2015 MERCEDES-BENZ B-CLASS SPORTS check engine light

Display messagesPossible causes/consequences andMSolutions
b
Active Headlamps
Inoperative
The light sensor is defective.
X Visit a qualified specialist workshop.
b
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 Ã.
Engine
Display messagesPossible causes/consequences and MSolutions
+
Check Coolant
Level See OperaZ
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 273).
X If coolant needs to be added more often than usual, have the
engine coolant system checked at a qualified specialist work-
shop.
?The fan motor is faulty. XAt 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.
222Display messages
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
Ð
PowerSteeringMalZ
function See OperZ
ator's Manual
The power steering is malfunctioning.
A warning tone also sounds.
GWARNING
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.
Ð
Steering MalfuncZ
tion See OperaZ
tor's Manual
The electric steering lock is malfunctioning.
GWARNING
The steering may be locked by the electric steering lock.
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 ( Ypage 152).
X Do not drive on and consult the nearest qualified specialist
workshop.
_
Before Starting
the Engine, Turn
Steering Wheel
The electric steering lock was unable to unlock the steering.
X Remove the SmartKey from the ignition lock.
X To unlock the steering, move the steering wheel slightly.
X Insert the SmartKey into the ignition lock again.
Phone No ServiceYour vehicle is outside the network provider's transmitter/
receiver range. XWait until the mobile phone operational readiness symbol
appears in the multifunction display.
¥
Check Washer Fluid
The washer fluid level in the washer fluid reservoir has dropped
below the minimum.
X Add washer fluid ( Ypage 273).
Wiper MalfunctionZ
ing
The windshield wipers are malfunctioning.
X Visit a qualified specialist workshop.
Hazard Warning
Flashers MalfuncZ
tioning
The hazard warning lamps are faulty.
X Visit a qualified specialist workshop.
Display messages233
On-board computer and displays
Z

ProblemPossible causes/consequences andMSolutions
F(USA only)
! (Canada only)
The red indicator lamp
for the electric parking
brake flashes or lights
up and/or the yellow
warning lamp for the
electric parking brake
lights up.X Observe the additional display messages in the multifunction
display.
6
The red restraint sys-
tem warning lamp is lit
while the engine is run-ning.The restraint system is faulty.
GWARNING
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 38).
Warning and indicator lamps in the instrument cluster243
On-board computer and displays
Z

Engine
ProblemPossible causes/consequences andMSolutions
;
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
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.
iIn 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.
æ
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.
æ
The yellow reserve fuel
warning lamp flashes
while the vehicle is in
motion.
In addition, the ;
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.
?
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 gauge is
defective.
The coolant temperature is no longer being monitored. There is arisk 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 ( Ypage 152).
X Consult a qualified specialist workshop.
244Warning and indicator lamps in the instrument cluster
On-board computer and displays

ProblemPossible causes/consequences andMSolutions
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 ( Ypage 273).
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
ProblemPossible causes/consequences and MSolutions
·
The red distance warn-
ing lamp lights up while
the vehicle is in motion. A warning tone alsosounds.You are approaching a vehicle or a stationary obstacle in your lineof 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.
For further information about the distance warning function of
COLLISION PREVENTION ASSIST PLUS, see ( Ypage 62).
246Warning and indicator lamps in the instrument cluster
On-board computer and displays

!Make sure that the windshield wipers are
not folded away from the windshield. You
could otherwise damage the windshield
wipers or the hood.
X Make sure that the windshield wipers are
switched off.
X Pull release lever :on the hood.
The hood is released.
X Reach into the gap between the hood and
the radiator trim and press hood catchlever ;to the left.
X Raise the hood.
XPull support strut ?out of bracket A.
X Lift up support strut ?and insert it into
yellow retaining clip =.
Closing the hood
X
Raise the hood slightly and, at the same
time, remove support strut ?from yellow
retaining clip =.
X Swing support strut ?down and press it
into bracket Auntil it engages.
X Lower the hood and let it fall from a height
of approximately 8 in (20 cm).
X Check that the hood has engaged properly.
If the hood can be raised slightly, it is not
properly engaged. Do not press the hood
closed. Open the hood again and close it
with a little more force.
Engine oil
General notes
Depending on your driving style, the vehicle
consumes up to 0.9 US qt (0.8 liters) of oil per 600 miles (1,000 km). The oil consumption
may be higher than this when the vehicle is
new or if you frequently drive at high enginespeeds.
Depending on the engine, the oil dipstick maybe in a different location.
When checking the oil level:
R park the vehicle on a level surface.
R the engine should be switched off for
approximately five minutes if the engine is
at normal operating temperature.
R if the engine is not at normal operating
temperature, e.g. if the engine was only
started briefly, wait about 30 minutes
before carrying out the measurement.
Engine compartment271
Maintenance and care
Z

