check engine light MERCEDES-BENZ CLS-Class 2015 W218 User Guide

Problem
Possible causes/consequences and
M
MSolutions The engine is not run-
ning smoothly and is
misfiring. There is a malfunction in the engine electronics or in a mechanical
component of the engine management system.
X Only depress the accelerator pedal slightly.
Otherwise, non-combusted fuel may get into the catalytic con-
verter and damage it.
X Have the cause rectified immediately at a qualified specialist
workshop. The coolant tempera-
ture gauge shows a
value above 248 ‡
(120 †). The coolant level is too low. The coolant is too hot and the engine
is no longer being cooled sufficiently.
X Stop as soon as possible and allow the engine and the coolant to
cool down.
X Check the coolant level (Y page 315). Observe the warning
notes as you do so and add coolant if necessary. Automatic transmission
Important safety notes
G
WARNING
If the engine speed is above the idling speed
and you engage transmission position Dor R,
the vehicle could pull away suddenly. There is a risk of an accident.
When engaging transmission position Dor R,
always firmly depress the brake pedal and do not simultaneously accelerate. G
WARNING
The automatic transmission switches to neu-
tral position Nwhen you switch off the engine.
The vehicle may roll away. There is a risk of an
accident.
After switching off the engine, always switch
to parking position P. Prevent the parked vehi-
cle from rolling away by applying the parking
brake. Selector lever (AMG vehicles)
Overview of transmission positions j
Park position with parking lock
k Reverse gear
i Neutral
h Drive
Transmission position and drive pro-
gram display !
If the transmission position display in the
multifunction display is not working, you
should pull away carefully to check whether the desired transmission position is
engaged. Ideally, you should select trans-
mission position Dand automatic drive pro-
gram Cor S. Automatic transmission
157Driving and parking Z

R
In order to prevent any salt build-up, apply
the brakes occasionally while paying atten- tion to the traffic conditions.
R Carefully depress the brake pedal and the
beginning and end of a journey.
R Maintain a greater distance to the vehicle
ahead.
Servicing the brakes !
If the red brake warning lamp lights up in
the instrument cluster and you hear a warn- ing tone while the engine is running, the
brake fluid level may be too low. Observe
additional warning messages in the multi-
function display.
The brake fluid level may be too low due to
brake pad wear or leaking brake lines.
Have the brake system checked immedi-
ately. This work should be carried out at a
qualified specialist workshop.
! Vehicles with 4MATIC:
function or per-
formance tests may only be carried out on
a 2-axle dynamometer. If you are planning
to have the vehicle tested on such a dyna-
mometer, contact an authorized Mercedes-
Benz Center to obtain further information
first. Otherwise, you could damage the
drive train or the brake system.
! Vehicles with 4MATIC:
as the ESP®
sys-
tem operates automatically, the engine and
the ignition must be switched off (Smart-
Key in position 0or 1in the ignition lock or
Start/Stop button in position 0or 1) while
the parking brake is being tested on a brake
dynamometer.
Braking maneuvers triggered automatically
by ESP ®
may seriously damage the brake
system. !
Vehicles with 4MATIC:
as the ESP®
sys-
tem operates automatically, the engine and
the ignition system must be switched off
(SmartKey in position 0or 1in the ignition
lock or Start/Stop button in position 0or 1)
when:
R testing the parking brake on a brake
dynamometer.
R you intend to have the vehicle towed with
one of the axles raised.
Braking maneuvers triggered automatically
by ESP ®
may seriously damage the brake
system.
All checks and maintenance work on the
brake system must be carried out at a quali-
fied specialist workshop. Consult a qualified
specialist workshop to arrange this.
Have brake pads installed and brake fluid
replaced at a qualified specialist workshop.
If the brake system has only been subject to
moderate loads, you should test the function-
ality of your brakes at regular intervals. To do so, press firmly on the brake pedal when driv-
ing at a high speed. This improves the grip of
the brake pads.
You can find a description of Brake Assist
(BAS) on (Y page 71) or of BAS PLUS on
(Y page 71).
The braking characteristics of the vehicle can be seriously impaired if:
R brake pads other than those recommended
are installed
R the recommended brake fluid is not used
Safe braking can no longer be guaranteed.
AMG high-performance and ceramic
brakes The high-performance brake system is only
available on AMG vehicles.176
Driving tipsDriving and parking

