ignition MERCEDES-BENZ GL-Class 2014 X166 Repair Manual

If you or others come into contact with fuel,
observe the following:
R Wash away fuel from skin immediately
using soap and water.
R If fuel comes into contact with your eyes,
immediately rinse them thoroughly with
clean water. Seek medical assistance
without delay.
R If fuel is swallowed, seek medical
assistance without delay. Do not induce
vomiting.
R Immediately change out of clothing which
has come into contact with fuel. G
WARNING
Electrostatic buildup can create sparks and
ignite fuel vapors. There is a risk of fire and
explosion.
Always touch the vehicle body before opening
the fuel filler flap or touching the fuel pump
nozzle. Any existing electrostatic buildup is
thereby discharged. G
WARNING
Vehicles with a diesel engine:
If you mix diesel fuel with gasoline, the flash
point is lower than that of pure diesel fuel.
When the engine is running, exhaust system
components could overheat without being
noticed. There is a risk of fire.
Never refuel with gasoline. Never mix gasoline
with diesel fuel.
! Do not use gasoline to refuel vehicles with
a diesel engine. Do not use diesel to refuel
vehicles with a gasoline engine. Do not
switch on the ignition if you accidentally
refuel with the wrong fuel. Otherwise, the
fuel will enter the fuel system. Even small
amounts of the wrong fuel could result in
damage to the fuel system and the engine.
The repair costs are high. Notify a qualified
specialist workshop and have the fuel tank
and fuel lines drained completely. !
Do not use diesel to refuel vehicles with a
gasoline engine. Do not switch on the
ignition if you accidentally refuel with the
wrong fuel. Otherwise, the fuel will enter
the fuel system. Even small amounts of the
wrong fuel could result in damage to the
fuel system and the engine. Notify a
qualified specialist workshop and have the
fuel tank and fuel lines drained completely.
! Overfilling the fuel tank could damage the
fuel system.
! Take care not to spill any fuel on painted
surfaces. You could otherwise damage the
paintwork.
! Use a filter when refueling from a fuel can.
Otherwise, the fuel lines and/or injection
system could be blocked by particles from
the fuel can.
Do not get into the vehicle again during the
refueling process. Otherwise, electrostatic
charge could build up again.
If you overfill the fuel tank, fuel could spray
out when the fuel pump nozzle is removed.
For further information on fuel and fuel quality
(Y page 446).
You will find further information on fuel and
fuel quality in the printed Operator's Manual
under "Technical data". Refueling
General information Pay attention to the important safety notes
(Y
page 182).
The fuel filler flap is unlocked or locked
automatically when you open or close the
vehicle with the SmartKey or with KEYLESS-
GO.
The position of the fuel filler cap is displayed
8 in the instrument cluster. The arrow
next to the filling pump indicates the side of
the vehicle. Refueling
183Driving and parking Z

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

Problems with fuel and the fuel tank
This section provides descriptions of and solutions to safety-relevant problems. Problem Possible causes/consequences and
M
MSolutions Fuel is leaking from the
vehicle. The fuel line or the fuel tank is faulty.
G WARNING
Risk of explosion or fire.
X Turn the SmartKey to position 0in the ignition lock and remove
it immediately (Y page 167).
X Do not restart the engine under any circumstances.
X Consult a qualified specialist workshop. The engine does not
start. The fuel tank of a vehicle with a diesel engine has been run
completely dry.
X
Refuel the vehicle with at least 5.3 US qt (5 liters) of diesel.
X Turn the ignition on for approximately ten seconds
(Y page 167).
X Start the engine continuously for up to ten seconds until it runs
smoothly.
If the engine does not start:
X Turn the ignition on again for approximately ten seconds
(Y page 167).
X Start the engine again continuously for up to ten seconds until
it runs smoothly.
If the engine does not start after three attempts:
X Consult a qualified specialist workshop. The fuel filler flap
cannot be opened. The fuel filler flap is not unlocked.
or
The SmartKey battery is discharged.
X
Unlock the vehicle (Y page 80).
or
X Unlock the vehicle using the mechanical key (Y page 82).The fuel filler flap is unlocked, but the opening mechanism is
jammed.
X
Consult a qualified specialist workshop. Refueling
185Driving and parking Z

