check engine light MERCEDES-BENZ GLA SUV 2017 User Guide

Problem
Possible causes/consequences and
M
MSolutions The engine does not
start. You cannot hear
the starter motor. The on-board voltage is too low because the battery is too weak or
discharged.
X Jump-start the vehicle (Y page 325).
If the engine does not start despite attempts to jump-start it:
X Consult a qualified specialist workshop. The starter motor was exposed to excessively high thermal load.
X Allow the starter motor to cool down for approximately two minutes.
X Try to start the engine again.
If the engine still does not start:
X Consult a qualified specialist workshop. Vehicles with a petrol
engine:
The engine is not running
smoothly and is misfir-
ing. The engine electronics or a mechanical component of the engine
management system is malfunctioning.
X Only depress the accelerator pedal slightly.
Otherwise, non-combusted fuel may get into the catalytic converter
and damage it.
X Have the cause rectified immediately at a qualified specialist work-
shop. The coolant temperature
display is showing more
than 120 †. The coolant warning lamp may also
be on and a warning tone
may sound. The coolant level is too low. The coolant is too hot and the engine is not
being cooled sufficiently.
X Stop as soon as possible and allow the engine and the coolant to
cool down.
X Check the coolant level (Y page 305). Observe the warning notes
as you do so and top up the coolant if necessary. If the coolant level is correct, the engine radiator fan may be faulty. The
coolant is too hot and the engine is not being cooled sufficiently.
X If the coolant temperature is below 120 †, you can continue driving
to the nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving in moun-
tainous terrain and stop-start traffic. DYNAMIC SELECT button (all vehicles
except Mercedes-AMG vehicles)
Use the DYNAMIC SELECT button to change the drive program. Depending on the drive program
selected, the following vehicle characteristics
will change:
R the drive (engine and transmission manage-
ment)
R the suspension (vehicles with adjustable
damping)
R the steering R
the availability of the ECO start/stop function
R the climate control
If the ignition is switched off for less than four
hours, the previously selected drive program is
activated when the engine is next started. If the ignition is switched off for more than four hours,
drive program Cis activated when the engine is
next started. DYNAMIC SELECT button (all vehicles except Mercedes-AMG vehicles)
151Driving and parking Z

Observe the following notes:
R Stop the vehicle before driving off-road. If
necessary, activate the off-road program
(Y page 151).
R To avoid damaging the vehicle, make sure
there is always sufficient ground clearance.
R Make sure that items of luggage and loads are
stowed safely and are well secured
(Y page 293).
R Always keep the engine running and in gear
when driving on a downhill gradient. Activate
DSR (Y page 190).
R Drive slowly and evenly, if necessary at walk-
ing 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 rea-
sons, get out of the vehicle first and survey
the off-road route.
R Check the depth of water before fording rivers
and streams.
R Watch out for obstacles.
R Take care when turning on an uphill or down-
hill slope or when driving across a slope. The
vehicle could otherwise tip over.
R Always keep the side windows and the pano-
rama sliding sunroof closed during the jour-
ney.
R Do not deviate from marked routes.
R Do not use the HOLD function when driving
off-road, on steep uphill or downhill gradients
or on slippery or loose surfaces. The HOLD
function cannot hold the vehicle on such sur- faces.
Checklist before off-road driving X
Engine oil level: check the engine oil and top
it up if necessary.
When driving on steep gradients, the oil level must be sufficiently high to ensure a correct
oil supply 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.
X Wheels: dented or bent wheels can lead to a
loss of tyre pressure and damage to the tyre
bead. Before driving off-road, check the
wheels and replace them if necessary.
Checklist after off-road driving !
If you detect damage to the vehicle after
driving off-road, have the vehicle checked
immediately at a qualified specialist work-
shop.
X Deactivate the off-road program
(Y page 151).
X Deactivate DSR (Y page 190).
X Clean the headlamps and rear lights and
check for damage.
X Clean the front and rear licence plates.
X Clean the wheels and tyres with a water jet
and remove any foreign objects.
X Clean the wheels, wheel arches and the vehi-
cle 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 air bellows of the axle joints and propeller shafts.
X After the trip, examine without fail the entire
undercarriage, wheels, tyres, brakes, body-
work structure, steering, chassis and exhaust
system for damage.
X After driving in sand, mud, gravel, water or
similar dirty conditions, have the following
checked and cleaned:
R brake discs
R wheels
R brake pads
R axle joints
X If you detect strong vibrations after driving
off-road, 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 over poor road surfaces 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. 174
Driving tipsDriving and parking

