01 Caravan with P0456 code

01 Caravan with 3.1 engine, 65K miles, gives P0456 code (evap system very small leak). What should I look for and in what order? Thanks for any feedback.

Bob

gas cap, cracked vacuum lines, Leak detection pump vent valve, rotted filler neck, etc I've postted lots of answers to these codes on these same
Caravans, check the forums. Probably just the cap or the lines around the purge solenoid or cannister, service port etc. a good visual under the hood should find it or try a new cap from the dealer first

good luck and keep me postted

Jeff

thanks Jeff. I exchanged gas caps with my 03 Caravan (I guess that was O.K.?), but I don't know whether to expect the code to self-erase if that was the fix or would it still require a scan unit that can do the erase? I did borrow a scan unit and erase the code (it hasn't come back....yet), but if it was the gas cap, I would assume that my 03 will soon show a check engine light and P0456 code also. Nothing so far.

Bob

Not sure if 03 and 01 are the same gas cap, might be, I'd have to check the part #'s. Might take a few days before the light will come back on if it's going to depending on distances, fuel tank levels, temps etc

Keep me postted

Jeff

Thanks again Jeff. Unfortunately, engine light came back on. So it's not the gas cap assuming they're interchangable (did you get a chance to check?). No engine light yet on the 03 that I stole from....

So, looks like it's back to looking for small leak elsewhere.

Does the code always have to be cleared using a scanner or will fixing the problem eventually automatically clear the code?

Bob

code doesn't always have to be clearred with a scanner or code reader but it can often take a lot longer time for the Pcm to turn it off. Leave the cap's switched for a few more days to see what happens to the 03, they should be the same cap, If the cap doesn't fix it then start at the front of the van under the hood like I said and work towards the rear doing a visual of the vaccum lines in the Evap system. Look around the service port fitting, it's the one with the green cap and around the tank, an cannister

good luck and keep us postted

Jeff

Jeff:

Well, I obviously have no idea what I'm looking at....or looking for. I see nothing with a "green cap". I think I see the leak detection pump and the LDP vent valve just above the alternator? I don't see anything I would call a "tank", or a "cannister"? Hate to ask, but how about a few more directions and "roadsigns" for the amateur who used to work on engines when they had points, rotors, distributer caps and not much else under the hood. Thanks.

Bob

remove the air filter box from behind the passengers side headlamp,
the service port should be right around there some where, the pump and cannister are under the van if I remember right. If all else fails look for your emissions decal that should show you the vaccum line schematic and trace them from the intake manifold outward. Sorry I can't draw you a picture or I would, have you purcahsed a Chiltons or Haynes manual for this van yet? I'd recommend both.

sorry I can't be of more hope without seeing the van

good luck and keep us postted

Jeff

Jeff:

Per your suggestion I purchased the Chilton repair manual. In the section about the evaporative emissions control system it says in bold print:

"NOTE: The evaporative control system, like all emission control systems, is protected by a Federally-mandated extended warranty. The EVAP system probably won't fail during the service life of the vehicle; however, if it does, the hoses or charcoal canister are usually to blame."

Could / would a "small leak" in this system as indicated by the P0456 code be covered by this "extended warranty" of the emission control system and I should really just take the car to the dealership for repair under this extended warranty? I think I see you are in Canada. Do you have any knowledge of this "extended warranty" provision in the U.S.?

Bob

Never seen a hose, filler neck etc, be covered by the extended emissions warranty, as per the pump, valves etc might be but likely the dealer will want to diag it at your expense first before putting parts into it and some parts are, some aren't ! If it's warranty you're after call the dealer, don't trust the chiltons manual for that! Have you checked anywhere for a leak?

Jeff:

Haven't checked anything yet. Just got the book with pictures and explainations as to where to look for the pump / canister / etc. , etc. although, on first read, it's still not too clear. It shows a picture of the canister (primary and secondary) and says it's "under the driver seat". Does that really mean "under the seat" or under the car at the driver seat position? Can't imagine a part of the EVAP system "within" the passenger compartment. So, anyway, guess I'm just going to have to poke around and see if I can match-up the pictures. I really doubt it would be a rusted out filler pipe or anything like that. I think that would be likely to be associated with road-salt corrosion. Not a issue in Houston. But it's hotter than Hades here with lots of hungry mosquitos. I'm not looking forward to this. The question may become...will this show up and cause me to fail the Texas inspection which is due next month? I know they do a hook-up at the gas filler cap, so I assume they're doing a leak test of the EVAP system....or maybe just the cap. But is it as sensitive as the on-board computer? Or can I erase the code (so that it at least doesn't show up on the dashboard), see if I can pass the inspection, and wait a month or two for more reasonable weather to be outside and under a car.

Bob

yeah it's under the van, right on the skid plate I guess you'd call it just over from the power steering cooler, the cannister is straight back from there in frt of the fuel tank, that's one of the common places for the hose to split, the hose kinda looks like a hockey stick! Clearing it right before
the emissions test might get you through the test, It's not a system that affects the tailpipe emissions so if there running it on a dyno and looking at the exhaust gases then assuming everything else is fine you should get through, the gas cap is likely just a visual inspection so you'res is probably okay. If they do the test by reading the emissions monitors and checking the ready staut then you'll fail on that the evap monitor portion
because it won't be in ready staut and if it is the failure will be there.
I'm not sure how emissions testting is done in the Lonestar state. It's hot up here too if you can believe it! I one day hope to trave to Texas and see Austin City Limits and the memorial to Stevie Ray Vaughan! The greatest guitar player of all time nd eat some BBQ!

good luck and keep me postted

Jeff

Jeff:

Nope, no dyno.....at least I don't think there's a dyno. One of those things that you stand there and watch....but really don't pay that much attention to what they're doing. And I've slept since then.

But I do have a mental picture of them using a replacement gas cap with a hose (cable?) attached to it that goes to a monitor of some type and takes some kind of pass/fail readings. Maybe I'd better walk up and watch while they're doing someone elses car.

Looks like we're getting some rain today and tomorrow. Maybe that will cool things down a bit......but it's bound to hatch the next batch of mosquitos. It's always something.....

You'll like Austin. Great music scene. And great college town (University of Texas) to live in. But it helps to be rich. They say it has the highest percentage of people with doctorate degrees driving taxi's, tending bar and working as waiters because even though there's no jobs for doctorates, nobody wants to leave. So you have lots of people with doctorate degrees working menial jobs just so they can stay.

Bob

sounds like they pressurize the system with that machine when they are testing! Might fail the test if you still have a leak!

good luck and keep us postted

Jeff

Jeff,

I have the exact same problem as Bob.

I have a 2001 Grand Caravan with 114K miles. I reset the code, replaced the gas cap (I dont think it was OEM) and drove it and the light came back on afterawhile. I reset it again, and this time measured how far I drove before it came back on. I had driven in excess of 175 miles before it came back on.

I have it in the shop (Non dealership) right now, and their first response was tighten the gas cap. I told them I had already replaced the cap and teh light came back on. They're checking into it now. If they don't find anything, and I get it back. Can you give me some idea on where to look under the car to check for cracks or leaks? Do I just trace the lines from the gas tank? is it easy to see around there?

thanks,

george louie