check engine light MERCEDES-BENZ GL-Class 2014 X166 User Guide

Problems with the seat ventilation
Problem Possible causes/consequences and
M
MSolutions The seat ventilation has
switched off
prematurely or cannot
be switched on. The on-board voltage is too low because too many electrical
consumers are switched on.
X
Switch 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 will
switch back on automatically. Steering wheel
Important safety notes
G
WARNING
You could lose control of your vehicle if you
do the following while driving:
R adjust the driver's seat, head restraint,
steering wheel or mirrors
R fasten the seat belt
There is a risk of an accident.
Adjust the driver's seat, head restraint,
steering wheel and mirror and fasten your
seat belt before starting the engine. G
WARNING
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. Adjusting the steering wheel
manually
G
WARNING
If the steering wheel is unlocked while the
vehicle is in motion, it could change position
unexpectedly. This could cause you to lose
control of the vehicle. There is a risk of an
accident. Before starting off, make sure the steering
wheel is locked. Never unlock the steering
wheel while the vehicle is in motion.
:
Release lever
; To adjust the steering wheel height
= To adjust the steering wheel position
(fore-and-aft adjustment)
X Push release lever :down completely.
The steering column is unlocked.
X Adjust the steering wheel to the desired
position.
X Push release lever :up completely.
The steering column is locked.
X Check 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 wheel
119Seats, steering wheel and mirrors Z

A
p To switch the right-hand front
reading lamp on/off
B To switch the automatic interior lighting
control on
X To switch the front interior lighting on:
set the switch to the cposition.
X To switch the interior lighting off: set the
switch to the |position or (if the door
is closed) to the center position.
X To switch the rear interior lighting on/
off: press the ubutton.
X To switch the reading lamps on/off:
press the pbutton. Crash-responsive emergency lighting
The interior lighting is activated automatically
if the vehicle is involved in an accident.
X To switch off the crash-responsive
emergency lighting: press the hazard
warning lamp button.
or
X Lock and then unlock the vehicle using the
SmartKey. Replacing bulbs
Important safety notes
G
DANGER
Xenon bulbs carry a high voltage. You can get
an electric shock if you remove the cover of
the Xenon bulb and touch the electrical
contacts. There is a risk of fatal injury.
Never touch the parts or the electrical
contacts of the Xenon bulb. Always have work
on the Xenon bulbs carried out at a qualified
specialist workshop.
If your vehicle is equipped with Xenon bulbs,
you can recognize this by the following: the
cone of light from the Xenon bulbs moves
from the top to the bottom and back again
when you start the engine. For this to be observed, the lights must be switched on
before starting the engine. G
WARNING
Bulbs, lamps and connectors can get very hot
when operating. If you change a bulb, you
could burn yourself on these components.
There is a risk of injury.
Allow these components to cool down before
changing a bulb.
Do not use a bulb that has been dropped or if
its glass tube has been scratched.
The bulb may explode if:
R you touch it
R it is hot
R you drop it
R you scratch it
Only operate bulbs in enclosed lamps
designed for that purpose. Only install spare
bulbs of the same type and the specified
voltage.
Marks on the glass tube reduce the service
life of the bulbs. Do not touch the glass tube
with your bare hands. If necessary, clean the
glass tube when cold with alcohol or spirit and
rub it off with a lint-free cloth.
Protect bulbs from moisture during
operation. Do not allow bulbs to come into
contact with liquids.
There are bulbs other than the Xenon bulbs
that you cannot replace. Replace only the
bulbs listed (Y page 138). Have the bulbs that
you cannot replace yourself changed at a
qualified specialist workshop.
If you require assistance changing bulbs,
consult a qualified specialist workshop.
If the new bulb still does not light up, consult
a qualified specialist workshop.
Bulbs and lamps are an important aspect of
vehicle safety. You must therefore make sure
that these function correctly at all times.
Have the headlamp setting checked regularly. Replacing bulbs
137Lights and windshield wipers Z

Problems with the windshield wipers
Problem Possible causes/consequences and
M
MSolutions The windshield wipers
are jammed. Leaves or snow, for example, may be obstructing the windshield
wiper movement. The wiper motor has been deactivated.
X
For safety reasons, you should remove the SmartKey from the
ignition lock.
or
X Switch off the engine using the Start/Stop button and open the
driver's door.
X Remove the cause of the obstruction.
X Switch the windshield wipers back on. The windshield wipers
fail completely. The windshield wiper drive is malfunctioning.
X
Select another wiper speed on the combination switch.
X Have the windshield wipers checked at a qualified specialist
workshop. Windshield wipers
143Lights and windshield wipers Z

