Execution order
1. When the front wheel rotates at the start of movement, the speed sensors know about it by the different values of the wheel rotation frequency.
2. The combined ABS and EDS control unit activates the disc brake on the spinning wheel. This is done by an additional pair of electromagnetic valves in the ABS hydraulic module. ABS opens the connection from the pressure manifold to the wheel cylinder of the corresponding disc brake until the wheel is braked so much that the other front wheel can transmit force.
3. As soon as the same slip conditions occur on both wheels, the control unit completes the adjustment process and closes the electromagnetic valves. The driver does not need to intervene, he notices the differential lock only by the change in the nature of the noise.
4. To prevent failure, EDS is controlled by a locking circuit. Based on the brake pressure and after a set maximum period of time, EDS is switched off to avoid overloading the brakes. At speeds above 40 km / h, EDS is always switched off. The electromagnetic valve circuits are designed so that the front brakes cannot operate without control.
5. If the control unit detects a malfunction in the EDS, the EDS is switched off. The anti-lock system continues to function. In all cases, the Audi is ready to brake at any time.
6. The fault memory device operates in the same way as described in the ABS section.
(The original text of the material can be found on the website: AUDIMANUAL.ru)