2019 MERCEDES-BENZ SLC brake sensor

Selecting the Comfort or Economy
drive programs
In theComfortandEconomydrive programs,the driving characteristics of your vehicle aremore comfortable. Select one of these driveprograms if you favor a more comfortable driv-ing style. Also select these drive programswhen driving fast on straight roads, e.g. onstraight stretches of highway.
In urban traffic and stop-start traffic, drive pro-gramCis recommended.
XPress DYNAMIC SELECT buttonCrepeat-edly until theComfortorEconomydriveprogram is selected.
Selecting Sport mode
The firmer setting of the suspension tuning intheSportdrive program ensures even bettercontact with the road. Select this drive pro-gram when employing a sporty driving style,e.g. on winding country roads.
XPress DYNAMIC SELECT buttonCas manytimes as necessary until theSportdriveprogram is selected.
Selecting Sport Plus mode
The firmer suspension settings in theSportPlusdrive program ensure even better contactwith the road. Select this mode when employ-ing a sporty driving style, e.g. on winding coun-try roads or, ideally, when driving on closedrace circuits.
XPress DYNAMIC SELECT buttonCrepeat-edly until theSport Plusdrive program isselected.
Parking Assist PARKTRONIC
Important safety notes
Parking Assist PARKTRONIC is an electronicparking aid with ultrasound. It monitors thearea around your vehicle using six sensors inthe front bumper and four sensors in the rearbumper. Parking Assist PARKTRONIC visuallyand audibly indicates the distance betweenyour vehicle and an object.
Parking Assist PARKTRONIC is only an aid. It isnot a replacement for your attention to yourimmediate surroundings. You are alwaysresponsible for safe maneuvering, parking andexiting a parking space. Make sure that thereare no persons, animals or objects in themaneuvering area when you are maneuveringor parking.
!When parking, pay particular attention toobjects above or below the sensors, such asflower pots or trailer drawbars.PARKTRONIC does not detect such objectswhen they are in the immediate vicinity ofthe vehicle. You could damage the vehicleor 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 on a truckor a pneumatic drill could causePARKTRONIC to malfunction.
PARKTRONIC may not function correctly onuneven terrain.
Parking Assist PARKTRONIC is activated auto-matically when you:
Rswitch on the ignition
Rshift the transmission to position[,^or\\
Rrelease the electric parking brake
Parking Assist PARKTRONIC is deactivated atspeeds above 11 mph (18 km/h). It is reacti-vated at lower speeds.
Driving systems153
Driving and parking
Z

Display messagesPossible causes/consequences andPPSolutions
The yellow$warning lamp lights up and the redI(USAonly) or$(Canada only) indicator lamp flashes.
It is not possible to apply the electric parking brake manually.
XShift the transmission to position].
XVisit a qualified specialist workshop.
'(USA only)
M(Canada only)
Check Brake FluidCheck Brake FluidLevelLevel
There is not enough brake fluid in the brake fluid reservoir.
In addition, the'(USA only) orM(Canada only) warninglamp lights up in the instrument cluster and a warning tone sounds.
GWARNING
The braking effect may be impaired.
There is a risk of an accident.
XPull over and stop the vehicle safely as soon as possible, payingattention to road and traffic conditions. Do not continue drivingunder any circumstances.
XSecure the vehicle against rolling away (Ypage 134).
XConsult a qualified specialist workshop.
XDo not add brake fluid. This does not correct the malfunction.
&
Check Brake PadCheck Brake PadWearWear
The brake pads/linings have reached their wear limit.
XVisit a qualified specialist workshop.
PRE-SAFE Inopera‐PRE-SAFE Inopera‐tive See Opera‐tive See Opera‐tor's Manualtor's Manual
Important functions of PRE-SAFE®have failed. All other occupantsafety systems, e.g. air bags, remain available.
XVisit a qualified specialist workshop immediately.
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 134).
XRestart the engine.
188Displaymessages
On-b oard computer and displays

