2015 MERCEDES-BENZ M-Class check engine

Problem
Possible causes/consequences and
0050
0050Solutions 00AC
The red coolant warn-
ing lamp comes on
while the engine is run-
ning.
The coolant level is too low.
! Avoid making long journeys with too little coolant in the engine
cooling system. The engine will otherwise be damaged.
If the coolant level is correct, the airflow to the engine radiator may be blocked or the electric engine radiator fan may be malfunc-
tioning.
The coolant is too hot and the engine is no longer being cooled
sufficiently.
X Observe the additional display messages in the multifunction
display.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 182).
X Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and add coolant, observing the warning
notes (Y page 369).
X If you need to add coolant more often than usual, have the
engine coolant system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
X Do not start the engine again until the coolant temperature is
below 248 ‡(120 †). Otherwise, the engine could be damaged.
X Drive to the nearest qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. driving in moun-
tainous terrain, and stop-and-go traffic. 00AC
The red coolant warn-
ing lamp comes on
while the engine is run-
ning. A warning tone
also sounds.
The coolant temperature has exceeded 248 ‡ (120 †). The air-
flow 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.
Do not drive when your engine is overheated. This can cause some
fluids which may have leaked into the engine compartment to
catch fire.
Steam from the overheated engine can also cause serious burns
which can occur just by opening the hood.
There is a risk of injury. Warning and indicator lamps in the instrument cluster
329On-board computer and displays Z

Problem
Possible causes/consequences and
0050
0050Solutions X
Observe the additional display messages in the multifunction
display.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 182).
X Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and add coolant, observing the warning
notes (Y page 369).
X If you need to add coolant more often than usual, have the
engine coolant system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
X At coolant temperatures below 248 ‡ (120 †), drive to the
nearest qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. driving in moun-
tainous terrain, and stop-and-go traffic. Driving systems
Problem
Possible causes/consequences and
0050 0050Solutions 00BA
The red distance warn-
ing function warning
lamp comes on while
the vehicle is moving. A
warning tone also
sounds. You are approaching a vehicle or a stationary obstacle in your line
of travel at too high a speed.
X Be prepared to brake immediately.
X Pay careful attention to the traffic situation. You may have to
brake or take evasive action.
Further information on DISTRONIC PLUS (Y page 198).
Further information on PRE‑ SAFE®
Brake (Y page 75).
Further information on the distance warning function (Y page 70).330
Warning and indicator lamps in the instrument clusterOn-board computer and displays

!
Make sure that the windshield wipers are
not folded away from the windshield. You
could otherwise damage the windshield
wipers or the hood. X
Make sure that the windshield wipers are
turned off.
X Pull release lever 0043on the hood.
The hood is released. X
Reach into the gap, pull hood catch han-
dle 0044up and lift the hood.
If you lift the hood by approximately 15 in
(40 cm), the hood is opened and held open automatically by the gas-filled strut.
Closing the hood X
Lower the hood and let it fall from a height
of approximately 8 in (20 cm).
X Check that the hood has engaged properly.
If the hood can be raised slightly, it is not
properly engaged. Open it again and close
it with a little more force. Radiator
Vehicles with a diesel engine: do not cover
the radiator, for example with a winter front or bug cover. The readings of the on-board-diag-
nostic system may otherwise be inaccurate.
Some of these readings are required by law
and must be accurate at all times. Engine oil
General notes Depending on your driving style, the vehicle
consumes up to 0.9 US qt (0.8 liters) of oil per
600 miles (1,000 km). The oil consumption
may be higher than this when the vehicle is
new or if you frequently drive at high engine
speeds.
Depending on the engine, the oil dipstick may be in a different location.
When checking the oil level:
R park the vehicle on a level surface.
R the engine should be switched off for
approximately five minutes if the engine is
at normal operating temperature.
R if the engine is not at normal operating
temperature, e.g. if the engine was only
started briefly, wait about 30 minutes
before carrying out the measurement.
Checking the oil level using the oil dip-
stick G
WARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and touch only the components described in the
following. Engine compartment
367Maintenance and care Z

