check engine MERCEDES-BENZ CLA 2019 Owner's Manual

Important safety notes
GWARNING
If you operate information systems and com-
munication equipment integrated in the vehi-
cle when driving, you may be distracted from
the traffic situation. You could also lose con-
trol of the vehicle. There is a risk of an acci-
dent.
Only operate this equipment when the traffic
situation permits. If you are not sure that this
is possible, park the vehicle paying attention
to traffic conditions and operate the equip-
ment when the vehicle is stationary.
You must observe the legal requirements for thecountry in which you are currently driving whenoperating the on-board computer.
GWARNING
If the instrument cluster has failed or mal-
functioned, you may not recognize function
restrictions in systems relevant to safety. The
operating safety of your vehicle may be
impaired. There is a risk of an accident.
Drive on carefully. Have the vehicle checked
at a qualified specialist workshop immedi-
ately.
The on-board computer only shows messages orwarnings from certain systems in the multifunc-tion display. You should therefore make sureyour vehicle is operating safely at all times.
If the operating safety of your vehicle isimpaired, pull over as soon as it is safe to do so.Contact a qualified specialist workshop.
For an overview, see the instrument panel illus-tration (Ypage 33).
Displays and operation
Instrument cluster lighting
The light sensor in the instrument cluster auto-matically controls the brightness of the multi-function display. In daylight, the displays in theinstrument cluster are not illuminated.
The lighting in the instrument cluster, in the dis-plays and the controls in the vehicle interior canbe adjusted using the brightness control knob.
The brightness control knob is located on thebottom left of the instrument cluster(Ypage 33).
XTurn the brightness control knob clockwise orcounter-clockwise.If the light switch is set to theX,`orXposition, the brightness is dependentupon the brightness of the ambient light.
Speedometer with segments
The speedometer is only divided into segmentsin vehicles with Active Distance AssistDISTRONIC.
The segments in the speedometer indicatewhich speed range is available.
RActive Distance Assist DISTRONIC activated(Ypage 152):
One or two segments in the set speed rangelight up.
RActive Distance Assist DISTRONIC detects avehicle in front moving more slowly than thestored speed:
The segments between the speed of the vehi-cle in front and the stored speed light up.
Tachometer
!Do not drive in the overrevving range, as thiscould damage the engine.
The red band in the tachometer indicates theengine's overrevving range.
The engine is limited within a range to protectthe engine when the red band is reached.
Outside temperature display
You should pay special attention to road condi-tions when temperatures are around freezingpoint.
Bear in mind that the outside temperature dis-play indicates the temperature measured anddoes not record the road temperature.
The outside temperature display is in the multi-function display (Ypage 181).
178Displays and operation
On-board computer and displays

Warning/indicatorlamp
QQSignal type
Possible causes/consequences andPPSolutions
$IQI(USA only),$(Canada only): the red indicator lamp for the electricparking brake flashes or lights up and/or the yellow warning lamp for the electricparking brake lights up.
XObserve the additional display messages in the multifunction display.
uQThe red restraint system warning lamp is lit while the engine is running.
The restraint system is malfunctioning.
GWARNING
The air bags or Emergency Tensioning Devices may either be triggered uninten-tionally or, in the event of an accident, may not be triggered.
There is an increased risk of injury.
XObserve the additional display messages in the multifunction display.
XDrive on carefully.
XContact a qualified specialist workshop and have the restraint system checked.
For further information about the restraint system, see (Ypage 40).
Engine
Warning/indicatorlamp
QQSignal type
Possible causes/consequences andPPSolutions

Example: engine oil cap
XTurn capCcounter-clockwise and remove it.
XAdd engine oil.If the oil level is at or below the MIN mark onthe oil dipstick, add 1.1 US qt (1.0 liter) ofengine oil.
XReplace capCon the filler neck and turnclockwise.Ensure that the cap locks into place securely.
XCheck the oil level again with the oil dipstick(Ypage 261).
Further information on engine oil (Ypage 322).
Checking and adding other service
products
Checking coolant level
GWARNING
The cooling system is pressurized, particularly
when the motor is warm. If you open the cap,
you could be scalded if hot coolant sprays out.
There is a risk of injury.
Let the engine cool down before you open the
cap. Wear protective gloves and protective
eyewear when opening. Open the cap slowly
to release pressure.
!The coolant level must only be checked andcorrected when the engine has cooled down(coolant temperature under 104 ‡ (40 †).Checking the coolant level when the coolanttemperature is over 104‡(40 †) can lead todamage to the engine or the engine coolingsystem.
XPark the vehicle on a level surface.
Only check the coolant level when the vehicleis on a level surface and the engine has cooleddown.
XTurn the SmartKey to positionHin the igni-tion lock (Ypage 123).
XCheck the coolant temperature display in theinstrument cluster.The coolant temperature must be below104 ‡ (40 †).
XTurn the SmartKey to positionZ(Ypage 123) in the ignition lock .
XSlowly turn capCcounter-clockwise and torelieve excess pressure.
XTurn capCfurther counter-clockwise andremove it.If the coolant is at the level of marker bar

