OBD Diagnostic Monitors
During vehicle operation, the on-board diagnostic (OBD) facilities of the Engine Control Module (ECM) and Transmission Control Module (TCM), continuously check the Engine Management and Transmission Control systems. The Powertrain OBD incorporates several diagnostic monitors; each monitor has an associated group of DTCs. The diagnostic monitors will complete the diagnostic test(s) if a specified service "drive cycle" is carried out.
The diagnostic monitors are: