Motronic malfunctions and self-diagnosis (Audi A4 B5)

The electronic control unit of the Motronic injection system can recognize and store faults that occur during engine operation. The detected faults are stored in the computer memory. If you suspect a fault in the ignition/injection control system, you can only have the computer interrogated by an Audi workshop. However, you can also use our troubleshooting tips, which list numerous possible faults that have been identified by self-diagnosis.

Tip: The Motronic ignition/injection control unit can recognize 46 types of faults in the electrical components of the ignition/injection system and store them in the computer memory. Sporadic faults are erased from the computer memory after 50 cold engine starts if they do not recur.