One problem related to transmission gear slipping has been reported for the 2003 Chevrolet Trailblazer. The most recently reported issues are listed below.
I bought a used 2003 Trailblazer. I took it in because it was having issues with the engine light coming on. The engine light no longer comes on but the problem has gotten worse. The transmission slips constantly, I have only had this vehicle for 4 months. I am afraid this is going to happen when I am in the middle of traffic and my children and I will be in serious trouble.