Section 123 (Engine Controls Self-Diagnostics): Summary
WARNING: This page is about a different car, the 2003 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
If no hard fault DTCs are present, driveability symptoms exist or intermittent DTC(s) exist, proceed to TROUBLE SHOOTING - NO CODES - 5.7L CORVETTE article for diagnosis by symptom (i.e., ROUGH IDLE, NO-START, etc.) or intermittent diagnostic procedures, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.