One problem related to back up lights has been reported for the 2004 Chevrolet Trailblazer. The most recently reported issues are listed below.
2004 Trailblazer has 40 second turn on of headlights and back up lights when remote key used to unlock doors. This has on 2 occasions has caused vehicles in travel lanes to suddenly brake because with the back up lights on blazer appears to be backing into traffic. Solution: only occurs after dark, so must be relayed thru daylight running detector. Needs to do as brake and turn signals do, flash on and then off. Headlights have stayed on shining into a group who threaten me with bodily harm. Dealer said a gm problem, they can't change. Had 2002,2001,1998 blazers, never a problem.