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-   -   "Check Gas Cap" warning (https://www.gmforum.com/2000-2005-90/check-gas-cap-warning-223096/)

Paul 10-03-2005 11:16 AM

"Check Gas Cap" warning
 
Would anyone know what the reason are for my 2001 SSEi with 62k miles to get a "Check Gas Cap" warning on the Driver Information Center?

Thanks.

1993 SLE 10-03-2005 11:22 AM

because the Gas cap needs to make a seal when tightened. Sometimes the Gas cap will throw a SES, you just lucky enough to have the DIC.....some times reeeeealy tightening it down solves the problem and sometimes a replacement cap will take care of it too

Paul 10-03-2005 12:08 PM

Quote:

Originally Posted by 1993 SLE
because the Gas cap needs to make a seal when tightened. Sometimes the Gas cap will throw a SES, you just lucky enough to have the DIC.....some times reeeeealy tightening it down solves the problem and sometimes a replacement cap will take care of it too

So it seems to be some kind of gas tank pressurization fault?

1993 SLE 10-03-2005 12:26 PM

yes, and there would be a CEL light thrown with a specific code if you didnt have the DIC

banned3800 10-03-2005 12:30 PM

Quote:

Originally Posted by Paul
Quote:

Originally Posted by 1993 SLE
because the Gas cap needs to make a seal when tightened. Sometimes the Gas cap will throw a SES, you just lucky enough to have the DIC.....some times reeeeealy tightening it down solves the problem and sometimes a replacement cap will take care of it too

So it seems to be some kind of gas tank pressurization fault?

Very possible.... There is a pressure sensor on the tank that measures pressure... If there is little or no pressure, the PCM sees that as a problem and illuminates the SES light... Usually this can occour if the gas cap is not tightened as it should be, or the cap is faulty... If thats what the code is for you can have it reset, or if the gas cap is ok, and the PCM sees the pressure in the tank, the light will go off after so many driving cycles..

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SuperchargedFury 10-03-2005 04:04 PM

Another problem that you could be having is that the Purge Vent Solenoid is not Functioning Correctly. On our 2k SSEi the Check Gas Cap warning kicked on everytime you started the car. Thats what we had to replace!

EDIT: I deleted what i had originally posted - what i had origanally posted pertained to what the Purge Vent Solenoid did, what i had posted was not correct.

markwb 10-03-2005 07:19 PM

Actually, when the purge valve opens (commanded open by PCM) it pulls a small vacum on the fuel tank & evap system. The whole purpose is to purge the charcoal canister and check the integrity of the evap system for any leaks.

SuperchargedFury 10-03-2005 07:46 PM

Edit: deleted this post - markwb sorry if i said that the wrong way. :D

markwb 10-03-2005 08:41 PM

Super, I wasn't trying to correct you, I was just giving a brief description of that portion of the evap system. :)

compyelc4 10-03-2005 10:35 PM

I had the same problem with my 01 SSEi. Can't tell you how many times I had the gas cap checked when I did the E-check thing. I even applied a film of silicon to the gas cap o'ring. This seemed to lessen the number of Check Gas Cap messages I got over time.

Finally, I compared the cap with an identical one on my '99 GrandAm GT. What I found is that the Bonne's gas cap had much lower ratcheting resistance than the GT, meaning the internal clutch spring on the cap was worn. Also, the comparison showed that the cap o'ring was smashed down pretty good. I replaced the cap with an OEM about 3 months ago.

I'm happy to report that the Check Gas Cap message is finally resolved.

Oh, one other thing. I also found out that the Bonne's gas filler tube lip was slightly corroded, compared to the GT's, which was almost teflon smooth. I used emory paper to smooth her down and that allows the cap to ratchet down even tighter than just a new cap would provide.

You might try a new cap. About $23 around here.


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