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"Tighten Fuel Cap"/P0455 Code

cheeba

Full Member
Joined
Jul 2, 2005
Messages
45
Location
Virginia Beach, VA
Good Morning All,

Ok, so I have run into my first issue since the warranty has run out (unless you count the "Service 4 Wheel Drive") which I ignore and it goes away.  :badidea:

I checked the threads here on the subject code, most said to change out your gas cap.  So I did that with a new GM cap.  Check engine light is still on, and the "Tighten Fuel Cap" keeps coming on in the DIC after 2 weeks of waiting for the code to clear.  I dont like clearing codes.  I'd rather attempt to correct the condition and wait for the vehicle to recognize it.  Flawed?

Also saw where it was recommended to check the vacuum lines.  Can anyone provide a decent diagram to check the fuel lines, or a pic with arrows denoting some lines to check that are most suspect OR even just a description of where the most likely lines would be.  That'd be a start, I took a quick look but didnt really see anything suspect.

And finally I saw where some replaced the vent solenoid but I didnt get that code I dont think. 

Any help would be appreciated.  Thanks again.
 
clear the codes and go from there,it will be faster than waiting for the system to "recognize" the fix. (y)
 
ditto to what jimbo said .... I had the same issue .... they replaced the cap AND cleared the code .... have yet to see the code again .... (y)

John
 
Ok, I'll try that.  Its been weeks and it still keeps telling me to tighten the cap.  Is the only way to clear the code to disconnect the battery?
 
yes ... unless you have a reader that will clear the codes for you .... if not just disconnect your battery for about 30 minutes ....
 
Ok so I stopped by the local auto parts store yesterday after work and I reset the code (there were actually 2 codes both the same P0455) so the Check Engine light went off.  On the way into work this morning I got the Tighten Fuel Cap again in the DIC.  So its only a matter of time till it throws another code.

And ideas?  I cant find any of the vacuum lines to check if someone could give me some direction there it would help.  Auto parts guy couldnt find any either so I dont feel too dumb.
 
That first one I think will help me.  Driving to work this morning the Check Engine went on again.  So obviously the gas cap wasnt the problem.  I'll check the lines.  I guess if there are no cracks/holes in the lines than Im just looking at replacing the evap purge valve and solenoid?
 
I got the tighten fuel cap on my DIC 3 times, then the check engine light came on! I went to check the codes and it was a maf code and some shift D link code  ??? nothing about the fuel cap! I cleared them out and am going to wait and see if they come back on! I wonder why the fuel cap wasnt a code though???
 
I changed the cap and the check engine keeps check engine keeps coming back, along with the tighten gas cap message.  I definately have an issue that needs to be resolved.  That yellow light is starting to really bother me.
 
Cheeba, I have the same issue with my rig.  I too also replaced the gas cap hoping for the cheap 'n easy fix.  but the CEL comes on and keeps throwin that code.  It's strange though, I will reset it, and go through like 2 tanks of gas before it rears it's ugly head again. 

ItsStopher  gave you the correct links to what could be causing this.  I've gone through them but I have yet to chance the purge valve, ect as I'm a boob at determining what problems are on this truck.  I keep forgetting to take it in when I get the code, I just erase it with my Predator and go on my merry way.  Not the best ider, but I hate that yellow light.  I'll probably get it fixed here when I'm off for a bit at christmas.  Good luck troubleshooting your problem.    :B: 
 
Just wanted to close the loop on this thread.  Finally got some nice weather this weekend so I went to the dealership, and bought a new Evap Canister Vent Solinoid Valve (this is the one located by the gas tank, the one near the engine is called the Purge Solinoid Valve).  It was $29 and it was a 15 minute job, one electrical plug, one hose and a slide in clip release it from the truck (use a screw driver here to bend out the center of the clip, slides right out, put it back and bend center back in to hold it in) REAL EASY.  The hose is a little tricky.  Need to squeeze the ring to get it to clear the lip, I actually used a flathead screwdrive to "help" it.

I didnt go and clear the CEL.  Wanted to see if it'd clear itself.  Just went off this morning on the way in so Im pretty happy about that.  I bought the gas cap first which I didnt need but total, about 55/60 bucks I fixed it myself.  I think it would have been 2 or 3 times that if I just went straight to the dealership with the problem.
 
cheeba said:
Just wanted to close the loop on this thread.  Finally got some nice weather this weekend so I went to the dealership, and bought a new Evap Canister Vent Solinoid Valve (this is the one located by the gas tank, the one near the engine is called the Purge Solinoid Valve).  It was $29 and it was a 15 minute job, one electrical plug, one hose and a slide in clip release it from the truck (use a screw driver here to bend out the center of the clip, slides right out, put it back and bend center back in to hold it in) REAL EASY.  The hose is a little tricky.  Need to squeeze the ring to get it to clear the lip, I actually used a flathead screwdrive to "help" it.

