ECU MERCEDES-BENZ GLC SUV 2017 X253 Repair Manual

Safety systems
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
$JN$ (USA only), J(Canada only): the red brake system warning lamp is lit
while the engine is running.
A warning tone also sounds.
GWARNING
The brake boosting effect is malfunctioning and the braking characteristics may be
affected.
There is a risk of an accident.
XPull over and stop the vehicle safely as soon as possible, paying attention to road
and traffic conditions. Do not continue driving under any circumstances.
XSecure the vehicle against rolling away (Ypage 154).
XConsult a qualified specialist workshop.
XObserve the additional display messages in the multifunction display.
$JN $ (USA only), J(Canada only): the red brake system warning lamp lights
up while the engine is running.
A warning tone also sounds.
There is not enough brake fluid in the brake fluid reservoir.
GWARNING
The braking effect may be impaired.
There is a risk of an accident.
XPull over and stop the vehicle safely as soon as possible, paying attention to road
and traffic conditions. Do not continue driving under any circumstances.
XSecure the vehicle against rolling away (Ypage 154).
XDo not add brake fluid. Adding more will not correct the malfunction.
XConsult a qualified specialist workshop.
XObserve the additional display messages in the multifunction display.
$N USA only: the red brake system warning lamp is lit while the engine is running.
The multifunction display also shows a display message with the #symbol.
The brake pads/linings have reached their wear limit.
XVisit a qualified specialist workshop.
258Warning and indicator lamps in the instrument cluster
On-board computer and displays

Engine
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
;NThe yellow Check Engine warning lamp lights up while the engine is running.
There may be a malfunction, for example:
Rin the engine management
Rin the fuel injection system
Rin the exhaust system
Rin the ignition system (for vehicles with gasoline engines)
Rin the fuel system
The emission limit values may be exceeded and the engine may be in emergency
mode.
XVisit a qualified specialist workshop immediately.
In some states, you must immediately visit a qualified specialist workshop as soon as the yellow Check Engine warning lamp lights up. This is due to the legal require-
ments in effect in these states. If in doubt, check whether such legal regulations
apply in the state in which you are currently driving.
Vehicles with a diesel engine: the fuel tank has been run dry (
Ypage 151).
XStart the engine three to four times after refueling.
If the yellow Check Engine warning lamp goes out, emergency running mode is
canceled. The vehicle need not be checked.
8N The yellow reserve fuel warning lamp lights up while the engine is running.
The fuel level has dropped into the reserve range.
XRefuel at the nearest gas station.
8N The yellow reserve fuel warning lamp flashes while the vehicle is in motion.
In addition, the ;Check Engine warning lamp may light up.
The fuel filler cap is not closed correctly or the fuel system is leaking.
XCheck that the fuel filler cap is correctly closed.
XIf the fuel filler cap is not correctly closed: close the fuel filler cap.
XIf the fuel filler cap is closed:visit a qualified specialist workshop.
?NThe red coolant warning lamp lights up while the engine is running and the
coolant temperature gauge is at the start of the scale.
The temperature sensor for the coolant temperature gauge is malfunctioning.
The coolant temperature is no longer being monitored. There is a risk of engine
damage if the coolant temperature is too high.
XPull over and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions. Do not continue driving under any circumstances.
XSecure the vehicle against rolling away (Ypage 154).
XConsult a qualified specialist workshop.
Warning and indicator lamps in the instrument cluster263
On-board computer and displays
Z

Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
?NThe red coolant warning lamp comes on while the engine is running.
The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator may be blocked or
the electric engine radiator fan may be defective.
The coolant is too hot and the engine is no longer being cooled sufficiently.
XObserve the additional display messages in the multifunction display.
XPull over and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 154).
XLeave the vehicle and keep a safe distance from the vehicle until the engine has cooled down.
XCheck the coolant level and add coolant, observing the warning notes
(Ypage 309).
XIf you have to add coolant frequently, have the engine cooling system checked.
XMake sure that the air supply to the engine radiator is not blocked, e.g. by snow,
slush or ice.
XDo not start the engine again until the coolant temperature is below 248 ‡
(120 †). Otherwise, the engine could be damaged.
XDrive to the nearest qualified specialist workshop.
XAvoid heavy loads on the engine as you do so, e.g. driving in mountainous terrain
and stop-and-go traffic.
?N The red coolant warning lamp comes on while the engine is running. A warning
tone also sounds.
The coolant temperature has exceeded 248 ‡(120 †). The airflow to the engine
radiator may be blocked or the coolant level may be too low.
GWARNING
The engine is not being cooled sufficiently and may be damaged.
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.
XObserve the additional display messages in the multifunction display.
XPull over and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 154).
XLeave the vehicle and keep a safe distance from the vehicle until the engine has
cooled down.
XCheck the coolant level and add coolant, observing the warning notes
(Ypage 309).
XIf you have to add coolant frequently, have the engine cooling system checked.
XMake sure that the air supply to the engine radiator is not blocked, e.g. by snow,
slush or ice.
264Warning and indicator lamps in the instrument cluster
On-board computer and displays

Tires
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
hNThe yellow tire pressure monitor warning lamp (pressure loss/malfunction) is lit.
The tire pressure monitor has detected a loss of pressure in at least one of the tires.
GWARNING
Tire pressures that are too low pose the following hazards:
Rthey may burst, especially as the load and vehicle speed increase.
Rthey may wear excessively and/or unevenly, which may greatly impair tire trac-
tion.
Rthe driving characteristics, as well as steering and braking, may be greatly
impaired.
There is a risk of an accident.
XStop the vehicle without making any sudden steering or braking maneuvers. Pay
attention to the traffic conditions as you do so.
XSecure the vehicle against rolling away (Ypage 154).
XObserve the additional display messages in the multifunction display.
XCheck the tires and, if necessary, follow the instructions for a flat tire
(Ypage 321).
XCheck the tire pressure (Ypage 345).
XIf necessary, correct the tire pressure.
hN The yellow tire pressure monitor warning lamp (pressure loss/malfunction)
flashes for approximately one minute and then remains lit.
The tire pressure monitor is faulty.
GWARNING
The system is possibly unable to recognize or register low tire pressure.
There is a risk of an accident.
XObserve the additional display messages in the multifunction display.
XVisit a qualified specialist workshop immediately.
266Warning and indicator lamps in the instrument cluster
On-board computer and displays

Adding your own favorite
XSelectVehicl eQClimate Contro l.
XPress and hold theg buttonuntil th e
favorite sare displayed.
XAd d a favorite at th edesired position.
If afavorite has already been added at this
position, it will be overwritten .
Climate control settings
General notes
You can adjust th eclimat econtrol settings
usin gth eclimat econtrol bar or th eclimat econ-
trol menu.
Importan tclimat econtrol function scan be set
in th eclimat econtrol bar:
RTemperatur e
RAirflow
RAir distribution
The climat econtrol bar is visible in mos tdis-
plays.
You can fin dall available climat econtrol func-
tions in th eclimat econtrol menu. You can use
th eclimat econtrol bar to switch to th eclimat e
control menu.
Overview
Climat econtrol bar (COMAND)
:
Adjusts temperature, air distribution on th e
left and airflow, displays th ecurren tsettings
;Calls up th eclimat econtrol menu, displays
th ecurren tcoolin gand climat emod eset -
tings
=Adjusts temperature and air distribution on
th eright ,displays th ecurren tsettings
Ther emay be fewe rsettings or none depending
on your vehicle's equipment.
Calling up the climate control bar
Multimedia system:
XSelec tVehicl e.
The vehicl emen uis displayed.
XSlide 6thecontroller repeatedly until th e
climat econtrol bar is activated.
Calling up the climate control menu
Multimedia system:
XSelec tVehicl e.
The vehicl emen uis displayed.
XSlide 6thecontroller repeatedly until th e
climat econtrol bar is activated.
XTo select from climat econtrol bar ;:turn
and press th econtroller.
The men ufor selecting th eclimat econtrol
function is activated.
XTo select th eclimat econtrol function :tur n
and press th econtroller.
The selected climat econtrol function
appears.
Settings in the climate menu
Adjusting the climate mode settings
The climat emod edetermine sth etyp eof air-
flow. The settin gis active when th eair-condi-
tionin gsystem is set to Ã(
Ypage 125).
XCall up th eclimat econtrol men u
(Ypage 272).
XTo select ClimateMod e:tur nand press th e
controller.
XTo chang eth esetting: tur nth econtroller.
XTo exit th emenu: press th e% button.
The climat emod ebar displays th ecurren tair-
flo wsetting: DIFFUSE
,MEDIUMor FOCUS.
Starting/stopping the perfu meatomi zer
The perfum eatomizer makes it possible to scen t
th eair in individual compartments in th evehicl e
interior. Further information (
Ypage 128).
XCall up theclimat econtrol men u
(Ypage 272).
XTo select AirFreshener:tur nand press th e
controller.
The settin gelemen tis active.
XTo start/sto pth eperfum eatomizer: press
th econtroller.
272Operating system
Multimedia system