Example: engine oil cap
X Turn cap 0043counter-clockwise and remove
it.
X Add engine oil.
If the oil level is at or below the MIN mark on
the oil dipstick, add 1.1 US qt (1.0 l)of
engine oil.
X Replace cap 0043on the filler neck and turn
clockwise.
Ensure that the cap locks into place
securely.
X Check the oil level again with the oil dip-
stick (Y page 367).
Further information on engine oil
(Y page 452). Additional service products
Checking coolant level G
WARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and touch only the components described in the
following. G
WARNING
The engine cooling system is pressurized, par- ticularly when the engine is warm. When
opening the cap, you could be scalded by hotcoolant spraying out. There is a risk of injury. Let the engine cool down before opening the
cap. Wear eye and hand protection when
opening the cap. Open the cap slowly half a
turn to allow pressure to escape.
X
Park the vehicle on a level surface.
Only check the coolant level when the vehi-
cle is on a level surface and the engine has
cooled down.
X Turn the SmartKey to position 2in the igni-
tion lock (Y page 157).
On vehicles with KEYLESS-GO, press the
Start/Stop button twice (Y page 158).
X Check the coolant temperature gauge in
the multifunction display.
The coolant temperature must be below
158 ‡ (70 †).
X Turn the SmartKey to position
0(Y page 157) in the ignition lock.
X Slowly turn cap 0043half a turn counter-
clockwise to allow excess pressure to
escape.
X Turn cap 0043further counter-clockwise and
remove it.
If the coolant is at the level of marker bar 0087
in the filler neck when cold, there is enough coolant in coolant expansion tank 0044.
If the coolant level is approximately 0.6 in
(1.5 cm) above marker bar 0087in the filler
neck when warm, there is enough coolant
in expansion tank 0044.
X If necessary, add coolant that has been tes-
ted and approved by Mercedes-Benz.
X Replace cap 0043and turn it clockwise as far
as it will go. Engine compartment
369Maintenance and care Z

time during which the battery is disconnec-
ted.
Maintaining the time-dependent service
schedule:
X Note down the service due date displayed
in the multifunction display before discon-
necting the battery.
or X After reconnecting the battery, subtract
the battery disconnection periods from the service date shown on the display. Hiding a service message
X Press the 0038or0076 button on the steer-
ing wheel. Displaying service messages
X Switch on the ignition.
X Press the 0059or0065 button on the steer-
ing wheel to select the Serv. Serv.menu.
X Press the 0063or0064 button to select the
ASSYST PLUS
ASSYST PLUS submenu and confirm by
pressing the 0076button.
The service due date appears in the multi-
function display. Information about Service
Resetting the ASSYST PLUS service
interval display !
If the ASSYST PLUS service interval dis-
play has been inadvertently reset, this set-
ting can be corrected at a qualified special-
ist workshop.
Have service work carried out as described in the Maintenance Booklet. This may oth-
erwise lead to increased wear and damage
to the major assemblies or the vehicle.
A qualified specialist workshop, e.g. an
authorized Mercedes-Benz Center, will reset
the ASSYST PLUS service interval display after the service work has been carried out.
You can also obtain further information on
maintenance work, for example.
Special service requirements The specified maintenance interval takes only
the normal operation of the vehicle into
account. Under arduous operating conditions
or increased load on the vehicle, mainte-
nance work must be carried out more fre-
quently, for example:
R regular city driving with frequent intermedi-
ate stops
R if the vehicle is primarily used to travel
short distances
R use in mountainous terrain or on poor road
surfaces
R if the engine is often left idling for long peri-
ods
Under these or similar conditions, have, for
example, the air filter, engine oil and oil filter
replaced or changed more frequently. Under
arduous operating conditions, the tires must
be checked more often. Further information
can be obtained at a qualified specialist work- shop, e.g. an authorized Mercedes-Benz Cen-
ter.
Driving abroad An extensive Mercedes-Benz Service network
is also available in other countries. You can
obtain further information from any author-
ized Mercedes-Benz Center. Care
General notes
H
Environmental note
Dispose of empty packaging and cleaning
cloths in an environmentally responsible man- ner. Care
371Maintenance and care Z

X
Lift the cargo compartment floor up
(Y page 344).
X Remove "Minispare" emergency spare
wheel (Y page 441). Flat tire
Preparing the vehicle
Your vehicle may be equipped with: R MOExtended tires (tires with run-flat prop-
erties) (Y page 383)
Vehicle preparation is not necessary on
vehicles with MOExtended tires.
R a TIREFIT kit (Y page 382)
R an emergency spare wheel (only for certain
countries) (Y page 440)
Information on changing/mounting a wheel
(Y page 423).
X Stop the vehicle on solid, non-slippery and
level ground, as far away as possible from
traffic.
X Switch on the hazard warning lamps.
X Secure the vehicle against rolling away
(Y page 182).
X If possible, bring the front wheels into the
straight-ahead position.
X Vehicles with the AIRMATIC package:
make sure that highway level is selected
(Y page 211).
X Switch off the engine.
X Vehicles without KEYLESS-GO: remove
the SmartKey from the ignition lock.
X Vehicles with KEYLESS-GO: open the
driver's door.
The on-board electronics now have status
0. This is the same as the SmartKey having been removed.
X Vehicles with KEYLESS-GO: remove the
Start/Stop button from the ignition lock
(Y page 158).
X All occupants must get out of the vehicle.
Make sure that they are not endangered as they do so. X
Make sure that no one is near the danger
area while a wheel is being changed. Any-
one who is not directly assisting in the
wheel change should, for example, stand
behind the barrier.
X Get out of the vehicle. Pay attention to traf-
fic conditions when doing so.
X Close the driver's door.
X Unload heavy luggage.
i Only operate the tire inflation compressor
using a 12 V socket, even if the ignition is
turned off (Y page 349).
An emergency cut-out ensures that the on- board voltage does not drop too low. If the on-board voltage is too low, the power to
the sockets is automatically cut. This
ensures that there is sufficient power to
start the engine. MOExtended tires (tires with run-flat
properties)
General notes With MOExtended tires (tires with run flat
characteristics), you can continue to drive
your vehicle even if there is a total loss of
pressure in one or more tires. The affected
tire must not show any clearly visible damage.
You can recognize MOExtended tires by the
MOExtended marking which appears on the
sidewall of the tire. You will find this marking
next to the tire size designation, the load-
bearing capacity and the speed index
(Y page 417).
MOExtended tires may only be used in con-
junction with an active tire pressure loss
warning system or with an active tire pressure
monitor.
If the pressure loss warning message
appears in the multifunction display:
R Observe the instructions in the display
messages (Y page 312).
R Check the tire for damage.
R If driving on, observe the following notes. Flat tire
383Breakdown assistance

