2019 MERCEDES-BENZ CLA check engine light

helps you to avoid overheating the brakes andwearing them out excessively.
When you take advantage of engine braking, itis possible that a drive wheel will not rotate forsome time, e.g. on a slippery road surface.This could cause damage to the drive train.This type of damage is not covered by theMercedes-Benz warranty.
Briefly depressing the accelerator pedal ondownhill gradients while the manual drive pro-gramMis temporarily activated: the automatictransmission may switch to the last active auto-matic drive programEorS. The automatic trans-mission may shift to a higher gear. This canreduce the engine's braking effect.
Heavy and light loads
GWARNING
If you rest your foot on the brake pedal while
driving, the braking system can overheat. This
increases the stopping distance and can even
cause the braking system to fail. There is a
risk of an accident.
Never use the brake pedal as a footrest. Never
depress the brake pedal and the accelerator
pedal at the same time.
!Depressing the brake pedal constantlyresults in excessive and premature wear tothe brake pads.
If the brakes have been subjected to a heavyload, do not stop the vehicle immediately. Driveon for a short while. This allows the airflow tocool the brakes more quickly.
Wet roads
If you have driven for a long time in heavy rainwithout braking, there may be a delayed reac-tion from the brakes when braking for the firsttime. This may also occur after the vehicle hasbeen washed or driven through deep water.
You have to depress the brake pedal morefirmly. Maintain a greater distance from thevehicle in front.
After driving on a wet road or having the vehiclewashed, brake firmly while paying attention tothe traffic conditions. This will warm up thebrake discs, thereby drying them more quicklyand protecting them against corrosion.
Limited braking performance on salt-
treated roads
If you drive on salted roads, a layer of salt resi-due may form on the brake discs and brakepads. This can result in a significantly longerbraking distance.
RIn order to prevent any salt build-up, apply thebrakes occasionally while paying attention tothe traffic conditions.
RCarefully depress the brake pedal and thebeginning and end of a journey.
RMaintain a greater distance to the vehicleahead.
Servicing the brakes
!The brake fluid level may be too low, if:
Rif the red brake warning lamp lights up inthe instrument cluster and
Ryou hear a warning tone while the engine isrunning
Observe additional warning messages in themultifunction display.
The brake fluid level may be too low due tobrake pad wear or leaking brake lines.
Have the brake system checked immediately.Consult a qualified specialist workshop toarrange this.
!A function or performance test should onlybe carried out on a 2-axle dynamometer. Ifyou wish to operate the vehicle on such adynamometer, please consult a qualified spe-cialist workshop in advance. You could oth-erwise damage the drive train or the brakesystem.
!As the ESP®system operates automatically,the engine and the ignition must be switchedoff (the SmartKey must be in position

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

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