Check Gas Cap message...
 

Hey everyone:

Well, I just got the Check Gas Cap message that I remember seeing posted on here a few months ago.

Is there a fix for it?

I would hope so.

Let me know.

Thanks!

I searched, and found lot's of posts with your same issue. You could try what these guys did. Clean the filler neck, check the valve.
https://www.gmforum.com/showthread.p...as+cap+message

I'm just gonna say this, even though it may seem dumb. But, have you actually checked the cap to make sure it's on all the way?

Bro I love you for sayin this. LOLOL!!!

Well I would hate for him to try stuff before checking the blatantly obvious. I understand we all like to think we don't screw up, but we all do at time to time.

From when i worked at the chevy garage the first thing we asked the customer was if they filled the tank with gas while the vehicle was running and if the cap was not put on tight or left off. Then we checked for evap leaks. If the cap is ok and and the stuff above is not the reason. If more than likely a evap leak.

Yeah, several times actually...

I thought it might have been a vapor lock or the equivalent, so took the gas cap off and put back on several times...

I thought it may have had something to do with bad gas, so I went and filled it up with gas - took the cap off and put back on...

So yeah..... LMAO

Ok, just making sure. Don't want to be throwing out ideas to ya if the very bare minimum hadn't been covered.

Make sure the filler neck and the cap gasket are VERY clean. Grit or sand will break the seal and set off the code. Try some light grease on the cap gasket and drive it for 300 miles or so and see if the light goes out. That was my problem on my 2002 and wife's Explorer.

I just replaced my first gas cap three weeks ago. I had an SES light and then the DIC displayed the message"Check Gas Cap".

It was the gas cap.

Can someone provide more detail on how to check these items on a 2003 Bonneville n/a? I am having the gas cap problem and have snaded the filler neck and purchased a new cap. message still on.

"There's also a purge vent unit you need to clean... I think it's hooked to one of the lines that goes to the evap canister under the passenger side rear floor board."

"It was the purge canister solenoid causing the problem. The solenoid is mounted on a bracket on top of the engine very close to the firewall"

Does anyone know the details on what the purge unit vent looks like

There's also a purge vent unit you need to clean... I think it's hooked to one of the lines that goes to the evap canister under the passenger side rear floor board.

I got this last week too, somehow I didnt put it on correctly (must have been in a rush) I felt stupid plugging in the Tech2 to see a code....something that GM should have just made an icon for somewhere on the instrument cluster.

Its bad enough my Oil Pressure Sensor just went bad and I'm reading 120psi on the I/P, sensor voltage reads almost 5volts, so I know its fried. I dont think it'll do any damage I haven't got any SES lights or odd performance because It'll have to wait a few days.

Does this help any?? I kinda skimmed over this topic so im not sure if its what your asking for.