I own a 2005 Chevy Trailblazer the check engine light came on and will not go off.

the scout troop will not point and laugh because the tank wasn't filled until malfunctions occur~....have it tattooed on your ring finger "FIRST CLICK"~

the check engine light will go off in time, but there very well may be other complications...you must use a code reader or take it to a parts store that'll send a guy out to connect to your obd-2 port....you will read and RESET the codes with a 15 dollar scanner~

You mean when you're filling the tank stop at the first click don't over fill and go beyond the tanks capacity? Living in Oregon the attendants fill the car. Could this be the problem?

find it in your owner's manual where it gives the instructions for filling the tank and Xerox copies to hand out to the attendant~ he might learn something~

Not beyond the capacity, but beyond malfunction of the evaporative system~

Alrighty then. Sounds like I need to take it to get the code read, and go from there. @judge_roy I get what your laying down, but don't think this is the problem (even being a girl). I did however notice that small piece was broken off near that gas cap which could be causing the computer to read an error for the gas cap being ajar. Hoping the problem is inexpensive to fix being as I'm a cheap ass. Procrastinating getting a second opinion and all ;)

you're crafty....in a good way, I'm sure....if a hose is fallen off...the evaporative system cannot get it's "arms around" the outgassing of the fuel tank and will put up the light....you know where/what it is....do you need instructions/diagram...is so can come up with a cartoon or two for you~

My Buick Tarraza (2005) does the same thing when I fill the tank or nearly fill the tank. The gas gauge will read empty. I was told it is the sending unit inside the tank that has malfunctioned. After a while the gauge will act normal and the light will go off after it sits a while and the car is re-started. I reset my trip-o-meter to zero and start looking for gas at 325 miles in town or 400 on road trips. The gauge is accurate until 1/8 tank then it plummets to empty. $800+ to repair according to the dealer because the tank has to be pulled to replace the sending unit. It may be in 2005 there was a bad batch of sending units coming over from China. I know others having 2005 and 2006 GM vehicles with the same problem.

yeah, bud---but you're not oregoncarson...they've got their tanks filled by a 16 year old kid who doesn't think about overfillin'~

wouldn't you really rather own a Buick? exciting new buick? http://www.aboutautomobile.com/TSB/2005/Buick/Terraza/Fuel+Gauge

I never leave the key on or even in the ignition. I don't do burn well, and here in Southern California the temptation to steal a car, (car jack) is too tempting.

I have a 2006 Chevy trail blazer ls and shortly after I bought it used the check engine light came on. I have had it hooked up to check for error codes and it shows a black screen. I have had maybe 4 different people try to get an error code or anything to help me but it's like the computer isn't even registering that the code reader is plugged in. Nobody has ever seen it happen before and I still can't get answers from anyone. The car runs great but as far as resale I'm in a little trouble. Any ideas?

The main computer may be the issue. Or there is a sensor wire lose and causing a little glitch that activates the check engine light. GM has a machine that can run all the systems on the car to locate anything not functioning properly. I had it done twice under warranty. I don't know what it will cost out of pocket, It takes the better part of a day to run it. think about that for running down the issue. The service writer or shop mech. may have seen this before and know what to check before hooking up the big check machines. Big check might mean what it will cost?

Thanks a lot

The oxgen sensors going bad or Cadillac converter is stopping up if it drives sluggish and or smell like rotten eggs odds is changing the Cadillac converter will improve your vehicle