Self-Diagnostic System: Notes

WARNING: This page is about a different car, the 2000 GMC Yukon, 2000 Chevrolet Tahoe, 2000 Chevrolet Pickup, and 2000 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: If vehicle is equipped with THEFTLOCK(R) anti-theft device, obtain code from customer prior to disconnecting power to vehicle. See owner's manual for proper THEFTLOCK(R) procedures.

Body Control Module (BCM) is equipped with a self-diagnostic system which detects system failures or abnormalities. When a malfunction occurs, BCM will store a numerical code. Malfunctions are recorded as history or current failures. Intermittent failures may be caused by problems with electrical circuit. If a visual inspection does not locate problem, vehicle may be driven with a DVOM attached to suspect circuit. Abnormal voltage or resistance readings when problem occurs indicates problem is within that circuit. However, a damaged Electronic Variable Orifice (EVO)/Passlock module can occasionally be the cause.