2019 MERCEDES-BENZ CLA warning light

ProblemPossible causes/consequences andPPSolutions
The engine does notstart. You cannot hearthe starter motor.
The on-board voltage is too low because the battery is too weak ordischarged.
XJump-start the vehicle (Ypage 282).
If the engine does not start despite attempts to jump-start it:
XConsult a qualified specialist workshop.
The starter motor was exposed to a thermal load that was too high.
XAllow the starter motor to cool down for approximately two minutes.
XTry to start the engine again.
If the engine still does not start:
XConsult a qualified specialist workshop.
The engine is not runningsmoothly and is misfir-ing.
There is a malfunction in the engine electronics or in a mechanicalcomponent of the engine management system.
XOnly depress the accelerator pedal slightly.Otherwise, non-combusted fuel may get into the catalytic converterand damage it.
XHave the cause rectified immediately at a qualified specialist work-shop.
The coolant temperaturegauge shows a valueabove 248 ‡ (120 †).The coolant warninglamp may also be on anda warning tone maysound.
The coolant level is too low. The coolant is too hot and the engine is nolonger being cooled sufficiently.
XStop as soon as possible and allow the engine and the coolant tocool down.
XCheck the coolant level (Ypage 263). Observe the warning notesas you do so and add coolant if necessary.
Notes on towing vehicles
The vehicle is not suitable for attaching tow barsystems, such as those used for flat towing ordinghy towing.
Attaching or using tow bar systems may result indamage to the vehicle.
When towing a vehicle with tow bar systems,safe driving characteristics cannot be guaran-teed for the towing vehicle or the towed vehicle.
The vehicle/trailer combination may swerve.
Observe the permissible towing methods(Ypage 287) and the notes on towing with bothaxles on the ground (Ypage 286).
DYNAMIC SELECT button (all vehicles
except Mercedes-AMG vehicles)
Use the DYNAMIC SELECT button to change thedrive program. Depending on the drive programselected the following vehicle characteristicswill change:
Rthe drive (engine and transmission manage-ment)
Rthe suspension (vehicles with damping sys-tem or AMG adaptive sport suspension sys-tem)
Rthe sound of the exhaust system (vehicleswith sports exhaust system)
Rthe steering
Rthe availability of the ECO start/stop function
Rthe climate control
Each time you start the engine with the Smart-Key or the Start/Stop button, drive programCis
DYNAMIC SELECT button (all vehicles except Mercedes-AMG vehicles)129
Driving and parking
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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

Parking Assist PARKTRONIC is activated auto-matically when you:
Rswitch on the ignition
Rshift the transmission to position[,^or\\
Parking Assist PARKTRONIC is deactivated atspeeds above 11 mph (18 km/h). It is reactiva-ted at lower speeds.
Range of the sensors
General notes
Parking Assist PARKTRONIC does not take intoaccount obstacles located:
Rbelow the detection range, such as persons,animals or objects
Rabove the detection range, e.g. overhangingloads, tail sections or loading ramps of trucks
CSensors in the front bumper, left-hand side(example)
The sensors must be free from dirt, ice or slush.They can otherwise not function correctly. Cleanthe sensors regularly, taking care not to scratchor damage them (Ypage 269).
Range
CDetection range of front sensors
DDetection range of rear sensors
Front sensors
CenterApprox. 40 in (approx.100 cm)
CornersApprox. 24 in (approx.60 cm)
Rear sensors
CenterApprox. 48 in (approx.120 cm)
CornersApprox. 32 in (approx.80 cm)
Minimum distance
CenterApprox. 8 in (approx. 20 cm)
CornersApprox. 6 in (approx. 15 cm)
If an obstacle is detected within this range, therelevant warning displays light up and a warningtone sounds. If the distance falls below the min-imum, the distance may no longer be shown.
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Problems with Parking Assist PARKTRONIC
ProblemPossible causes/consequences andPPSolutions
Only the red segments inthe Parking AssistPARKTRONIC warningdisplays are lit. You alsohear a warning tone forapproximately two sec-onds.
Parking AssistPARKTRONIC is thendeactivated and the indi-cator lamp on thePARKTRONIC buttonlights up.
Parking Assist PARKTRONIC has malfunctioned and has been deacti-vated.
XIf problems persist, have Parking Assist PARKTRONIC checked at aqualified specialist workshop.
Only the red segments inthe Parking AssistPARKTRONIC warningdisplays are lit. ParkingAssist PARKTRONIC isthen deactivated.
The Parking Assist PARKTRONIC sensors are dirty or there is inter-ference.
XClean the Parking Assist PARKTRONIC sensors (Ypage 269).
XSwitch the ignition back on.