DEF (BlueTEC vehicles only)
Important notes on use To function properly, BlueTEC exhaust gas
aftertreatment must be operated with the
reducing agent DEF. Adding DEF is one of the
tasks performed during maintenance. Under
normal operating conditions, a tank of DEF
lasts until the next service due date.
When the supply of DEF is almost used up,
the Check Additive See Operator's
Check Additive See Operator's
Manual
Manual message is shown in the
multifunction display.
If you drive the vehicle faster than 10 mph
(16 km/h), the Check Additive See
Check Additive See
Operator's
Operator's Manual Manualmessage goes out after
approximately one minute.
When the supply of DEF is down to a reserve
of approximately 1 gal (3.8 l) the Refill Refill
AdBlue/DEF See Operator's Manual
AdBlue/DEF See Operator's Manual
message is shown in the multifunction
display.
When the DEF supply drops to a minimum, the
Remaining Starts: 16
Remaining Starts: 16 message is shown
in the multifunction display.
If the Refill AdBlue/DEF No Start in
Refill AdBlue/DEF No Start in
XXXX km
XXXX km message is shown in the
multifunction display, you can still drive the
vehicle over the distance shown. If DEF is not
refilled, you will subsequently be unable to
start the engine. If the Refill AdBlue/
Refill AdBlue/
DEF Eng. Start Not Poss
DEF Eng. Start Not Poss message
appears in the multifunction display and the
engine does not start, you must add DEF.
X Add at least 1 gal (3.8l) of DEF.
X Switch on the ignition for at least 60
seconds.
X Start the engine.
i Have the DEF tank refilled at a qualified
specialist workshop.
Use the special DEF refill bottle when adding
DEF between maintenance intervals. Contact
an authorized Mercedes-Benz Center with
any questions or, if necessary, contact
Roadside Assistance (Y page 25).If the outside temperature is below 12 ‡
(Ò11 †) it may be difficult to top up. If DEF is
frozen and there is an active warning
indicator, it may not be possible to add DEF.
Park the vehicle in a warmer place, e.g. in a
garage, until DEF has become fluid again. It
will then be possible to add DEF again.
Alternatively, have the DEF tank refilled at a
qualified specialist workshop.
Further information about BlueTEC exhaust
gas aftertreatment and DEF is available at any
authorized Mercedes-Benz Center.
Important safety notes on the refilling
procedure
DEF is a water-soluble fluid for the exhaust
gas aftertreatment of diesel engines. It is:
R not poisonous
R colorless and odorless
R not flammable
When you open the DEF container, small
amounts of ammonia vapor may be released.
Ammonia vapors have a pungent odor and are
particularly irritating to the skin, to mucous
membranes and to the eyes. You may
experience a burning sensation in your eyes,
nose and throat. Coughing and watering of
the eyes are possible.
Do not inhale ammonia vapors. Fill the DEF
tank only in well-ventilated areas.
DEF must not come into contact with your
skin, eyes or clothing and must not be
swallowed. Keep DEF away from children.
If you or other persons come into contact with
DEF, observe the following:
R Rinse DEF from your skin immediately with
soap and water.
R If DEF comes into contact with your eyes,
immediately rinse them thoroughly with
clean water. Seek medical assistance
without delay.
R If DEF has been swallowed, rinse your
mouth out immediately. Drink plenty of 186
RefuelingDriving and parking

water. Seek medical assistance without
delay.
R Change out of clothing contaminated with
DEF immediately.
! Only use DEF in accordance with
ISO 22241. Do not mix any additives with
DEF, and do not dilute DEF with water. This
may destroy the BlueTEC exhaust gas
aftertreatment system.
! The vehicle must be parked on level
ground to fill the DEF tank. The DEF tank
can only be filled as intended with the
vehicle parked on a level surface. This
avoids false level readings. Filling the tank
is not permitted if the vehicle is not parked
on a level surface. There is a danger of
overfilling, which could result in damage to
components of the BlueTEC exhaust gas
aftertreatment.
! Rinse surfaces that have come into
contact with DEF immediately with water or
remove DEF using a damp cloth and cold
water. If the DEF has already crystallized,
use a sponge and cold water to clean it. DEF
residues crystallize after time and
contaminate the affected surfaces.
! DEF is not a fuel additive and must not be
added to the fuel tank. If DEF is added to
the fuel tank, this can lead to engine
damage.
For further information on DEF, see
(Y page 448).
You will find further information on DEF in the
printed Operator's Manual under "Technical
data". Opening the DEF filler cap The fuel filler flap is unlocked or locked
automatically when you open or close the
vehicle with the SmartKey or with KEYLESS-
GO.
X
Switch the ignition off.
X Press the fuel filler flap in the direction of
arrow :.
The fuel filler flap swings up.
X Turn blue DEF filler cap ;counter-
clockwise and remove it.
DEF filler cap ;is secured with a plastic
strip.
DEF refill bottle !
Only screw on the DEF refill bottle hand-
tight. It could otherwise be damaged. X
Unscrew the protective cap from DEF refill
bottle :.
X Place DEF refill bottle :on the filler neck
as shown and screw it on clockwise until
hand-tight. Refueling
187Driving and parking Z

X
Press DEF refill bottle :towards the filler
neck.
The DEF tank is filled. This may take up to
one minute.
i When DEF refill bottle :is no longer
pressed, filling stops and the bottle may be
taken off again after being only partially
emptied.
X Release DEF refill bottle :.
X Turn DEF refill bottle :counter-clockwise
and remove it.
X Screw the protective cap onto DEF refill
bottle :again.
DEF refill bottles can be obtained at many gas
stations or at an authorized Mercedes-Benz
Center. Refill bottles without a threaded cap
do not provide overfill protection. DEF may
leak if overfilled. Mercedes Benz offers
special refill bottles with a threaded seal.
These are available at any authorized
Mercedes-Benz Center.
Closing the DEF filler cap X
Mount DEF filler cap ;on the filler neck
and turn it clockwise.
X To close the fuel filler flap, press it in the
direction of arrow :.
X Drive faster than 10 mph (16 km/h).
The Check Additive See Operator's
Check Additive See Operator's
Manual
Manual message goes out after
approximately one minute.
i If the Check Additive See Check Additive See
Operator's Manual
Operator's Manual message continues to be shown in the multifunction display,
you must add more DEF. Parking
Important safety notes
G
WARNING
Flammable material such as leaves, grass or
twigs may ignite if they come into contact with
hot parts of the exhaust system or exhaust
gas flow. There is a risk of fire.
Park the vehicle so that no flammable
materials come into contact with parts of the
vehicle which are hot. Take particular care not
to park on dry grassland or harvested grain
fields. G
WARNING
If you switch off the ignition while driving,
safety-relevant functions are only available
with limitations, or not at all. This could affect,
for example, the power steering and the brake
boosting effect. You will require considerably
more effort to steer and brake. There is a risk
of an accident.
Do not switch off the ignition while driving. G
WARNING
If you leave children unsupervised in the
vehicle, they could set it in motion by, for
example:
R release the parking brake.
R shift the automatic transmission out of the
parking position P.
R start the engine.
In addition, they may operate vehicle
equipment and become trapped. 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 unsupervised in the vehicle.
! Always secure the vehicle correctly
against rolling away. Otherwise, the vehicle
or its drivetrain could be damaged. 188
ParkingDriving and parking

To ensure that the vehicle is secured against
rolling away unintentionally:
R the electric parking brake must be applied.
R the transmission must be in position Pand
the SmartKey must be removed from the
ignition lock.
R the front wheels must be turned towards
the curb on steep uphill or downhill
gradients.
R the empty vehicle must be secured at the
front axle with a wheel chock or similar, for
example, on uphill or downhill gradients.
R a laden vehicle must also be secured at the
rear axle with a wheel chock or similar, for
example, on uphill or downhill gradients. Switching off the engine
Important safety notes G
WARNING
The automatic transmission switches to
neutral position Nwhen you switch off the
engine. The vehicle may roll away. There is a
risk of an accident.
After switching off the engine, always switch
to parking position P. Prevent the parked
vehicle from rolling away by applying the
parking brake.
Using the SmartKey X
Apply the electric parking brake.
X Shift the transmission to position P.
X Turn the SmartKey to position 0in the
ignition lock and remove it.
The immobilizer is activated.
i If you turn off the engine with the
SmartKey and then remove it from the
ignition lock or open a front door, the
automatic transmission shifts to P
automatically.
If you shift the automatic transmission to
N before switching off the engine, the automatic transmission remains in
Neven
if a door is opened.
Using KEYLESS-GO X
Apply the electric parking brake.
X Shift the transmission to position P.
X Press the Start/Stop button (Y page 167).
The engine stops and all the indicator
lamps in the instrument cluster go out.
i If you turn off the engine with the Start/
Stop button, the automatic transmission
shifts to N. If you then open one of the front
doors, the automatic transmission shifts to
P.
i In the event of an emergency, the engine
can be turned off while the vehicle is in
motion by pressing and holding the Start/
Stop button for three seconds. Electric parking brake
General notes G
WARNING
If you leave children unsupervised in the
vehicle, they could set it in motion by, for
example:
R release the parking brake.
R shift the automatic transmission out of the
parking position P.
R start the engine.
In addition, they may operate vehicle
equipment and become trapped. 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 unsupervised in the vehicle. Parking
189Driving and parking Z

