check engine MERCEDES-BENZ CLS 2014 Owner's Guide

Display messagesPossible causes/consequences andSolutions
Adaptive Highbeam
Assist Inoperative
Adaptive Highbeam Assistisfaulty.
XVisitaqualified specialist workshop.
Adaptive Highbeam
Assist Currently
Unavailable See
Operator's Manual
Adaptive Highbeam Assist is deactivated and temporarily
inoperative. Possible causes are:
Rthe windshieldinthe camera's field of vision is dirty.
Rvisibility is impaired due to heavy rain, snow or fog.
XCleanthe windshield.
If the system detectsthat the camera is fully operational again,
theAdaptive Highbeam Assist Now Availablemessage is
displayed.
Adaptive Highbeam Assist is operational again.
Engine
Display messagesPossible causes/consequencesandSolutions

Check Coolant
Level See
Operator'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.
XAdd coolant, observing the warning notes before doing so
(Ypage 308).
XIf coolant needs to be added more often than usual, have the
engine coolant system checked ataqualified specialist
workshop.
The fan motor is faulty.
XAt coolant temperatures below 248‡(120 †), drive to the
nearest qualified specialist workshop.
XAvoid subjecting the engine to heavy loads, e.g. driving in
mountainous terrain, and stop-and-go traffic.
248Display messages
On-board computer and displays

Display messagesPossible causes/consequences andSolutions
The battery is notbeing charged.
Awarning tone also sounds.
Possible causes are:
Radefective alternator
Ratornpoly-V-belt
Ramalfunctionintheelectronics
XPull overand stop the vehiclesafelyand switch off the engine,
paying attentiontoroadand traffic conditions.
XSecure the vehicleagainst rolling away (Ypage 167).
XOpenthe hood.
XCheck whether the poly-V-belt is torn.
If the poly-V-belt is torn:
!Do not continue driving. The engine could otherwise overheat.
XConsultaqualified specialist workshop.
If the poly-V-belt is not damaged:
XVisitaqualified specialist workshop.

Check Engine Oil
Level At Next
Refueling
The engine oil level has dropped to the minimum level.
Awarning tone also sounds.
XCheckthe oil level when next refueling, at the latest
(Ypage 307).
XIf necessary, add engine oil (Ypage 308).
XHave the engine checked ataqualified specialist workshop if
engine oil needs to be added 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.
250Display messages
On-board computer and displays

Display messagesPossible causes/consequences andSolutions

Check Engine Oil
Level(Add1quart)
AMGvehicles: theengineoil level is toolow.
XCheckthe oil level when next refueling, at the latest
(Ypage 307).
XIf necessary, add engine oil (Ypage 308).
XHave the engine checked ataqualified specialist workshop if
engine oil needs to be added 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.

Fuel Level Low
The fuel level has dropped into the reserve range.
XRefuel at the nearest gas station.
There is onlyavery small amount of fuel in the fuel tank.
XRefuel at the nearest gas station without fail.

Gas Cap Loose
The fuel system pressure is too low. The fuel filler cap is not closed
correctly or the fuel system is leaking.
XCheck that the fuel filler cap is correctly closed.
If the fuel filler cap is not correctly closed:
XClose the fuel filler cap.
If the fuel filler cap is correctly closed:
XVisitaqualified specialist workshop.
Driving systems
Display messagesPossible causes/consequencesandSolutions


Attention Assist:
TakeaBreak!
Based on certain criteria, ATTENTION ASSIST has detected fatigue
oralack of concentrationonthe part of thedriver.Awarning tone
alsosounds.
XIf necessary,takeabreak.
During long journeys, take regular breaks in good time so you get
enoughrest.