Information about Service
Resetting the ASSYST PLUS service
interval display
!If the ASSYST PLUS service interval displayhas been inadvertently reset, this setting canbe corrected at a qualified specialist work-shop.
Have service work carried out as described inthe Maintenance Booklet. This may otherwiselead to increased wear and damage to themajor assemblies or the vehicle.
A qualified specialist workshop, e.g. an author-ized Mercedes-Benz Center, will reset theASSYST PLUS service interval display after theservice work has been carried out. You can alsoobtain further information on maintenancework, for example.
Special service requirements
The specified maintenance interval takes onlythe normal operation of the vehicle intoaccount. Under arduous operating conditions orincreased load on the vehicle, maintenancework must be carried out more frequently, forexample:
Rregular city driving with frequent intermediatestops
Rif the vehicle is primarily used to travel shortdistances
Ruse in mountainous terrain or on poor roadsurfaces
Rif the engine is often left idling for long periods
Rin particularly dusty conditions, or if air-recir-culation mode is frequently used
In these or similar operating conditions, havethe interior filter, engine air cleaner, engine oiland oil filter, for example, changed more fre-quently. Under arduous operating conditions,the tires must be checked more often. Furtherinformation can be obtained at a qualified spe-cialist workshop, e.g. an authorized Mercedes-Benz Center.
Driving abroad
An extensive Mercedes-Benz Service network isalso available in other countries. You can obtainfurther information from any authorizedMercedes-Benz Center.
Care
General notes
HEnvironmental note
Dispose of empty packaging and cleaning
cloths in an environmentally responsible man-
ner.
!When cleaning your car, do not use:
Rdry, coarse or hard cloths
Rabrasive cleaning agents
Rsolvents
Rcleaning agents containing solvents
Do not scrub.
Do not touch the surfaces and films with hardobjects, e.g. rings or ice scrapers. Otherwise,you may scratch or damage the surfaces andfilms.
!Do not park your vehicle for a long period oftime directly after cleaning, particularly aftercleaning the wheel rim with wheel cleaner.Wheel cleaner can lead to the increased cor-rosion of the brake discs and pads. Therefore,drive for a few minutes after cleaning. Byheating up the brakes, the brake discs andpads dry. The vehicle can then be parked for along period of time.
Regular care of your vehicle is a condition forretaining the quality in the long term.
Use care products and cleaning agents recom-mended and approved by Mercedes-Benz.
Washing the vehicle and cleaning the
paintwork
Automatic car wash
GWARNING
Braking efficiency is reduced after washing
the vehicle. There is a risk of an accident.
After the vehicle has been washed, brake
carefully while paying attention to the traffic
conditions until full braking power is restored.
!When Active Distance Assist DISTRONIC orthe HOLD function is activated, the vehiclebrakes automatically in certain situations.
Care265
Maintenance and care
Z

