108 Instruments and controlsWarning chimesWhen starting the engine orwhilst drivingOnly one warning chime will sound ata time.The warning chime regarding notfastened seat belts has priority overany other warning chime.■ If seat belt is not fastened.■ If a door or the tailgate is not fullyclosed when starting off.■ If a certain speed is exceeded withparking brake applied.■ If a programmed speed isexceeded.■ If a warning message or a warningcode appears in the DriverInformation Centre.■ If the parking assist detects anobject.■ If the diesel particle filter hasreached the maximum filling level.When the vehicle is parked and/or the driver's door is opened■ When the key is in the ignitionswitch.■ With exterior lights on.■ If the trailer hitch is not engaged.Battery voltageWhen the battery voltage is runninglow, a warning message or warningcode 174 will appear in the DriverInformation Centre.1. Switch off immediately electricalconsumers which are not requiredfor a safe ride, such as seatheating, heated rear window orother main consumers.2. Charge the battery by drivingcontinuously for a while or byusing a charging device.The warning message or warningcode will disappear after the enginehas been started two times runningwithout voltage drop.If the battery cannot be recharged,have the cause of the fault remediedby a workshop.
