Conditions for Setting the DTC

WARNING: This page is about a different car, the 2006 Pontiac Montana SV6, 2006 Chevrolet Uplander, and 2006 Buick Terraza. However, it is still accessible from the selected car via links, so may be relevant.

When the CHMSL BACK/UP Fuse is open.
When the backup lamps supply voltage circuit is shorted to ground or shorted to voltages.
When the backup lamps supply voltage circuit is open before the first splice.
When circuit 1240 is open or shorted to voltage.