TheSamba.com :: View topic - P0455 (large EVAP leak) after battery change?

Fri May 19, 2017 9:56 am

Our Eurovan was in storage for a few months, and came back with a thoroughly-dead vehicle battery. After swapping it out (and cursing the engineer who put the battery clip screw behind the fuse box), everything started up just fine. After driving it for 30 minutes, the CEL came on, and my OBD-II tool says its P0455 - large leak EVAP system.

When we bought the van (at 110k miles), it had the same code, but cleared, and no CEL. Our mechanic smoke tested the system and found nothing. We haven't put that many miles on it in the year we've owned it.

So my questions: is it possible that this code resurfaced solely as a result of the battery swap? Is it possible that the five months of storage introduced some sort of air into the fuel system that threw the code? Is this something I should have immediately checked by a mechanic, or should I, after clearing the code, drive the van for a couple hours and see if it comes back?

Fri May 19, 2017 11:31 am

A flat dead bat or swap should not raise old codes.

Storing should not have any effect on EVAP. That said, I suppose that buildup of evaporated gas over a long storage could hypothetically expedite an issue that was on its way.

I'd reset and drive it a bit. Biggest issue will be fuel economy & performance.

And maybe a quick check of these things just because they are so easy:

1. Check the gas cap.
2. Check engine bay for animal activity and/or brittle hoses.
3. Check underneath just behind the drive side door for animal chewing. The EVAP box is down there more or less in plain sight.

Fri May 19, 2017 11:31 am

If it keeps coming back after you cleared it, then there a leak somewhere. First place to look is the gas cap. After that you can do some output tests with the VCDS. The N80 could be at fault too.

Sun May 21, 2017 10:03 pm

So...cleared it, re-sat the gas cap, and the van sat overnight. Then drove it for about an hour (somewhat strenuous driving going up a windy road) with no CEL. Thought it was all good, but light came on the next day, same code.

Before I take this into the mechanic, does the Eurovan EVC come with a locking gas cap? It never feels tight in the fill nozzle, no matter how many clicks it goes past closed. But we had 1,000 trouble-free miles without the problem, so this is probably just wishful thinking.

Mon May 22, 2017 2:27 am

When your battery went dead, it reset your ECU cycles, and the evap test can take up to a few hundred miles to complete.

That battery clip is fun, isn't it!

If a car sat, I would check all the evap hides for rodent damage. A smoke test is how to find your leak quickly

My EV cap spins after locking too, it's ratcheted.

The EVAP system on this car is really robust IMHE, mine is 16 years old and has never been serviced

Mon May 22, 2017 4:59 am

Even a cheap gas cap from Wal Mart will work on an EV. My wife lost mine at least 10 years ago while we were on a trip. Down the road the check engine light came on. I stopped by a Wal-mart and got a cap. By the time I got home the light went off (the code was still there). That cap has been on there ever since and it really doesn't seem to go tight enough to work at all, yet it does (you can spin it with your pinky on the ratchet, it's that easy. Even the cap from my TDI Jetta works on it.

My guess is that either a valve is stuck or a broken hoes somewhere because it was sitting for a long time.

Tue May 23, 2017 5:02 pm

My "ghosty" evap leak ended up being caused by a faulty leak detection pump. If you can plug the line that goes to the canister and it still fails the test that means the leak is in the pump itself.

Tue Jun 27, 2017 8:14 pm

Any more developments on this?

I have a 2001 EV, and last week the CEL come on with the P0455 code. A few days prior to that I heard clicking near the N80 valve, so I replaced that (all I had at the time was a non-OEM) on the day the CEL lit up, and then cleared the code. 50 miles later, the CEL came back on, and this time the code was P0442, EVAP leak-small.

2 days later, on the 400 mile drive home from San Diego, immediately after fueling up, the car would not turn over, and the entire gauge cluster was lit up. I checked for codes at that time, but the reader came back with none. I then tried to start the car again, and it started right up and made it the last 200 miles home without issue.

I've had no issues since, with no check engine light, the only thing I've noticed is occasional sluggish acceleration, and possibly decrease gas mileage, though that's hard to tell as it's only been a couple days since filling up.

I have a 3000 mile road trip coming up next week any input is greatly appreciated!!!

Wed Jun 28, 2017 8:25 am

Looks like you have an evap leak but it can be something as simple as a gas cap or what we've been suggesting in this thread. As for the no start, that's something completely unrelated. If it was mine, I'd start with an ignition switch as they are known to fail.

Wed Jun 28, 2017 8:32 am

Billy - if you lost power to the ECU, it will reset the codes and take a while for an EVAP code to come back - see up thread.

Also, your adaptive will take a while to reset so the car might drive funny after a battery disconnect or other loss of power.

Wed Jun 28, 2017 9:44 pm

Thank you for feedback.

I'm in the 400-500 mile range since resetting the second CEL (EVAP leak - small), and 300 or so miles since the incident at the gas station.

Fuel mileage today seemed right where it should be 18-19 mph avg city/hwy per the OBD reader stats.

I have a new brake booster vac line coming (I've been running a braided rubber hose with an implanted spring to prevent collapsing since that's all I had access to at the time - this was put in prior to this run of CELs).

Obviously I have a few different issues on the go - I will keep the thread updated with any changes/resolution - unfortunately haven't been able to get in to a decent VW shop for a smoke test prior to the holiday week coming up.

Thanks again.

Mon Sep 28, 2020 11:22 am

Just had P0455 hit my 03 EV. Reset it, while filling tank. Had a hard time restarting initially but seemed to drive for 15 miles back to house. Going to poke around now - have road trip in 2 days so hopefully a quick sort or just a burp as I had run tank down lower than typical.

Sun Nov 01, 2020 5:31 am

Well - I'm still getting the P0455 on occasion. Drove the EV from ATL to Red River Gorge KY and no CEL. Return it lit up again. Took 10 seconds of turning it over to start it at gas stop but all good for driving - consistent behavior and I believe ECU reacting with fuel delivery based on code tripping rather than mechanical concern.

So - up to the dealer who suggests replacing most of the components: D0-906-271-A, LDPUMP (leak Detection Pump) and 1C0-906-517-A, VALVE (Purge Valve) as well as 7D0-201-801-E, EVAPCANIST (Carcon Cannister - VW no longer makes these)

This tells me they found nothing obvious during their review (cracks/loose hoses/bad solenoid) which is consistent with van's variable behavior. I expect the issue is intermittent with either the LDPUMP or purge valve.

So far my www queries have not turned up leftover stock of the carbon canister that is no longer in production. But it does not make sense to me that there would be a blockage here that only sometimes triggered CEL. Anyone want to weigh in with experience?

Thu Jan 07, 2021 10:10 am

I am also getting P0455. Had the purge valve by the pump replaced. My mechanic says the purge valve by the canister needs to be replaced, but they're no longer made so they want to retrofit an Audi purge valve on it. Does this sound reasonable? I know nothing about the EVAP system. They tried to find parts, but haven't been successful.

Thu Jan 07, 2021 11:26 am

I have been holding off on an update to validate my experience with time tested miles. I am only several tanks past repair but no CEL since replacement of D0-906-271-A, LDPUMP (leak Detection Pump) and 1C0-906-517-A, VALVE (Purge Valve)

I believe VW SOP is replace all three but I suggest trying the two pieces still available (use www to source - prices vary widely) and hold off on no longer made. 7D0-201-801-E, EVAPCANIST