2000 SSEI Gas Cap Problem??

I have a 2000 SSEI and I keep getting a "Check Gas Cap" message from the car. I have some problem in the gas cap system but I can't really troubleshoot it well because I'm not sure how it works. Could someone help me with this problem. It seems kind of common. Thanks.

First is the cap tight and making a good seal. If so you will need to scan it for a more exact diagnosis, a leak anywhere in the evap sysem can can this.

Yep, you MUST tighten the cap to at least 3 clicks or you'll get a code. If the cap is tight, try replacing the cap with a new one and see if that fixes it. No sense doing a bunch of extra diagnosis when you haven't corrected the indicated problem.

Take it to someone who has a smoke machine and it will find the evap leak real easy.there is a connector under the hood in the engine compartment for the smoke machine to hook up to.It is a colored cap in the line with a label saying for the evap system

Also be careful cause if the plastic wire that connects it to the fuel door is broken, the warning will stay on all the time.

Check all connections at the EVAP cannister are tight.Others had this problem and connection wasnt tight from evap solonoid to cannister .

defrost3 is wrong dont worry about the plastic connecting the gas cap to the gas door if that breaks its nothing. Just think about it how can they sense if something plastic isn't connected come on a sensor next to something highly flamable

on all the newer cars they have this where if the gas cap isn't on or isn't on at all they check engine light goes on or in your case a check gas cap light i think you either need to put the cap back on correctly or get a new one all together because this one might be bad if you make sure you put it on right and it still does it

The fill tube is junk,one of my father's friends went through that after hooking up to a smoke machine and that wehere the smoke from the smoke machine was smoking from there.A new fill tube is about $42.00 from the dealer only and the dealer needs the vin to get the part

The GM part number for that fill tube is 25727011. If he'll sell it to you for $42, grab it, as I show dealer cost is $63.63 for your year and model Bonne. Retail is $109.

My father gets it that price since the GM dealer where he gets parts for GM vehicles except Saturn from treats my father right and the delivery is that same day or the next day.

Like I said, the dealer's COST is $63.63, so unless he guessed at the price, he's offering it for $21 below what it costs him.

K sorry I was wrong, but if it isnt that the plastic connector is broken then why does the check gas cap light stay on all the time when the cap is fine? I am not being a smart ass, i just assumed that since that was the only thing wrong that had to be what it was.

That was the price of the fill tube and it fixed the problem,this one was a 1998 or 1999 Bonneville.It has not come back yet.

cool, glad you got a deal and it fixed the problem. Just for reference, 98-99 are different and much cheaper (GM#25642323, dealer cost $33.56, trade $42.54)