XMake sure that the engine cannot be startedvia your smartphone (Ypage 124).
XMake sure that the passengers are not endan-gered as they do so. Make sure that no one isnear the danger area while a wheel is beingchanged. Anyone who is not directly assistingin the wheel change should, for example,stand behind the barrier.
XGet out of the vehicle. Pay attention to trafficconditions when doing so.
XClose the driver's door.
MOExtended tires (tires with run-flat
properties)
General notes
With MOExtended tires (tires with run flat char-acteristics), you can continue to drive your vehi-cle even if there is a total loss of pressure in oneor more tires. The affected tire must not showany clearly visible damage.
You can recognize a MOExtended tire by theMOExtended marking which appears on thesidewall of the tire. You will find this markingnext to the tire size designation, the load-bear-ing capacity and the speed index (Ypage 305).
MOExtended tires may be used only in conjunc-tion with an activated tire pressure loss warningsystem (Canada only) or tire pressure monitor(USA only).
If a pressure loss warning message appearsin the multifunction display:
Robserve the instructions in the display mes-sages (Ypage 213).
Rcheck the tire for damage
Rif driving on, observe the following notes
The driving distance possible in run-flat mode isapproximately 50 miles (80 km) when the vehi-cle is partially laden. When the vehicle is fullyladen it is approximately 19 miles (30 km).
In addition to the vehicle load, the driving dis-tance possible depends upon:
Rvehicle speed
Rroad condition
Routside temperature
The driving distance possible in run-flat modemay be reduced by extreme driving conditionsor maneuvers, or it can be increased through amoderate style of driving.
The driving distance possible in run-flat mode iscounted from the moment the tire pressure losswarning appears in the multifunction display.
You must not exceed a maximum speed of50 mph (80 km/h).
When replacing one or all tires, please observethe following specifications for your vehicle'stires:
Rsize
Rtype and
Rthe "MOExtended" marking
If a tire has gone flat and cannot be replacedwith a MOExtended tire, a standard tire may beused as a temporary measure. Make sure thatyou use the proper size and type (summer orwinter tire).
Vehicles equipped with MOExtended tires arenot equipped with a TIREFIT kit at the factory. Itis therefore recommended that you additionallyequip your vehicle with a TIREFIT kit if you mounttires that do not feature run-flat properties, e.g.winter tires. A TIREFIT kit may be obtained froma qualified specialist workshop.
Important safety notes
GWARNING
When driving in emergency mode, the driving
characteristics deteriorate, e.g. when corner-
ing, accelerating quickly and when braking.
There is a risk of an accident.
Do not exceed the stated maximum speed.
Avoid abrupt steering and driving maneuvers,
and driving over obstacles (curbs, potholes,
off-road). This applies in particular to a laden
vehicle.
Stop driving in emergency mode if:
Ryou hear banging noises.
Rthe vehicle starts to shake.
Ryou see smoke and smell rubber.
RESP®is intervening constantly.
Rthere are tears in the sidewalls of the tire.
After driving in emergency mode, have the
wheel rims checked at a qualified specialist
workshop with regard to their further use. The
defective tire must be replaced in every case.
Flat tire275
Breakdown assistance
Z

plenty of clean water and seek medical atten-
tion.
HEnvironmental note
Batteries contain pollutants.
It is illegal to dispose of them
with the household rubbish.
They must be collected sep-
arately and disposed of in an
environmentally responsible
recycling system.
Dispose of batteries in an
environmentally responsible
manner. Take discharged
batteries to a qualified spe-
cialist workshop or to a col-
lection point for used batter-
ies.
!Have the battery regularly checked at aqualified specialist workshop.
Comply with the service intervals in the Main-tenance Booklet, or contact a qualified spe-cialist workshop for more information.
!You should have all work involving the bat-tery carried out at a qualified specialist work-shop. In the exceptional case that it is neces-sary for you to disconnect the battery your-self, make sure that:
Rswitch off the engine and remove theSmartKey. On vehicles with KEYLESS-GO,make sure that the ignition is switched off.Check that all the indicator lamps in theinstrument cluster are off. Otherwise, elec-tronic components, such as the alternator,may be damaged.
Ryou first remove the negative terminalclamp and then the positive terminalclamp. Never swap the terminal clamps.Otherwise, the vehicle's electronic systemmay be damaged.
Rin vehicles with automatic transmission,the transmission is locked in position]after the battery is disconnected. The vehi-cle is secured against rolling away. You canthen no longer move the vehicle.
The battery and the cover of the positive ter-minal clamp must be installed securely duringoperation.
Comply with safety precautions and take pro-tective measures when handling batteries.
Risk of explosion.
Fire, open flames and smoking areprohibited when handling the bat-tery. Avoid creating sparks.
Battery acid is caustic. Avoid contactwith skin, eyes or clothing.
Wear suitable protective clothing,especially gloves, apron and face-guard.
Rinse any acid spills immediatelywith clear water. Contact a physicianif necessary.
Wear eye protection.
Keep children away.
Observe this Operator's Manual.
For safety reasons, Mercedes-Benz recom-mends that you only use batteries which havebeen tested and approved for your vehicle byMercedes-Benz. These batteries provideincreased impact protection to prevent vehicleoccupants from suffering acid burns should thebattery be damaged in the event of an accident.
In order for the battery to achieve the maximumpossible service life, it must always be suffi-ciently charged.
Like other batteries, the vehicle battery maydischarge over time if you do not use the vehicle.In this case, have the battery disconnected at aqualified specialist workshop. You can alsocharge the battery with a charger recommendedby Mercedes-Benz. Contact a qualified special-ist workshop for further information.
Have the battery condition of charge checkedmore frequently if you use the vehicle mainly forshort trips or if you leave it standing idle for alengthy period. Consult a qualified specialistworkshop if you wish to leave your vehicleparked for a long period of time.
280Battery (vehicle)
Breakdown assistance

