Audi Workshop Service and Repair Manuals

Electronic brake pressure distribution

The control unit -J104 is programmed with specially designed software for electronic brake pressure distribution which assumes the function of the brake pressure regulator.

Bosch 5.0 and Bosch 5.3 without EPBD emergency running

A fault occurring in the ABS entails failure of the EPBD. This is indicated by lighting up of the ABS/EDL warning lamp -K47 and the red symbol "Brake system fault". The vehicle must then only be moved to a very limited extent.

Bosch 5.3 with EPBD emergency running and ESP 5.3

If the ABS fails, only the ABS/EDL warning lamp -K47 lights up. The EPBD function is maintained by specially co-ordinated software.

If it is not possible to maintain the EPBD function, the red symbol "Brake system fault" also lights up. The vehicle must then only be moved to a very limited extent.

•     1 -    → Terminal 15
•     2 -    Signal for actuation of ABS/EDL warning lamp and red brake fault symbol.
•     3 -    Voltage supply for the ABS/EDL warning lamp.
•     4 -    Voltage supply for red brake fault symbol.
•     A -    During a phase "A" (after ignition is switched on) ABS/EDL warning lamp is actuated for two seconds during self test by means of signal "2" and comes on. During this phase an internal function in the dash panel insert suppresses the activation of the red brake fault symbol.
•     B -    Signal "2" is not present during phase "B". The ABS/EDL warning lamp and red brake fault symbol do not light up.
•     C -    In phase "C" self-diagnosis has detected a fault which does not cause electronic brake pressure distribution function to be deactivated. Signal "2" is pulsed. Only the ABS/EDL warning lamps illuminates
•     D -    In phase "D" self-diagnosis has detected a fault which causes electronic brake pressure distribution function to be deactivated. Signal "2" is present continuously. Both the ABS/EDL warning lamp and the red brake fault symbol light up.