check engine MERCEDES-BENZ M-Class 2015 W166 Service Manual

Display messages
Possible causes/consequences and
0050
0050Solutions 003D
Stop Vehicle See Stop Vehicle See
Operator's Manual Operator's Manual The battery is no longer being charged and the battery charge level
is too low.
A warning tone also sounds.
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 Observe the instructions in the display message 003DSee See
Operator's Manual
Operator's Manual .
X Consult a qualified specialist workshop. 00B2
Check Engine Oil Check Engine Oil
At Next Refueling At Next Refueling The engine oil level has dropped to the minimum level.
A warning tone also sounds.
X Check the oil level when next refueling, at the latest
(Y page 367).
X If necessary, add engine oil (Y page 368).
X Have the engine checked at a qualified specialist workshop if the
engine oil needs topping up more often than usual.
! Avoid long journeys with too little engine oil. The engine will
otherwise be damaged.
Information on approved engine oils can be obtained from any
qualified specialist workshop or on the Internet at http://
bevo.mercedes-benz.co m.00B2
Check Engine Oil Check Engine Oil
Level Level
(Add
(Add1
1quart)
quart) AMG vehicles: the engine oil level is too low.
X Check the oil level when next refueling, at the latest
(Y page 367).
X If necessary, add engine oil (Y page 368).
X Have the engine checked at a qualified specialist workshop if the
engine oil needs topping up more often than usual.
! Avoid long journeys with too little engine oil. The engine will
otherwise be damaged.
Information on approved engine oils can be obtained from any
qualified specialist workshop or on the Internet at http://
bevo.mercedes-benz.com. 00B6
Fuel Level Low Fuel Level Low The fuel level has dropped into the reserve range.
X Refuel at the nearest gas station. 00A8 There is only a very small amount of fuel in the fuel tank.
X Refuel at the nearest gas station without fail. 302
Display messagesOn-board computer and displays

Display messages
Possible causes/consequences and
0050
0050Solutions 00B6
Gas Cap Loose Gas Cap Loose 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.
If the fuel filler cap is not correctly closed: X Close the fuel filler cap.
If the fuel filler cap is correctly closed: X Visit a qualified specialist workshop. 00B6
Ultra Low-sulfur Ultra Low-sulfur
Diesel Fuel Only Diesel Fuel Only Vehicles with a diesel engine: the fuel level has fallen below the
reserve range.
X Refuel at the nearest gas station.
X Only use commercially available vehicular ULTRA-LOW SULFUR
HIGHWAY DIESEL FUEL (ULSD, 15 ppm sulfur MAXIMUM). 009E
Replace Air Filter Replace Air Filter Vehicles with a diesel engine: the engine air filter is dirty and must
be replaced.
X Visit a qualified specialist workshop. 003A
Check Fuel Filter Check Fuel Filter Vehicles with a diesel engine: there is water in the fuel filter. The
water must be drained off.
X Visit a qualified specialist workshop. 00C8
Check Check
Additive
Additive See
See
Operator's Manual
Operator's Manual The DEF tank is almost empty.
X Have the DEF tank filled as soon as possible at a qualified spe-
cialist workshop (Y page 180). 00C8
Remaining Starts: Remaining Starts:
16 16 The DEF level has fallen to a minimum. You can start the engine a
further 16 times.
X Have the DEF tank filled immediately at a qualified specialist
workshop (Y page 180).
i You can start the engine a further 16 times. If DEF is not added,
it will then not be possible to restart the engine. Refill the DEF
tank with approximately 1 gal (3.8l)DEF (Y page 180). Display
messages
303On-board computer and displays Z