Only replace a battery with a battery that hasbeen recommended by Mercedes-Benz.
Remove the SmartKey if you park the vehicleand do not require any electrical consumers.The vehicle will then use very little energy, thusconserving battery power.
If the power supply has been interrupted, e.g. ifyou reconnect the battery, you will have to:
Rset the clock using the multimedia system(see the Digital Operator's Manual)
Rreset the function for folding the exterior mir-rors in/out automatically, by folding the mir-rors out once (Ypage 98)
Charging the battery
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
ventilation while charging and jump-starting.
Do not lean over a battery.
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 maximumcharging voltage of 14.8 V.
!Only charge the battery using the jump-starting connection point.
The jump-starting connection point is in theengine compartment (Ypage 282).
XOpen the hood.
XConnect the battery charger to the positiveterminal and ground point in the same orderas when connecting the donor battery in thejump-starting procedure (Ypage 282).
If the indicator/warning lamps do not light up inthe instrument cluster at low temperatures, it isvery likely that the discharged battery has fro-zen. In this case you may neither jump-start thevehicle nor charge the battery. The service life ofa thawed-out battery may be shorter. The start-ing characteristics can be impaired, particularlyat low temperatures. Have the thawed-out bat-tery checked at a qualified specialist workshop.
Only charge the installed battery with a batterycharger which has been tested and approved byMercedes-Benz. A battery charger unit speciallyadapted for Mercedes-Benz vehicles and testedand approved by Mercedes-Benz is available asan accessory. It permits the charging of the bat-tery in its installed position. Contact an author-ized Mercedes-Benz Center for further informa-tion and availability. Read the battery charger'soperating instructions before charging the bat-tery.
Replacing the 12 V battery
Observe the notes on the 12 V battery(Ypage 279).
Mercedes-Benz recommends that you have the12 V battery replaced at a qualified specialistworkshop, e.g. at an authorized Mercedes-BenzCenter.
If you want to replace the battery yourself,observe the following notes:
RAlways replace a defective battery with a bat-tery which meets the specific requirements ofthe vehicle.
The vehicle is equipped with a battery usingAGM (absorbent glass mat) technology or abattery using EFB (enhanced flooded battery)technology. Full vehicle functionality is guar-anteed only with an AGM or EFB battery. Ifreplacement is necessary, always use the bat-tery technology originally installed. Switchingbetween the battery technologies is not per-mitted. For safety reasons, Mercedes-Benzrecommends that you only use batteries
Battery (vehicle)281
Breakdown assistance
Z

If the indicator/warning lamps do not light up in the instrument cluster at low temperatures, it is verylikely that the discharged battery has frozen. In this case you may neither jump-start the vehicle norcharge 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-outbattery checked at a qualified specialist workshop.
Do not start the vehicle using a rapid charging device. If your vehicle's battery is discharged, theengine can be jump-started from another vehicle or from a second battery using jumper cables.Observe the following points:
RThe battery is not accessible in all vehicles. If the other vehicle's battery is not accessible, jump-start the vehicle using a second battery or a jump-starting device.
RYou may only jump-start the vehicle when the engine and exhaust system are cold.
RDo not start the engine if the battery is frozen. Let the battery thaw first.
ROnly jump-start from batteries with a 12 V voltage rating.
ROnly use jumper cables that are not damaged and have a sufficient cross-section and insulatedterminal clamps.
RMake sure that the two vehicles do not touch.
Make sure that:
RThe jumper cables are not damaged.
RNon-insulated parts of the terminal clamps do not come into contact with other metal parts whilethe jumper cables are connected to the battery.
RThe jumper cables cannot come into contact with parts that can move when the engine is running,such as the V-belt pulley or the fan.
XSecure the vehicle by applying the electric parking brake.
XShift the transmission to position].
XTurn the SmartKey to positionZin the ignition lock and remove it.
XSwitch off all electrical consumers, e.g. rear window defroster, lighting, etc.
XOpen the hood.
Jump-starting283
Breakdown assistance
Z

