Mercedes-Benz GL-Class: Braking - ABS (Anti-lock Braking System) - Driving safety systems - Safety - Mercedes-Benz GL-Class Owner's ManualMercedes-Benz GL-Class: Braking

If ABS intervenes when braking, you will feel a pulsing in the brake pedal.

If ABS intervenes: continue to depress the brake pedal with force until the braking situation is over.
To make a full brake application:

depress the brake pedal with full force.

The pulsating brake pedal can be an indication of hazardous road conditions, and functions as a reminder to take extra care while driving.

WARNING Do not pump the brake pedal. Use firm, steady 
Do not pump the brake pedal. Use firm, steady brake pedal pressure instead. Pumping the brake pedal defeats the purpose of the ABS and significantly reduces braking effectiveness.

    Important safety notes
    Observe the "Important safety notes" section. ABS regulates brake pressure in such a way that the wheels do not lock when you brake. This allows you to continue steering the vehicl ...

    Off-road ABS
    An ABS mode specifically suited to off-road terrain is activated automatically if the offroad drive program is activated or the LOW RANGE off-road gear is selected. At speeds below 18 mph(30 km ...

    See also:

    Remote Keyless Entry (RKE) System Operation
    The Remote Keyless Entry (RKE) transmitter functions work up to 60m (195 ft) away from the vehicle. There are other conditions which can affect the performance of the transmitter. See Remote Keyl ...

    Capacities and Specifications
    The following approximate capacities are given in metric and English conversions. See Recommended Fluids and Lubricants   for more information. ...

    Displaying the digital speedometer oroutside temperature
    If you have selected the digital speedometer for the status bar, the outside temperature is displayed here. ► Press the button on the steering wheel to select the standard display. ...