Connecting a mobile phone
Requirements
For telephony via the Bluetooth®interface, you
require a Bluetooth®-capable mobile phone. The
mobile phone must support Hands-Free Profile
1.0 or above.
Multimedia system:
XSelect VehicleQSystem Set‐tingsQActivate Bluetooth.
XActivate Bluetooth®O.
Mobile phone:
XActivate Bluetooth®and, if necessary, Blue-
tooth®visibility for other devices (see the
manufacturer's operating instructions).
The Bluetooth
®device names for all of one man-
ufacturer's products might be identical. To
make it possible to clearly identify your mobile
phone, change the device name (see the man-
ufacturer's operating instructions).
If the mobile phone supports the PBAP (Phone
B ook Access Profile) and MAP (M essage
Access Profile) Bluetooth
®profiles, the follow-
ing information will be transmitted after you
connect:
RPhone book
RCall lists
RMessages
iFurther information on suitable mobile
phones can be obtained on the Internet at:
http://www.mercedes-benz.com/
connect
iIn the USA, you can get in touch with the
Mercedes-Benz Customer Assistance Center
on 1-800-FOR-MERCedes (1-800-367-6372 ).
In Canada, you can get in touch with the Cus-
tomer Relations Center on 1-800-387-0100.
Searching for and authorizing a mobile
phone
Before using your mobile phone with the multi-
media system for the first time, you will need to
search for the phone and then authorize (con-
nect) it. Depending on the mobile phone, author- ization either takes place by means of Secure
Simple Pairing or by entering a passkey. The
multimedia system automatically makes the
procedure that is relevant for your mobile phone available. The mobile phone is always connec-
ted automatically after authorization. Further
information on using a mobile phone with the
multimedia system (see the Digital Operator's
Manual).
If the multimedia system does not detect your
mobile phone, this may be due to particular
security settings on your mobile phone (see the
manufacturer's operating instructions).
Only one mobile phone can be connected to the
multimedia system at any one time.
Searching for a mobile phone
Audio 20:
XSelect
Tel/®QConnectDeviceQSearch for PhonesQStartSearch.
The available mobile phones are displayed.
COMAND:
XSelect PhoneQConnectDeviceQSearch for PhonesQStartSearch.
The available mobile phones are displayed.
Symbols in the device list
Sym-
bolExplanation
ÏNew mobile phone found, not yet
authorized.
ÑMobile phone is authorized, but is
not connected.
#Mobile phone is authorized and
connected.
Connecting a mobile phone
Authorization using Secure Simple Pairing:
XSelect mobile phone.
A code is displayed in the multimedia system
and on the mobile phone.
XIf codes match: selectYeson the multimedia
system.
XConfirm code on the mobile phone. Depend-
ing on the mobile phone used, confirm the
connection to the multimedia system and for
the PBAP and MAP Bluetooth
®profiles. The
prompt to confirm may take up to two
Operating system275
Multimedia system
Z

