DTC 21/31: Courtesy Lights Feed (Circuit Shorted To Ground): Description

BCM provides a 12-volt input to courtesy lights on courtesy lights feed circuit when commanded by instrument panel dimmer switch, left or right door jamb switch or rear compartment lid ajar indicator switch inputs.

DTC 21 will set when battery circuit is open due to a problem with COURTESY fuse No. 8, faulty harness or connector, courtesy lights feed circuit is shorted to ground for more than 50 milliseconds while BCM is providing input on circuit, or BCM is defective.

When DTC 21 is set, courtesy lights will not illuminate and instrument panel dimmer switch will not operate. Glove box and center console lights will also be inoperative. DTC 21 will clear when fault is corrected and memory is cleared.