If a system malfunction occurs, the vehicle is
braked to a standstill. To drive on, depress the
accelerator again. Rear view camera
General notes Example: CLS Coupe
Rear view camera :is an optical parking and
maneuvering aid. It shows the area behind
your vehicle with guidelines in the Audio 20 or
COMAND display.
The area behind the vehicle is displayed as a
mirror image, as in the rear view mirror.
i The text shown in the Audio 20 or
COMAND display depends on the language
setting. The following are examples of rear view camera messages in the COMAND
display.
Important safety notes The rear view camera is only an aid. It is not a
replacement for your attention to your imme- diate surroundings. You are always responsi-
ble for safe maneuvering and parking. When
maneuvering or parking, make sure that there are no persons, animals or objects in the area
in which you are maneuvering.
Under the following circumstances, the rear
view camera will not function, or will function
in a limited manner:
R if the trunk lid or tailgate is open
R in heavy rain, snow or fog R
at night or in very dark places
R if the camera is exposed to very bright light
R if the area is lit by fluorescent bulbs or LED
lighting (the display may flicker)
R if there is a sudden change in temperature,
e.g. when driving into a heated garage in
winter
R if the camera lens is dirty or obstructed.
Observe the notes on cleaning
(Y page 321)
R if the rear of your vehicle is damaged. In this
event, have the camera position and setting
checked at a qualified specialist workshop
The field of vision and other functions of the
rear view camera may be restricted due to
additional accessories on the rear of the vehi-
cle (e.g. license plate holder, bicycle rack).
On vehicles with height-adjustable chassis,
leaving the standard height can result in inac- curacies in the guide lines, depending on
technical conditions.
i The rear view camera is protected from
raindrops and dust by means of a flap.
When the rear view camera is activated,
this flap opens.
The flap closes again when:
R you have finished the maneuvering proc-
ess
R you switch off the engine
R you open the trunk
Observe the notes on cleaning
(Y page 321).
For technical reasons, the flap may remain
open briefly after the rear view camera has been deactivated.
Activating/deactivating the rear view
camera X
To activate: make sure that the SmartKey
is in position 2in the ignition lock.
X Make sure that the Activation by R Activation by R
gear
gear function is selected in Audio 20 or Driving systems
205Driving and parking Z

Display messages
Possible causes/consequences and
M
MSolutions #
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 170).
X Observe the instructions in the #See SeeOperator's
Operator's Manual
Manual
display message.
X Consult a qualified specialist workshop. #
Start Engine See Start Engine See
Operator's Manual Operator's Manual The engine is switched off and the battery charge level is too low.
X Switch off electrical consumers that you do not need, such as
the rear window defroster and interior lighting.
X Leave the engine running for a few minutes or drive a long dis-
tance.
The battery is being charged. 4
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.
! Avoid long journeys with too little engine oil. The engine will
otherwise be damaged.
X Check the oil level when next refueling, at the latest
(Y page 313).
X If necessary, add engine oil (Y page 314).
X Have the engine checked at a qualified specialist workshop if
engine oil needs to be added more often than usual.
Information on approved engine oils can be obtained from any
qualified specialist workshop or on the Internet at http://
bevo.mercedes-benz.com. 4
Check Engine Oil Check Engine Oil
Level Level
(Add
(Add1
1quart)
quart) AMG vehicles: the engine oil level is too low.
!
Avoid long journeys with too little engine oil. The engine will
otherwise be damaged.
X Check the oil level when next refueling, at the latest
(Y page 313).
X If necessary, add engine oil (Y page 314).
X Have the engine checked at a qualified specialist workshop if
engine oil needs to be added more often than usual.
Information on approved engine oils can be obtained from any
qualified specialist workshop or on the Internet at http://
bevo.mercedes-benz.com. 260
Display
messagesOn-board computer and displays

Engine
Problem
Possible causes/consequences and
M
MSolutions ;
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.
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. 8
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. 8
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 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 170).
X Consult a qualified specialist workshop. 280
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem
Possible causes/consequences and
M
MSolutions 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 315).
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
M MSolutions ·
The red distance warn-
ing lamp lights up while
the vehicle is in motion. A warning tone also
sounds. You are approaching a vehicle, a pedestrian or a stationary obsta-
cle 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.
Observe the additional information on PRE‑ SAFE®
Brake
(Y page 79).
Observe the additional information on the distance warning func-
tion of COLLISION PREVENTION ASSIST PLUS (Y page 73).282
Warning and indicator lamps in the instrument clusterOn-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
turned off.
X Pull release lever :on the hood.
The hood is released. X
Reach into the gap, pull hood catch han-
dle ;up and lift the hood.
If you lift the hood by approximately 15 in
(40 cm), the hood is opened and held open automatically by the gas-filled strut.
Closing the hood 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. Open it 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 engine
speeds.
Depending on the engine, the oil dipstick may be 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.
Checking the oil level using the oil dip-
stick G
WARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and touch only the components described in the
following. Engine compartment
313Maintenance and care Z

!
Only use battery chargers with a maxi-
mum charging voltage of 14.8 V.
! Only charge the battery using the jump-
starting connection point.
The jump-starting connection point is in the
engine compartment (Y page 335).
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 335).
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 charge the battery nor jump-
start the vehicle. The service life of a thawed-
out battery may be shorter. The starting char- acteristics may be impaired, especially at low
temperatures. Have the thawed-out battery
checked at a qualified specialist workshop.
Never charge a battery still installed in the
vehicle unless a battery charger unit
approved by Mercedes-Benz is being used . 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 bat- tery in its installed position. Contact an
authorized Mercedes-Benz Center for further
information and availability. Read the battery charger's operating instructions before
charging the battery. 334
Battery (vehicle)Roadside Assistance