One problem related to horn assembly has been reported for the 2008 Chevrolet Trailblazer. The most recently reported issues are listed below.
Low beams stopped working, took it to the dealer who replaced both bulbs and it worked for a couple weeks now low beams randomly shut off while driving, especially at night. Airbag sensor keeps turning on and off and the horn stopped working. The airbag sensor seems to come on more on longer trips around the city with more turns.