Start/Stop button
=
USA only
? Canada only Starting the engine
Important safety notes G
WARNING
If children are left unsupervised in the vehicle,
they could:
R open the doors, thus endangering other
people or road users.
R get out and disrupt traffic.
R operate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they:
R release the parking brake.
R shifting the automatic transmission out of
park position P
R Start the engine.
There is a risk of an accident and injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children or animals unattended in the
vehicle. Always keep the SmartKey out of
reach of children. G
WARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Inhaling
these exhaust gases leads to poisoning. There
is a risk of fatal injury. Therefore never leave the engine running in enclosed spaces
without sufficient ventilation.
G
WARNING
Flammable materials introduced through
environmental influence or by animals can
ignite if in contact with the exhaust system or
parts of the engine that heat up. There is a risk
of fire.
Carry out regular checks to make sure that
there are no flammable foreign materials in
the engine compartment or in the exhaust
system.
i Vehicles with a gasoline engine: the
catalytic converter is preheated for up
30 seconds after a cold start. The sound of
the engine may change during this time.
Automatic transmission X
Shift the transmission to position P
(Y page 173).
The transmission position display in the
multifunction display shows P
(Y page 173).
i You can also start the engine when the
transmission is in position N.
Starting procedure with the SmartKey X
To start a gasoline engine: turn the
SmartKey to position 3in the ignition lock
(Y page 167) and release it as soon as the
engine is running.
X To start a diesel engine: turn the
SmartKey to position 2in the ignition lock
(Y page 167).
The % preglow indicator lamp in the
instrument cluster lights up.
X When the %preglow indicator lamp
goes out, turn the SmartKey to position 3
(Y page 167) and release it as soon as the
engine is running.
i You can start the engine without preglow
if the engine is warm. Driving
169Driving and parking Z

Problems with the engine
Problem Possible causes/consequences and
M
MSolutions The engine does not
start. The starter motor
can be heard. R
There is a malfunction in the engine electronics.
R There is a malfunction in the fuel supply.
X Try to start the engine again (Y page 169). 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:
X Consult 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.
X
Jump-start the vehicle (Y page 395).
If the engine does not start despite attempts to jump-start it:
X Consult a qualified specialist workshop. The starter motor was exposed to a thermal load that was too high.
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. The engine is not
running smoothly and
is misfiring. There is a malfunction in the engine electronics or in a mechanical
component of the engine management system.
X
Only depress the accelerator pedal slightly.
X Have the cause rectified immediately at a qualified specialist
workshop.
Otherwise, non-combusted fuel may get into the catalytic
converter and damage it. The coolant
temperature 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.
X Stop as soon as possible and allow the engine and the coolant
to cool down.
X Check the coolant level (Y page 373). Observe the warning
notes as you do so and add coolant if necessary. 172
DrivingDriving and parking

Opening the fuel filler flap
:
To open the fuel filler flap
; To insert the fuel filler cap
= Fuel type to be used
? Tire pressure table
X Switch the engine off.
X Remove the SmartKey from the ignition
lock.
X KEYLESS-GO: open the driver’s door.
This corresponds to key position 0: "key
removed".
The driver’s door can be closed again.
X Press the fuel filler flap in the direction of
arrow :.
The fuel filler flap swings up.
X Turn the fuel filler flap counter-clockwise
and remove it.
X Insert the fuel filler cap into the holder
bracket on the inside of filler flap ;.
X Completely insert the filler neck of the fuel
pump nozzle into the tank, hook in place
and refuel.
X Only fill the tank until the pump nozzle
switches off.
i Vehicles with a diesel engine: the filler
neck is designed for refueling at diesel
filling pumps.
i Do not add any more fuel after the pump
stops filling for the first time. Otherwise,
fuel may leak out. Closing the fuel filler flap X
Replace the cap on the filler neck and turn
clockwise until it engages audibly.
X Close the fuel filler flap.
i Close the fuel filler flap before locking the
vehicle.
i If you are driving with the fuel filler cap
open, the 8reserve fuel warning lamp
flashes.
In addition, the ;Check Engine warning
lamp may light up (Y page 333).
A message appears in the multifunction
display ( Ypage 308).
For further information on warning and
indicator lamps in the instrument cluster,
see (Y page 333). 184
RefuelingDriving and parking

