Anyone have their engine light come on and stay on...Advice please (Pic)
 

My check engine light came on this afternoon and Onstar did a dignostic on it and says something to do with my gas cap and it detecting vapor/fumes.... They said it appeared to be nothing major and they ask if I had just gotten gas recently, but I had not. Has anyone else had this happen. The only thing I did this afternoon when leaving my office is, I gunned it on a turn to get in front of traffic....so in other words I turned very sharp while getting on it. This is when the check engine light came on. I am taking her in to the dealership to have them do a MDI diognostic check. Could this just be a sensor that needs to be reset? Perfomrance is fine and she is running great but the light is still on and Onstar says the gas cap needs to be checked. I am hoping it is just a very sensitive sensor ;). If I have explained this correctly, does anyone know what this could be or does it sound like a simple sensor reset?

Here is a pic of what I am referring to....

http://i55.photobucket.com/albums/g1...nginelight.jpg

Thanks for the help and any advice as it would be greatly appreciate.

Don

You must not have tighten the gas cap enough. All you have to do is disconnect your battery cable for 5 minutes. Once you plug it back in it should clear out the code from the computer and you should be fine. You will probably lose you radio station settings and other setting you might have.

If it comes back then you will have to take it to the dealer to swap out your gas cap due to a faulty gasket or such. :thumbsup:

Don't know if this will help or not, but I've had this happen before and the cause was me not turning the gas cap until it clicks a few times...

Make sure you gas cap tight. Make it click several times when tightening it esspecially after filling it up.

:word: i agree

I did do that. I pulled over after talking with Onstar earlier and checked it. All was tight and fine. I then went to the gas station and filled her up to see if that would reset it. At the time it popped on, I had a half a tank. it is odd that it came on when made that hard tune while gunning it earlier.

Just drove it to the store and it is still on.....ugh I did get on it pretty hard to make sure performance was there and all was fine. Always something...lol ugh

Tighten your cap..will go away with key cycles.

Cool...I will head to the garage and give that a try. With my luck....it will be a faulty gasket ... ;)

Key cycles meaning after a few days or a few cranks from now? Should I even worry with taking it to the dealership in the morning do you think?

sometimes key cycles (key on, key off) will reset a check engine light.

Sometimes it goes off on its own.

Most times, it stays on util reset with ODBC code reader.

Autozone can read / reset codes for free. They have a generic code reader tool.

So can the dealer, obviously.

If it is the gas cap, the computer (PCM) will relearn the normal code after throwing the code. It took a few days and key cycles (start and stop) for the SES light to go off in my T/A after I replaced the MAF, O2's or TPS.

Unplugging the battery IMO is not recommended as the entire car may have to relearn ALL the settings (A/F ratio, throttle settings etc.) over the same 40 or so cycling starts and you are only prolonging the fix. Car will run rough until relearns.

This is a simple problem that with a few days should fix itself. If after that, SES light stays on, see a dealer.

And I wouldn't recommend starting and stopping the engine 40 times (or more) in succession to get the code to reset..give it time. no need to wear out and heat up starter/solenoid.

Thanks very much for the detailed explanation. It sounds like I should just keep my appointment with the dealer in the morning and let him run the MDI diognostic on it.

By letting the dealer do this, can he reset just that sensor without resetting the entire settings of sensors. I would hate to have to reset all the sensors as you stated the battery unplugging would do and then my car have to relearn the program again.

It almost sounds like I should just see if it fixes itself eventually....hmmm

I've seen this happen when filling up and topping off the gas too much, but you said this started with a half full tank...:iono: Banshee is right... Don't disconnect your battery cable, this would also erase trouble codes.

Give it a few more cycles and take to the dealer if it persists.:thumbsup: Possibly a bad gas cap