I didnt go and clear the CEL.  Wanted to see if it'd clear itself.  Just went off this morning on the way in so Im pretty happy about that.  I bought the gas cap first which I didnt need but total, about 55/60 bucks I fixed it myself.  I think it would have been 2 or 3 times that if I just went straight to the dealership with the problem.
hey im right behind you i just changed the purge valve today,gonna due the vent valve solenoid this week man i hope it clears my problem, im happy for ya, hope that idiot light stays out
 
Its been over a month and no more CEL.  So I'm good to go!  Just ripped off the plastic "deflector" from under the front bumper yesterday.  Pissed me off, easy enough to fix but money I dont want to spend.  Arrrrrrhhhhh!!!
 
Tighten Fuel Cap popped up on my DIC about 2 weeks ago and went away, haven't seen it since, well not until the day after my extended warranty expired and the CEL pops up.  Had On star run the diagnostic test and they came up wit 2 codes. p0455 and p0449.  This has happen before,  Went to the dealership and bought the Evaporator control solenoid (p/n 25932571) and the Evaporator Purge valve (p/n 12581282)  $75.24 for the parts and changed them out.  Cleared the codes and went fill it up.  Had On Star run another diagnostic test and it came up clean.   (y)
 
More information.  I have a 2003 Avalanche Z-71 (with the 5.3 engine).  My engine check light is on (was also getting a P0449 code), I checked the gas cap, and thought the vent solenoid may need to be replaced. 

I ordered the Vent Solenoid from GMPARTSDIRECT.COM (cost was $14.43, shipping was $12.95, total cost was $27.3:cool: .  I sent GMPARTSDIRECT.COM the VIN on my truck and was told the part number for the solenoid i needed was 25932571.  Well the part I received is NOT similar to the part currently on the truck.  The part on the truck is basically square, the part I received is round and bigger them the original part.  So big, that it will not fit in the allocated space.  I'm not sure if I received the wrong part or if hardware is missing.  I e-mailed GMPARTSDIRECT.COM and am currently waiting on a response.  I have photos, but can seem to get them on here.  Will keep you posted.
 
I keep getting a Check Engine light and the "Tighten Fuel Cap" message on the DIC. Do you know if you can buy just the Vapor Canister Purge Valve or do you have to purchase the whole evap canister.  I have pictures of this lovely device that is giving so many truck owners grief it only takes 5 min to take off. It is locate on 04 Avalanches ON the passenger side rear near the right rear tire just right of the fuel tank. Pictures
IMG_0147.JPG


IMG_0148.JPG


IMG_0149.JPG


IMG_0150.JPG


IMG_0151.JPG



Hope this helps someone looking for this defunct equipment giving errors. P0445 -  ...
...  Emission Control System Purge Control Valve Circuit Shorted

P0449 - EVAP Canister Vent Solenoid Valve Control Circuit


I replaced the part that has the blue O-ring on it the Valve. but you have to buy both They come as a set (GM P/N#25932571)Valve Solenoid Electrovalve cost $27.45 takes all of 5 min to take off and put the new one on.

No service manual, Just went off the the P codes checked the connections with a multimeter with them attached to the solenoid . The solenoid by the engine read 12volts took it off and cleaned it anyway applied 12 volts to the solenoid and watched and listened to it function , Moved on to the solenoid in the rear by the gas tank checked the voltage with the solenoid attached and got 0 volts disconnected the solenoid  and checked the voltage got 12 volts, applied 12volts to the solenoid and the part did not move or do anything. (y)  This is the culprit!!! (y)  I have since changed three of these for three of my friends that have avalanches and the CEL has not been back. Everyone kept telling them to change the gas cap but our trucks only have 70k on them. To sum it up if you get a P445 or P449 and CEL with tighten gas cap. You can take it to the bank it either one of two solenoids the one up front by the engine or the one by the gas tank has burned out. Parts guy said they keep them in stock Wink Wink so I think chevy knows about this defect. Looks to me that if you keep the truck long enough you will have to replace it because their is 12 volts applied to the solenoid while the truck is running to keep the solenoid closed because it is a normally open solenoid then when the truck is off it opens which seems the switch should be normally closed and have the ECM open it before and after a Run cycle instead of full on closed position while running. Chevy Dealerships wants to charge $99.00 Diagnostic fee and waive it if you have your truck fixed with them for a  $27.00 part. Which as you see at the begging of this thread "Dropped $100+ at the Dealership." When You can fix yourself for $27.00 and your own labor. If you can change a car Battery this task is just that easy.
 
