Conditions for Setting the DTC

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

When the BCM receives a backup lamp request signal and the backup lamp supply voltage circuit is shorted to ground.
When the BCM is not receiving a backup lamp request signal and the backup lamp supply voltage circuit is open or shorted to voltage.
There is a loss of the instrument panel fuse block TBC 2B battery supply voltage to the BCM for 1 second.