The problem may be caused by an external source of radio or ultra-sound waves.
XCheck to see if Parking Assist PARKTRONIC works at a differentlocation.
Active Parking Assist
General notes
Active Parking Assist is an electronic parking aidwith ultrasound. It measures the road on bothsides of the vehicle. A parking symbol indicatesa suitable parking space. Active steering inter-vention and brake application can assist youduring parking and when exiting a parkingspace. You can also still use Parking AssistPARKTRONIC (Ypage 162).
Important safety notes
Active Parking Assist is merely an aid. It is not areplacement for your attention to your immedi-ate surroundings. You are always responsiblefor safe maneuvering, parking and exiting aparking space. Make sure that there are no per-sons, animals or objects in the maneuveringarea when you are maneuvering or parking.
When Parking Assist PARKTRONIC is deactiva-ted, Active Parking Assist is also unavailable.
GWARNING
While parking or pulling out of a parking
space, the vehicle swings out and can drive
onto areas of the oncoming lane. This could
cause you to collide with other road users or
objects. There is a risk of an accident.
Pay attention to other road users or objects.
Stop the vehicle if necessary or cancel the
Active Parking Assist parking procedure.
!If they cannot be avoided, drive over obsta-cles such as curbs slowly and at an obtuseangle. Otherwise, you may damage thewheels or tires.
Active Parking Assist may possibly indicateparking spaces which are not suitable for park-ing, for example:
Rwhere parking or stopping is prohibited
Rin front of driveways or entrances and exits
Ron unsuitable surfaces
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Rif the camera lens is dirty or obstructed.Observe the notes on cleaning(Ypage 269)
Rif the rear of your vehicle is damaged. In thiscase, have the camera position and settingchecked at a qualified specialist workshop.
The field of vision and other functions of the rearview camera may be restricted due to additionalaccessories on the rear of the vehicle (e.g.license plate holder, rear bicycle rack).
iThe contrast of the display may be affectedby the sudden presence of sunlight or otherlight sources, e.g. when exiting a garage. Payparticular attention in this situation.
iIf usability is severely restricted, e.g. due topixel errors, have the display repaired orreplaced.
Activating/deactivating the rear view
camera
XTo activate:make sure that the SmartKey isin positionHin the ignition lock.
XMake sure that theActivation by R gearActivation by R gearfunction is selected in the multimedia system;see the Digital Operator's Manual.
XEngage reverse gear.The area behind the vehicle is shown withguide lines in the multimedia system display.
The image from the rear view camera is avail-able throughout the maneuvering process.
To deactivate:the rear view camera deacti-vates if you shift the transmission to]or afterdriving forwards a short distance.
The inner segments of the warning indicator aredisplayed in red if there is a complete systemfailure. The indicator lamp in the PARKTRONICbutton lights up.
If the system fails at the rear of the vehicle:
Rthe rear segments are shown in red whenbacking up.
Rthe rear segments are hidden when drivingforwards.
Messages in the multimedia system dis-
play
The rear view camera may show a distorted viewof obstacles, show them incorrectly or not at all.The rear view camera does not show objects inthe following positions:
Rvery close to the rear bumper
Runder the rear bumper
Rin close range above the handle on the trunklid
!Objects not at ground level may appear tobe further away than they actually are, e.g.:
Rthe bumper of a parked vehicle
Rthe drawbar of a trailer
Rthe ball coupling of a trailer tow hitch
Rthe rear section of an HGV
Ra slanted post
Use the guidelines only for orientation.Approach objects no further than the bottom-most guideline.
CYellow guide line at a distance of approx-imately 13 ft (4.0 m) from the rear of thevehicle
DWhite guide line without steering input –vehicle width including the exterior mirrors(static)

Any unauthorized modification to this devicecould void the user’s authority to operate theequipment.
Radar sensors
The radar sensors for Blind Spot Assist are inte-grated into the rear bumper. Make sure that thebumpers are free from dirt, ice or slush. Thesensors must not be covered, for example bycycle racks or overhanging loads. Following asevere impact or in the event of damage to thebumpers, have the function of the radar sensorschecked at a qualified specialist workshop.Blind Spot Assist may no longer work properly.
Monitoring range of the sensors
In particular, the detection of obstacles can beimpaired if:
Rthere is dirt on the sensors or anything elsecovering the sensors
Rthere is poor visibility, e.g. due to fog, heavyrain or snow
Ra narrow vehicle traveling in front, e.g. amotorbike or bicycle
Rthe road has very wide lanes
Rthe road has narrow lanes
Ryou are not driving in the middle of the lane
Rthere are barriers or other road boundaries
Vehicles in the monitoring range are then notindicated.