GWARNING
Battery acid is caustic. There is a risk of injury.Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten-tion.
GWARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing the vehicle or charging the battery, gases can escape from the battery. There is a risk of
an explosion.
Allow the frozen battery to thaw out before
charging it or jump-starting.
!Only use battery chargers with a maxi-
mum charging voltage of 14.8 V.
!Onlycharge the battery using the jump-
starting connection point.
The jump-starting connection point is in the
engine compartment ( Ypage 293).
X Open the hood.
X Connect the battery charger to the positive
terminal and ground point in the same
order as when connecting the donor bat-
tery in the jump-starting procedure( Y page 293).
If the indicator/warning lamps do not light up at low temperatures, it is very likely that the
discharged battery has frozen. In this case
you may neither jump-start the vehicle nor
charge the battery. The service life of a
thawed-out battery may be shorter. The start-
ing characteristics can be impaired, particu-
larly at low temperatures. Have the thawed-
out battery checked at a qualified specialist
workshop.
Only charge the installed battery with a bat-
tery charger which has been tested and
approved by Mercedes-Benz. A battery
charger unit specially adapted for Mercedes-
Benz vehicles and tested and approved by Mercedes-Benz is available as an accessory.
It permits the charging of the battery in its
installed position. Contact an authorized
Mercedes-Benz Center for further informa-
tion and availability. Read the battery charg-
er's operating instructions before charging
the battery.
292Battery (vehicle)
Roadside Assistance

Jump-starting
For the jump-starting procedure, use only the jump-starting connection point, consisting of apositive terminal and a ground point, in the engine compartment.
GWARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do not inhale any battery gases. Do not lean over the
battery. Keep children away from batteries. Wash away battery acid immediately with plenty of
clean water and seek medical attention.
GWARNING
During charging and jump-starting, explosive gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, open flames, creating sparks and smoking. Ensure there is sufficient ven-
tilation while charging and jump-starting. Do not lean over a battery.
GWARNING
During the charging process, a battery produces hydrogen gas. If a short circuit occurs or sparks
are created, the hydrogen gas can ignite. There is a risk of an explosion.
R Make sure that the positive terminal of a connected battery does not come into contact with
vehicle parts.
R Never place metal objects or tools on a battery.
R It is important that you observe the described order of the battery terminals when connecting
and disconnecting a battery.
R When jump-starting, make sure that the battery poles with identical polarity are connected.
R It is particularly important to observe the described order when connecting and disconnecting
the jumper cables.
R Never connect or disconnect the battery terminals while the engine is running.
GWARNING
A discharged battery can freeze at temperatures below freezing point. When jump-starting the
vehicle or charging the battery, gases can escape from the battery. There is a risk of an explosion.
Allow the frozen battery to thaw out before charging it or jump-starting.
!Avoid repeated and lengthy starting attempts. Otherwise, the catalytic converter could be
damaged by the non-combusted fuel.
If the indicator/warning lamps do not light up at low temperatures, it is very likely that the
discharged battery has frozen. In this case you may neither jump-start the vehicle nor charge
the battery. Let the battery thaw first. The service life of a thawed-out battery may be shorter.
The starting characteristics can be impaired, particularly at low temperatures. Have the
thawed-out battery checked at a qualified specialist workshop.
Jump-starting293
Roadside Assistance
Z