Pulling codes

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the evap emission system small leak is usually the gas cap, but not always! it can also be a hair pin leak in a vacuum line.
 
I took the gas cap off, put it on drove it, started it, re-started it, no cigar. I have a feeling it is more than a gas cap. She has over 1/4 tank, I was thinking of filling it up and seeing if it would go out. Then I thought of trying some plastic wrap under the cap, to make an air tight seal to test the cap itself, if it flunks both those trys it goes back to the dealer. They can deal with it, at least if I get to this point I can safely say they can't charge her for not screwing the gas cap on the right way.

If it were the gas cap, how long would it take for the code to clear itself in a Jeep? They told her at the parts store it was against the law for them to reset the computer.
 
Originally Posted By: SteveSRT8
never a scanner needed unless you want one. Federal law requires the key dance to show you the codes.


could not be farther from the truth. the manufacturers providing code lookup with the key dance is not required in any way shape or form. its merely a luxury that they provide, there are MANY Fords that do not have this feature.

on my Volvo I have to use the factory scan tool to pull most codes, especially ones for the suspension.
 
The "gas cap" code clears pretty quick.

One can't say with too much certainty pulling the fuse will work-- sometimes, but not always... and the "Minor" codes like the gas cap are more likely to be easily extinguished. Shoot... give it a try.

The car should do "extra" diagnostics with the code, in an effort to extinguish it faster. IOW, a test that's run once per warmup will often run multiple times in an attempt to fix it. One needs the Jeep FSM or a real good online resource to see the logic tree to clear stuff like that out.

I have a $45 scan tool from ebay somewhere-or-other that doesn't do CANBUS, but does show "I/M readiness monitors" which proves that everything has been tested and passed. Otherwise you're left wondering over a week's worth of drive cycles if something will reappear.
 
Most OBD2 car's computers can be reset by yanking a battery cable for a few minutes.
But not always.
If the engine light goes off after you 'fixed' the gas cap, great! It may store a code, however.
Give it a week or two and see where it is at.
 
Well normally the light should go out after 3 drive cycles if the problem has disappeared and then the code should disappear completely from memory after about 40 drive cycles, but I'm not sure about Chryslers.

Just about any OBDII code reader can read those types of codes and clear them. I would drive it a while, and if it doesn't clear see if you can get Autozone or someone to clear it, or maybe buy a code reader/scanner. I think Innova makes a decent scanner for under $150.
 
The guy at parts store told my GF it was against the law to clear the code. I can understand why, I wonder if a $20 bill would have cleared it.

She started it up about 4 times today, I turned the key from the on to off position w/o starting it at least half a dozen times.

Should we drive it a while, or should I disconnect the battery and then drive it a while? I know this code means that it is strictly an emission thing, and not something that will effect drivability of the Jeep.

Would gassing it up do anything? She said a while ago she was trying to round off the $$$$ on the pump and spilled a little gas, but that might have been 2 tanks ago.

She had a car totaled by a dealer a few years back, and is sick at the thought of taking her Jeep in. Now you guys can understand why I'm posting here.
 
Originally Posted By: ADFD1
The guy at parts store told my GF it was against the law to clear the code. I can understand why, I wonder if a $20 bill would have cleared it.


in CA they are not even supposed to pull a code unless the person doing it has a smog license. and i can guarantee you someone with a smog license will not be flying a desk in a aftermarket parts house.
 
I don't know about your state law but I never heard of it being illegal to clear a code because what would it really matter? If the problem was still there it would just prompltly reset the code. In California i could believe it's against the law. A lot of times auto parts stores say things just to get out of something they might really not know how to do.

I'm not sure about Chrysler, but on GM I think unhooking the battery would clear this particular code and the the light may go out because when the battery is unhooked I think the diagnostic retests the EVAP looking for a problem again.

Anyway, yes you want to drive it at various speeds and conditions like city and highway to get the emissions readiness test to all run and hopefully reset the code.
 
I guess there is nothing to lose by disconnecting the [-] battery cable for a little while, just a PIA resetting the radio etc. Unless these newer Jeeps remember the radio and driver perf's.

