Conditions for Setting the DTC

When the BCM receives a courtesy lamp illumination request signal and the courtesy lamp supply voltage circuit is shorted to ground.
When the BCM is not receiving a courtesy lamp illumination request signal and the courtesy lamp supply voltage circuit is shorted to voltage or open only to the first splice from the BCM.
There is a loss of the rear fuse block truck body controller (TBC) 3 battery supply voltage to the BCM for more than 1 second.