawed battery checked at a qualified spe-
cialist workshop.
Vehicles with a lithium-ion battery: at low
temperatures, do not charge a battery which
has been removed using a battery charger. Battery (vehicle)
441Breakdown assistance Z

Jump-starting
For the jump-starting procedure, use only the jump-starting connection point, consisting of a positive terminal and an earth point, in the engine compartment.
All vehicles except vehicles with a lithium-ion battery: G
WARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with the skin, eyes or clothing. Do not breathe in any battery gases. Do not lean over the battery. Keep the batteries out of the reach of children. Immediately rinse off battery acid
thoroughly with plenty of clean water and seek medical attention at once. G
WARNING
During charging and jump-starting, explosive gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, naked flames, creating sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting. Do not lean over a battery. G
WARNING
During the charging process, a battery produces hydrogen gas. If a short circuit occurs or sparks
are created, the hydrogen gas can ignite. There is a risk of an explosion.
R Make sure that the positive terminal of a connected battery does not come into contact with
vehicle parts.
R Never place metal objects or tools on a battery.
R It is important that you observe the described order of the battery terminals when connecting
and disconnecting a battery.
R When jump-starting, make sure that the battery poles with identical polarity are connected.
R It is particularly important to observe the described order when connecting and disconnecting
the jump leads.
R Never connect or disconnect the battery terminals while the engine is running. G
WARNING
A discharged battery can freeze at temperatures below freezing point. When jump-starting the
vehicle or charging the battery, gases can escape from the battery. There is a risk of an explosion.
Allow the frozen battery to thaw out before charging it or jump-starting.
! Vehicles with a petrol engine:
avoid repeated and lengthy starting attempts. Otherwise,
the non-combusted fuel may damage the catalytic converter.
If the indicator/warning lamps do not light up at low temperatures, it is very likely that the
discharged battery has frozen. In this case you may neither jump-start the vehicle nor charge
the battery. The service life of a battery that has been thawed may be reduced. The starting
characteristics may be impaired, especially at low temperatures. Have the thawed battery
checked at a qualified specialist workshop.
All vehicles: Jump-starting
443Breakdown assistance Z

X
Slide cover Aof positive terminal :in the direction of the arrow.
X Connect positive terminal :on your vehicle to positive terminal ;of donor battery B
using the jump lead. Always begin with positive terminal :on your own vehicle first.
X Start the engine of the donor vehicle and run it at idling speed.
X Connect negative terminal =of donor battery Bto earth point ?of your vehicle using the
jump lead, connecting the jump lead to donor battery Bfirst.
X Start the engine.
X Before disconnecting the jump leads, let the engines run for several minutes.
X First, remove the jump leads from earth point ?and negative terminal =, then from pos-
itive clamp :and positive terminal ;. Begin each time at the contacts on your own vehicle
first.
X Close cover Aof positive clamp :after removing the jump leads.
X Have the battery checked at a qualified specialist workshop.
PLUG-IN HYBRID vehicles: if your vehicle has been jump-started, it may not be possible to
use the electric drive for approximately 30 minutes.
Jump-starting is not considered to be a normal operating condition.
i Jump-starting cables and further information regarding jump starting can be obtained at
any qualified specialist workshop. Towing away and tow-starting
Important safety notes
G
WARNING
Safety relevant functions are restricted or no
longer available if:
R the engine is not running
R the brake system or power steering is mal-
functioning
R there is a malfunction in the voltage supply
or the vehicle's electrical system
When your vehicle is towed away or towed
started, you may require considerably more
effort to steer and brake. There is a risk of an
accident.
In such cases use a rigid towing bar. Before
being towed away or tow started, make sure
the steering moves freely. G
WARNING
If the steering wheel lock is engaged, the vehi- cle can no longer be steered. There is a risk of
an accident. Always switch on the ignition when towing
with a tow rope or a towing bar.
G
WARNING
When towing or tow-starting another vehicle
and its weight is greater than the permissible gross weight of your vehicle, the:
R towing eye may be torn off
R car/trailer combination may swerve or
even overturn
There is a risk of an accident.
When towing or tow-starting another vehicle,
its weight should not be greater than the per- missible gross weight of your vehicle.
Details on the permissible gross vehicle
weight of your vehicle can be found on the
vehicle identification plate (Y page 480). Towing away and tow-starting
445Breakdown assistance Z