I'm going to take it for a ride when I get off. I'm an Ford guy, and not familiar with anything this new, or Chrysler products.
 
Read somewhere some of these systems sense how much gas is in the tank and only run the test between 1/4 and 3/4 tank. So put some gas in, might shake something loose in the computer.
 
She typically runs the tank down to half a tank, she is a little closer to 1/4 tank. I gave her a bottle of FI cleaner, I wonder if she added it to this tank of gas.

If it is a pin hole somewhere in the Evap system is this the kind of vacuum leak that can cause engine issues? Or is it a seperate system not effecting the engine? From what I've read this is strictly an emission item and has nothing to do with the engine.
 
Evap system is closed except when a solenoid opens to let a small amount of gassy air into the intake... which gets adjusted for with the closed loop running. They rig it so the solenoid only opens when you're on the highway and wouldn't notice it. The car doesn't really know if it's going to get a lot of HCs or a few so any vacuum leaks won't really matter.

Any leaks in the EVAP system make the hydrocarbons evaporate in the parking lot... which isn't earth friendly, so the car has to check its own integrity and whine if a problem is found. You'll notice old cars, lawnmowers, etc stink of gas if you get close enough to them but not the modern tin, thanks to those charcoal canisters.
 
I don't think it would hurt the engine really. It might serve as a slight vaccuum leak to the engine and possibly draw in some dust. I don't know if the dust would make it all the way up to the engine or not. I would maybe unhook the neg Batt for a bit, put about 3/4 tank of gas in, then drive it around a few times and see what happens.
 
The check engine light light came on in my Crown Vic about 6 months ago as it was going in for service...I told the dealer not to bother with it at that time...After the oil change I found a 115 buck charge on my bill...They said that was for checking to see why the check engine light was on...Turns out the gas cap was not on tight enough...After I threatened to put them on the internet and threatened to take my fleet elsewhere they gave me credit for it.
 
Originally Posted By: mechanicx
I don't think it would hurt the engine really. It might serve as a slight vaccuum leak to the engine and possibly draw in some dust. I don't know if the dust would make it all the way up to the engine or not. I would maybe unhook the neg Batt for a bit, put about 3/4 tank of gas in, then drive it around a few times and see what happens.


Sounds like a plan. Will do just that, I might even pick up a scanner.
 
I don't know why dealers do that. If they are just pulling the code, maybe tightening up the gas cap, and clearing the code the charge is a little excessive in the first place. If the car is under warranty seems they could just charge warranty dignostics and say problem couldn't be repeated. When I would take my Pontiac in the shop sometimes, the shop foreman would hook up the Tech II right there on the spot and send me on my way with no paperwork and no charge. Maybe partly because I was sort of familiar to him, but that is how all dealers should operate.

I'll give Honda credit for one thing. On some of their models it tells you in the driver info center to check fuel cap instead of just setting a check engine light. They would be smart to all do that.
 
Originally Posted By: ADFD1
Originally Posted By: mechanicx
I don't think it would hurt the engine really. It might serve as a slight vaccuum leak to the engine and possibly draw in some dust. I don't know if the dust would make it all the way up to the engine or not. I would maybe unhook the neg Batt for a bit, put about 3/4 tank of gas in, then drive it around a few times and see what happens.


Sounds like a plan. Will do just that, I might even pick up a scanner.


Hope the code clears quickly for you with no repairs needed. At least you'll know that it is more than a loose gas cap if it won't clear when you take it in.
 
I really believe that the gas cap is a goose that laid the golden egg for some of these dealers. The girl I mentioned earlier on that got hosed by Toyota, lived on Long Island. If it took them all of 5 minutes to rip her off of $140 it was a long time. It is things like that which make dealers some nice extra bucks. It is also things like that which can lose customers, or gain them had they reset the light and sent her home with no bill.
 
You will also find dealers love stupid stuff like theft proof cassette radios that need a special code to unlock when the battery gets disco'd.

Not to mention state inspection laws that demand CELs get taken care of.
 
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