PO456

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08PathPounder
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PO456

Postby 08PathPounder » Mon Feb 23, 2015 9:50 am

Evap leak

Service bulletin is for 05-07 I drive an 08. Is this an issue? I have the dealership 36k mile warranty and then of coarse the Nissan warranty. I'm on my way to the dealership now to have the in dash defroster switch replaced. Which last time I was there at the dealership to get the defroster switch ordered, the SEL light was on and they claimed to to be a loose gas cap so they just reset my battery and left my damn airbag light flashing ( found the sequence to shut it off and it was quick & easy). They clearly didn't want to do the work but now I'm going to make sure they do.

Note: it's a Chevy dealership I'm trying to get transferd to a legit Nissan dealer they told me I have to live outside 40 miles from the dealership, WHICH I DO. So I plan on raising hell if there are any more issues.


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Postby 08PathPounder » Mon Feb 23, 2015 10:18 am

Screen shot of what is supposed to come up when hooked up to scan tool
http://m.autoserviceprofessional.com/ar ... -dtc-p0456

05-07 service bulletin
http://engine-codes.com/p0456_nissan.html

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Postby smj999smj » Mon Feb 23, 2015 12:22 pm

As you can see from your own link, there are several different possibilities that can cause the P0456 evap small leak code. Often, the first thing checked or replaced is the gas cap, but unless it is improperly installed, it's often not the problem. As far as the TSB, it doesn't apply to the 2008 model in as far as the filter kit, because you probably have it installed from the factory. The other part of the TSB, which is the canister vent control valve, is a very good possibility. The vent control valves, which have been updated several times over the years, have been a common source of problems since they were introduced in 1995. Their function is simple; they are normally open allowing the evaporative emissions system to vent through the charcoal canister, which stores fuel vapors until they can be later sent to the engine to be burned in the combustion process. The evaporative emissions system has a self-test process to check for leaks in the system. When this occurs, the vent control valve is closed and vacuum is applied from the intake manifold and this is monitored by the evap pressure sensor. The vent control valves have had a history of sticking, either closed or open. You can component test it by removing it from the canister and blowing through it. Remember, it is normally open. Apply 12v and ground to the appropriate terminals and the valve should close, and you should not be able to blow through it.
The vent control valve being the most common cause, any leak in the system or a bad purge valve can cause the code, so the only way to be 100% sure is to test the system per the factory service manual, which includes using a scantool to operate the vent valve and the ability to monitor the pressure sensor as well as an evap test port adapter and vacuum pump. A smoke machine is an even better way to test for leaks, but it is an expensive piece of equipment.

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08PathPounder
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Postby 08PathPounder » Mon Feb 23, 2015 12:46 pm

smj999smj wrote:As you can see from your own link, there are several different possibilities that can cause the P0456 evap small leak code. Often, the first thing checked or replaced is the gas cap, but unless it is improperly installed, it's often not the problem. As far as the TSB, it doesn't apply to the 2008 model in as far as the filter kit, because you probably have it installed from the factory. The other part of the TSB, which is the canister vent control valve, is a very good possibility. The vent control valves, which have been updated several times over the years, have been a common source of problems since they were introduced in 1995. Their function is simple; they are normally open allowing the evaporative emissions system to vent through the charcoal canister, which stores fuel vapors until they can be later sent to the engine to be burned in the combustion process. The evaporative emissions system has a self-test process to check for leaks in the system. When this occurs, the vent control valve is closed and vacuum is applied from the intake manifold and this is monitored by the evap pressure sensor. The vent control valves have had a history of sticking, either closed or open. You can component test it by removing it from the canister and blowing through it. Remember, it is normally open. Apply 12v and ground to the appropriate terminals and the valve should close, and you should not be able to blow through it.
The vent control valve being the most common cause, any leak in the system or a bad purge valve can cause the code, so the only way to be 100% sure is to test the system per the factory service manual, which includes using a scantool to operate the vent valve and the ability to monitor the pressure sensor as well as an evap test port adapter and vacuum pump. A smoke machine is an even better way to test for leaks, but it is an expensive piece of equipment.
I read this as I'm sitting in the CHEVY dealership I bought my Pathy from & I can't help but want to transfer my warranty to a Nissan dealership and run! They tried pulling the old gas cap trick on me last week and when they couldn't figure it out they just unhooked my battery for an hour to reset it. I have a hunch they did so due to the fact that when I got my car back my damn air bag light was flashing. Guess they couldn't take the 5 minutes to google the key on-key off sequence to get it to turn off. I did it in my driveway in literally 5 minutes from Google to done. Pathetic.

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Postby 08PathPounder » Mon Feb 23, 2015 12:54 pm

http://engine-codes.com/uploads/NTB09-020.pdf


flow chart issued for 1998 - later Nissan models with Evap service port

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Postby 08PathPounder » Mon Feb 23, 2015 4:14 pm

Update (aka rant continued) :

SO....I sat in the dealership waiting room for just over 3 &1/2 hours until they realized they couldn't figure it out in a reasonable time. Really? Just a plug in switch swap ( say that 5 times in a row fast) and a replacement Evap canister?
WRONG. Lolol... They never even got to the Service Engine Light or p0456 Evap small leak.
The defrosters are giving the "Ex Nissan Master Tech" working in the Chevrolet dealer, an incredibly difficult time. He put the new switch in and nothing. He's said he's checked fuses relays & power supply's and is now hunting a bad ground somewhere...could this be Nissan and there ground-over-paint problem biting me in my ass? We'll see. Regardless it's on their dime and time not mine, they gave me a loaner and I said have fun see ya later.
Has anyone else had this much trouble ?


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