!
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 front-passenger door.
X To open: fold cover :out towards the rear
and remove it.
X To close: clip in cover :at the rear.
X Fold cover :forwards until it engages. Fuse box in the engine compartment
G
WARNING
When the bonnet is open, and the windscreen wipers are set in motion, you can be injured by
the wiper linkage. There is a risk of injury.
Always switch off the windscreen wipers and
the ignition before opening the bonnet.
! 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. Fuse box cover (example)
X Open the bonnet.
X To open: press safety clips :on the cover
together.
X Remove fuse box cover ;upwards. Fuse box in the engine compartment (exam-
ple)
X Remove any existing moisture from the
fuse box using a dry cloth.
X Loosen screws =, fold up fuse box lid ?
and remove it.
X To close: check whether the seal is posi-
tioned correctly in lid ?.
X Insert lid ?into the bracket at the rear of
the fuse box.
X Fold down lid ?of the fuse box and tighten
screws =.
Fuse box cover (example)
X Insert cover ;on both sides and engage
safety clips :.
X Close the bonnet. 450
Electrical fusesBreakdown assistance

Tyre-fitting tools should not be applied in
the area of the valve, as this could damage
the electronic components.
Only have tyres changed at a qualified spe- cialist workshop.
Interchanging the front and rear wheels of
differing dimensions can render the general
operating permit invalid.
Observe the instructions and safety notes in
the "Fitting a wheel" section (Y page 464).
The wear patterns on the front and rear tyres differ depending on the operating conditions.Interchange the wheels before a clear wear
pattern has formed on the tyres. Front tyres
typically wear more on the shoulders and the
rear tyres in the centre.
On vehicles that have the same size front and rear wheels, you can interchange the wheels
every 5,000 to 10,000 km depending on the
degree of tyre wear. Ensure the direction of
rotation is maintained.
Clean the contact surfaces of the wheel and
the brake disc thoroughly every time a wheel
is interchanged. Check the tyre pressure and,
if necessary, restart the tyre pressure loss
warning system (Y page 460) or the tyre pres-
sure monitor (Y page 462). Direction of rotation
Tyres with a specified direction of rotation
have additional benefits, e.g. if there is a risk of aquaplaning. These advantages can only begained if the tyres are fitted corresponding to
the direction of rotation.
An arrow on the sidewall of the tyre indicates
its correct direction of rotation. Storing wheels
Store wheels in a cool, dry and preferably
dark place if they are not being used. Protect the tyres against oil, grease, petrol and diesel. Fitting a wheel
Preparing the vehicle X
Stop the vehicle on solid, non-slippery and
level ground.
X Apply the electric parking brake manually.
X Move the front wheels to the straight-
ahead position.
X Shift the transmission to position P.
X Make sure that the vehicle level is set to
"Normal" on vehicles with AIR BODY CON-
TROL (Y page 252).
X Switch off the engine.
X Vehicles without KEYLESS-GO: remove
the key from the ignition lock.
X Vehicles with KEYLESS-GO start-func-
tion or KEYLESS-GO: open the driver's
door.
The on-board electronics now have status
0. This is the same as the key having been removed.
X Vehicles with KEYLESS-GO start-func-
tion or KEYLESS-GO: remove the Start/
Stop button from the ignition lock
(Y page 187).
X If included in the vehicle equipment,
remove the tyre-change tool kit from the
vehicle.
X Safeguard the vehicle against rolling away.
i Apart from some country-specific var-
iants, vehicles are not equipped with tyre-
changing tools. Some tools for changing a
wheel are specific to the vehicle. For more information on which tools are required to
perform a wheel change on your vehicle,
consult a qualified specialist workshop.
Necessary tyre-changing tools may
include, for example:
R Jack
R Wheel chock
R Wheel wrench
R Centring pin 464
Changing a wheelWheels and tyres