Stowage areas
Loading guidelines
GWARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. If the tailgate
is open when the engine is running, particu-
larly if the vehicle is moving, exhaust fumes
could enter the passenger compartment.
There is a risk of poisoning.
Turn off the engine before opening the tail-
gate. Never drive with the tailgate open.
GWARNING
If objects, luggage or loads are not secured or
not secured sufficiently, they could slip, tip
over or be flung around and thereby hit vehicle
occupants. There is a risk of injury, particu-
larly in the event of sudden braking or a sud-
den change in direction.
Always store objects so that they cannot be
flung around. Secure objects, luggage or
loads against slipping or tipping before the
journey.
GWARNING
The exhaust tail pipe and tail pipe trim can
become very hot. If you come into contact
with these parts of the vehicle, you could burn
yourself. There is a risk of injury.
Always be particularly careful around the
exhaust tail pipe and the tail pipe trim. Allow
these components to cool down before touch-
ing them.
The handling characteristics of a laden vehicle
are dependent on the distribution of the load
within the vehicle. For this reason, you should
observe the following notes when transporting a
load:
RNever exceed the maximum permissible
gross vehicle mass or the gross axle weight
rating for the vehicle (including occupants).
The values are specified on the vehicle iden-
tification plate on the B-pillar of the driver's
door.
RThe cargo compartment is the preferred place
to carry objects.
RPosition heavy loads as far forwards as pos-
sible and as low down in the cargo compart-
ment as possible.
RThe load must not protrude above the upper
edge of the seat backrests.
RAlways place the load behind unoccupied
seats if possible.
RHook in the cargo net when loading.
RSecure the load with sufficiently strong and
wear-resistant tie-downs. Pad sharp edges for protection.
Stowage spaces
Important safety notes
GWARNING
If you transport objects in the vehicle interior
and these are not adequately secured, they
could slip or be flung around and thereby
strike vehicle occupants. In addition, cup
holders, open stowage spaces and mobile
phone brackets may not always be able to
hold the objects placed in them in the event of
an accident. There is a risk of injury, particu-
larly in the event of sharp braking or sudden
changes of direction.
RAlways stow objects in such a way that they cannot be tossed about in these or similar
situations.
RAlways make sure that objects do not pro-
trude out of the stowage spaces, luggage
nets or stowage nets.
REnsure that closable stowage spaces are
shut before beginning your journey.
RAlways stow and secure heavy, hard, poin-
ted, sharp-edged, fragile or large objects in
the cargo compartment.
Observe the loading guidelines (
Ypage 278).
278Stowage areas
Stowage and features

Vehicle occupants could be struck in the
event of sudden braking or an accident, for
instance, if you:
Rtransport other heavy or sharp-edged
objects in the skibag
Rdo not secure the skibag with the lashing
straps
There is a risk of accident and injury.
Store only skis in the skibag. Always secure
the skibag with the lashing straps so that it
cannot move around.
A maximum of four pairs of skis or two snow-
boards can be transported in the ski and snow-
board bag.
Securing the ski/snowboard bag in the
cargo compartment
XFold the middle rear seat backrest forwards
(Ypage 281).
XSlide the ski and snowboard bag between the
two outside rear seat backrests. Ensure that
the wheels of the ski/snowboard bag are in
the cargo compartment.
XOpen the ski/snowboard bag with zip :and
place the skis or snowboards inside it.
XClose the ski and snowboard bag.
XPull tensioning strap ;tight by the loose end
until the skis or snowboards are held firmly
inside the ski/snowboard bag.
XEngage tensioning strap =in a diagonal pat-
tern on hooks ?in cargo tie-down rings Aas
shown.
EASY-PACK Quickfold rear bench seat
Important safety notes
GWARNING
If the rear bench seat/rear seat and seat
backrest are not engaged they could fold for-
wards, e.g. when braking suddenly or in the
event of an accident.
RThe vehicle occupant would thereby be
pushed into the seat belt by the rear bench
seat/rear seat or by the seat backrest. The
seat belt can no longer offer the intended
level of protection and could even cause
injuries.
RObjects or loads in the trunk/cargo com-
partment cannot be restrained by the seat
backrest.
There is an increased risk of injury.
Before every trip, make sure that the seat
backrests and the rear bench seat/rear seat
are engaged.
!When folding the rear seat backrest for-
wards, ensure that there are no items lying on the seat cushions. These items could other-
wise be damaged or could themselves dam-
age the rear seats.
Observe the loading guidelines (
Ypage 278).
The outside and the middle rear seat backrests
can be folded down separately to increase the
cargo compartment capacity. The division ratio
is 40/20/40.
Stowage areas281
Stowage and features
Z

