Self-Diagnostic System: Notes

NOTE: PCM diagnostic memory is retained by direct power supply from battery. Memory is not erased by turning off ignition, but it will be erased if battery or PCM is disconnected.

PCM has an On-Board Diagnostics-II (OBD-II) system. PCM monitors input and output signals of sensors and actuators. OBD-II also performs tests on, and monitors for deterioration of, emissions systems. When sufficient criteria are met, PCM will set a Diagnostic Trouble Code (DTC). If DTC is emission system related, Malfunction Indicator Light (MIL) will also illuminate. For non-emission related problems, DTC will set, but MIL will not illuminate. DTCs can only be read using a scan tester via OBD-II Data Link Connector (DLC). For additional information on OBD-II system, see appropriate SELF-DIAGNOSTICS article.