The function of the electric parking brake is
dependent on the on-board voltage. If the on-
board voltage is low or there is a malfunction
in the system, it may not be possible to apply
the released parking brake.
X If this is the case, only park the vehicle on
level ground and secure it to prevent it
rolling away.
X Shift the automatic transmission to
position P.
It may not be possible to release an applied
parking brake, if the on-board voltage is low
or there is a malfunction in the system.
Contact a qualified specialist workshop.
i The electric parking brake performs a
function test at regular intervals while the
engine is switched off. The sounds that can
be heard while this is occurring are normal.
Applying/releasing manually X
To engage: push handle :.
When the electric parking brake is
engaged, the F(USA only) or !
(Canada only) red indicator lamp lights up
in the instrument cluster.
i The electric parking brake can also be
applied when the SmartKey is removed.
X To release: pull handle:.
The red F(USA only) or !(Canada
only) indicator lamp in the instrument
cluster goes out.
i The electric parking brake can only be
released: R
if the SmartKey is in position 1in the
ignition lock or
R if the ignition was switched on using the
Start/Stop button.
To ensure that you do not roll backwards
when pulling away on an uphill slope, engage
the electric parking brake (Y page 170).
Applying automatically The electric parking brake is applied
automatically:
R
if DISTRONIC PLUS brings the vehicle to a
standstill or
R if the HOLD function is keeping the vehicle
stationary
In addition, at least one of the following
conditions must be fulfilled:
R the engine is switched off.
R the driver's door is open and the seat belt
is not fastened.
R the vehicle is stationary for a lengthy
period.
The red F(USA only) or !(Canada
only) indicator lamp in the instrument cluster
lights up.
Releasing automatically The electric parking brake is released
automatically when all of the following
conditions are fulfilled:
R
the engine is running.
R the transmission is in position Dor R.
R the seat belt has been fastened.
R you depress the accelerator pedal.
If the transmission is in position R, the trunk
lid must be closed.
If your seat belt is not fastened, the following
conditions must be fulfilled to automatically
release the electric parking brake:
R the driver's door is closed.
R you have shifted out of transmission
position Por you have previously driven
faster than 2 mph (3 km/h). 190
ParkingDriving and parking

i
Ensure that you do not depress the
accelerator pedal unintentionally.
Otherwise the parking brake will be
released and the vehicle will start to move.
Emergency braking X
While driving, push handle :of the electric
parking brake.
The vehicle can also be braked during an
emergency by using the electric parking
brake.
i The vehicle is braked for as long as the
handle of the electric parking brake is
pressed. The longer the electric parking
brake handle is depressed, the greater the
braking force.
During braking:
R a warning tone sounds
R the Release Parking Brake
Release Parking Brake message
appears
R the red F(USA only) or !(Canada
only) indicator lamp in the instrument
cluster flashes
When the vehicle has been braked to a
standstill, the electric parking brake is
engaged. Parking the vehicle for a long period
If you leave the vehicle parked for longer than
four weeks, the battery may be damaged by
exhaustive discharging. X
Connecting a trickle charger.
i You can obtain information about trickle
chargers from a qualified specialist
workshop.
If you leave the vehicle parked for longer than
six weeks, the vehicle may suffer damage as
a result of lack of use.
X Visit a qualified specialist workshop and
seek advice. Driving tips
General notes
Important safety notes G
WARNING
If you switch off the ignition while driving,
safety-relevant functions are only available
with limitations, or not at all. This could affect,
for example, the power steering and the brake
boosting effect. You will require considerably
more effort to steer and brake. There is a risk
of an accident.
Do not switch off the ignition while driving. G
WARNING
If you operate mobile communication
equipment while driving, you will be
distracted from traffic conditions. You could
also lose control of the vehicle. There is a risk
of an accident.
Only operate this equipment when the vehicle
is stationary.
Observe the legal requirements for the
country in which you are driving. Some
jurisdictions prohibit the driver from using a
mobile phone while driving a vehicle.
If you make a call while driving, always use
hands-free mode. Only operate the telephone
when the traffic situation permits. If you are
unsure, pull over to a safe location and stop
before operating the telephone.
Bear in mind that at a speed of only 30 mph
(approximately 50 km/h) the vehicle covers Driving
tips
191Driving an d parking Z

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