Driving on sand
Observe the following rules when driving on
sand:
R Activate the off-road program (Y page 151).
R Avoid high engine speeds.
R Use the left-hand steering wheel gearshift
paddle to shift to a lower gear appropriate to
the terrain.
R Drive quickly to overcome the rolling resist-
ance. Otherwise, the vehicle could dig itself
into the sand.
R Drive in the tracks of other vehicles if possi-
ble. Make sure that:
- the tyre ruts are not too deep
- the sand is firm enough
- your vehicle has sufficient ground clear-
ance
Tyre ruts and unpaved roads !
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.
Observe the following rules when driving along
ruts in off-road terrain or on roads with loose
gravel: R Activate the off-road program (Y page 151).
R Avoid high engine speeds.
R Shift to a lower gear using the left-hand steer-
ing wheel gearshift paddle.
R Drive slowly.
R Where ruts are too deep, drive with the
wheels on one side on the middle section of
turf if possible. Travelling uphill
Approach/departure angle G
WARNING
If you drive on a steep incline at an angle or
turn on a steep incline, the vehicle could slip
sideways, tip and overturn. There is a risk of
an accident.
When driving on an incline, drive into the line of fall (upwards or downwards in a straight
line) and do not turn. R
Observe the warnings for off-road driving
(Y page 173).
R Follow the line of fall when driving on slopes
and steep inclines.
R Before driving on extreme uphill and extreme
downhill gradients, select the off-road pro-
gram (Y page 151).
R Drive slowly.
R Accelerate gently and make sure that the
wheels are gripping.
R Avoid high engine speeds, except when driv-
ing on sandy and muddy routes with high driv-
ing resistance.
R Use the left-hand steering wheel gearshift
paddle to shift to a lower gear appropriate to
the gradient.
R Use the left-hand gearshift paddle to shift to a
lower gear on long and steep downhill gradi-
ents.
Hill start assist will aid you when pulling away on
a hill. Further information on hill start assist
(Y page 147).
Do not shift into transmission position iwhen
driving off-road. You could lose control of the
vehicle if you attempt to brake the vehicle using
the service brake. If the gradient is too steep for your vehicle, back up in reverse gear.
Always observe the approach/departure angle
values (Y page 359).
Maximum gradient-climbing capability Always observe the maximum gradient climbing
ability values (Y page 359).
Hilltops When driving up an uphill gradient, slightly
reduce pressure on the accelerator immediately
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 tips
175Driving and pa rking Z

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 forwards. Oth-
erwise, the vehicle could slip sideways, tip
and overturn.
R Before tackling steep downhill gradients, use
the left-hand steering wheel gearshift paddle
to shift to a lower gear.
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.
Off-road ABS is activated when the off-road pro- gram 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 during off-road driving. The steerability of the vehicle is considerably reduced if the
wheels lock. Driving systems
Cruise control
General 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
lower gear in good time on long and steep down-
hill gradients, especially if the vehicle is laden or towing a trailer. For vehicles with automatic
transmission, you need to shift manually using
the steering wheel gearshift paddles. By doing
so, you will make use of the braking effect of the engine. This relieves the load on the brake sys-
tem and prevents the brakes from overheating
and wearing too quickly.
When the engine is running, you can use the
cruise control lever to limit the speed to any
speed between 30 km/h and the maximum
design speed of the vehicle. If the set value of
the permanent limiter is lower, then this value
applies (Y page 180).
Use cruise control only if road and traffic con-
ditions are appropriate for maintaining a steady speed for a prolonged period. The speed indicated in the speedometer may
differ slightly from the speed stored.
Important safety notes If you fail to adapt your driving style, cruise con-
trol can neither reduce the risk of an accident
nor override the laws of physics. Cruise control
cannot take into account road, weather or traffic conditions. Cruise control is only an aid. You are
responsible for the distance to the vehicle in
front, for vehicle speed, for braking in good time
and for staying in lane.
Do not use cruise control:
R in road and traffic conditions that do not allow
you to maintain a constant speed, e.g. in
heavy traffic or on winding roads.
R on icy or slippery roads. Braking or acceler-
ating can cause the drive wheels to lose trac-
tion and the vehicle could then skid.
R in poor visibility, e.g. due to fog, heavy rain or
snow.
If a new driver takes over, advise the new driver
of the speed stored.
Cruise control lever :
To activate or increase speed
; LIM indicator lamp
= To activate at the current speed/last stored
speed
? To activate or reduce speed
A To switch between cruise control and the
variable speed limiter
B To deactivate cruise control
You can operate cruise control and the variable
speed limiter with the cruise control lever. 176
Driving syste
msDriving and parking

