Self-Diagnostic System: Notes

CAUTION: Electronic modules are sensitive to static electrical charges. Proper grounding of technician and workplace is essential to prevent damage.

NOTE: Diagnostic Trouble Code (DTC) tests are written specifically for use with GM Tech 2 scan tool. Generic scan tool can be used but may have limited functions. This article only covers the portion of those systems which relates to body control module system diagnosis.

Body Control Module (BCM) is equipped with a self-diagnostic system which detects system abnormalities. When a malfunction occurs, BCM will store a DTC. Malfunctions are recorded as current and/or history (intermittent) failures. Current DTCs indicate BCM has detected a fault which is currently present. A history DTC indicates that BCM has previously detected a malfunction that is not currently present.