[haa21]

Problem solved-Check Engine Light-Problem Solved!!

I have a 2000 Camry with a V6 and automatic transmission. I have about 38,000 miles on it. Recently, my check engine light came on. I did a search in the Camry Forum and found many threads. I got found some good advice about going to AutoZone so they could diagnose the problem for free. AutoZone told me my gas cap wasn't tightened enough at my last fill-up. The guy at AutoZone re-tightened my cap and re-set the ECU. The check engine light was gone. After a couple of days it came back on. I went back to AutoZone and they told me it was the cap again. We removed and then tightened the gas cap. The ECU was reset. Today I was driving to work and the light came on again. I have a feeling that if I go to AutoZone they will tell me that the scanner shows a code for a loose gas cap, again. Does anyone have any thoughts on what could be causing my problem? I could see having a loose gas cap once, but not three times.

 

[CamNub]

The gas tank is pressurized. The problem should go away in like a week if you tighten it.

Do a search. I started a thread about how gas tanks are pressurized before.

 

[haa21]

CamNub-

The cap was tightened. The computer was re-set. Several days passed. The light came on again. The cap was still tight. The cap was re-tighted anyway. The computer was re-set again. 4 days have passed and now the light is on again. It has already been over a week. Are you saying that even after the supposed problem is rectified and the computer is re-set, the check engine light will still come on? Your thread states that the light will go away in 8 days on its own. My situation is different as I had the ECU re-set. The light was gone and came back. AutoZone told me that when the light goes away the error code is still in the computer if the computer is not re-set.

 

[98CamryLE]

try buying a new gas cap. Just buy the one at autozone. It's like 6 bucks.

 

[CamNub]

Just erasing/resetting ur ECU shouldn't solve ur problem...
Its just hiding the fact that you have a problem...

Did this problem just randomly come up or did you not tighten ur cap very well? If its random, either take it to the dealer or get a new cap..

 

[haa21]

98CamryLE-

Thanks. I will try getting a new cap. Perhaps mine has lost it's ability to hold the pressure.

Does anyone else have any ideas in addition to getting a new cap??

Thanks.

 

[csaxon]

You should hear an audible "click" when the cap is tightened properly. You might also check your charcoal canister for cracked, loose or disconnected vacuum hoses. I believe there was a TSB about factory installed malformed crimped hoses on some models that caused the error code you get.

 

[CamNub]

I did a search in the Camry Forum and found many threads. I got found some good advice about going to AutoZone so they could diagnose the problem for free.

Oh sorry if i offended you when i told you to search...I just skimmed thru your post..

Have you been in any accidents or anythin lately?

 

[alex]

my CEL came on in my 4runner.......i thought it was the gas cap as well........but my fuel system was actually running lean.....i had deposits on my MAF.......cleaned that off and now it works fine

so check that out....maybe its running lean for some reason

 

[CDub LXi]

Sounds to me like it's the cap itself or possibly the tank system. Since you're retightening the cap and resetting the ecu only to have it come back on, somehow it's losing pressurization. Try the replacement cap and if it still happens I'd just take it to the dealership.

 

[haa21]

Alex-

What is the MAF?


Again, I want to thank everyone for their replies!

 

[ttreat]

Check Engine Codes

I doubt it is a problem with the gas cap. Autozone gets a code when they connect the OBD II scanner. I would be willing to bet it may be one or both of these codes
P0441 EVAP Control System Improper Purge Flow.
P0446 EVAP Control System Vent Control.
There are many things that could cause these codes and a gas cap being on of them. It also could be a vacuum leak, canister, or a solenoid not functioning properly. I have the same problem with my '99 Solara. When you find the fix, let me know.

 

[dj14901]

Re: Check Engine Codes

I doubt it is a problem with the gas cap. Autozone gets a code when they connect the OBD II scanner. I would be willing to bet it may be one or both of these codes
P0441 EVAP Control System Improper Purge Flow.
P0446 EVAP Control System Vent Control.
There are many things that could cause these codes and a gas cap being on of them. It also could be a vacuum leak, canister, or a solenoid not functioning properly.

ttreat's right on the $$$. I had this same problem a few years back, what ended up working for me was to replace my Vacuum Switching Valve with the updated part. If you check out the FAQ (http://www.toyotanation.com/faq/download/gen4-tsb.pdf), I've put together a PDF of many Gen4 Camry TSBs, and the #s he references in his post P0441, P0446 are all there...

Troubleshooting the EVAP system is a pain, if you look through those TSBs you'll understand why. In my case I bought a new gas cap 1st, and after that didn't work, my next step was to see if any of the parts had been updated (which they had been). The original Toyota VSV had been replaced with an updated model, so I figured I'd give that a shot 1st. The part was around $50 from http://www.partznet.com (Conicelli Toyota - highly recommended)...

HTH -

DJ

 

[Phi]

the VSV (Vacuum Switching Valve) problem rears it's ugly head again....dun dun dun

http://www.toyotanation.com/forum/showthread.php?threadid=35284&highlight=switching

 

[haa21]

dj14901-

I checked out the FAQ you posted and decided that this looks really hard to change!!

What problems can result from having a bad VSV?

 

[dj14901]

Actually, it's really not that hard to change. The toughest part is getting the Philips head screw out (an offset screwdriver is a big help here). I wouldn't be afraid to tackle it yourself, just take a picture before so you can see where all of the vacuum hoses are going...

DJ

 

[alex]

Alex-

What is the MAF?


Again, I want to thank everyone for their replies!

mass airflow sensor........in your intake......the big black thingy

 

[haa21]

Update...it's back!

I have a 2000 Camry LE with a V6 and an automatic transmission. I have 43,000 miles on the car. My check engine light came on in 5/04 (when I first started this thread). I went to Autozone and they told me I had the following codes.....P0440, P0441, and the P0446. They told me the gas cap was loose. I didn't believe it as I am alway careful to tighten the cap and make sure it clicks. Anyway, they reset the computer. After three days the light came back on. I went to back to Autozone. They told me it could take 1 or two tanks of gas before the light stayed off. They reset the computer again. Three days later the light came on. I decided to wait a couple weeks to see if the light went off on its own. It did. Just a couple of weeks ago the light came on, again. I went to Autozone. They told me it was a loose gas cap, again. The scan tool showed the same codes as last time.....the P0440, P0441, and the P0446. I am 100% sure that the cap was tight. I have been extremally careful, especially after what happened to me in May. Anyway, Autozone reset the computer for me. I decided to go to the Toyota dealer and buy a new cap. It cost $15.00. I filled the gas tank and put the new cap on. The next day the check engine light came on again. I drove a few (4)days with the light on. I decided to go to different Autozone last night (09/26/04) and have the light reset again. Today is 09/27/04. The light didn't come on on my way to work. I expect it will come on within the next two days. Tonight I will check all of the hoses that connect to the charcoal canister. Does anyone have a good picture of the canister valve?

 

[ttreat]

You can save yourself a trip to Autozone by pulling the EFI fuse for about 30 seconds. That will reset the computer and the light will go off until whatever is triggering the light sends the signal again. I found that after the light was reset, my light would go on after about 10 minutes of driving.

 

[haa21]

Pulling the EFI fuse only resets the light. It doesn't erase the codes out of the computer. That is why your light re-appears so quickly.