?
To activate or reduce speed
A To switch between cruise control and the
variable speed limiter
B To switch off the speed limiter
With the cruise control lever, you can operate
cruise control or Distance Pilot DISTRONIC and
the variable speed limiter.
The LIM indicator lamp on the cruise control
lever indicates which system you have selected:
R LIM indicator lamp off: cruise control or Dis-
tance Pilot DISTRONIC is selected.
R LIM indicator lamp on: variable speed lim-
iter is selected.
When the engine is running, you can use the
cruise control lever to limit the speed to any
speed between 30 km/h and the maximum
design speed of the vehicle. If the set value of
the permanent limiter is lower, then this value
applies (Y page 180).
Selecting the variable speed limiter
X Check whether LIM indicator lamp ;is on.
If it is on, the variable speed limiter is already
selected.
If it is not, press the cruise control lever in the direction of arrow A.
LIM indicator lamp ;in the cruise control
lever lights up. The variable limiter is selected.
Storing the current speed You can use the cruise control lever to limit the
speed to any speed above 30 km/h while the
engine is running.
X Briefly press the cruise control lever up :or
down ?.
The current speed is stored and shown in the multifunction display.
Storing or calling up the speed G
WARNING
If you call up the stored speed and it is lower
than the current speed, the vehicle deceler-
ates. If you do not know the stored speed, the vehicle could decelerate unexpectedly. There
is a risk of an accident.
Pay attention to the road and traffic condi-
tions before calling up the stored speed. If you do not know the stored speed, store the
desired speed again. X
Briefly pull the cruise control lever towards
you =.
Setting a speed
X To adjust the set speed in 10 km/h incre-
ments: briefly press the cruise control lever
up : beyond the pressure point for a higher
speed, or down ?for a lower speed.
or X Keep the cruise control lever pressed beyond
the pressure point until the desired speed is
set. Press the cruise control lever up :for a
higher speed or down ?for a lower speed.
X To adjust the set speed in 1 km/h incre-
ments:
briefly press the cruise control lever
up : to the pressure point for a higher speed
or down ?for a lower speed.
or X Keep the cruise control lever pressed to the
pressure point until the desired speed is set.
Press the cruise control lever up :for a
higher speed or down ?for a lower speed.
Switching the speed limiter to passive
If you depress the accelerator pedal beyond the pressure point (kickdown), the limiter is
switched to passive mode. The Limiter pas‐
Limiter pas‐
sive sive message appears in the multifunction dis-
play.
You can then exceed the stored speed. The lim-
iter is activated again if, without kickdown, you:
R drive more slowly than the stored speed
R set a new speed or
R call up the last speed stored again
The Limiter passive
Limiter passive message in the multi-
function display disappears.
Switching off the variable speed limiter You cannot switch the variable speed limiter offby braking.
There are several ways to deactivate the varia-
ble speed limiter:
X Briefly press the cruise control lever forwards
B.
or
X Briefly press the cruise control lever in the
direction of arrow A.
LIM indicator lamp ;in the cruise control
lever goes out. The variable speed limiter is
switched off. Driving systems
179Driving and parking Z

Due to the nature of the system:
R warnings may be issued in error when driving
close to crash barriers or similar solid boun-
daries
R warnings may be interrupted when you are
driving alongside particularly long vehicles,
such as lorries, for a prolonged time
Warning display :
Warning display
Blind Spot Assist is not active at speeds below
approximately 30 km/h. Vehicles in the moni-
toring range are then not indicated.
If Blind Spot Assist is activated, indicator
lamp :in the exterior mirrors lights up yellow
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 correspond-
ing 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 deac- tivated.
The brightness of the indicator/warning lamps
is adjusted automatically according to the ambi-
ent light.
Collision warning
If a vehicle is detected in the blind spot moni-
toring range and you switch on the correspond-
ing 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 Blind Spot Assist X Make sure that Blind Spot Assist is activated
in the on-board computer (Y page 227).
X Turn the key to position 2in the ignition
lock.
Warning lamps :in the exterior mirrors light
up red for approximately 1.5 second s and
then turn yellow.
Towing a trailer
If you couple up a trailer, make sure that you
have correctly established the electrical con-
nection. This can be accomplished by checking
the trailer lighting. Blind Spot Assist is then
deactivated. The indicator lamps in the exterior
mirrors light up yellow and the Blind Spot
Blind Spot
Assist not available when towing a Assist not available when towing a
trailer See Owner's Manual trailer See Owner's Manual message
appears in the multifunction display.
i You can deactivate the indicator lamps in
the exterior mirrors.
To do so, you will need to 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 General notes
Lane Keeping Assist monitors the area in front of
your vehicle by means of multifunction cam-
era :attached at the top of the windscreen.
Lane Keeping Assist detects lane markings on 210
Driving systemsDriving an
d parking

Important safety notes
G
WARNING
If you operate information and communica-
tion equipment integrated in the vehicle when driving, you could be distracted from the traf-
fic situation. This could also cause you to lose control of the vehicle. There is a risk of an
accident.
Only operate this equipment when the traffic
situation permits. If you cannot be sure of this,
stop the vehicle paying attention to road and
traffic conditions and operate the equipment
with the vehicle stationary.
You must observe the legal requirements for the
country in which you are currently driving when operating the on-board computer. G
WARNING
If the instrument cluster has failed or mal-
functioned, you may not recognise function
restrictions relevant to safety. The operating
safety of your vehicle may be impaired. There is a risk of an accident.
Drive on carefully. Have the vehicle checked
at a qualified specialist workshop immedi-
ately.
The on-board computer shows only display mes- sages or warnings from certain systems on the
multifunction display. You should therefore
make sure your vehicle is operating safely at alltimes.
If the operating safety of your vehicle is
impaired, park the vehicle safely as soon as pos-
sible. Contact a qualified specialist workshop.
For an overview, see the instrument cluster illus-
tration (Y page 34). Displays and operation
Instrument cluster lighting
The light sensor in the instrument cluster auto-
matically controls the brightness of the multi-
function display. In daylight, the displays in the
instrument cluster are not illuminated. The lighting in the instrument cluster, in the dis-
plays and the controls in the vehicle interior can
be adjusted using the brightness control knob.
The brightness control knob is located on the
bottom left of the instrument cluster
(Y page 34).
X Turn the brightness control knob clockwise or
anti-clockwise.
If the light switch is set to the Ã,Tor
L position, the brightness is dependent
upon the brightness of the ambient light. Speedometer with segments
The speedometer is divided into segments on
vehicles with Distance Pilot DISTRONIC.
The segments in the speedometer indicate
which speed range is available.
R Variable speed limiter is activated
(Y page 178):
The segments light up from the start of the
scale to the selected speed limitation.
R Distance Pilot DISTRONIC is activated
(Y page 180):
One or two segments in the stored speed
range light up.
R Distance Pilot DISTRONIC detects a vehicle in
front moving more slowly than the stored
speed:
The segments between the speed of the vehi- cle in front and the stored speed light up. Rev counter
! Do not drive in the overrevving range. Doing
so will damage the engine.
The red band in the rev counter indicates the
engine's overrevving range.
The engine is limited within a range to protect
the engine when the red band is reached. Outside temperature display
You should pay special attention to road condi-
tions when temperatures are around freezing
point.
Bear in mind that the outside temperature dis-
play indicates the measured air temperature
and not the road surface temperature. Displays and operation
217On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions 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 on the instrument
cluster and a warning tone sounds.
G WARNING
Braking efficiency may be impaired.
There is a risk of an accident.
X Stop the vehicle safely as soon as possible, paying attention to road
and traffic conditions. Do not drive on.
X Secure the vehicle against rolling away (Y page 166).
X Consult a qualified specialist workshop.
X Do not top up the brake fluid. This does not correct the fault. #
Check Check
brake
brakepad
padwear
wear The brake pads/linings have reached their wear limit.
X Consult a qualified specialist workshop. G
Inoperative Inoperative One or more main features of the Mercedes-Benz Contact system is/
are malfunctioning.
X Consult a qualified specialist workshop. Active
Active
Brake
BrakeAssist
Assist
Functions
Functions currently
currently
limited
limited See
SeeOwner's
Owner's
Manual
Manual Active Brake Assist is temporarily inoperative.
Possible causes:
R the radar sensor system is temporarily inoperative, e.g. due to elec-
tromagnetic radiation emitted by nearby TV or radio stations or
other sources of electromagnetic radiation
R the system is outside the operating temperature range
R the on-board voltage is too low
Once the causes listed above no longer apply, the display message
disappears.
Active Brake Assist is operational again.
If the display message does not disappear:
X Stop the vehicle, paying attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 166).
X Restart the engine. Active Brake Active Brake
Assist: Assist:
System
Systeminop‐
inop‐
erative
erative Active Brake Assist is unavailable due to a malfunction. Situation-
dependent braking assistance may also have failed.
X Consult a qualified specialist workshop immediately. PRE-SAFE inopera‐
PRE-SAFE inopera‐
tive See Owner's tive See Owner's
Manual Manual
Important PRE-SAFE
®
functions have failed. All other occupant safety
systems, e.g. airbags, remain available.
X Consult a qualified specialist workshop immediately. Display
messages
241On-board computer and displays Z

Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
M Solutions !
N
The red indicator lamp for the electric parking brake flashes or is lit and/or the
yellow warning lamp for the electric parking brake is lit.
X Observe the additional display messages on the multifunction display. 6
N
The red restraint system warning lamp is lit while the engine is running.
The restraint system is malfunctioning.
G WARNING
The airbags or belt tensioners may either be triggered unintentionally or, in the
event of an accident, may not be triggered.
This poses an increased risk of injury.
X Observe the additional display messages on the multifunction display.
X Drive on carefully.
X Consult a qualified specialist workshop immediately and have the restraint sys-
tem checked.
Further information about the restraint system (Y page 41).Engine
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
M Solutions ;
N
The yellow engine diagnostics warning lamp lights up while the engine is run-
ning.
There may be a fault with the following, for example:
R Engine management
R Fuel injection system
R Exhaust system
R Ignition system (for vehicles with petrol engines)
R Fuel system
The emission limit values may be exceeded and the engine may be running in
emergency mode.
X Consult a qualified specialist workshop immediately.
Vehicles with a diesel engine: the fuel tank has been run dry (Y page 165).
X Start the engine three to four times after refuelling.
If the yellow engine diagnostics warning lamp goes out, emergency mode is
cancelled. The vehicle does not have to be checked. æ
N
The yellow reserve fuel warning lamp lights up while the engine is running.
The fuel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated if the fuel level drops into the
reserve range.
X Refuel at the nearest filling station. 272
Warning and indicator lamps on the instrument clusterOn-board computer and displays

Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
M Solutions ?
N
The red coolant warning lamp lights up 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 malfunctioning.
The coolant is too hot and the engine is not being cooled sufficiently.
X Observe the additional display messages in the multifunction display.
X Stop the vehicle immediately, paying attention to road and traffic conditions,
and switch off the engine.
X Secure the vehicle against rolling away (Y page 166).
X Leave the vehicle and keep a safe distance from the vehicle until the engine has
cooled down.
X Check the coolant level and top up the coolant, making sure to observe the
warning notes (Y page 305).
X If you have to top up the coolant frequently, have the engine cooling system
checked.
X Make sure that the air supply to the engine radiator is not blocked, e.g. by frozen
slush.
X Do not start the engine again until the coolant temperature is below 120 †. The
engine may otherwise be damaged.
X Drive to the nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving in mountainous terrain
and stop-start traffic. ?
N
The red coolant warning lamp lights up while the engine is running. A warning
tone also sounds.
The coolant temperature has exceeded 120 †. The airflow to the engine radiator may be blocked or the coolant level may be too low.
G WARNING
The engine is not being cooled sufficiently and may be damaged.
Never drive with an overheated engine. Driving when your engine has overheated
can cause any fluids that may have leaked into the engine compartment to catch fire.
In addition, steam from an overheated engine can cause serious burns, which can
occur just by opening the bonnet.
There is a risk of injury.
X Observe the additional display messages in the multifunction display.
X Stop the vehicle immediately, paying attention to road and traffic conditions,
and switch off the engine.
X Secure the vehicle against rolling away (Y page 166).
X Leave the vehicle and keep a safe distance from the vehicle until the engine has
cooled down.
X Check the coolant level and top up the coolant, making sure to observe the
warning notes (Y page 305).
X If you have to top up the coolant frequently, have the engine cooling system
checked. 274
Warning and indicator lamps on the instrument clusterOn-board computer and displays