Section 7 (Engine Controls - Tests W/Codes): Summary
WARNING: This page is about a different car, the 1995 BMW 525iT, 1995 BMW 525i, 1995 BMW 325is, and 1995 BMW 325i. However, it is still accessible from the selected car via links, so may be relevant.
If no hard fault codes (or only pass codes) are present, driveability symptoms exist or intermittent codes exist, proceed to TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnosis procedures.