coolant level MERCEDES-BENZ M-Class 2015 W166 Owner's Manual

Combination switch
.......................... 123
Combined cargo cover and net ........ 341
Consumption statistics (on-board
computer) .......................................... 269
Convenience closing feature .............. 95
Convenience opening feature ............ 95
Coolant (engine) Checking the level ........................ .369
Display message ............................ 300
Filling capacity ............................... 454
Important safety notes .................. 453
Temperature (on-board com-
puter) ............................................. 281
Temperature gauge ........................ 266
Warning lamp ................................. 328
Cooling
see Climate control
Copyright ............................................. 31
Cornering light function Display message ............................ 297
Function/notes ............................ .125
Crash-responsive emergency light-
ing ....................................................... 129
Cruise control Activating ....................................... 196
Activation conditions ..................... 196
Cruise control lever ....................... 196
Deactivating ................................... 197
Display message ............................ 311
Driving system ............................... 195
Function/notes ............................ .195
Important safety notes .................. 196
Storing and maintaining current
speed ............................................. 196
Cup holder
Center console .............................. 346
Important safety notes .................. 345
Rear compartment ......................... 346
Temperature controlled ................. 346
Customer Assistance Center
(CAC) ..................................................... 29
Customer Relations Department ....... 29 D
Dashboard see Instrument cluster
Data
see Technical data
Daytime running lamps
Display message ............................ 299
Function/notes ............................ .120
Switching on/off (on-board com-
puter) ............................................. 277
Declarations of conformity ................. 28
DEF Adding .......................................... .180
Display message ............................ 303
Filling capacity ............................... 452
Important safety notes .................. 451
Delayed switch-off
Exterior lighting (on-board com-
puter) ............................................. 278
Interior lighting .............................. 279
Diagnostics connection ......................28
Diesel .................................................. 449
Differential lock (display mes-
sage) .................................................. .306
Digital speedometer ......................... 270
DIRECT SELECT lever Automatic transmission ................. 168
Display messages
ASSYST PLUS ................................ 370
Calling up (on-board computer) ..... 284
Driving systems ............................ .304
Engine ............................................ 300
General notes ................................ 284
Hiding (on-board computer) ........... 284
KEYLESS-GO .................................. 317
Lights ............................................. 297
Safety systems .............................. 285
SmartKey ....................................... 317
Tires ............................................... 312
Vehicle .......................................... .315
Distance recorder
see Odometer
see Trip odometer
Distance warning (warning lamp) .... 3308
Index

Trim pieces (cleaning instruc-
tions)
.................................................. 378
Trip computer (on-board com-
puter) .................................................. 269
Trip odometer Calling up ....................................... 269
Resetting (on-board computer) ...... 270
Trunk
see Tailgate
Turn signals
Display message ............................ 297
Switching on/off ........................... 123
TWR (Tongue Weight Rating) (defi-
nition) ................................................. 422
Type identification plate see Vehicle identification plate U
Unlocking Emergency unlocking ....................... 88
From inside the vehicle (central
unlocking button) ............................. 87 V
Vanity mirror (in the sun visor) ........ 347
Vehicle Correct use ...................................... 29
Data acquisition ............................... 30
Display message ............................ 315
Equipment ....................................... 25
Individual settings .......................... 277
Limited Warranty ............................. 30
Loading .......................................... 412
Locking (in an emergency) ............... 88
Locking (SmartKey) .......................... 80
Lowering ........................................ 428
Maintenance .................................... 26
Parking for a long period ................ 185
Pulling away ................................... 160
Raising ........................................... 425
Reporting problems ......................... 29
Securing from rolling away ............ 424
Towing away .................................. 393
Transporting .................................. 395
Unlocking (in an emergency) ........... 88 Unlocking (SmartKey) ...................... 80
Vehicle data ................................... 456
Vehicle battery
see Battery (vehicle)
Vehicle data ....................................... 456
Vehicle data (off-road driving) Approach/departure angle ............ 458
Fording depth ................................ 457
Maximum gradient climbing abil-
ity .................................................. 458
Vehicle dimensions ........................... 456
Vehicle emergency locking ................ 88
Vehicle identification number see VIN
Vehicle identification plate .............. 446
Vehicle level AMG adaptive sport suspension
system ........................................... 216
Vehicle level (display message) ....... 304
Vehicle maintenance see ASSYST PLUS
Vehicle tool kit .................................. 382
Video Operating the DVD ........................ .273
VIN ...................................................... 446 W
Warning and indicator lamps ABS ................................................ 321
Brakes .......................................... .320
Check Engine ................................. 327
Coolant .......................................... 328
Distance warning ........................... 330
DISTRONIC PLUS ........................... 330
ESP ®
.............................................. 323
ESP ®
OFF ....................................... 324
Overview .......................................... 36
PASSENGER AIR BAG OFF .............. .45
Reserve fuel .................................. .327
Restraint system ............................ 326
Seat belt ........................................ 318
Tire pressure monitor .................... 331
Warranty .............................................. 25
Washer fluid Display message ............................ 316 22
Index

