2013 MERCEDES-BENZ E-Class SEDAN ECU

Display messages Possible causes/consequences and
M Solutionsh
Tire Press. Check
Tire Pressure The tire pressure in one or more tires has dropped significantly.
G WARNING
With tire pressures which are too low, there is a risk of the
following hazards:
R they may burst, especially as the load and vehicle speed
increase.
R they
may wear excessively and/or unevenly, which may greatly
impair tire traction.
R the driving characteristics, as well as steering and braking, may
be greatly impaired.
There is a risk of an accident.
X Stop the vehicle without making any sudden steering or braking
maneuvers.

Pay attention to the traffic conditions as you do so.
X Secure the vehicle against rolling away ( Y page 175).
X If there is a flat tire, inspect the tires ( Y page 344).
X Check the tire pressure (Y page 370).
X If necessary, correct the tire pressure. h
Correct Tire
Pressure The tire pressure is too low in at least one of the tires, or the tire
pressure difference between the wheels is too great.
X
Check the tire pressures at the next opportunity (Y page 370).
X If necessary, correct the tire pressure. Vehicle
Display messages Possible causes/consequences and
M SolutionsShift to 'P' or 'N'
to Start Engine You have attempted to start the engine with the transmission in
position R or D.
X
Shift the transmission to position P or N.Auxiliary Battery
Malfunction The auxiliary battery for the automatic transmission is no longer
being charged.
X
Visit a qualified specialist workshop. Apply Brake to
Shift
from 'P' You have attempted to move the transmission selector lever to
position D, R or N without depressing the brake pedal.
X
Depress the brake pedal. Display messages
271
On-board computer and displays Z

Display messages Possible causes/consequences and
M SolutionsRisk of Rolling
Away
Vehicle Not in P The driver's door is open and the transmission is in position
R, N
or D.
A warning tone also sounds.
X Shift the transmission to position P.
X Secure the vehicle against rolling away ( Y page 175).Service Required
Do Not Shift Gears You cannot change the transmission position due to a malfunction.
A warning tone also sounds.
If transmission position
D is selected:
X Drive to a qualified specialist workshop without shifting the
transmission from position D.
If transmission position R, N or P is selected:
X Notify a qualified specialist workshop or breakdown service. Only Shift
to 'P' when
Vehicle is
Stationary The vehicle is moving.
X
Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Shift the transmission to position P.N Sedan: the trunk lid is open.
X
Close the trunk lid. A Wagon: 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. M or ? The hood is open. A warning tone also sounds.
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 175).
X Close the hood.272
Display messagesOn-board computer and displays

SmartKey
Display messages Possible causes/consequences and
M SolutionsÂ
Key Does Not
Belong to Vehicle You have put the wrong SmartKey in the ignition lock.
X
Use the correct SmartKey. Â
Take
Your Key from
Ignition The SmartKey is in the ignition lock.
X
Remove the SmartKey. Â
Obtain a New Key The SmartKey needs to be replaced.
X
Visit a qualified specialist workshop. Â
Replace

Key Battery The batteries of the KEYLESS-GO key are discharged.
X
Change the batteries ( Y page 81).Â
Don't Forget Your
Key The display message is shown for a maximum of 60 seconds and
is only a reminder.
You have opened the driver's door with the engine switched off.
The KEYLESS-GO key is not in the ignition lock.
X
Remember to take the KEYLESS-GO key with you when you
leave the vehicle. Â
Key Not Detected 
(red display message) The KEYLESS-GO key is not in the vehicle.
A warning tone also sounds.
If the engine is switched off, you can no longer lock the vehicle
centrally or start the engine.
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 175).
X Locate the KEYLESS-GO key. The KEYLESS-GO key is not detected while the engine is running
because

there is interference from a strong source of radio waves.
A warning tone also sounds.
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 175).
X Operate the vehicle with the SmartKey in the ignition lock.274
Display messages
On-board computer and displays