Display messages
Possible causes/consequences and
0050
0050Solutions 00F6
Different. Lock Different. Lock
Sys. Malfunction Sys. Malfunction The differential lock is faulty.
X Do not drive at speeds above 50 mph (80 km/h).
X Have the vehicle checked at a qualified specialist workshop. 00F6
Different. Different.
Locking
Locking
Sys. Cooling Down
Sys. Cooling Down
Please Wait Please Wait The differential lock is too hot and has been disengaged.
X Drive on carefully.
X Allow the differential lock to cool down.
The differential lock re-engages as soon as it has cooled down. LOW RANGE Stop LOW RANGE Stop
Apply Apply
Parking
Parking Brake
Brake A gearshift process has been canceled. LOW RANGE is in the neu-
tral position. There is no connection between the engine and the
drive wheels.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Apply the electric parking brake. Do not continue driving under
any circumstances.
X Repeat the gearshift process. LOW RANGE Malfunc‐
LOW RANGE Malfunc‐
tion To Park, tion To Park,
Apply Brake Apply Brake LOW RANGE is malfunctioning.
X Do not drive at speeds above 50 mph (80 km/h).
X When parking, secure the vehicle against rolling away
(Y page 182).
X Have the vehicle checked at a qualified specialist workshop. LOW RANGE Max. LOW RANGE Max.
Speed 25 mph Speed 25 mph You have exceeded the maximum speed for the gearshift process.
X Drive more slowly.
The gear change is made. LOW RANGE Max. LOW RANGE Max.
Speed 40 mph Speed 40 mph You have exceeded the maximum speed for the gearshift process.
X Drive more slowly.
The gear change is made. LOW LOW
RANGE
RANGE Shift
Shiftto
to
Position N Briefly
Position N Briefly You have reduced the vehicle speed, but the automatic transmis-
sion is not in position N.
X Briefly shift the automatic transmission to position N.LOW
LOW
RANGE
RANGE Shifting
Shifting
Canceled Please
Canceled Please
Reactivate Reactivate The gearshift process has been canceled.
X Repeat the gearshift process. 00C6
Inoperative Inoperative DSR (Downhill Speed Regulation) is deactivated due to a malfunc-
tion.
X Have DSR checked at a qualified specialist workshop. 306
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
0050
0050Solutions DISTRONIC
DISTRONIC
PLUS
PLUSCur‐
Cur‐
rently
rently Unavailable
Unavailable
See
See Operator's
Operator's Man‐
Man‐
ual
ual DISTRONIC PLUS is temporarily inoperative. Possible causes are:
R function is impaired due to heavy rain or snow.
R the sensors in the radiator trim and the bumper are dirty.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation.
R the system is outside the operating temperature range.
R the on-board voltage is too low.
A warning tone also sounds.
When the causes stated above no longer apply, the display mes-
sage disappears.
DISTRONIC is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 182).
X Clean the sensors in the radiator trim and the bumper
(Y page 375).
X Restart the engine. DISTRONIC PLUS DISTRONIC PLUS
Inoperative Inoperative DISTRONIC PLUS is defective.
BAS PLUS (Brake Assist PLUS) and PRE-SAFE
®
Brake may be
inoperative as well.
A warning tone also sounds.
X Visit a qualified specialist workshop. DISTRONIC DISTRONIC
PLUS
PLUSSus‐
Sus‐
pended
pended You have depressed the accelerator pedal. DISTRONIC PLUS is no
longer controlling the speed of the vehicle.
X Remove your foot from the accelerator pedal. DISTRONIC PLUS
DISTRONIC PLUS
- - - mph - - - mph An activation condition for DISTRONIC PLUS is not fulfilled.
X Check the activation conditions for DISTRONIC PLUS
(Y page 198). 310
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
0050
0050Solutions 0065 The tailgate is open.
G WARNING
When the engine is running, exhaust gases can enter the vehicle
interior if the tailgate is open.
There is a risk of poisoning.
X Close the tailgate. 0066 The hood is open.
G WARNING
The open hood may block your view when the vehicle is in motion.
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.
X Secure the vehicle against rolling away (Y page 182).
X Close the hood. 0051 At least one door is open.
A warning tone also sounds.
X Close all the doors. 00CC
Power Power
Steering
Steering Mal‐
Mal‐
function See Oper‐
function See Oper‐
ator's Manual ator's Manual The power steering is malfunctioning.
A warning tone also sounds.
G WARNING
You will need to use more force to steer.
There is a risk of an accident. X Check whether you are able to apply the extra force required.
X If you are able to steer safely: carefully drive on to a qualified
specialist workshop.
X If you are unable to steer safely: do not drive on. Contact the
nearest qualified specialist workshop. No Service No Service Your vehicle is outside the network provider's transmitter/
receiver range.
X Wait until the mobile phone operational readiness symbol
appears in the multifunction display. 00B2
Check Washer Fluid Check Washer Fluid The washer fluid level in the washer fluid reservoir has dropped
below the minimum.
X Add washer fluid (Y page 370).316
Display
messagesOn-board computer and displays

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 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 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