Problems with trailer towing
Problem
Possible causes/consequences and
M
MSolutions The displaced ball cou-
pling does not reach the
securely locked position. R
The indicator lamp in the button flashes.
R The Check trailer hitch lock Check trailer hitch lock message appears in the multi-
function display.
X Initiate a new swivelling procedure.
If the ball coupling does not reach the safely engaged position as a
result:
X Start the engine
or
X Pull and hold the button during the whole swivelling procedure.
If the unlocked ball coupling does not reach the safely engaged posi- tion even after several attempts:
X Make sure that there is sufficient ground clearance before continu-
ing the journey.
X Consult a qualified specialist workshop.
As long as the Check trailer hitch lock
Check trailer hitch lock display message is
shown in the multifunction display, no trailer should be attached. Unlocking using the
button in the tailgate:
The ball coupling does
not swivel, even though:
R
the vehicle is station-
ary
R no trailer cable is con-
nected
R the button was briefly
pulled The on-board voltage is too low.
X Start the engine.
If the ball coupling still does not unlock:
X Consult a qualified specialist workshop. Towing a trailer
279Driving and parking Z
Problem
Possible causes/consequences and
M
MSolutions Unlocking using the
button in the driver's
door (all vehicles
except PLUG-IN
HYBRID):
The ball coupling does
not swivel, even though:
R the vehicle is station-
ary
R no trailer cable is con-
nected The on-board voltage is too low.
X Engage park position P.
X Switch on the power supply.
or X Start the engine.
If the ball coupling still does not unlock: X Consult a qualified specialist workshop. The ball coupling does
not swivel. The indicator
lamp in the button is
flashing permanently.
The
Check trailer Check trailer
hitch lock
hitch lock message
appears in the multifunc- tion display. There is a malfunction in the release electronics.
X When the ball coupling is retracted: pull and hold the button in
the tailgate until the ball coupling engages into a securely engaged
and locked in a vertical position and then engages again under the
bumper.
X When the ball coupling is extended: pull and hold the button in
the tailgate until the ball coupling engages underneath the bumper.
If the ball coupling still does not unlock:
X Consult a qualified specialist workshop. 280
Towing a trailerDriving and parking
Display messages
Possible causes/consequences and
M
MSolutions !
Parking brake inop‐ Parking brake inop‐
erative erative The yellow
!warning lamp lights up. The red !indicator lamp
flashes for about ten seconds after the electric parking brake has been applied or released. It then goes out or remains lit.
The electric parking brake is malfunctioning, e.g. because of over-
voltage or undervoltage.
X Rectify the cause of the overvoltage or undervoltage, e.g. by charg-
ing the battery or restarting the engine.
X Apply or release the electric parking brake.
If the electric parking brake still cannot be applied or released: X Switch off the ignition and turn it back on.
X Apply or release the electric parking brake.
If the electric parking brake still cannot be released: X Consult a qualified specialist workshop.
If it is still not possible to apply the electric parking brake:
X Consult a qualified specialist workshop. The yellow
!warning lamp lights up and the red !indicator
lamp flashes.
It is not possible to apply the electric parking brake manually.
X Shift the transmission to position P.
X Consult a qualified specialist workshop. J
Check brake fluid Check brake fluid
level level There is insufficient brake fluid in the brake fluid reservoir. In addition,
the J warning lamp in the instrument cluster lights up and a warn-
ing tone sounds.
G WARNING
Braking efficiency 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 Safeguard the vehicle against rolling away (Y page 191).
X Consult a qualified specialist workshop.
X Do not top up the brake fluid. This does not correct the fault. #
Check Check
brake
brakepad
padwear
wear The brake pads/linings have reached their wear limit.
X Consult a qualified specialist workshop. G
Inoperative
Inoperative One or more main features of the Mercedes-Benz Contact system are
malfunctioning.