Problems with the engine
Problem
Possible causes/consequences and
0050
0050Solutions 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 Before attempting to start the engine again, turn the SmartKey
in the ignition back to position 0or press the Start/Stop button
repeatedly until all indicator lamps in the instrument cluster go out.
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 391).
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. Vehicles with a gaso-
line engine:
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.
X Only depress the accelerator pedal slightly.
Otherwise, non-combusted fuel may get into the catalytic con-
verter and damage it.
X Have 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.
X Stop as soon as possible and allow the engine and the coolant to
cool down.
X Check the coolant level (Y page 369). Observe the warning
notes as you do so and add coolant if necessary. Driving
167Driving and parking Z

using the brake controller and check
whether the brakes function correctly.
R Secure any objects on the trailer to prevent
the cargo from slipping when the vehicle is
in motion.
R When 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.
R Bear in mind that the handling will be less
stable when towing a trailer than when driv- ing without one. Avoid sudden steering
movements.
R The 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.
R If 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.
R If 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.
R When 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.
R If 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.
R When overtaking, pay particular attention
to the extended length of your vehicle/
trailer combination.
Due to the length of the vehicle/trailer
combination, you require additional road
space in relation to the vehicle you are
overtaking before you can change back to
the original lane. Decoupling a trailer
G
WARNING
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. G
WARNING
Vehicles with level control:
The vehicle is lowered as soon as you discon-
nect the trailer cable. This could result in your limbs or those of other people that are
between the vehicle body and tires or under-
neath the vehicle being trapped. There is a
risk of injury.
Make sure that nobody is in the immediate
vicinity of the wheel housings or under the
vehicle when you disconnect the trailer cable.
! Do not disconnect a trailer with an
engaged overrun brake. Otherwise, your
vehicle could be damaged by the rebound- ing of the overrun brake.
X Make sure that the automatic transmission
is set to position P.
X Apply the vehicle's electric parking brake.
X Start the engine.
X Close all doors and the tailgate.
X Apply the trailer's parking brake. Towing a trailer
261Driving and parking Z

The coolant temperature gauge is in the
instrument cluster on the right-hand side
(Y page 35).
Under normal operating conditions and with
the specified coolant level, the coolant tem-
perature may rise to 248 ‡ (120 †). Tachometer
! Do not drive in the overrevving range, as
this could damage the engine.
The red band in the tachometer indicates the
engine's overrevving range.
The fuel supply is interrupted to protect the
engine when the red band is reached. Outside temperature display
You should pay special attention to road con-
ditions when temperatures are around freez-
ing point.
Bear in mind that the outside temperature
display indicates the temperature measured
and does not record the road temperature.
The outside temperature display is in the mul- tifunction display (Y page 268).
Changes in the outside temperature are dis-
played after a short delay. Speedometer with segments
The segments in the speedometer indicate
which speed range is available.
R Cruise control activated (Y page 195):
The segments light up from the stored
speed to the maximum speed.
R DISTRONIC PLUS activated (Y page 198):
One or two segments in the set speed
range light up.
R DISTRONIC PLUS detects a vehicle in front:
The segments between the speed of the
vehicle in front and the stored speed light
up. Operating the on-board computer
Overview 0043
Multifunction display
0044 Switches on the Voice Control System;
see the separate operating instructions
0087 Right control panel
0085 Left control panel
0083 Back button
X To activate the on-board computer: turn
the SmartKey to position 1in the ignition
lock.
You can control the multifunction display and
the settings in the on-board computer using
the buttons on the multifunction steering
wheel. Displays and operation
267On-board computer and displays Z

Display messages
Possible causes/consequences and
0050
0050Solutions 0049
Auto Auto
Lamp
LampFunction
Function
Inoperative
Inoperative The light sensor is defective.
X Visit a qualified specialist workshop. 0049
Switch Off Lights Switch Off Lights The lights are still switched on when you leave the vehicle. A
warning tone also sounds.
X Turn the light switch to 0058.Adaptive Highbeam Adaptive Highbeam
Assist Inoperative Assist Inoperative Adaptive Highbeam Assist is faulty.
X
Visit a qualified specialist workshop. Adaptive Highbeam Adaptive Highbeam
Assist Currently Assist Currently
Unavailable See Unavailable See
Operator's Manual Operator's Manual Adaptive Highbeam Assist is deactivated and temporarily inoper-
ative. Possible causes are:
R the windshield in the camera's field of vision is dirty.
R visibility is impaired due to heavy rain, snow or fog.
X Clean the windshield.
If the system detects that the camera is fully operational again, the
Adaptive Highbeam Assist Now Available
Adaptive Highbeam Assist Now Available message is dis-
played.
Adaptive Highbeam Assist is operational again. Engine
Display messages
Possible causes/consequences and
0050 0050Solutions 00BD
Check Coolant Check Coolant
Level See Opera‐ Level See Opera‐
tor's Manual tor's Manual 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.
X Add coolant, observing the warning notes before doing so
(Y page 369).
X If coolant needs to be added more often than usual, have the
engine coolant system checked at a qualified specialist work-
shop. 00AC The fan motor is faulty.
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. 300
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
0050
0050Solutions 00AC
Coolant Too Hot Coolant Too Hot
Stop Vehicle Turn Stop Vehicle Turn
Engine Off Engine Off The coolant is too hot.
A warning tone also sounds.
G WARNING
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.
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 Wait until the engine has cooled down.
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 display message goes out
and the coolant temperature is below 248 ‡ (120 †). Other-
wise, the engine could be damaged.
X Pay attention to the coolant temperature display.
X If the temperature increases again, visit a qualified specialist
workshop immediately.
Under normal operating conditions and with the specified coolant
level, the coolant temperature may rise to 248 ‡ (120 †). 003D
See See
Operator's
Operator's Man‐
Man‐
ual
ual The battery is not being charged.
A warning tone also sounds.
Possible causes are:
R a defective alternator
R a torn poly-V-belt
R a malfunction in the electronics
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
! Do not continue driving. The engine could otherwise overheat.
X Secure the vehicle against rolling away (Y page 182).
X Consult a qualified specialist workshop. Display
messages
301On-board computer and displays Z

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

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