check engine MERCEDES-BENZ M-Class 2014 W166 Owner's Guide

Problems with the engine
Problem Possible causes/consequences and
0001 Solutions
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 159). 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 389).
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 367). Observe the warning
notes as you do so and add coolant if necessary. 164
DrivingDriving and parking

Automatic transmission
Important safety notes
G
WARNING
If the engine speed is above the idling speed
and you engage transmission position Dor
R, the vehicle could pull away suddenly. There
is a risk of an accident.
When engaging transmission position Dor R,
always firmly depress the brake pedal and do
no tsimultaneously accelerate. 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 fro mrolling away by applying the
parking brake. DIRECT SELECTl
ever
Overview of transmission positions 0012
Park position with parking lock
000F Reverse gear
0010 Neutral
0011 Drive
The DIRECT SELECT lever is on the righ tofthe
steering column.
i The DIRECT SELECT lever always returns
to its original position. The current transmission position
P,R, Nor Dappears
in the transmission position display
(Y page 165) in the multifunction display.
Transmission position and drive
program display !
If the transmission position display in the
multifunction display is not working, you
should pull away carefully to check whether
the desired transmission position is
engaged. Ideally, you should select
transmission position Dand, in AMG
vehicles, drive program Cor S. Transmission position and drive program display
0002
Transmission position display
0003 Drive program display
The current transmission position and drive
program appearint he multifunction display.
i The arrows in the transmission position
display show how and into which
transmission positions you can change
using the DIRECT SELECT lever.
Engaging parkp osition P !
If the engine speed is to ohigh or the
vehicle is moving, do not shift the
automatic transmission directly from Dto
R, from Rto Dor directly to P.The
automatic transmission could otherwise be
damaged. Automatic transmission
165Driving and parking Z

Using the SmartKey:
R
Make sure that the ignition is switched on.
R When the vehicle is stationary, depress the
brake pedal and keep it depressed.
R Shift to neutral N.
R Release the brake pedal.
R If the electric parking brake is engaged,
release it.
R Switch off the ignition and leave the
SmartKey in the ignition lock.
Using KEYLESS-GO:
R Make sure that the ignition is switched on.
R When the vehicle is stationary, depress the
brake pedal and keep it depressed.
R Engage park position P.
R Release the brake pedal.
R Remove the Start/Stop button from the
ignition lock.
R Insert the SmartKey into the ignition lock.
R Switch on the ignition.
R Depress the brake pedal and keep it
depressed.
R Shift to neutral N.
R Release the brake pedal.
R If the electric parking brake is engaged,
release it.
R Switch off the ignition and leave the
SmartKey in the ignition lock.
Engaging drive position D X
When the vehicle is stationary, depress the
brake pedal.
X Push the DIRECT SELECT lever down past
the first point of resistance. Transmission positions
0004
Par
kposition
Do not shift the transmission into
position P(Ypage 179) unless the
vehicle is stationary. The parking
lock should not be used as a brake
when parking .Always apply the
electronic parking brake in
additio nto the parking lock in order
to secure the vehicle.
If the vehicle electronics are
malfunctioning, the transmission
may be locked in position P. Have
the vehicle electronics checked
immediately at a qualified
specialist workshop.
The automatic transmission shifts
to Pautomatically if you:
R remove the SmartKey
R switch off the engine when in R
or Dand open one of the front
doors 0006
Reverse gear
Only shift the transmission to
R
when the vehicle is stationary. Automatic transmission
167Driving and parking Z

Problems with the transmission
Problem Possible causes/consequences and
0001 Solutions
The transmission has
problems shifting gear. The transmission is losing oil.
X
Have the transmission checked at a qualified specialist
workshop immediately. The acceleration ability
is deteriorating.
The transmission no
longer changes gear. The transmission is in emergency mode.
It is only possible to shift into
secondgear and reverse gear.
X Stop the vehicle.
X Shift the transmission to position P.
X Switch off the engine.
X Wait at least ten seconds before restarting the engine.
X Shift the transmission to position Dor R.
If D is selected, the transmission shifts into secondgear; ifRis
selected, the transmission shifts into reverse gear.
X Have the transmission checked at a qualified specialist
workshop immediately. Transfer case
! Performance tests may only be carried
out on a 2-axle dynamometer. The brake
system or transfer case could otherwise be
damaged. Contact a qualified specialist
workshop for a performance test.
! 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.
! Vehicles with 4MATIC must not be towed
with either the front or the rear axle raised,
as doing so will damage the transmission.
This section is only valid for vehicles with 4-
wheel drive (4MATIC). Power is always
transmitted to both axles. Refueling
Important safety notes
G
WARNING
Fuel is highly flammable. If you handle fuel
incorrectly, there is a risk of fire and
explosion.
You must avoid fire, open flames, creating
sparks and smoking. Switch off the engine
and, if applicable, the auxiliary heating before
refueling. G
WARNING
Fuel is poisonous and hazardous to health.
There is a risk of injury.
You must make sure that fuel does not come
into contact with your skin, eyes or clothing
and that it is not swallowed. Do not inhale fuel
vapors. Keep fuel away from children. Refueling
173Driving and parking
Z

