Conditions for Setting the DTC

WARNING: This page is about a different car, the 2002 GMC Safari, 2002 Chevrolet Astro, 2001 GMC Safari, and 2001 Chevrolet Astro. However, it is still accessible from the selected car via links, so may be relevant.

The BCM will inspect for a valid code when the ignition is rotated from ON to CRANK and will continue to monitor the signal during the engine running period.
The BCM is reading a valid but different code value than previously learned form the Passlock™ sensor.