Before handling the battery, touch the vehicle
body to remove any existing electrostatic
build-up.
The highly flammable gas mixture forms when
charging the battery as well as when jump-
starting.
Always make sure that neither you nor the
battery is electrostatically charged. A build-
up of electrostatic charge can be caused, for
example:
R by wearing clothing made from synthetic
fibers
R due to friction between clothing and seats
R if you push or pull the battery across the
carpet or other synthetic materials
R if you wipe the battery with a cloth G
WARNING
During the charging process, a battery produ- ces hydrogen gas. If a short circuit occurs or
sparks are created, the hydrogen gas can
ignite. There is a risk of an explosion.
R Make sure that the positive terminal of a
connected battery does not come into con-
tact with vehicle parts.
R Never place metal objects or tools on a bat-
tery.
R It is important that you observe the descri-
bed order of the battery terminals when
connecting and disconnecting a battery.
R When jump-starting, make sure that the
battery poles with identical polarity are
connected.
R It is particularly important to observe the
described order when connecting and dis-
connecting the jumper cables.
R Never connect or disconnect the battery
terminals while the engine is running. G
WARNING
Battery acid is caustic. There is a risk of injury. Avoid contact with the skin, eyes or clothing.
Do not inhale any battery gases. Do not lean
over the battery. Keep children away from batteries. Wash battery acid immediately with
water and seek medical attention. H
Environmental note Batteries contain dangerous
substances. It is against the
law to dispose of them with
the household rubbish. They
must be collected separately
and recycled to protect the
environment. Dispose of batteries in an
environmentally friendly
manner. Take discharged
batteries to a qualified spe-
cialist workshop or a special
collection point for used bat-
teries.
! Have the battery checked regularly at a
qualified specialist workshop.
Observe the service intervals in the Main-
tenance Booklet or contact a qualified spe-
cialist workshop for more information.
! You should have all work involving the
battery carried out at a qualified specialist
workshop. In the exceptional case that it is
necessary for you to disconnect the battery yourself, make sure that:
R you switch off the engine and remove the
SmartKey. On vehicles with KEYLESS-
GO, ensure that the ignition is switched
off. Check that all the indicator lamps in
the instrument cluster are off. Otherwise, electronic components, such as the
alternator, may be damaged.
R you first remove the negative terminal
clamp and then the positive terminal
clamp. Never swap the terminal clamps.
Otherwise, the vehicle's electronic sys-
tem may be damaged.
R the transmission is locked in position P
after disconnecting the battery. The vehi-
cle is secured against rolling away. You
can then no longer move the vehicle. 388
Battery (vehicle)Breakdown assistance

!
Only use battery chargers with a maxi-
mum charging voltage of 14.8 V.
! Only charge the battery using the jump-
starting connection point.
If, at low temperatures, the indicator lamps/
warning lamps in the instrument cluster do
not light up, it is highly likely that the dis-
charged battery has frozen. In this case you
may neither jump-start the vehicle nor charge the battery. The service life of a thawed-out
battery may be shorter. The starting charac-
teristics can be impaired, particularly at low
temperatures. Have the thawed-out battery
checked at a qualified specialist workshop.
Never charge a battery still installed in the
vehicle unless a battery charger unit
approved by Mercedes-Benz is being used. An
accessory battery charge unit specially adap- ted for Mercedes-Benz vehicles and tested
and approved by Mercedes-Benz is available.
It permits the charging of the battery in its
installed position. Contact an authorized
Mercedes-Benz Center for further informa-
tion and availability. Charge the battery in
accordance with the separate instructions for the battery charger.
The jump-starting connection point is in the
engine compartment (Y page 391).
Read the battery charger's operating instruc- tions before charging the battery.
X Open the hood.
X Connect the battery charger to the positive
terminal and ground point in the same
order as when connecting the donor bat-
tery in the jump-starting procedure
(Y page 391). 390
Battery (vehicle)Breakdown assistance