vehicle with the SmartKey or with KEYLESS-
GO.
The position of the fuel filler cap is displayed
0012 in the instrument cluster. The arrow
next to the filling pump indicates the side of
the vehicle.
Opening the fuel filler flap 0002
To open the fuel filler flap
0003 To insert the fuel filler cap
0023 Fuel type to be used
0022 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 0002.
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 0003.
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
Do not add any more fuel after the pump
stops filling for the first time. Otherwise,
fuel may leako ut.
Closing the fuel filler flap X
Replace the cap on the fille rneck 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 0012reserve fuel warning lamp
flashes.
In addition, the 0010Check Engine warning
lamp may light up (Y page 325).
Am essage appears in the multifunction
display (Y page 300).
For further information on warning and
indicator lamps in the instrument cluster,
see (Y page 325). Refueling
175Driving and parking Z

DEF (BlueTEC vehicles only)
Important notes on use To function properly, BlueTEC exhaus
tgas
aftertreatment must be operated with the
reducing agent DEF.
When the supply of DE Fis almost used up,
the Check Additive See Operator's Manual message is shown in the
multifunction display.
When the DEF supply drops to a minimum, the
Remaining Starts: 16 message is shown
in the multifunction display.
If the Remaining Starts: 16 message
appears in the multifunction display, you can
start the engine another 16 times. If DEF is
not refilled, you will subsequently be unable
to start the engine. Fill the DEF tank with
approximately 1gal (3. 8l) DEF. Have the DEF
tan krefilled at a qualified specialist
workshop.
i If you drive the vehicle faster than
10 mph (16 km/h), the Check Additive See Operator's Manual message goes
out after approximately one minute.
If the outside temperature is below 12 ‡
(001911 †) 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 you reyes,
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 mus tnot be
swallowed. Keep DEFa way fromchildren.
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
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 Refueling
177Driving and parking Z

Closing the DEF filler cap
X
Mount DEF filler cap 0003on the filler neck
and turn it clockwise.
X To close the fuel fille rflap, press it in the
direction of arrow 0002.
X Drive faster than 10 mph (16 km/h).
The Check Additive See Operator's Manual message goes out after
approximately one minute.
i If the Check Additive See Operator's Manual message continues
to be shown in the multifunction display,
you must add more DEF. Parking
Important safety notes
G
WARNING
If flammable materials such as leaves, grass
or twigs are exposed to prolonged contac tto
parts of the exhaust system that heat up, they
could ignite. 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 function sare only available
with limitations, or not at all.T his could affect,
for example, the power steering and the brake boosting effect.Y
ou 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 releasing the parking brake
R shifting the automatic transmission out of
the parking position P
R starting the engine.
They could also operate the vehicle's
equipment. 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.O therwise, the vehicle
or its drivetrai ncould be damaged.
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 on steep uphill or downhill gradients, turn
the front wheels towards the curb.
R on steep uphill or downhill gradients, the
front axle of an empty vehicle must be
secured, for example with awheel chock.
R on steep uphill or downhill gradients, the
rear axle of a laden vehicle must be
additionally secured, for example with a
wheel chock. Parking
179Driving and parking Z

R
Brake occasionally to remove any possible
salt residue. Make sure that you do not
endanger othe rroad 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 a2-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
electri cparking brake is being tested on a
brake dynamomete r(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 67) or of BAS PLUS on
(Y page 68).
Mercedes-Benz recommends that you only
have brake pads/linings installed on your
vehicle which have been approved for
Mercedes-Benz vehicles or which correspond
to an equivalent quality standard. Brake
pads/linings which have not been approved
for Mercedes-Benz vehicles or which are not
of an equivalent quality could affect your
vehicle's operating safety.
Mercedes-Benz recommends that you only
use brake fluid that has been specially
approved for your vehicle by Mercedes-Benz,
or which corresponds to an equivalent quality
standard. Brake fluid which has not been
approved for Mercedes-Benz vehicles or
which is not of an equivalent quality could
affect your vehicle's operating safety.
High-performance brake system for
AMG vehicles The high-performance brake system is
installed only on the ML 63 AMG.
The high-performance brake system is
designed for heavy loads. This may lead to
noise when braking. This will depend on:
R
Speed
R Braking force
R Environmental conditions, such as
temperature and humidity
The wear of individual components of the
brake system, such as the brake pads/linings
or brake discs, depends on the individual
driving style and operating conditions.
For this reason, it is impossible to state a
mileage that will be valid under all
circumstances. An aggressive driving style Driving tips
185Driving and parking Z

