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

Problem
Possible causes/consequences and
0050
0050Solutions 00E9
The red seat belt warn-
ing lamp lights up after
the engine starts, as
soon as the driver's or
the front-passenger
door is closed.
The driver or front passenger has not fastened their seat belt.
X Fasten your seat belt (Y page 48).
The warning lamp goes out. There are objects on the front-passenger seat.
X Remove the objects from the front-passenger seat and stow
them in a secure place.
The warning lamp goes out. 00E9
The red seat belt warn-
ing lamp flashes and an
intermittent audible
warning sounds. The driver or front passenger has not fastened their seat belt. The
vehicle is being driven faster than 15 mph (25 km/h) or has briefly been driven faster than 15 mph (25 km/h).
X Fasten your seat belt (Y page 48).
The warning lamp goes out and the intermittent warning tone
ceases. There are objects on the front-passenger seat. The vehicle is being
driven faster than 15 mph (25 km/h) or has briefly been driven
faster than 15 mph (25 km/h).
X Remove the objects from the front-passenger seat and stow
them in a secure place.
The warning lamp goes out and the intermittent warning tone
ceases. Warning and indicator lamps in the instrument cluster
319On-board computer and displays Z

Safety systems
Problem
Possible causes/consequences and
0050
0050Solutions 0027
(USA only)
004D (Canada only)
The red brake system
warning lamp comes on while the engine is run-
ning. A warning tone
also sounds. G
WARNING
The brake boosting effect is malfunctioning and the braking char- acteristics may be affected.
There is a risk of an accident.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away (Y page 182).
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction
display. 0027
(USA only)
004D (Canada only)
The red brake system
warning lamp comes on while the engine is run-
ning. A warning tone
also sounds. There is not enough brake fluid in the brake fluid reservoir.
G WARNING
The braking effect may be impaired.
There is a risk of an accident. X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away (Y page 182).
X Do not add brake fluid. Adding more will not remedy the mal-
function.
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction
display. 320
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem
Possible causes/consequences and
0050
0050Solutions 0025
The yellow ABS warning
lamp is lit while the
engine is running. ABS (Anti-lock Braking System) is deactivated due to a malfunc-
tion. For this reason, BAS (Brake Assist), BAS PLUS, ESP ®
(Elec-
tronic Stability Program), PRE‑SAFE ®
, PRE‑SAFE ®
Brake, COLLI-
SION PREVENTION ASSIST, the HOLD function, hill start assist and
ESP ®
trailer stabilization are also deactivated, for example.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the functions listed above. The wheels could therefore lock if you
brake hard, for example.
The steerability and braking characteristics may be severely affec-ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop.
If the ABS control unit is faulty, there is also a possibility that other
systems, such as the navigation system or the automatic trans-
mission, will not be available. Warning and indicator lamps in the instrument cluster
321On-board computer and displays Z

Problem
Possible causes/consequences and
0050
0050Solutions 0025
The yellow ABS warning
lamp is lit while the
engine is running. ABS is temporarily unavailable. Therefore, BAS, BAS PLUS, ESP
®
,
EBD (electronic brake force distribution), PRE‑ SAFE®
,
PRE‑SAFE ®
Brake, COLLISION PREVENTION ASSIST, the HOLD
function, hill start assist, and ESP ®
trailer stabilization, for exam-
ple, are also deactivated.
ATTENTION ASSIST is deactivated.
Possible causes are:
R Self-diagnosis is not yet complete.
R The on-board voltage may be insufficient.
G WARNING
The brake system continues to function normally, but without the functions listed above. The front and rear wheels could therefore
lock if you brake hard, for example.
The steerability and braking characteristics may be severely affec-ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is a risk of an accident.
X Carefully drive a suitable distance, making slight steering move-
ments at a speed above 12 mph (20 km/h).
The functions mentioned above are available again when the
warning lamp goes out.
If the warning lamp is still on: X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. 322
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem
Possible causes/consequences and
0050
0050Solutions 0025
The yellow ABS warning
lamp is lit while the
engine is running. A
warning tone also
sounds. EBD is malfunctioning. Therefore, ABS, BAS, BAS PLUS, ESP
®
,
PRE‑SAFE ®
, PRE ‑SAFE ®
Brake, COLLISION PREVENTION ASSIST,
the HOLD function, hill start assist and ESP ®
trailer stabilization,
for example, are not available either.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the functions listed above. The front and rear wheels could therefore
lock if you brake hard, for example.
The steerability and braking characteristics may be severely affec-ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. 0027
(USA only)
004D (Canada only)
00E500BB0025
The red brake warning
lamp, the yellow ESP ®
and ESP ®
OFF warning
lamps and the yellow
ABS warning lamp are
lit while the engine is
running. ABS and ESP
®
are malfunctioning. Therefore, BAS, BAS PLUS,
PRE ‑SAFE ®
, PRE ‑SAFE ®
Brake, COLLISION PREVENTION ASSIST,
the HOLD function, hill start assist and ESP ®
trailer stabilization,
for example, are also not available.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the functions listed above. The front and rear wheels could therefore
lock if you brake hard, for example.
The steerability and braking characteristics may be severely affec-ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
323On-board computer and displays Z

