2019 MERCEDES-BENZ GLA brake sensor

objects when they are in the immediatevicinity of the vehicle. You could damage thevehicle or the objects.
The sensors may not detect snow and otherobjects that absorb ultrasonic waves.
Ultrasonic sources such as an automatic carwash, the compressed-air brakes of a truckor a pneumatic drill could cause ParkingAssist PARKTRONIC to malfunction.
Parking Assist PARKTRONIC may not func-tion correctly on uneven terrain.
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 reacti-vated 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 oftrucks
CSensors in the front bumper, left-hand side(example)
The sensors must be free from dirt, ice orslush. They can otherwise not function cor-rectly. Clean the sensors regularly, taking carenot to scratch or damage them (Ypage 282).
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 warn-ing tone sounds. If the distance falls below theminimum, the distance may no longer beshown.
172Driving systems
Driving and parking

Problems with Parking Assist PARKTRONIC
ProblemPossible causes/consequences andPPSolutions
Only the red segmentsin the Parking AssistPARKTRONIC warningdisplays are lit. You alsohear a warning tone forapproximately two sec-onds.
Parking AssistPARKTRONIC is thendeactivated and theindicator lamp on thePARKTRONIC buttonlights up.
Parking Assist PARKTRONIC has malfunctioned and has been deac-tivated.
XIf problems persist, have Parking Assist PARKTRONIC checked ata qualified specialist workshop.
Only the red segmentsin the 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 282).
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 parkingaid with ultrasound. It measures the road onboth sides of the vehicle. A parking symbolindicates a suitable parking space. Activesteering intervention and brake applicationcan assist you during parking and when exitinga parking space. You can also still use ParkingAssist PARKTRONIC (Ypage 171).
Important safety notes
Active Parking Assist is merely an aid. It is nota replacement for your attention to your imme-diate surroundings. You are always responsi-ble for safe maneuvering, parking and exiting aparking space. Make sure that there are nopersons, animals or objects in the maneuver-ing area 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 overobstacles such as curbs slowly and at anobtuse angle. Otherwise, you may damagethe wheels 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
174Driving systems
Driving and parking

Display messagesPossible causes/consequences andPPSolutions
Active BrakeActive BrakeAssist FunctionsAssist FunctionsCurrently LimitedCurrently LimitedSee Operator's Man‐See Operator's Man‐ualual
Active Brake Assist is temporarily inoperative.
Possible causes are:
Rthe radar sensor system is temporarily inoperative, e.g. due toelectromagnetic radiation emitted by nearby TV or radio stationsor other sources of electromagnetic radiation
Rthe system is outside the operating temperature range
Rthe on-board voltage is too low
When the causes stated above no longer apply, the display messagedisappears.
Active Brake Assist is operational again.
If the display message does not disappear:
XPull over and stop the vehicle safely as soon as possible, payingattention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 145).
XRestart the engine.
Active BrakeActive BrakeAssist: SystemAssist: SystemInoperativeInoperative
Active Brake Assist is unavailable due to a malfunction. Situation-dependent braking assistance may also have failed.
XVisit a qualified specialist workshop immediately.
Radar SensorsRadar SensorsDirty See Opera‐Dirty See Opera‐tor's Manualtor's Manual
The radar sensor system is malfunctioning.
Possible causes are:
Rdirt on sensors
Rheavy rain or snow
Rwhen driving on inter-urban roads without traffic or infrastructure,e.g. in desert-like areas
At least one driving system or driving safety system is malfunction-ing or is temporarily unavailable:
RActive Brake Assist
RActive Distance Assist DISTRONIC
A warning tone also sounds.
Once the cause of the problem is no longer present, the driving anddrive safety systems will be available again. The display messagedisappears.
If the display message does not disappear:
XPull over and stop the vehicle safely as soon as possible, payingattention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 145).
XSwitch off the engine.
XClean all sensors (Ypage 282).
XRestart the engine.The display message disappears.
210Displaymessages
On-b oard computer and displays

Display messagesPossible causes/consequences andPPSolutions
Check TiresCheck TiresUSA only:
The tire pressure in one or more tires has dropped significantly. Thewheel position appears in the multifunction display.
A warning tone also sounds.
GWARNING
Tire pressures that are too low pose the following hazards:
Rthey may burst, especially as the load and vehicle speed increase.
Rthey may wear excessively and/or unevenly, which may greatlyimpair tire traction.
Rthe driving characteristics, as well as steering and braking, maybe greatly impaired.
There is a risk of an accident.
XStop the vehicle without making any sudden steering or brakingmaneuvers. Pay attention to the traffic conditions as you do so.
XSecure the vehicle against rolling away (Ypage 145).
XCheck the tires and, if necessary, follow the instructions for a flattire (Ypage 287).
XCheck the tire pressure (Ypage 311).
XIf necessary, correct the tire pressure.
Warning Tire Mal‐Warning Tire Mal‐functionfunctionUSA only:
The tire pressure in one or more tires has dropped suddenly. Thewheel position appears in the multifunction display.
GWARNING
Driving with a flat tire poses a risk of the following hazards:
Ra flat tire affects the ability to steer or brake the vehicle
Ryou could lose control of the vehicle
Rcontinued driving with a flat tire will cause excessive heat build-up and possibly a fire
There is a risk of an accident.
XStop the vehicle without making any sudden steering or brakingmaneuvers. Pay attention to the traffic conditions as you do so.
XSecure the vehicle against rolling away (Ypage 145).
XCheck the tires and, if necessary, follow the instructions for a flattire (Ypage 287).
Tire Press. Moni‐Tire Press. Moni‐tor Currentlytor CurrentlyUnavailableUnavailable
USA only:
Because there is interference from a strong source of radio waves,no signals from the tire pressure sensors are detected. The tirepressure monitor is temporarily malfunctioning.
XDrive on.The tire pressure monitor restarts automatically as soon as theproblem has been resolved.
224Displaymessages
On-b oard computer and displays

Display messagesPossible causes/consequences andPPSolutions
TirePress. Sen‐TirePress. Sen‐sor(s) Missingsor(s) MissingUSA only:
There is no signal from the tire pressure sensor of one or severaltires. The pressure of the affected tire does not appear in the multi-function display.
XHave the faulty tire pressure sensor replaced at a qualified spe-cialist workshop.
Tire Pressure Moni‐Tire Pressure Moni‐tor Inoperative Notor Inoperative NoWheel SensorsWheel Sensors
USA only:
The wheels mounted do not have a suitable tire pressure sensor.The tire pressure monitor is deactivated.
XMount wheels with suitable tire pressure sensors.The tire pressure monitor is activated automatically after drivingfor a few minutes.
Tire Press. Moni‐Tire Press. Moni‐tor Inoperativetor InoperativeUSA only:
The tire pressure monitor is faulty.
XVisit a qualified specialist workshop.
Vehicle
Display messagesPossible causes/consequences andPPSolutions
Depress Brake toDepress Brake toStart EngineStart EngineYou have attempted to start the engine with the transmission inposition\\without depressing the brake pedal.
XDepress the brake pedal.
To Deselect P orTo Deselect P orN, Depress BrakeN, Depress Brakeand Start Engineand Start Engine
You attempted to shift the transmission to position^or[with-out starting the engine.
XStart the engine.
XDepress the brake pedal.
iIt is possible to shift the transmission from position]to thedesired position only if you depress the brake pedal. Only thencan the parking lock be deactivated. If you do not depress thebrake pedal, the DIRECT SELECT lever can still be moved but theparking lock remains engaged.
iAt transmission fluid temperatures below