2016 MERCEDES-BENZ GLC-Class check engine light

ProblemPossible causes/consequences andMSolutions
The engine cannot be
started using the
SmartKey.The on-board voltage is too low.
XSwitch off non-essential consumers, e.g. seat heating or interior
lighting, and try to start the engine again.
If this does not work:
XCheck the starter battery and charge it if necessary
(
Ypage 363).
or
XJump-start the vehicle (Ypage 365).
or
XConsult a qualified specialist workshop.
The engine cannot be
started using the Start/
Stop button. The
SmartKey is in the vehi-
cle.The vehicle is locked.
XUnlock the vehicle and try to start the vehicle again.
The SmartKey battery is discharged or nearly discharged.
XCheck the SmartKey battery (Ypage 86) and replace it if nec-
essary (
Ypage 86).
If this does not work:
XStart your vehicle with the SmartKey in the ignition lock.
There is interference from a powerful source of radio waves.
XStart your vehicle with the SmartKey in the ignition lock.
You have lost a Smart-
Key.XHave the SmartKey deactivated at a qualified specialist work-
shop.
XReport the loss immediately to the vehicle insurers.
XIf necessary, have the locks changed as well.
You have lost the
mechanical key.XReport the loss immediately to the vehicle insurers.
XIf necessary, have the locks changed as well.
88SmartKey
Opening and closing

Useful information
i
This Operator's Manual describes all
models and all standard and optional equip-
ment of your vehicle available at the time of
publication of the Operator's Manual.
Country-specific differences are possible.
Please note that your vehicle may not be
equipped with all features described. This
also applies to safety-related systems and
functions.
iRead the information on qualified special-
ist workshops (
Ypage 27).
Correct driver's seat position
GWARNING
You could lose control of your vehicle if you do the following while driving:
Radjust the driver's seat, head restraint,
steering wheel or mirrors
Rfasten the seat belt
There is a risk of an accident.
Adjust the driver's seat, head restraint, steer-
ing wheel and mirror and fasten your seat belt before starting the engine.
XObserve the safety guidelines on seat
adjustment (
Ypage 109).
XMake sure that seat =is adjusted prop-
erly.
Electrical seat adjustment (
Ypage 110)
When adjusting the seat, make sure that:
Ryou are as far away from the driver's air bag
as possible
Ryou are sitting in a normal upright position
Ryou can fasten the seat belt properly
Ryou have moved the backrest to an almost
vertical position
Ryou have set the seat cushion angle so that
your thighs are gently supported
Ryou can depress the pedals properly
Ryour legs are not fully extended
XCheck whether the head restraint is adjus-
ted properly.
When doing so, make sure that you have
adjusted the head restraint so that the back
of your head is supported at eye level by the
center of the head restraint.
XObserve the safety guidelines on steering
wheel adjustment (
Ypage 115).
XMake sure that steering wheel :is adjus-
ted properly.
Adjusting the steering wheel manually
(
Ypage 115)
Adjusting the steering wheel electrically
(
Ypage 116)
When adjusting the steering wheel, make
sure that:
Ryou can hold the steering wheel with your
arms slightly bent
Ryou can move your legs freely
Ryou can see all the displays in the instru-
ment cluster clearly
XObserve the safety guidelines for seat belts
(
Ypage 44).
XCheck whether you have fastened seat
belt ;properly (
Ypage 46).
108Correct driver's seat position
Seats, steering wheel and mirrors

Problems with the seat ventilation
ProblemPossible causes/consequences andMSolutions
The seat ventilation has
switched off prema-
turely or cannot be
switched on.The on-board voltage is too low because too many electrical con-
sumers are switched on.
XSwitch off electrical consumers that you do not need, such as
the rear window defroster or interior lighting.
Once the battery is sufficiently charged, the seat ventilation can
be switched back on.
Steering wheel
Important safety notes
GWARNING
You could lose control of your vehicle if you do the following while driving:
Radjust the driver's seat, head restraint,
steering wheel or mirrors
Rfasten the seat belt
There is a risk of an accident.
Adjust the driver's seat, head restraint, steer-
ing wheel and mirror and fasten your seat belt before starting the engine.
GWARNING
Children could injure themselves if they
adjust the steering wheel. There is a risk of
injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children unsupervised in the vehicle.
The electrically adjustable steering wheel can
still be adjusted when there is no key in the
ignition lock.
Adjusting the steering wheel man-
ually
:Release lever
;To adjust the steering wheel height
=To adjust the steering wheel position
(fore-and-aft adjustment)
XPush release lever :down completely.
The steering column is unlocked.
XAdjust the steering wheel to the desired
position.
XPush release lever :up completely.
The steering column is locked.
XCheck if the steering column is locked.
When doing so, try to push the steering
wheel up or down or try to move it in the
fore-and-aft direction.
Steering wheel115
Seats, steering wheel and mirrors
Z

