Self-Diagnostic System: Notes

The PCM is equipped with a self-diagnostic system which detects system failures or abnormalities. When a malfunction occurs, PCM will illuminate the Malfunction Indicator Light (MIL) located on instrument cluster. When malfunction is detected and MIL is turned on, a corresponding diagnostic trouble code will be stored in PCM memory. Malfunctions are designated as either "hard failures" or as "intermittent failures". To retrieve stored codes, see appropriate appropriate TESTS W/CODES article in the ENGINE PERFORMANCE section below.

• TESTS W/CODES - 4.3L (for Caprice Only)
• TESTS W/CODES - 5.7L (for All Models)