Section 1 (Engine Controls - Self-Diagnostics): Summary
WARNING: This page is about a different car, the 1993 Audi 90 and 1993 Audi 100. However, it is still accessible from the selected car via links, so may be relevant.
If no hard codes (or pass codes only) are present, driveability symptoms exist or intermittent codes exist, proceed to the TESTS W/O CODES article for diagnosis by symptom (i.e. ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.