X Consult a qualified specialist workshop. 306
Display
messagesOn-board computer and displays
Engine
Display messages
Possible causes/consequences and
M
MSolutions +
Top up coolant See Top up coolant See
Owner's Manual Owner'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 Top up the coolant, observing the warning notes before doing so
(Y page 376).
If you have to top up the coolant frequently: X Contact a qualified specialist workshop and have the engine cooling
system checked. ? The fan motor is faulty.
X If the coolant temperature is below 120 †, you can continue driving
to the nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving in moun-
tainous terrain and stop-start traffic. ?
Coolant Stop vehi‐ Coolant Stop vehi‐
cle Switch engine cle Switch engine
off off The coolant is too hot.
A warning tone also sounds.
G WARNING
Never drive with an overheated engine. Driving when your engine is
overheated can cause some fluids which may have leaked into the
engine compartment to catch fire.
In addition, steam from an overheated engine can cause serious
burns, which can occur just by opening the bonnet.
There is a risk of injury.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 191).
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 frozen slush.
X Do not start the engine again until the display message goes out and
the coolant temperature is below 120 †. The engine may otherwisebe damaged.
X Pay attention to the coolant temperature display.
If the temperature increases again:
X Consult a qualified specialist workshop immediately.
Under normal operating conditions and with the specified coolant
level, the coolant temperature may rise to 120 †. 316
Display messagesOn-board computer and displays
Display messages
Possible causes/consequences and
M
MSolutions #
See Owner's Manual See Owner's Manual The battery is not being charged.
A warning tone also sounds.
Possible causes:
R faulty alternator
R defective power electronics (PLUG-IN HYBRID vehicles)
R torn poly-V-belt
R a malfunction in the electronics
! Do not continue driving. The engine could otherwise overheat.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 191).
X Consult a qualified specialist workshop. #
Stop vehicle See Stop vehicle See
Owner's Manual Owner's Manual The battery is no longer being charged and the battery charge level is
too low.
A warning tone also sounds.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 191).
X Observe the instructions in the #See SeeOwner's
Owner's Manual
Manualdisplay
message.
X Consult a qualified specialist workshop. 4
Check Check
eng.
eng.oil
oillev.
lev.
when
when next
nextrefuelling
refuelling The engine oil level has dropped to the minimum level.
A warning tone also sounds.
! Avoid long journeys when there is too little coolant in the cooling
system. Otherwise the engine will be damaged.
X Check the oil level when next refuelling, at the latest (Y page 375).
X If necessary, top up the engine oil (Y page 375).
If you have to top up the engine oil frequently:
X Contact a qualified specialist workshop and have the engine
checked.
Information on approved engine oils can be obtained from any quali-
fied specialist workshop or on the Internet at http://bevo.mercedes-
benz.co m. Display
messages
317On-board computer and displays Z
Display messages
Possible causes/consequences and
M
MSolutions 4
Add 1 litre engine Add 1 litre engine
oil when next refu‐ oil when next refu‐
elling elling Mercedes-AMG vehicles: the engine oil level is too low.
! Avoid long journeys when there is too little coolant in the cooling
system. Otherwise the engine will be damaged.
X Check the oil level when next refuelling, at the latest (Y page 375).
X If necessary, top up the engine oil (Y page 375).
If you have to top up the engine oil frequently:
X Contact a qualified specialist workshop and have the engine
checked.
Information on approved engine oils can be obtained from any quali-
fied specialist workshop or on the Internet at http://bevo.mercedes-
benz.co m. 4
Engine oil level Engine oil level
Stop Stop
vehicle
vehicle Switch
Switch
engine off
engine off Mercedes-AMG vehicles: the engine oil level is too low.
There is a risk of engine damage.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 191).
X Check the engine oil level (Y page 375).
X If necessary, top up the engine oil (Y page 375).8
Reserve fuel level Reserve fuel level The fuel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated if the fuel level drops
into the reserve range.
X Refuel at the nearest filling station. C There is very little fuel in the fuel tank.
The auxiliary heating cannot be operated.