AttentionAssist
Inoperative
ATTENTION ASSIST is inoperative.
XVisitaqualified specialist workshop.
Display messages251
On-boar dc omputer and displays
Z

Display messagesPossible causes/consequences andSolutions
DISTRONIC PLUS
Currently
Unavailable See
Operator'sManual
DISTRONIC PLUSistemporarily inoperative.
Possible causes are:
Rfunction is impaired due to heavy rain or snow.
Rthe sensors in the radiator grill and the bumper are dirty.
Rthe radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio
stations or other sources of electromagnetic radiation.
Rthe system is outside the operating temperature range.
Rthe on-board voltage is too low.
Awarning tone also sounds.
When thecauses statedabovenolonger apply, thedisplay
message disappears.
DISTRONICisoperational again.
If thedisplay message does notdisappear:
XPull over and stop the vehicle safely as soon as possible,paying
attention to road and traffic conditions.
XSecure the vehicle against rollingaway (Ypage 167).
XClean the sensors in the radiator grill and the bumper
(Ypage 315).
XRestartthe engine.
DISTRONIC PLUS
Inoperative
DISTRONIC PLUS is defective.
The following may have also failed:
RBAS PLUS (Brake Assist System PLUS)
RPRE-SAFE®Brake
Awarning tone also sounds.
XVisitaqualified specialist workshop.
DISTRONIC PLUS
Suspended
You have depressed the accelerator pedal. DISTRONIC PLUS is no
longer controlling the speed of the vehicle.
XRemove your foot from the accelerator pedal.
DISTRONIC PLUS
---mph
An activation condition for DISTRONIC PLUS is not fulfilled.
XCheck the activation conditionsfor DISTRONIC PLUS
(Ypage 177).
256Display messages
On-boar dc omputer and displays

Display messagesPossible causes/consequences andSolutions

Remove 'Start'
Button and Insert
Key
The KEYLESS-GO keycan continuouslynotbe detected.
KEYLESS-GO is temporarily malfunctioningorisdefective. A
warningtonealso sounds.
XInserttheSmartKey into theignition lockand turnittothe
desiredposition.
XVisitaqualified specialist workshop.

Close Doors to
LockVehicle
At leastone door is open.Awarning tone also sounds.
XClose all doorsand lockthe vehicle again.
Indicator and warning lamps in the
instrument cluster
Warning and indicator lamps
overview
Low-beam headlamps
(Ypage 118)
Parking lamps (Ypage 118)
High-beam headlamps
(Ypage 119)

Turn signal (Ypage 119)
Seat belts (Ypage 265)
(USA) Brakes (Ypage 266)

(Canada)Brakes (Ypage266)
ABS (Ypage267)
ESP®(Ypage269)
ESP®OFF (Ypage269)
SPORT handling mode in
AMG vehicles (Ypage270)
SRS (Ypage272)
\nCheck Engine (Ypage273)
Reserve fuel (Ypage273)
Coolant (Ypage273)
Distance warning signal
(Ypage275)
Tire pressure monitor
(Ypage276)
264Indicator and warninglamps in the instrument cluster
On-board computer and displays

ProblemPossible causes/consequences andSolutions

The yellowESP®
warning lamp flashes
while the vehicle is in
motion.
ESP®or traction control has intervened because there isarisk of
skidding or at least one wheel has started to spin.
Cruise control or DISTRONIC PLUS is deactivated.
XWhen pulling away,only depress the accelerator pedal as far as
necessary.
XEase off the accelerator pedal while the vehicle is in motion.
XAdapt your driving style to suit the road and weather conditions.
XDo not deactivate ESP®.
For exceptions, see: (Ypage 68).

The yellowESP®OFF
warning lamp is lit while
the engine is running.
ESP®is deactivated.
GWARNING
If ESP®is switched off, ESP®is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
XReactivate ESP®.
For exceptions, see: (Ypage 68).
XAdapt your driving style to suit the road and weather conditions.
If ESP®cannot be activated:
XDrive on carefully.
XHave ESP®checked ataqualified specialist workshop.

AMG vehicles only:
The yellow SPORT
handling mode warning
lamp is lit while the
engine is running.
SPORT handling mode is activated.
GWARNING
When SPORT handling mode is switched on, ESP®is unable to
stabilize the vehicle.
There is an increased risk of skidding and an accident.
XOnly switch to SPORT handling mode in accordance with the
conditionsdescribed in the "Activating/deactivating SPORT
handling mode" section (Ypage 70).
270Indicator and warning lampsinthe instrument cluster
On-board computer and displays

ProblemPossible causes/consequences andSolutions
(USA only)

(Canada only)
The red brake system
warning lamp comes on
while the vehicle is
moving.Awarning tone
also sounds.
You are driving with the parking brake applied.
XRelease the parking brake.
The warning lamp goes out and the warning tone ceases.