increases the stopping distance and can even
cause the braking system to fail. There is a
risk of an accident.
Never use the brake pedal as a footrest. Never
depress the brake pedal and the accelerator
pedal at the same time.
! Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
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
airflow 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
reaction 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 then 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
vehicle washed, brake firmly while paying
attention to the traffic conditions. This will
warm up the brake discs, thereby drying them
more quickly and protecting them against
corrosion.
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.
R Brake occasionally to remove any possible
salt residue. Make sure that you do not
endanger other road users when doing so.
R Carefully depress the brake pedal and the
beginning and end of a journey.
R Maintain a greater distance to the vehicle
ahead. Servicing the brakes !
If the red brake warning lamp lights up in
the instrument cluster and you hear a
warning tone while the engine is running,
the brake fluid level may be too low.
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
immediately. This work should be carried
out at a qualified specialist workshop.
! A function or performance test should
only be carried out on a 2-axle
dynamometer. If you are planning to have
the vehicle tested on such a dynamometer,
contact an authorized Mercedes-Benz
Center to obtain further information first.
Otherwise, you could damage the drive
train or the brake system.
! Because ESP ®
is an automatic system,
the engine and ignition must be switched
off (SmartKey in position 0or 1or Start/
Stop button in position 0or 1) when the
electric parking brake is being tested on a
brake dynamometer (maximum
10 seconds).
Braking triggered automatically by ESP ®
may seriously damage the brake system.
All checks and maintenance work on the
brake system must be carried out at a
qualified specialist workshop. Consult a
qualified specialist workshop to arrange this.
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
functionality of your brakes at regular
intervals. To do so, press firmly on the brake
pedal when driving at a high speed. This
improves the grip of the brake pads.
You can find a description of Brake Assist
(BAS) on (Y page 68) or of BAS PLUS on
(Y page 68). 194
Driving tipsDriving and parking

R
Always keep the engine running and in gear
when driving on a downhill gradient.
Activate DSR (Y page 256).
R Always keep the doors, tailgate, windows
and sliding sunroof closed while driving.
R Adapt your speed to the terrain. The
rougher, steeper or more ruts on the
terrain, the slower your speed should be.
R Drive slowly and at an even speed through
the water. Ensure that a bow wave does not
form as you drive.
R Drive with extreme care on unfamiliar off-
road routes where visibility is poor. For
safety reasons, get out of the vehicle first
and survey the off-road route.
R Look out for obstacles, such as rocks,
holes, tree stumps and furrows.
R Check the depth of water before fording
rivers and streams.
R When fording, do not stop and do not
switch off the engine.
R On sand, drive quickly to overcome the
rolling resistance. Otherwise the vehicle's
wheels could become stuck in loose
ground.
R Do not jump with the vehicle as this will
interrupt the vehicle's propulsion.
R Always keep the engine running and in gear
when driving on a slope.
R Do not shift the automatic transmission to
transmission position N.
i 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 surfaces.
Checklist before driving off-road !
If the engine oil warning lamp lights up
while the vehicle is in motion, stop the
vehicle in a safe place as soon as possible.
Check the engine oil level. The engine oil
warning lamp warning must not be ignored.
Continuing the journey while the symbol is
displayed could lead to engine damage. X
Engine oil level: check the engine oil level
and add oil if necessary.
When driving on steep gradients, the
engine oil level must be sufficiently high to
ensure a correct oil supply in the vehicle.
X DEF tank (BlueTEC vehicles): check the
level and top up if necessary (Y page 186).
X Tire-changing tool kit: check that the jack
is working and make sure you have the lug
wrench, a robust tow cable and a folding
spade in the vehicle.
X Wheels and tires: check the tire tread
depth and tire pressure.
X Check for damage and remove any foreign
objects, e.g. small stones, from the
wheels/tires.
X Replace any missing valve caps.
X Replace dented or damaged wheels.
X Rims: dented or bent rims can result in a
loss of tire pressure and damage the tire
bead. Therefore, check your rims before
driving off-road and replace them as
required.
Checklist after driving off-road !
If you detect damage to the vehicle after
driving off-road, have the vehicle checked
immediately at a qualified specialist
workshop.
X Vehicles with the ON&OFFROAD
package: activate the on-road program
(Y page 258).
X Deactivate the LOW RANGE off-road gear
(Y page 259).
X Deactivate DSR ( Ypage 256).
X Vehicles with the AIRMATIC package:
lower the vehicle to a ride height suitable
for the road conditions, e.g. to the
highway/high-speed level.
X Clean the headlamps and rear lights and
check for damage.
X Clean the front and rear license plates.
X Clean the wheels/tires with a water jet and
remove any foreign objects. 198
Driving tipsDriving an
d parking

