104 Driving and operatingIf engine speed is too high thetransmission switches to a highergear, even in manual mode. Withoutkickdown this automatic shift is noteffected in manual mode.FaultIn the event of a fault, control indicatorÑ is shown in the transmissiondisplay.Continued driving is possible,provided the vehicle is driven withcare and anticipation. A warningmessage may appear in the DriverInformation Centre (DIC) inconjunction with a warning chime3 79.NoteThe volume of the warning chimecan also be adjusted via the DIC.Driver Information Centre (DIC)3 73.Have the cause of the fault remediedby a workshop.BrakesThe brake system comprises twoindependent brake circuits.If a brake circuit fails, the vehicle canstill be braked using the other brakecircuit. However, braking effect isachieved only when the brake pedalis depressed firmly. Considerablymore force is needed for this. Thebraking distance is extended. Seekthe assistance of a workshop beforecontinuing your journey.When the engine is not running, thesupport of the brake servo unitdisappears once the brake pedal hasbeen depressed once or twice.Braking effect is not reduced, butbraking requires significantly greaterforce. It is especially important to bearthis in mind when being towed.Control indicator R 3 69.Antilock brake systemAntilock brake system (ABS)prevents the wheels from locking.ABS starts to regulate brake pressureas soon as a wheel shows a tendencyto lock. The vehicle remainssteerable, even during hard braking.ABS control is made apparentthrough a pulse in the brake pedaland the noise of the regulationprocess.For optimum braking, keep the brakepedal fully depressed throughout thebraking process, despite the fact thatthe pedal is pulsating. Do not reducethe pressure on the pedal.After starting off the system performsa self-test which may be audible.Control indicator u 3 69.Fault9 WarningIf there is a fault in the ABS, thewheels may be liable to lock dueto braking that is heavier thannormal. The advantages of ABSare no longer available. During
