Check Engine Light

[reddemon71]

05 yukon, Message shows tighten fuel cap, but it's tight, then check engine light comes on. I have disconnected the battery to resest the light but ends up coming back on again after a few weeks. Any idea's. I'm bringin it in tomorrow and have a tech run the computer

 

[kilcher]

Same problem here. Anyone know of a way to stop this? Does the cap need to be replaced? We picked up our 2005 Tahoe last Saturday and the "tighten fuel cap" prompt has come up several times. I went to AutoZone to clear the codes and the check engine light.

 

[JKmotorsports]

Gas caps can go bad, causing the vapors to escape and trigger the SES and Gas Cap msg.

 

[kilcher]

Good to know. Guess I'll check into getting a new one. Thanks!

 

[41racing]

It could be your gas cap, but in my experience it don't happen very often. I'm going to go out on a limb here and say that you are going to need a new vent valve. GM has updated the valve several times. The problem is that it gets clogged with dirt. If you live or drive on gravel roads you're more than likely going to need a new vapor canister also. I've done tons of these on gm trucks, burbans, and hoes. I'd have it checked out though because the parts get kind of spendy if I remember right. If it has a code po455 (I'm pretty sure, but not 100% positive that's the right #) for a vent valve that's your problem.

 

[kilcher]

Ugh. I've gotten the message two more times. The check engine light hasn't come back on so I'm not sure there'll be any codes to check.

Until then I guess I'll get a new gas cap and hope for the best. We just got it last Saturday so I'm not sure how/where it's been driven. The dealer is an hour away and only gave us a 90 day powertrain warranty so I doubt they'll be of any help.

 

[kilcher]

It could be your gas cap, but in my experience it don't happen very often. I'm going to go out on a limb here and say that you are going to need a new vent valve. GM has updated the valve several times. The problem is that it gets clogged with dirt. If you live or drive on gravel roads you're more than likely going to need a new vapor canister also. I've done tons of these on gm trucks, burbans, and hoes. I'd have it checked out though because the parts get kind of spendy if I remember right. If it has a code po455 (I'm pretty sure, but not 100% positive that's the right #) for a vent valve that's your problem.

Well, I replaced the gas cap and everything seemed to be fine. The salesman called to follow up a couple days later and he told us they had already replaced the gas cap before they sold it to us. Looked at the old one and sure enough it looked new. Well, last night and this morning I got the same message. I suppose I could live with it but that check engine light is kind of annoying.

Any idea how much the vent valve and/or vapor canistor are?

 

[JKmotorsports]

... The salesman called to follow up a couple days later and he told us they had already replaced the gas cap before they sold it to us...

So if they already replaced the cap, it's quite possible they had the problems already before they sold it and didn't mention anything to you. Why else would they just replace a gas cap out of the blue? They won't do anything for you at all?

 

[kilcher]

So if they already replaced the cap, it's quite possible they had the problems already before they sold it and didn't mention anything to you. Why else would they just replace a gas cap out of the blue? They won't do anything for you at all?

I guess I can check with the salesman. The dealership is an hour away. And technically we only have a 3 month powertrain warranty. So I'm not expecting them to do anything. They obviously had the warning when they had the vehicle and at least made an attempt to "fix" it.