X Refuel at the nearest filling station without fail. ¸
Replace Replace
air
air cleaner
cleaner
element
element Vehicles with a diesel engine: the engine air filter is dirty and must be
replaced.
X Consult a qualified specialist workshop. !
Clean the fuel fil‐ Clean the fuel fil‐
ter ter Vehicles with a diesel engine: there is water in the fuel filter. The water
must be drained off.
X Consult a qualified specialist workshop. Ø
Refill AdBlue See Refill AdBlue See
Owner's Manual Owner's Manual The AdBlue
®
level has fallen below the reserve range. A warning tone
also sounds.
X Have AdBlue ®
refilled as soon as possible at a qualified specialist
workshop.
or X Add at least 3.8 lof AdBlue ®
immediately (Y page 180).318
Display messagesOn-board computer and displays
Display messages
Possible causes/consequences and
M
MSolutions Ø
Refill AdBlue No Refill AdBlue No
start in .. km start in .. km The AdBlue
®
level is only sufficient for the indicated distance. A warn-
ing tone also sounds.
X Have AdBlue ®
refilled as soon as possible at a qualified specialist
workshop.
or
X Add at least 3.8 l of AdBlue ®
immediately (Y page 180). Ø
Refill AdBlue No Refill AdBlue No
start in .. km start in .. km The AdBlue
®
level is only sufficient for the indicated distance. A warn-
ing tone also sounds.
X Have AdBlue ®
refilled as soon as possible at a qualified specialist
workshop.
or
X Add at least 3.8 l of AdBlue ®
immediately (Y page 180). Ø
Refill AdBlue Eng. Refill AdBlue Eng.
start not possible start not possible The AdBlue
®
tank is empty. A warning tone also sounds. You can no
longer start the engine.
X Consult a qualified specialist workshop immediately.
or X Add at least 3.8 l of AdBlue ®
immediately (Y page 180). Ø
Check AdBlue See Check AdBlue See
Owner's Manual Owner's Manual The AdBlue
®
system is malfunctioning. A warning tone also sounds.
X Consult a qualified specialist workshop. Ø
Eng. start not pos‐ Eng. start not pos‐
sible in ..km sible in ..km The AdBlue
®
system is malfunctioning. A warning tone also sounds.
X Consult a qualified specialist workshop immediately. Ø
Eng. start not pos‐ Eng. start not pos‐
sible sible The AdBlue
®
system is malfunctioning. A warning tone also sounds.
You can no longer start the engine.
X Consult a qualified specialist workshop immediately. Display
messages
319On-board computer and displays Z
Display messages
Possible causes/consequences and
M
MSolutions ý
Different. lock Different. lock
sys. Malfunction sys. Malfunction The differential lock is faulty.
X Do not drive at speeds above 80 km/h.
X Consult a qualified specialist workshop. ý
Different. locking Different. 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 parking brake Apply parking brake A gearshift process has been cancelled. LOW RANGE is in the neutral
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 tion
To
Topark,
park, apply
apply
parking brake
parking brake LOW RANGE is malfunctioning.
X Do not drive at speeds above 80 km/h.
X When parking, safeguard the vehicle against rolling away
(Y page 191).
X Consult a qualified specialist workshop. LOW RANGE max. LOW RANGE max.
speed 40 km/h speed 40 km/h 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 70 km/h speed 70 km/h You have exceeded the maximum speed for the gearshift process.
X Drive more slowly.
The gear change is made. LOW RANGE Shift to LOW RANGE Shift to
position N briefly position N briefly You have reduced the vehicle speed, but the automatic transmission
is not in position N.
X Briefly shift the automatic transmission to position N.LOW RANGE Shifting
LOW RANGE Shifting
cancelled Please cancelled Please
reactivate reactivate The gearshift process has been cancelled.
X Repeat the gearshift process. Ã
Inoperative
Inoperative DSR (Downhill Speed Regulation) is deactivated due to a fault.
X Have DSR checked at a qualified specialist workshop. 324
Display
messagesOn-board computer and displays