Problem
Possible causes/consequences and
0050
0050Solutions 00E5
The yellow ESP
®
warn-
ing lamp flashes while
the vehicle is in motion. ESP
®
or traction control has intervened because there is a risk of
skidding or at least one wheel has started to spin.
Cruise control or DISTRONIC PLUS is deactivated.
X When pulling away, only depress the accelerator pedal as far as
necessary.
X Ease off the accelerator pedal while the vehicle is in motion.
X Adapt your driving style to suit the road and weather conditions.
X Do not deactivate ESP ®
.
In rare cases (Y page 73), it may be best to deactivate ESP ®
. 00BB
The yellow ESP
®
OFF
warning lamp is lit while the engine is running. ESP
®
is deactivated.
G WARNING
If ESP ®
is switched off, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Reactivate ESP ®
.
In rare cases (Y page 73), it may be best to deactivate ESP ®
.
X Adapt your driving style to suit the road and weather conditions.
If ESP ®
cannot be activated:
X Have ESP ®
checked at a qualified specialist workshop. 00E500BB
The yellow ESP
®
and
ESP ®
OFF warning
lamps are lit while the
engine is running. ESP
®
, BAS, BAS PLUS, PRE-SAFE ®
, PRE-SAFE ®
Brake, COLLISION
PREVENTION ASSIST, the HOLD function, hill start assist and
ESP ®
trailer stabilization are not available due to a malfunction.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the functions listed above.
The braking distance in an emergency braking situation can thus
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. 324
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem
Possible causes/consequences and
0050
0050Solutions 00E500BB
The yellow ESP
®
and
ESP ®
OFF warning
lamps are lit while the
engine is running. ESP
®
, BAS, PRE-SAFE ®
, the HOLD function, hill start assist and
ESP ®
trailer stabilization are temporarily unavailable.
COLLISION PREVENTION ASSIST, BAS PLUS and
PRE‑SAFE ®
Brake may also have failed.
ATTENTION ASSIST is deactivated.
Self-diagnosis is not yet complete.
G WARNING
The brake system continues to function normally, but without the functions listed above.
The braking distance in an emergency braking situation can thus
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Carefully drive a suitable distance, making slight steering move-
ments at a speed above 12 mph (20 km/h).
The functions mentioned above are available again when the
warning lamp goes out.
If the warning lamp is still on:
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
325On-board computer and displays Z

Problem
Possible causes/consequences and
0050
0050Solutions 0049
(USA only)
0024 (Canada only)
The red electric parking brake indicator lamp
flashes or lights up
and/or
0024
warning lamp for the
electric parking brake
lights up. X
Observe the additional display messages in the multifunction
display. 0075
The red restraint sys-
tem warning lamp is lit
while the engine is run-
ning.
The restraint system is faulty.
G WARNING
The air bags or Emergency Tensioning Devices may either be trig- gered unintentionally or, in the event of an accident, may not be
triggered.
There is an increased risk of injury.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Have the restraint system checked at a qualified specialist
workshop immediately.
For further information about the restraint system, see
(Y page 44). 326
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Engine
Problem
Possible causes/consequences and
0050
0050Solutions 00B9
The yellow Check
Engine warning lamp
lights up while the
engine is running.
There may be a malfunction, for example:
R in the engine management
R in the fuel injection system
R in the exhaust system
R in the ignition system (for vehicles with gasoline engines)
R in the fuel system
The emission limit values may be exceeded and the engine may be
in emergency mode.
X Have the vehicle checked as soon as possible at a qualified
specialist workshop.
i In some states, you must immediately visit a qualified special-
ist workshop as soon as the yellow Check Engine warning lamp
lights up. This is due to the legal requirements in effect in these
states. If in doubt, check whether such legal regulations apply in the state in which you are currently driving. Vehicles with a diesel engine: the fuel tank has been run dry
(Y
page 180).
X Start the engine three to four times after refueling.
If the yellow Check Engine warning lamp goes out, emergency
running mode is canceled. The vehicle need not be checked. 00B6
The yellow reserve fuel
warning lamp lights up
while the engine is run-
ning.
The fuel level has dropped into the reserve range.
X Refuel at the nearest gas station. 00B6
The yellow reserve fuel
warning lamp flashes
while the vehicle is in
motion.
In addition, the
00B9
Check Engine warning
lamp may light up. The fuel system pressure is too low. The fuel filler cap is not closed
correctly or the fuel system is leaking.
X Check that the fuel filler cap is correctly closed.
X If the fuel filler cap is not correctly closed: close the fuel filler
cap.
X If the fuel filler cap is closed: visit a qualified specialist work-
shop. Warning and indicator lamps in the instrument cluster
327On-board computer and displays Z

Problem
Possible causes/consequences and
0050
0050Solutions 00AC
The red coolant warn-
ing lamp lights up while
the engine is running
and the coolant tem-
perature gauge is at the start of the scale. The temperature sensor for the coolant temperature gage is defec-
tive.
The coolant temperature is no longer being monitored. There is a risk of engine damage if the coolant temperature is too high.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions. Do not continue
driving under any circumstances.
X Secure the vehicle against rolling away (Y page 182).
X Consult a qualified specialist workshop. 328
Warning and indicator lamps in the instrument clusterOn-board computer and displays