LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Buick >> 2000 >> Century Custom >> Repair and Diagnosis >> External Pages >> Different car >> Section 249 (Engine Controls - Self-Diagnostics) >> Drive Cycles >> Inspection/Maintenance System Check >> Diagnostic Aids
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Aids

WARNING: This page is about a different car, the 2003 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.

The I/M System Status display provides an indication of when the control module has completed the required tests. This does not necessarily mean that the test has passed, only that a decision was made. If the diagnostic fails, a DTC will indicate the failure. If a failure indication is present for a DTC associated with one of the I/M regulated systems, it may prevent other required tests from running. For example, a DTC for the control circuit of the relay controlling an AIR pump may not be listed in the Inspection/Maintenance System DTC Table because it is a continuous test. If this DTC is set, the Active Tests for the AIR system may not run.