Problems with the windshield wipers
ProblemPossible causes/consequences andMSolutions
The windshield wipers
are jammed.Leaves or snow, for example, may be obstructing the windshield
wiper movement. The wiper motor has been deactivated.
XFor safety reasons, you should remove the SmartKey from the
ignition lock.
or
XSwitch off the engine using the Start/Stop button and open the driver's door.
XRemove the cause of the obstruction.
XSwitch the windshield wipers back on.
The windshield wipers
fail completely.The windshield wiper drive is malfunctioning.
XSelect another wiper speed on the combination switch.
XHave the windshield wipers checked at a qualified specialist
workshop.
The windshield washer
fluid from the spray
nozzles no longer hits
the center of the wind-
shield.The spray nozzles are misaligned.
XHave the spray nozzles adjusted at a qualified specialist work-
shop.
138Windshield wipers
Lights and windshield wipers

Problems with the engine
ProblemPossible causes/consequences andMSolutions
The engine does not
start. The starter motor
can be heard.RThere is a malfunction in the engine electronics.
RThere is a malfunction in the fuel supply.
Before attempting to start the engine again:
XTurn the SmartKey back to position 0in the ignition lock.
or
XPress the Start/Stop button repeatedly until all indicator lamps in the instrument cluster go out.
XTry to start the engine again (Ypage 155). Avoid excessively
long and frequent attempts to start the engine as these will drain
the battery.
If the engine does not start after several attempts:
XConsult a qualified specialist workshop.
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.
XJump-start the vehicle (Ypage 365).
If the engine does not start despite attempts to jump-start it:
XConsult a qualified specialist workshop.
The starter motor was exposed to a thermal load that was too high.
XTry to start the engine again (Ypage 155).
If the engine still does not start:
XConsult a qualified specialist workshop.
The engine is not run-
ning smoothly and is
misfiring.There is a malfunction in the engine electronics or in a mechanical
component of the engine management system.
XOnly depress the accelerator pedal slightly.
Otherwise, non-combusted fuel may get into the catalytic con-
verter and damage it.
XHave the cause rectified immediately at a qualified specialist
workshop.
The coolant tempera-
ture gauge shows a
value above 248 ‡
(120 †).The coolant level is too low. The coolant is too hot and the engine
is no longer being cooled sufficiently.
XStop as soon as possible and allow the engine and the coolant to
cool down.
XCheck the coolant level (Ypage 341). Observe the warning
notes as you do so and add coolant if necessary.
160Driving
Driving and parking

If the brakes have been subjected to a heavy
load, do not stop the vehicle immediately.
Drive on for a short while. This allows the air-
flow to cool the brakes more quickly.
Wet roads
If you have driven for a long time in heavy rain
without braking, there may be a delayed reac-
tion from the brakes when braking for the first
time. This may also occur after the vehicle has
been washed or driven through deep water.
You have to depress the brake pedal more
firmly. Maintain a greater distance from the
vehicle in front.
After driving on a wet road or having the vehi-
cle washed, brake firmly while paying atten-
tion to the traffic conditions. This will warm up
the brake discs, thereby drying them more
quickly and protecting them against corro-
sion.
Limited braking performance on salt-
treated roads
If you drive on salted roads, a layer of salt
residue may form on the brake discs and
brake pads. This can result in a significantly
longer braking distance.
RIn order to prevent any salt build-up, apply
the brakes occasionally while paying atten-
tion to the traffic conditions.
RCarefully depress the brake pedal and the
beginning and end of a journey.
RMaintain a greater distance to the vehicle
ahead.
Servicing the brakes
!The brake fluid level may be too low, if:
Rif the red brake warning lamp lights up inthe instrument cluster and
Ryou hear a warning tone while the engine
is running
Observe additional warning messages in
the multifunction display. The brake fluid level may be too low due to
brake pad wear or leaking brake lines.
Have the brake system checked immedi-
ately. Consult a qualified specialist work-
shop to arrange this.
!A function or performance test should
only be carried out on a 2-axle dynamom-
eter. If you wish to operate the vehicle on
such a dynamometer, please consult a
qualified specialist workshop in advance.
You could otherwise damage the drive train
or the brake system.
!The ESP®system operates automatically.
The engine and the ignition must therefore
be switched off (the SmartKey must be in
position 0or 1in the ignition lock or the
Start/Stop button must be in position 0or
1) if the electric parking brake is tested on
a brake dynamometer.
Braking triggered automatically by ESP
®
may cause severe damage to the brake
system.
All checks and maintenance work on the
brake system must be carried out at a quali-
fied specialist workshop.
Have brake pads installed and brake fluid
replaced at a qualified specialist workshop.
If the brake system has only been subject to
moderate loads, you should test the function-
ality of your brakes at regular intervals.
Information on BAS (Brake Assist) (
Ypage 68)
and BAS PLUS (Brake Assist PLUS)
(
Ypage 68).
For safety reasons, Mercedes-Benz recom-
mends only installing the following brake
disks and brake pads/linings:
Rbrake disks that have been approved by
Mercedes-Benz
Rbrake pads/linings that have been
approved by Mercedes-Benz or that are of
an equivalent standard of quality
Other brake disks or brake pads/linings can
compromise the safety of your vehicle.
Driving tips179
Driving and parking
Z

