Section 7 (Engine Control Systems Tests W/Codes): Introduction
WARNING: This page is about a different car, the 1997 Pontiac Bonneville, 1997 Oldsmobile Regency, 1997 Oldsmobile LSS, 1997 Oldsmobile Eighty-Eight, and 1997 Buick LeSabre. However, it is still accessible from the selected car via links, so may be relevant.
Most engine control problems are the result of mechanical breakdowns, poor electrical connections or damaged vacuum hoses. Before considering the computer system as a possible cause of problems, perform checks and inspections covered in the BASIC TESTING - 3.8L article. Failure to do so may result in lost diagnostic time.
If no faults found performing procedures in the BASIC TESTING - 3.8L article, proceed with DIAGNOSTIC PROCEDURE under SELF-DIAGNOSTIC SYSTEM. If no fault codes are present and driveability problems exist, proceed to the TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.). If only intermittent codes are present, see INTERMITTENTS in the TESTS W/O CODES article.