Two problems related to ignition module have been reported for the 2006 Chevrolet Trailblazer. The most recently reported issues are listed below.
I came out to my vehicle today, unlocked the door with the keyless remote but the driver's door was unresponsive. Upon starting the vehicle I realized the windows don't work on the driver's side as well. I removed the driver door control module to find a burn mark internally on the door as well as burnt plastic on the door module itself. The window and lock worked fine the night before so I'm concerned with the short circuit occurring over night without a key in the ignition.
While driving, my headlights will intermittently turn off on their own. This does not happen frequently but has occurred several times per month for about 3 months duration. I had experienced this same event about 6 times before contacting gm directly. I contacted gm directly due to the fact that I consider this problem to be a safety issue. This vehicle is equipped with automatic headlights which turn on when darkness is detected. This automatic activation cannot be overridden with manual controls when the headlights turn off unexpectedly. I attempted to pull over and manually turn the headlights back on without resolution. I attempted to turn off the vehicle's ignition and restart the engine without resolution. Nothing I could do would make the headlights turn back on. The headlights seem to have a mind of their own and will eventually turn back on but this is completely random, sometimes taking a few minutes or maybe up to 20 minutes. A certified gm service center claimed the issue to be with the body control module and provided an estimate for replacement. I elected to not have the dealer replace the body control module for a significant amount of money. I instead started searching for another solution. I turned to the internet and found that this same issue has been reported on this make of vehicle since at least 2002 continuing until the late 2000's. Gm informed me over the phone that they had not heard of this issue before. The certified gm service center claimed that they have not heard of this issue before. A simple google search will tell you a different story. I ultimately followed the direction of a youtube video which directed me to replace a relay located on the vehicle's fuse plate. The cost of the part was approximately $30. My headlights are working again. In my opinion gm should issue a recall for this part and not the body control module.