branx86 said:
I keep getting a Check Engine light and the "Tighten Fuel Cap" message on the DIC. Do you know if you can buy just the Vapor Canister Purge Valve or do you have to purchase the whole evap canister.  I have pictures of this lovely device that is giving so many truck owners grief it only takes 5 min to take off. It is locate on 04 Avalanches ON the passenger side rear near the right rear tire just right of the fuel tank.

Hope this helps someone looking for this defunct equipment giving errors. P0445 -  ...
...  Emission Control System Purge Control Valve Circuit Shorted

P0449 - EVAP Canister Vent Solenoid Valve Control Circuit


I replaced the part that has the blue O-ring on it the Valve. but you have to buy both They come as a set (GM P/N#25932571)Valve Solenoid Electrovalve cost $27.45 takes all of 5 min to take off and put the new one on.


That's right on the money, I replaced the fuel cap last week just to do it since it was factory and cleared the codes. The code come back immediately by just starting the truck....so today I changed out the (GM P/N#25932571) Valve Solenoid and cleared the codes. After a lengthy drive and a few WOT bursts the only code that was set was multiple random missfires.  (y) On to fight that code another day since it only gets set when it's hot rodded..... >:D
The valve cost me $37.62 from the stealership. They do need the last 8 digits of the VIN to help get the right part....as mentioned in other posts.

Thanks to you guys that posted info and pictures to help diagnose the issue at hand, it saved ALOT of time and probably wasted money!  (y)
 
Update all, just got another CEL a couple of weeks ago.  Finally got a chance and went to my local Autozone and read the codes.  This time it came up P0449.  This code calls out a Evap Emission Vent Valve Solanoid malfunction.  I actually picked up the part at Autozone for $27.  Replaced it and in a day the CEL ent off.  That was yesterday.  A little different than the last senario, but with the same fix.

Also there is a limited lifetime warranty on the part from Autozone.  Being as I only replaced the last one 2 years ago I'm going to save my packaging and the receipt this time and see what happens in 2014 when I have to do it again!  Till next time...and I knooooow there will be a next time.
 
Ok, got the P0455 after clearing the code several times with "tighten fuel cap", which I have done.
Appears to be the vapor canister purge valve that is located just ahead of the spare tire...

Here's the picture of what I have...
When I check Rock Auto for my 2006 Av 1500 I see several that look the same with the exception of the hose connection.
The ACDelco 2142149 valve( http://www.rockauto.com/dbphp/x,catalog,321,partnum,2142149,d,ACDELCO_2142149.html click on "more info for pic.) has a straight hose connection but mine has some kind of right angle adaptor...will it come off and connect to the ACDelco?
The electrical and mount appear the same.

Any ideas?


P0455%20001.JPG
 
Success!!

The item noted above in my post from Rock Auto is the ACDelco unit and it is an exact replacement for what is on my 2006 Av.
The hose is connected via a right angle adapter that has to be disconnected from the valve...no need to pull off hose itself.  A screw driver to release two clips that hold the adapter on must be bent outward then the entire adapter pulls off.

Easy replacement and as soon as I started the AV the light went out!
Until next time I guess as it appears this is problem waiting to happen again.
 
I had the Primary fuel pump top rusted so bad it leaked fuel when filled. I was getting P0449 and P0455. Changed the pump and still get the tighten fuel cap message and after a few times, the P0455 code comes back. Changed the gas cap, purge solenoid and Vent solenoid and still get the code. I don't know what else to check other than the rear fuel pump  :E:
 
I dropped the rear fuel tank today. About 10 inches of a Evap hose was gone. Chewed up by mice. Repaired the section and reinstalled the tank. The fuel pump was rusted but not as bad as the front tank unit that was leaking out the top. So I didn't change it. I drove it into town and did not get a "Tighten fuel cap" message. I will waste some big block gas and take it to work tomorrow to see if the Evap readiness monitor clears  (y)
 
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