Safety
Seat belts Problem Possible causes/consequences and
M Solutionsü
After starting the
engine, the red seat
belt
warning lamp lights
up for 6 seconds. The seat belt warning lamp reminds the driver and front passenger
to fasten their seat belts.
X
Fasten your seat belt ( Y page 57).ü
After starting the
engine, the red seat
belt

warning lamp lights
up. In addition, a
warning tone sounds
for up to six seconds. The driver's seat belt is not fastened.
X
Fasten your seat belt ( Y page 57).
The warning tone ceases. ü
The red seat belt
warning 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 57).
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. ü
The red seat belt
warning lamp flashes
and an intermittent
audible warning
sounds.
The driver or front passenger has not fastened their seat belt. You
are driving faster than 15 mph (25 km/h

) or have briefly driven
faster than 15 mph (25 km/h).
X Fasten your seat belt ( Y page 57).
The warning lamp goes out and the intermittent warning tone
ceases. There are objects on the front-passenger seat. You are driving
faster than 15 mph (25 km/h

) or have briefly 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.276
Indicator and warning lamps in the instrument cluster
On-board computer and displays

Safety systems
Problem Possible causes/consequences and
M Solutions$ (USA only)
J (Canada only)
The red brake system
warning
lamp comes on
while the engine is
running. A warning tone
also sounds. G
WARNING
The brake boosting effect is malfunctioning and the braking
characteristics 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 175).
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction
display. $ (USA only)
J (Canada only)
The red brake system
warning

lamp comes on
while the engine is
running. 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 175).
X Do not add brake fluid. Adding more will not remedy the
malfunction.
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction
display. Indicator and warning lamps in the instrument cluster
277
On-board computer and displays Z

Problem Possible causes/consequences and
M Solutions?
The red coolant
warning lamp lights up
while the engine is
running
and the coolant
temperature gauge is
at the start of the scale. The temperature sensor for the coolant temperature gauge is
defective.
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 175).
X Consult a qualified specialist workshop. Indicator and warning lamps in the instrument cluster
283
On-board computer and displays Z

Problem Possible causes/consequences and
M Solutions?
The red coolant
warning
lamp comes on
while the engine is
running. The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator
may be blocked or the electric engine radiator fan may be
malfunctioning.
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 175).
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 331).
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
under

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
mountainous terrain, and stop-and-go traffic. ?
The red coolant
warning

lamp comes on
while the engine is
running. A warning tone
also sounds. The coolant temperature has exceeded 248 ‡ (120 †). The
airflow
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.
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 175).284
Indicator and warning lamps in the instrument cluster
On-board computer and displays

Tires
Problem Possible causes/consequences and
M Solutionsh
USA only:
The
yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) is lit.
Canada only:
The yellow tire pressure
monitor warning lamp
(pressure loss) is lit. The tire pressure monitor has detected a loss of pressure in at
least one of the tires.
G WARNING
With tire pressures which are too low, there is a risk of the
following hazards:
R they may burst, especially as the load and vehicle speed
increase.
R they

may wear excessively and/or unevenly, which may greatly
impair tire traction.
R the driving characteristics, as well as steering and braking, may
be greatly impaired.
There is a risk of an accident.
X Stop the vehicle without making any sudden steering or braking
maneuvers.

Pay attention to the traffic conditions as you do so.
X Secure the vehicle against rolling away ( Y page 175).
X Observe the additional display messages in the multifunction
display.
X If there is a flat tire, inspect the tires ( Y page 344).
X Check the tire pressure (Y page 370).
X If necessary, correct the tire pressure. h
USA only:
The

yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) flashes for
approximately one
minute and then
remains lit. The tire pressure monitor is faulty.
G WARNING
The system is possibly unable to recognize or register low tire
pressure.
There is a risk of an accident.
X Observe the additional display messages in the multifunction
display.
X Visit a qualified specialist workshop.286
Indicator and warning lamps in the instrument cluster
On-board computer and displays