Audi Workshop Service and Repair Manuals

Electronic Stability Program (ESP)

The ESP is a further additional expansion stage of the familiar driving safety systems ABS/EDL and ABS/EDL/TCS.

ESP enhances the degree of control in critical dynamic conditions, i.e. when the driver approaches the handling limits of the vehicle. In comparison to other familiar driving safety systems it decreases the danger of spinning and improves the steerability.

However, ESP is not able to overcome the physical limits of the available road adhesion.

ESP, the Electronic Stability Program is a Drive Dynamics Control, DDC for short. These stabilise the vehicle during over and understeering. The functions of electronic brake pressure distribution, ABS, EDL and TCS are incorporated by the control system. However, the characteristic function of the ESP is controlled brake application at individual wheels.

If required, the TCS and ESP control functions can be switched off and then on again by means of the TCS/ESP switch in the centre console. This switch is overridden when the driver presses the brake pedal: ESP will remain active at all times during braking. Both functions, TCS and ESP, will be reactivated automatically the next time the ignition is switched on.

When the system is deactivated, the TCS/ESP warning lamp illuminates in the dash panel. The warning lamp flashes at rate of three times per second when the control function starts working.

Examples:

→ During oversteer the rear of the vehicle breaks out. The vehicle does not rotate far enough about its vertical axis to maintain course through the corner. The system counteracts this excessive movement by applying a controlled braking force at the outside front wheel.

→ During understeer the front end of the vehicle does not follow the required corner radius. It breaks away towards the outside of the bend. The vehicle does not rotate far enough about its vertical axis to maintain course through the corner. The system increases the amount of rotation by applying a controlled braking force at the inside rear wheel.