The red SRS warning
lamp is lit while the
engine is running.
There isamalfunction in the SRS (Supplemental Restraint
System).
GWARNING
The air bags or Emergency Tensioning Devices may either be
triggered unintentionally or, in the event of an accident, may not
be triggered.
There is an increased risk of injury.
XDrive on carefully.
XHave SRS checked ataqualified specialist workshop
immediately.
For further information about SRS, see (Ypage 41).
272Indicator and warning lampsinthe instrument cluster
On-board computer and displays

Engine
ProblemPossible causes/consequences andSolutions
\n
The yellow Check
Enginewarning lamp
lightsupwhile the
engineisrunning.
Theremay beamalfunction, for example:
Rin theenginemanagement
Rin thefuel injection system
Rin theexhaust system
Rin theignition system
Rin thefuel system
The emission limit values may be exceeded and theenginemay
be runninginemergencymode.
XHavethevehicle checked as soon as possible ataqualified
specialist workshop.
iIn somestates, you must immediately visitaqualified
specialist workshopassoon as theyellow CheckEngine 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.

The yellow reserve fuel
warning lamp lights up
while the engine is
running.
The fuel level has dropped into the reserve range.
XRefuel at the nearest gas station.

The yellow reserve fuel
warning lamp flashes
while the vehicle is in
motion.
In addition, the\n
Check Enginewarning
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.
XCheck that the fuel filler cap is correctly closed.
XIf the fuel filler cap is not correctly closed:close the fuel filler
cap.
XIf the fuel filler cap is closed:visitaqualified specialist
workshop.

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.
XPull 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.
XSecure the vehicle against rolling away (Ypage 167).
XConsultaqualified specialist workshop.
Indicator and warning lampsinthe instrument cluster273
On-board computer and displays
Z

ProblemPossible causes/consequences andSolutions

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.
XObserve the additional display messages in the multifunction
display.
XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 167).
XLeave the vehicle and keepasafe distance from the vehicle until
the engine has cooled down.
XCheck the coolant level and add coolant, observing the warning
notes (Ypage 308).
XIf you need to add coolant more often than usual, have the
engine coolant system checked.
XMake sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
XDo not start the engine again until the coolant temperature is
under 248‡(120 †). Otherwise,the engine couldbedamaged.
XDrive to the nearest qualified specialist workshop.
XAvoid subjecting the engine to heavy loads, e.g. driving in
mountainousterrain, and stop-and-go traffic.

The red coolant
warning lamp comes on
while the engine is
running.Awarning 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.
GWARNING
The engine is not being cooledsufficiently and may be damaged.
Do not drive whenyour engine is overheated. This can cause some
fluids which may have leaked into the engine compartment to
catchfire.
Steam from the overheated engine can also cause serious burns
which can occur just by opening the hood.
There isarisk of injury.
XObserve the additional display messages in the multifunction
display.
XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 167).
274Indicator and warning lampsinthe instrument cluster
On-board computer and displays

ProblemPossible causes/consequences andSolutions
XLeave the vehicle and keepasafe distance from the vehicle until
the engine has cooled down.
XCheck the coolant level and add coolant, observing the warning
notes (Ypage 308).
XIf you need to add coolant more often than usual, have the
engine coolant system checked.
XMake sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
XAt coolant temperatures under 248‡(120 †), drive to the next
qualified specialist workshop.
XAvoid subjecting the engine to heavy loads, e.g. driving in
mountainousterrain, and stop-and-go traffic.
Driving systems
ProblemPossible causes/consequencesandSolutions

The red distance
warning lamp lights up
while the vehicle is in
motion.
The distance to the vehicle in front is too smallfor the speed
selected.
XIncrease the distance.

The red distance
warning lamp lights up
while the vehicle is in
motion.Awarning tone
also sounds.
You are approachingavehicle orastationary obstacle in your line
of travel at too highaspeed.
XBe prepared to brake immediately.
XPay careful attention to the traffic situation. You may have to
brake or take evasive action.
Further information on PRE-SAFE®Brake (Ypage 72).
Indicator and warning lampsinthe instrument cluster275
On-board computer and displays
Z