Display messagesPossible causes/consequences andPPSolutions
Active BrakeActive BrakeAssist FunctionsAssist FunctionsLimited See Opera‐Limited See Opera‐tor's Manualtor's Manual
Active Brake Assist is unavailable due to a malfunction.
XVisit a qualified specialist workshop.
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
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 134).
XSwitch off the engine.
XClean all sensors (Ypage 250).
XRestart the engine.The display message disappears.
u
SRS MalfunctionSRS MalfunctionService RequiredService Required
The restraint system is malfunctioning. Theuwarning lamp alsolights up in the instrument cluster.
GWARNING
The air bags or Emergency Tensioning Devices may either be trig-gered unintentionally or, in the event of an accident, may not betriggered.
There is an increased risk of injury.
XVisit a qualified specialist workshop immediately.
Further information about the restraint system (Ypage 39).
Displaymessages189
On-b oard computer and displays
Z

Display messagesPossible causes/consequences andPPSolutions
Tire Pressure SoonTire Pressure SoonThe tire pressure in one or more tires has dropped significantly. Thewheel position is shown 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 134).
XCheck the tires and, if necessary, follow the instructions for a flattire (Ypage 252).
XCheck the tire pressure (Ypage 274).
XIf necessary, correct the tire pressure.
Warning Tire Mal‐Warning Tire Mal‐functionfunctionThe tire pressure in one or more tires has dropped suddenly. Thewheel position is shown 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 134).
XCheck the tires and, if necessary, follow the instructions for a flattire (Ypage 252).
Tire Press. Moni‐Tire Press. Moni‐tor Currentlytor CurrentlyUnavailableUnavailable
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.
TirePress. Sen‐TirePress. Sen‐sor(s) Missingsor(s) MissingThere is no signal from the tire pressure sensor of one or severalwheels. The pressure of the affected tire does not appear in themultifunction display.
XHave the faulty tire pressure sensor replaced at a qualified spe-cialist workshop.
202Displaymessages
On-b oard computer and displays

Display messagesPossible causes/consequences andPPSolutions
Tire Pressure Moni‐Tire Pressure Moni‐tor Inoperative Notor Inoperative NoWheel SensorsWheel Sensors
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 InoperativeThe tire pressure monitor is faulty.
XVisit a qualified specialist workshop.
Vehicle
Display messagesPossible causes/consequences andPPSolutions
Shift to 'P' orShift to 'P' or'N' to Start Engine'N' to Start EngineYou have attempted to start the engine with the transmission inposition^or[.
XShift the transmission to position]or\\.
Apply Brake toApply Brake toShift from 'P'Shift from 'P'You have attempted to shift the transmission to position[,^or\\without depressing the brake pedal.
XDepress the brake pedal.
To Shift out of PTo Shift out of Por N, Depressor N, DepressBrake and SwitchBrake and Switchon Engineon Engine
You have attempted to shift the transmission out of position]or\\into another transmission position with the engine switched off.
XDepress the brake pedal.
XStart the engine.
Driver's Door OpenDriver's Door Open& Transmission Not& Transmission Notin P Risk of Vehi‐in P Risk of Vehi‐cle Rolling Awaycle Rolling Away
The driver's door is not fully closed and the transmission is in posi-tion^,\\or[.
A warning tone also sounds.
GWARNING
The vehicle may roll away.
There is a risk of an accident.
XWhen parking the vehicle, shift the transmission to position].
Only Select ParkOnly Select Park(P) When Vehicle(P) When Vehicleis Stationaryis Stationary
The vehicle is moving.
XPull over and stop the vehicle safely as soon as possible, payingattention to road and traffic conditions.
XShift the transmission to position].
Apply Brake toApply Brake toSelect RSelect RYou have attempted to shift from position[to position^.
XDepress the brake pedal.
XShift the transmission to position^.
Displaymessages203
On-b oard computer and displays
Z