Test Procedures: Notes

NOTE: For additional information on self-diagnostic system, see the TESTS W/CODES article.

Five different diagnostic modes are available through ECM. Diagnostic Modes I and II monitor air/fuel mixture ratio using LED inspection lights. Mode III is self-diagnostic system, used to obtain trouble codes for component or circuit failures. Mode IV monitors for malfunctions in system's on-off control switches. Mode V is real-time diagnostic system: it monitors system and its components during actual driving and is particularly sensitive to intermittent symptoms.