cleaned, remove the ball coupling. The trailer
tow hitch must then not be used to tow a
trailer, as safe operation cannot be guaran-
teed.
Have the entire trailer tow hitch checked at a
qualified specialist workshop.
Coupling up a trailer
!
Do not connect the trailer's brake system
(if featured) to the hydraulic brake system
of the towing vehicle, as the latter is equip-
ped with an anti-lock brake system. Doing
so will result in a loss of function of the
brake systems of both the vehicle and the
trailer.
XShift the transmission to position P.
XApply the vehicle's electric parking brake.
XStart the engine.
XVehicles with AIR BODY CONTROL:
selectComfort driving program or Trailer
off-road program.
XSwitch off the engine.
XClose the doors and tailgate.
XCouple up the trailer.
XEstablish the electrical connection
between the vehicle and the trailer.
XCheck that the trailer lighting system is
working.
XPush the combination switch upwards/
downwards and check whether the corre-
sponding turn signal on the trailer flashes.
A trailer that is connected is recognized only
when the electrical connection is established
correctly and when the lighting system is
working properly. The function of other sys-
tems also depends on this, for example:
RESP®
RPARKTRONIC
RActive Parking Assist
RActive Blind Spot Assist
RActive Lane Keeping Assist
iVehicles with AIR BODY CONTROL: if you
couple up a trailer, the vehicle always
remains at highway level. When coupling up
a trailer, please observe the following:
RUnless highway level has been set man-
ually, the vehicle is automatically low-
ered to highway level. This is the case if a
speed of 5 mph (8 km/h) is reached.
These restrictions apply to all accessories
powered through a connection to the trailer
power socket of your vehicle, e.g. a bicycle
carrier.
Observe the maximum permissible trailer
dimensions (width and length).
Most U.S. states and all Canadian provinces
require by law:
RSafety chains between the towing vehicle
and the trailer. The chains should be cross-
wound under the trailer drawbar. They must
be fastened to the vehicle's trailer cou-
pling, not to the bumper or the axle.
Leave enough play in the chains to make
tight cornering possible.
RA separate brake system for certain types
of trailer.
RSafety switch for braked trailers. Check the specific legal requirements applicable to
your state.
If the trailer becomes detached from the
towing vehicle, the safety switch applies
the trailer brakes.
Towing a trailer
There are numerous legal requirements con-
cerning the towing of a trailer, e.g. speed
restrictions. Make sure that your car/trailer
combination complies with the local regula-
tions:
Rin your place of residence
Rin the location to which you are driving
The police and local authorities can provide
reliable information.
232Towing a trailer
Driving and parking

Observe the following when towing a trailer:
RTo gain driving experience and to become
accustomed to the new handling charac-
teristics, you should practice the following
in a traffic-free location:
-cornering
-stopping
-backing up
RBefore driving, check:
-trailer tow hitch
-safety switch for braked trailers
-safety chains
-electrical connections
-lights
-wheels
RAdjust the exterior mirrors to provide an
unobstructed view of the rear section of the
trailer.
RIf the trailer has electronically controlled
brakes, pull away carefully. Brake manually
using the brake controller and check
whether the brakes function correctly.
RSecure any objects on the trailer to prevent
the cargo from slipping when the vehicle is
in motion.
RWhen you couple up a trailer, check at reg-
ular intervals that the load is firmly secured.
If the trailer is equipped with trailer lights
and brakes, check the trailer to ensure that
these are working.
RBear in mind that the handling will be less
stable when towing a trailer than when driv-
ing without one. Avoid sudden steering
movements.
RThe vehicle/trailer combination is heavier,
accelerates more slowly, has a decreased
gradient climbing capability and a longer
braking distance.
It is more susceptible to side winds and
requires more careful steering.
RIf possible, do not brake suddenly, but
instead depress the brake pedal moder-
ately at first so that the trailer can activate its brakes. Then increase the pressure on
the brake pedal.
RIf the automatic transmission repeatedly
shifts between gears on uphill or downhill
gradients, shift to a lower gear using the
left-hand steering wheel paddle shifter.
A lower gear and lower speed reduce the
risk of engine failure.
RWhen driving downhill, shift to a lower gear
to utilize the engine's braking effect.
Avoid continuous brake application as this
may overheat the vehicle brakes and, if
installed, the trailer brakes.
RIf the coolant temperature increases dra-
matically while the air-conditioning system is switched on, switch off the air-condition-
ing system.
Coolant heat can also be dissipated by
opening the windows and switching the
ventilation blower and the interior temper-
ature to the highest level.
RWhen overtaking, pay particular attention
to the extended length of your vehicle/
trailer combination.
Due to the length of the vehicle/trailer
combination, you require addi

tional road
space in relation to the vehicle you are
overtaking before you can change back to
the original lane.
Decoupling a trailer
GWARNING
If you uncouple a trailer with the overrun
brake engaged, you could trap your hand
between the vehicle and the trailer drawbar.
There is a risk of injury.
Do not uncouple a trailer if the overrun brake
is engaged.
!Do not disconnect a trailer with an
engaged overrun brake. Otherwise, your
vehicle could be damaged by the rebound-
ing of the overrun brake.
Towing a trailer233
Driving and parking
Z