wise, components or systems could be dam-aged.
!Make sure that no moisture can enter thefuse box when the cover is open.
!When closing the cover, make sure that it islying correctly on the fuse box. Moisture seep-ing in or dirt could otherwise impair the oper-ation of the fuses.
The fuses in your vehicle serve to close downfaulty circuits. If a fuse blows, all the compo-nents on the circuit and their functions stopoperating.
Blown fuses must be replaced with fuses of thesame rating, which you can recognize by thecolor and value. The fuse ratings are listed in thefuse allocation chart.
The fuse allocation chart is in the fuse box in thefront-passenger footwell (Ypage 289).
If a newly inserted fuse also blows, have thecause traced and rectified at a qualified special-ist workshop, e.g. an authorized Mercedes-BenzCenter.
Before changing a fuse
XSecure the vehicle against rolling away(Ypage 142).
XSwitch off all electrical consumers.
XVehicles without KEYLESS-GO:remove theSmartKey from the ignition lock.
XVehicles with KEYLESS-GO start-functionor KEYLESS-GO:open the driver's door.The vehicle electronics are now in positionZ. This corresponds to the SmartKey beingremoved from the ignition.
The fuses are located in various fuse boxes:
RFuse box in the engine compartment on theleft-hand side of the vehicle, when viewed inthe direction of travel
RFuse box in the front-passenger footwell
The fuse allocation chart is on the fuse box in thefront-passenger footwell (Ypage 289).
Fuse box in the engine compartment
GWARNING
When the hood is open and the windshield
wipers are set in motion, you can be injured by
the wiper linkage. There is a risk of injury.
Always switch off the windshield wipers and
the ignition before opening the hood.
XOpen the hood.
XUse a dry cloth to remove any moisture fromthe fuse box.
XTo open:open clampsD.
XFold up coverCin the direction of the arrowand remove it.
XTo close:check whether the seal is lying cor-rectly in coverC.
XInsert coverCat the back into openings

Tire-mounting tools should not be used nearthe valve. This could damage the electroniccomponents.
Only have tires changed at a qualified spe-cialist workshop.
Observe the instructions and safety notes in the"Changing a wheel" section (Ypage 310).
The wear patterns on the front and rear tiresdiffer, depending on the operating conditions.Rotate the wheels before a clear wear patternhas formed on the tires. Front tires typicallywear more on the shoulders and the rear tires inthe center.
On vehicles that have the same size front andrear wheels, you can rotate the wheels accord-ing to the intervals in the tire manufacturer'swarranty book in your vehicle documents. If nowarranty book is available, the tires should berotated every 3,000 to 6,000 miles (5,000 to10,000 km). Depending on tire wear, this maybe required earlier. Do not change the directionof wheel rotation.
Clean the contact surfaces of the wheel and thebrake disc thoroughly every time a wheel is rota-ted. Check the tire pressure and, if necessary,restart the tire pressure loss warning system(Canada only) or the tire pressure monitor (USAonly).
Direction of rotation
Tires with a specified direction of rotation haveadditional benefits, e.g. if there is a risk of hydro-planing. These advantages can only be gained ifthe tires are installed corresponding to thedirection of rotation.
An arrow on the sidewall of the tire indicates itscorrect direction of rotation.
Storing wheels
Store wheels that are not being used in a cool,dry and preferably dark place. Protect the tiresfrom oil, grease, gasoline and diesel.
Mounting a wheel
Preparing the vehicle
XStop the vehicle on solid, non-slippery andlevel ground.
XApply the electric parking brake manually.
XBring the front wheels into the straight-aheadposition.
XShift the transmission to position].
XSwitch off the engine.
XVehicles without KEYLESS-GO:remove theSmartKey from the ignition lock.
XVehicles with KEYLESS-GO start-functionor KEYLESS-GO:open the driver's door.The vehicle electronics are now in position