will lead to high wear. You can obtain further
informatio
nabout this from your authorized
Mercedes-Benz Center.
New and replaced brake pads and discs only
reach their optimum braking effect after
several hundred kilometers of driving.
Compensate for this by applying greater force
to the brake pedal. Keep this in mind, and
adapt your driving and braking accordingly
during this break-in period.
Excessive heavy braking results in
correspondingly high brake wear. Observe
the 0009 brake wear warning lamp in the
instrument cluster and note any brake status
messages in the multifunction display.
Especially for high performance driving, it is
important to maintain and have the brake
system checked regularly. Driving on wet roads
Hydroplaning If water has accumulated to a certain depth
on the road surface, there is a danger of
hydroplaning occurring, even if:
R
you drive at low speeds.
R the tires have adequate tread depth.
For this reason, in the event of heavy rain or
in conditions in which hydroplaning may
occur, you must drive in the following
manner:
R lower your speed.
R avoid ruts.
R brake carefully.
Driving on flooded roads !
Do not drive through flooded areas.
Check the depth of any water before driving
through it. Drive slowly through standing
water. Otherwise, water may enter the
vehicle interior or the engine compartment.
This can damage the electronic
components in the engin eorthe automatic
transmission. Water can also be drawn in by the engine's air suction nozzles and this
can cause engine damage.
i Vehicles with the AIRMATIC package:
set the raised level before driving through
standing water.
Off-road fording !
Under no circumstances should you
accelerate before entering the water. The
bow wave could cause water to enter and
damage the engine and other assemblies.
! Do not open any of the vehicle's doors
while fording. Otherwise, water could get
into the vehicle interior and damage the
vehicle's electronics and interior
equipment.
R Establish how deep the water is and the
characteristics of the body of water before
fording.
R Vehicles with the AIRMATIC package:
select the highest possible vehicle level.
R Shift to a lower gear using the left-hand
steering wheel paddle shifter.
R Avoid high engine speeds.
R Enter and exit the water at a flat place and
at a steady walking pace.
R Drive slowly and at an even speed through
the water.
R Do not stop.
R Water offers a high degree of resistance,
and the ground is slippery and in some
cases unstable. Therefore, it is difficult and
dangerous to pull away in the water.
R Ensure that a bow wave does not form as
you drive.
R Clean any mud from the tire tread after
fording.
R Apply the brakes to dry them after fording.
Always observe the fording depth values
(Y page 454). 186
Driving tipsDriving and parking

G
WARNING
If the vehicle level is high, the vehicle center
of gravity is raised. This could cause the
vehicle to tip over more easily on uphill or
downhill gradients. There is arisk of an
accident.
Selec tthe lowest possible vehicle level.
When driving off-road, sand, mud and water,
possibly mixed with oil, for example, could get
into the brakes. This could result in a reduced
braking effect or in total brake failure and also
in increased wear and tear. The braking
characteristics change depending on the
material ingressing the brakes. Cleant he
brakes after driving off-road. If you detect a
reduced braking effect or grinding noises,
have the brake system checked in a qualified
specialist workshop as soon as possible.
Adapt your driving style to the different
braking characteristics.
Driving off-road increases the likelihood of
damage to the vehicle, which, in turn, can lead
to failure of the mechanical assembly or
systems. Adapt your driving style to suit the
terrain conditions. Drive carefully. Have
damage to the vehicle rectified immediately
at a qualified specialist workshop.
Do not switch to transmission position N
when driving off-road. You could lose control
of the vehicle if you attempt to brake using
the service brake. If the gradient is too steep,
drive backwards in reverse gear.
General notes Read this section carefully before driving your
vehicle off-road. Practice by driving over more
gentle off-road terrain first.
Familiarize yourself with the characteristics
of your vehicle and the gear shift operation
before driving through difficult terrain. The following driving systems are specially
adapted to off-road driving:
R
Off-road ABS (Y page 67)
R AIRMATIC package (vehicle level)
(Y page 207)
R DSR (Downhill Speed Regulation)
(Y page 246)
Observe the following notes:
R Stop the vehicle before starting to drive
along an off-road route.
R For vehicles with the AIRMATIC
package: select a vehicle level that is
suitable for the off-road terrain. To avoid
damaging the vehicle, make sure there is
always sufficient ground clearance.
R Check that items of luggage and loads are
stowed safely and are well secured
(Y page 337).
R Always keep the engine running and in gear
when driving on a downhill gradient.
Activate DSR (Y page 246).
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. 188
Driving tipsDriving and parking