Observe the following rules when driving over
tree stumps, large stones and other
obstacles:
R Select the LOW RANGE (Y page 259) off-
road gear.
R Raise the vehicle level.
R Avoid high engine speeds.
R Shift to a lower gear using the left-hand
steering wheel paddle shifter.
R Drive very slowly.
R Drive straight over the center of obstacles. Traveling uphill
Approach/departure angle G
WARNING
If you drive on a steep incline at an angle or
turn when driving on an incline, the vehicle
could slip sideways, tip and rollover. There is
a risk of an accident.
Always drive on a steep incline in the line of
fall (straight up or down) and do not turn the
vehicle.
R Observe the rules on off-road driving.
R Do not drive at an angle on slopes, inclines
or gradients, but instead follow the direct
line of fall. The maximum gradient-climbing
capability of your vehicle is 100%, which
corresponds to an approach/departure
angle of 45°. Note that the climbing ability
of your vehicle depends on the terrain
conditions. R
When driving down an incline, make use of
the engine's braking effect. Observe the
engine speed; do not overrev the engine.
R Before driving on extreme uphill and
downhill gradients, select the LOW RANGE
off-road gear (Y page 259).
R Drive slowly.
R Avoid high engine speeds. Drive at
appropriate engine speeds (maximum
3,000 rpm).
R Use the left-hand paddle shifter to shift into
a lower gear in good time on long and steep
downhill gradients.
R Check the brakes after prolonged off-road
driving.
i Hill start assist will aid you when pulling
away on a hill.
For further information about hill start
assist, see (Y page 171).
Do not switch to transmission position N
when driving off-road. If you try to brake the
vehicle using the service brake, you could
lose control of the vehicle. If the gradient is
too steep for your vehicle, drive back down in
reverse gear.
Always observe the approach/departure
angle values (Y page 455).
Maximum gradient-climbing capability Always observe the maximum gradient
climbing ability values (Y
page 455).
Hilltops When driving up an uphill gradient, slightly
reduce pressure on the accelerator
immediately before reaching the brow of the
hill. Use the vehicle's own impetus to drive
over the top of the hill.
This style of driving prevents:
R the vehicle from lifting off the ground on the
brow of a hill
R the vehicle from traveling too quickly down
the other side 200
Driving tipsDriving and parking

corresponding side lights up red. This warning
is always emitted 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 7 mph (12 km/h).
The yellow indicator lamp goes out if reverse
gear is engaged. In this event, Blind Spot
Assist is no longer active.
The brightness of the indicator/warning
lamps is adjusted automatically according to
the ambient light.
Collision warning
If a vehicle is detected in the monitoring range
of Blind Spot Assist and you switch on the
corresponding turn signal, a double warning
tone sounds. Red warning lamp :flashes. If
the turn signal remains on, vehicles detected
are indicated by the flashing of red warning
lamp :. There are no further warning tones.
Switching on Blind Spot Assist X
Make sure that the radar sensor system
(Y page 285) and Blind Spot Assist
(Y page 281) are activated in the on-board
computer.
X Turn the SmartKey to position 2in the
ignition lock.
Warning lamps :in the exterior mirrors
light up red for approximately
1.5 seconds and then turn yellow. Towing a trailer
When you attach a trailer, make sure you have
correctly established the electrical
connection. This can be accomplished by
checking the trailer lighting. In this event,
Blind Spot Assist is deactivated. The indicator
lamp in the exterior mirrors lights up yellow,
and the Blind Spot Assist Currently
Blind Spot Assist Currently
Unavailable See Operator's Manual Unavailable See Operator's Manual
message appears in the multifunction
display.
i You can deactivate the indicator lamps in
the exterior mirrors.
To do so, switch off Blind Spot Assist when:
R the SmartKey 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 camera
Lane Keeping Assist monitors the area in
front of your vehicle by means of a
camera :at the top of the windshield. Lane
Keeping Assist detects lane markings on the
road and warns you before you leave your
lane unintentionally.
If you select km kmon the on-board computer in
the Display Unit Speed-/Odometer
Display Unit Speed-/Odometer
function ( Ypage 282), Lane Keeping Assist
is active starting at a speed of 60 km/h. If the Driving systems
245Driving and parking Z