Vehicles with the stowage space package: to
enlarge the cargo compartment, you can adjust
the rear seat backrests to a 10 degrees steeper
angle (cargo position).
XFold the seat backrest forward (Ypage 281).
XMove handle:in the direction of the arrow.
XPush back seat backrest ;as far as han-
dle :until the backrest engages.
The cargo position has been reached.
Securing loads
Cargo tie-down rings
Observe the following notes on securing loads:
RObserve the loading guidelines (Ypage 278).
RSecure the load using the cargo tie-down
rings.
RDistribute the load on the cargo tie-down
rings evenly.
RDo not use elastic straps or nets to secure a
load, as these are only intended as an anti-slip
protection for light loads.
RDo not route tie-downs across sharp edges or corners.
RPad sharp edges for protection.
:Cargo tie-down rings in the rear-compart-
ment footwell (vehicles with cargo net)
:Cargo tie-down rings in the cargo compart-
ment
Bag hook
GWARNING
The bag hooks cannot restrain heavy objects
or items of luggage. Objects or items of lug-
gage could be flung around and thereby hit
vehicle occupants when braking or abruptly
changing directions. There is a risk of injury.
Only hang light objects on the bag hooks.
Never hang hard, sharp-edged or fragile
objects on the bag hooks.
!The bag hook can bear a maximum load of
6.6lbs (3kg) and should not be used to secure
a load.
:Bag hook
284Stowage areas
Stowage and features

Cargo compartment cover
Important safety notes
GWARNING
On its own, the cargo compartment cover
cannot secure or restrain heavy objects,
items of luggage and heavy loads. You could
be hit by an unsecured load during sudden
changes in direction, braking or in the event of
an accident. There is an increased risk of
injury or even fatal injury.
Always store objects so that they cannot be
flung around. Secure objects, luggage or
loads against slipping or tipping over, e.g. by
using tie downs, even if you are using the
cargo compartment cover.
!When loading the vehicle, make sure that
you do not stack the load in the cargo com-
partment higher than the lower edge of the
side windows. Do not place heavy objects on
top of the cargo compartment cover.
The cargo compartment cover is secured behind
the rear bench seat backrest.
Extending and retracting the cargo
compartment cover
XTo extend: pull cargo compartment cover
back by grab handle :and clip it into retain-
ers ;on the left and right.
XTo retract: unhook the cargo compartment
cover from retainers ;on the left and right
and guide it forward by grab handle :until it
is fully retracted.
Installing/removing the cargo compart-
ment cover
XTo remove: make sure that cargo compart-
ment cover :is rolled up.
XPush in the end cap of cargo compartment
cover :in the direction of the arrow on the
right-hand side using the grip =.
XPush cargo compartment cover :into oppo-
site anchorage ;.
XRemove cargo compartment cover :up.
XTo install: place cargo compartment
cover :into anchorage ;on the left-hand
side.
XPush in the opposite end cap of cargo com-
partment cover :in the direction of the
arrow and insert the cargo compartment
cover :into the right-hand anchorage from
above ;.
Cargo net
Important safety notes
GWARNING
On its own, the cargo net cannot secure or
restrain heavy objects, items of luggage and
heavy loads. You could be hit by an unsecured
load during sudden changes in direction,
braking or in the event of an accident. There is
an increased risk of injury or even fatal injury.
Always store objects so that they cannot be
flung around. Secure objects, luggage or
loads against slipping or tipping over, e.g. by
using tie downs, even if you are using the
cargo net.
Stowage areas285
Stowage and features
Z