Blind Spot Assist monitors the area up to 10 ft(3 m) behind your vehicle and directly next to it.
If the lanes are narrow, vehicles driving in thelane beyond the lane next to your vehicle may beindicated, especially if the vehicles are not driv-ing in the middle of their lane. This may be thecase if the vehicles are driving on the inner sideof their lane.
Due to the nature of the system:
Rwarnings may be issued in error when drivingclose to crash barriers or similar solid laneborders.
Rwarnings may be interrupted when you aredriving alongside particularly long vehicles,such as trucks, for a prolonged time.
Warning display
CWarning display
Blind Spot Assist is not active at speeds belowapproximately 20 mph (30 km/h). Vehicles inthe monitoring range are then not indicated.
When Blind Spot Assist is activated, indicatorlampCin the exterior mirrors lights up yellowat speeds of up to 20 mph (30 km/h). At speedsabove 20 mph (30 km/h), the indicator lampgoes out and Blind Spot Assist is operational.
If a vehicle is detected within the blind spotmonitoring range at speeds above 20 mph(30 km/h), warning lampCon the correspond-ing side lights up red. This warning is alwaysemitted when a vehicle enters the blind spotmonitoring range from behind or from the side.When you overtake a vehicle, the warning onlyoccurs if the difference in speed is less than7 mph (12 km/h).
The yellow indicator lamp goes out if reversegear is engaged. In this event, Blind Spot Assistis no longer active.
The brightness of the indicator/warning lampsis adjusted automatically according to the ambi-ent light.
Collision warning
If a vehicle is detected in the monitoring range ofBlind Spot Assist and you switch on the corre-sponding turn signal, a double warning tonesounds. Red warning lampCflashes. If the turnsignal remains on, vehicles detected are indica-ted by the flashing of red warning lampC.There are no further warning tones.
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Switching on Blind Spot Assist
XMake sure that Blind Spot Assist is activatedin the on-board computer (Ypage 188).
XTurn the SmartKey to positionHin the igni-tion lock.Warning lampsCin the exterior mirrors lightup red for approximately 1.5 seconds andthen turn yellow.
Lane Keeping Assist
General notes
Lane Keeping Assist monitors the area in front ofyour vehicle by means of multifunction cam-eraCwhich is attached behind the top of thewindshield. Lane Keeping Assist detects lanemarkings on the road and can warn you beforeyou leave your lane unintentionally.
This function is available in the range between40 mph and 120 mph (60 km/h and 200 km/h).
A warning may be given if a front wheel passesover a lane marking. It will warn you by means ofintermittent vibration in the steering wheel forup to 1.5 seconds.
Important safety notes
GWARNING
Lane Keeping Assist cannot always clearly
detect lane markings.
In such cases, Lane Keeping Assist can:
Rgive an unnecessary warning
Rnot give a warning
There is a risk of an accident.
Always pay particular attention to the traffic
situation and keep within the lane, especially
if Lane Keeping Assist alerts you.
GWARNING
The Lane Keeping Assist warning does not
return the vehicle to the original lane. There is
a risk of an accident.
You should always steer, brake or accelerate
yourself, in particular if warned by Lane Keep-
ing Assist.
If you fail to adapt your driving style, Lane Keep-ing Assist can neither reduce the risk of an acci-dent nor override the laws of physics. LaneKeeping Assist cannot take into account theroad, traffic and weather conditions. Lane Keep-ing Assist is merely an aid. You are responsiblefor the distance to the vehicle in front, for vehi-cle speed, for braking in good time and for stay-ing in your lane.
The Lane Keeping Assist does not keep the vehi-cle in the lane.
The system may be impaired or may not functionif:
Rthere is poor visibility, e.g. due to insufficientillumination of the road, or due to snow, rain,fog or spray
Rthere is glare, e.g. from oncoming traffic, thesun or reflection from other vehicles (e.g. ifthe road surface is wet)
Rthe windshield is dirty, fogged up, damaged orcovered, for instance by a sticker, in the vicin-ity of the camera
Rthere are no or several unclear lane markingsfor one lane, e.g. roadworks
Rthe lane markings are worn away, dark or cov-ered up, e.g. by dirt or snow
Rthe distance to the vehicle in front is too shortand thus the lane markings cannot be detec-ted
Rthe lane markings change quickly, e.g. lanesbranch off, cross one another or merge
Rthe road is narrow and winding
Rthere are highly variable shade conditions onthe roadway
Switching on Lane Keeping Assist
XSwitch on Active Lane Keeping Assist usingthe on-board computer; to do so, selectStandardStandardorAdaptiveAdaptive(Ypage 176).If you drive at speeds above 40 mph(60 km/h) and lane markings are detected,the lines in the assistance graphic are shown
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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