Engine Controls - Tests W/Codes - 4.3L: Introduction: Notes

Most engine control problems result from mechanical failures, poor electrical connections or damaged vacuum hoses. Before condemning the computer system, perform checks and inspections covered in BASIC TESTING - 4.3L article. Failure to do so may result in lost diagnostic time.

If no faults were found while performing BASIC TESTING - 4.3L, proceed with DIAGNOSTIC PROCEDURE. If no fault codes or only a non-running Code 12 is present and driveability problems exist, proceed to TESTS W/O CODES - GASOLINE article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.). If only intermittent codes are present, see INTERMITTENTS in TESTS W/O CODES - GASOLINE article.