Antilock brake system (ABS), function - GF42.30-P-0003F

MODEL 463.243 /244 /246 /247 /249 /250 /254 ## as of 127357 as of 1.9.01, 463.270 /271, 463.309 /322 /323 /332 /333 ## as of 127357 as of 1.9.01 with CODE (BB3) Electronic stability program (ESP) 

MODEL 463.248 ## as of 127357 as of 1.9.01 with CODE (BB3) Electronic stability program (ESP) except CODE (979) Special protected version 

Fig 1: Identifying Antilock Brake System Communication Diagram

Courtesy of MERCEDES-BENZ USA

1. General 
   • The "antilock brake system (ABS)" functionality is integrated as a software module in the ESP/BAS control module (N47-5).
   • The antilock brake system (ABS)
     • is an electronic system that prevents the wheels locking up when braking,
     • maintains directional stability and road adhesion when driving,
     • works irrespective of the road surface from a speed of approximately 8 km/h
     • and works if the driver applies the brakes gently when driving on slippery road surfaces.
2. Function in normal mode 
   • In the normal operating mode, when the driver is not applying the brakes or when the driver is applying the brakes but none of the braked wheels are locked up, the ABS is in the "ready for operation" mode.
   • The system must be free of faults for the ABS to be in the "ready for operation" mode. If a fault occurs with the ABS, the BAS, ESP and 4-ETS systems are also deactivated. The normal brake and driving functions are still available.
3. Function in control mode 
   • The ABS control mode is activated if one or more wheels begin to lock up, i.e. wheel slip occurs, when the driver applies the brakes.

     During the ABS control mode, the wheel that has locked up is braked by controlling the brake force as part of the braking torque control. The braking torque can be controlled at each wheel individually.