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


Asked by Dec 28, 2013 at 10:05 PM about the 2005 Chevrolet TrailBlazer LS 4WD

Question type: Maintenance & Repair

I've had this happen before after getting gas but it usually turns off after tightening gas cap
and driving for a while. What other reason could the check engine light be on for. Should I
be seriously concerned? It's nagging at the back of my mind, just not sure I want to spend
the money to take it to the dealership. Thoughts?

16 Answers

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"~

2 people found this helpful.

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~

2 people found this helpful.

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?

2 people found this helpful.

As long as the check engine light is not flashing it's safe to drive. Have your computer scanned and post the trouble code(s) here and we can help. Advance and Autozone auto parts stores do it for free. There are many things that can cause the check engine light to come on besides a loose or faulty gas cap. Getting the trouble code(s) will pinpoint the problem. HTH. -Jim

2 people found this helpful.

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~

2 people found this helpful.

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 ;)

2 people found this helpful.

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~

2 people found this helpful.

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'~


A faulty gas gauge sending unit won't make the check engine light come on. Do you, califcarson, leave your key on while fueling? If so, the gauge may be in "anti-slosh mode". The shop manual for my '08 Grand Marquis warns about this. If you leave the key on while fueling it may take up to 45 minutes or a few ignition cycles for the gauge to read correctly. HTH. -Jim

3 people found this helpful.

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.

1 people found this helpful.

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?

2 people found this helpful.

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?

1 people found this helpful.

Thanks a lot

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