Hydraulic System: Description and Operation

Definitions
These explanations refer only to this assembly group: Brake system. These definitions are not necessarily valid generally.

ABS
The Anti-Locking Brake System (ABS) is a regulating system in the brake system, that prevents locking when braking.

ABS/EDL
Anti-locking brake system with electronic differential lock. Further information on this can be found in the appropriate Self-study program No. 148.

TCS (Traction control system)
Further information on this can be found in the appropriate Self-study program.

Vehicle speed sensor
The vehicle speed sensor sends the speed signal to the control module.

ESP (Electronic Stabilization Program)
The ESP recognizes critical vehicle conditions and stabilizes the vehicle by braking individual wheels and intervening in the engine management system. This occurs independent of brake or accelerator pedal operations.
A description of the construction and function of the ESP is found in Self-study program.

On Board Diagnostic (OBD)
The capability of the control module:
to recognize malfunctions,
to react to malfunctions,
to store malfunctions,
to register malfunctions and make them available in the measured value block.

Performing On Board Diagnostic (OBD)
Connecting the scan tool to be able to check the Diagnostic Trouble Code (DTC) memory.

Vehicle diagnosis, testing and information system VAS 5051
Terms such as tester, scan tool, VAS 5051 refer to this device.

Sender for Rotation Rate
The sender for rotation rate registers the rotational behavior of the vehicle along its vertical axis in relation to the vehicle speed. There is an ESP intervention for rotational movements greater than 4- per second.

Steering angle sensor
The steering angle sensor sits on the steering column between the steering column switches and the steering wheel. It transmits the steering angle to the electronic control module. It detects 720 degrees and therefore two full turns of the steering wheel.

Sensor for transverse acceleration
Used to register the speed through bends/curves and on which side the ESP system should brake.

Guided fault finding
One of the VAS 5051's three operating modes. The other two are "Vehicle self-diagnosis" and "Test instruments".

Initiating basic setting
The values learn in the control module are turned back to the initial values.