Okay, I take back what I said about refusing to take it to a shop. Ain't nobody got time for that. Thanks for all of the info MasterTech.

 

Hello to all, my '02 Durango just started the same problem displaying a P0440 code. One thing I checked was placing a vacuum gauge with tee fiting in CAN line of Purge Sol Valve which is between the battery and fender well. The PSV is to operate every so often allowing the CAN and TANK be purged recycling the fumes to Engine intake. The vacuum gage allows me to see if the PSV opens. I also have a spare PSV to compare signals to. This is the first time the PSV has not opened and wonder if a signal is being submitted. A lack of electrical signal would send some sort of fault condition to the computer, is my guess. What are your thoughts Master Tech?

 

Greetings to all,
Re: 2002 Durango, 4.7, Sport 4x4

May I begin by complimenting MasterTech on an outstanding job of explaining the Evap system and areas to check. I agree this P-0440 code will teach you a new vocabulary.

My latest adventure with the P-0440 code leads me back to the Evaporative Canister Purge Solenoid (ECPS), not the valve itself but something electrical, upstream.
Pulled all hoses, changed gas cap back to original, checked Leak Detection Pump, reset error codes and the code returns in 2 to 3 days.
I am able to confirm the ECPS is not opening due to not receiving an electrical signal. The vacuum from the intake manifold is not traveling beyond the ECPS and I do not possess a schematic to inform me of the components before the ECPS which activate it, other than the PCM.
The ECPS is in normally closed N/C position and never opens. DC Volt Meter indicate no response.
Questions;
What am I missing here?
What is the correct voltage to activate the ECPS?
Has anyone encountered this same problem?
Were you able to fix the problem?
What was the fix?
Thanks to all for your input.

 

My 2003 4.7 had the same issue when I purchased it used 8 years ago. The dealer never could figure it out. I did, with some help from the guys at Motor Trend magazine. It turned out to be the NVLD module. less than 30 bucks at the time.

 

Thank you for that information and will try it since the dealer could not find the problem either.

I've been driving with the light on and actually getting an additional 45 miles to a tank of gas; was 310 mpt / now 355 mpt (21 gal when filling up)

The dealer informed me the gas leak test was good and since there was no voltage going to the solenoid that the PCM was bad and required replacement at a cost of over $600.00. These are available online under $250 and burned with your VIN code. NOTE / mechanic did not know there was no voltage going to the solenoid till I told him so the fancy computer testing equipment which costs over $100.00 is not always tuned to the problems, in my opinion.

 

Do you care to share what the NVLD is? I am unable to find NVLD in my Durango Service Manual or find NVLD online or at a parts store. Please advise? Thank you in advance for sharing.

 

Natural Vacuum Leak Detection.
Chrysler's NVLD, or Natural Vacuum Leak Detection, system was first introduced in 2002 as an alternative to its Leak Detection Pump (LDP) method for the onboard testing of the evaporative emissions system. This method of leak detection is based on the "Ideal Gas" law that states, in part, that the pressure in a sealed vessel will change linearly as a function of the temperature of the gas in that vessel. Any loss of seal will allow the internal pressure to equalize with the atmospheric pressure outside the container.

http://www.searchautoparts.com/motor...ystems-can-pre

See also:

http://www.factorychryslerparts.com/...roduct=4382031

 

Okay, thank you for your feedback. My 2002 Durango has the leak detection pump (LDP) not referred to as NVLD, and all checks out good with it, smoke test was good, NO voltage to Can Purge Sol. Therefore, the dealer informed me the PCM is bad. However, my MPG per tank has increased by 40 miles. Fix or not fix is my debate now as everything else is running great.

 

Put a plastic bag over the male end of the gas cap and reinstall. Reset the PCM and see if the code comes back up. Sometimes the cap/cap seal is the problem. As for them saying you have a bad PCM straight up is kinda shooting it with a .50 cal.

 

Original poster here....and I have the solution that worked for me.
1. I replaced every vacuum line and secured each connection with a hose clamp.
2. I kept throwing the code, so I replaced the gas cap with a locking gas cap from Autozone. Code continued about once a week when tank was 1/4 full.
3. Ordered a Mopar factory gas cap off of partsgeek
4. So far I am code free and livin' the dream!

Hope this helps someone!