Wells CounterPoint Ep. 26 - GM P0446 Vent System Performance-Diagnose & Fix it Right the First Time!

[@marcocarapia7724]

This is the kind of person that was smart enough to do anything he wanted in life but decided to become a mechanic, therefore a "best of the best" technician/instructor.

[@GoTechTraining]

Wow Marco, thank you so much for the kind words!!!! Mike Becker, Senior Instructor

[@samuelhernandez3902]

You said it so right! I feel the same, I agree with you all way

[@vincemartinez1436]

Great job troubleshooting - Teck like him will have customers for life!!!!

[@andydugan1911]

Very prepared, went smoothly, spoke clearly, and I learned something...Thanks Michael.

[@jackbommarito7678]

EXCELLENT troubleshooting / diagnostic testing !!! Just can’t say enough about this brilliant young man who put all of his diagnoses in laymen’s terms so a not so smart guy like me could comprehend .... lol . Very good ! Thanks so much .... Jack

[@billychavis539]

You sir deserve a medal of some sort. This has by far been the most informative video I have watched in the past week. Hundreds. Thank you sir.

[@GoTechTraining]

Thanks Billy!! :) Mike Becker, Senior Technical Services Instructor

[@doctube2020]

Excellent teacher. Well done on diagnosis! I have a p0446 on a 03 suburban. I’ll check the vent line and solenoid for clogs before having to drop the tank since top of suburban tank isn’t accessible unless tank is dropped. Tried a gas cap but of course that wasn’t the issue.

[@GoTechTraining]

That sounds like a good plan! Thanks for watching! ~Ryan

[@ftoddt77]

This was very informative and easy to follow along. Thanks especially for showing the need not to have to drop the gas tank.

[@roadkill5333]

Excellent video!! Very clear and precise!! I found a reference to this channel from Eric O. at South Main Auto channel! You should give him a shoutout back! In the system info, the number 12.XX mmHg, is a reference to millimeters of mercury!! Hg is the periodic table of elements symbol for Mercury!! When you measure Vacuum, as in a typical A/C system, it's measured in inches of mercury (in Hg). And a typical cross over measurement would be inches of water, in SAE numbers!! I recently had to do this specific job (private, for a friend)! He was showing a evap performance code. He replaced the purge solenoid, at the behest of the O'youknowwho parts store!! PARTS CANNON ATTEMPT #1. That didn't work, so, he called me for a favor! I came, and immediately tested the vent valve!! It worked, but after two or three tries, it started to work only intermittently! And I showed him my findings!! That it was partially working, it needed to be replaced! The money light returned!! PARTS CANNON ATTEMPT #2. I used the code scanner at the parts house, and noticed that the tank pressure was absolutely following the purge attempts, and the pressure spikes, however, it was working but showed 6 in/Hg as atmospheric!! So, even tho it switched up and down as necessary, it wasn't calibrated correctly!! A quick pop of the fuel cap, proved my points!! But changing the sensor was a bit bad for me!! The truck had been used by the previous owner, to haul mulch!! For a while I'm guessing!! And the mulch ended up on top of the fuel pump area, AND SOLIDIFIED! Half a tank of fuel, no way to disconnect the plugs. Laying on the ground, with jack and stands!! Oh boy what a favor that turned into!! We spent hours chipping out the mess, just to get the tank out!! And then the clean up began!! What a job!! But the tank went back in clean, dry, and empty!! With a new sensor!!

[@GoTechTraining]

Hey Roadkill5333 thanks for watching! I do shout out to Eric quite often in many videos! Thanks for joining us. Hope you subbed! Crazy story with the truck! Sometimes favors end up that way...i've been there too! Try to do something nice and end up spending way more time than you wanted. Nice job getting through all of the issues though and getting it fixed right! Mike Becker, Technical Services Instructor

[@michaelpigeon3591]

Excellent video. You definitely have what it takes to be a great teacher. Great explanations 😊

[@Toolslinging]

Great video. It was very professional, informative yet simple. And i loved how you showed the struggle of installing the sensor. I thought you removed the connectors and sensor WAY easier than most. So you are human like the rest of us. Haha

[@GoTechTraining]

Hey Channelboy9, thanks for watching! I am human, I bleed and swear like most techs out there ;) Mike Becker, Senior Technical Instructor

[@pilgrimj37]

Hey, I'm here for a 05 Express 3500 with a PO449 but thought I'd watch anyway and am very happy I did. I am definitely going to subscribe since this was one of the best "classes" I've ever seen on KZbin. Thank you very much.

[@pilgrimj37]

Boy, do I wish I had one of those scan tools!

[@michaelgiebler4967]

I need a better scan tool and need to brush up on my troubleshooting on wirer harnesses. My scan tool just kept reading P0446 vent control circuit. This taught me that not everything is as it seems. Kudos to you man, this video helped me fix my problem thank you.

[@quickchrome2012]

Just came back to say this fixed my check engine light with this code. Had I not seen this video I would have change the canister. It really is not easy but it's not impossible. I did it without a lift. Lowered the tank just enough to reach the sensor. Code clear and it's been six months

[@GoTechTraining]

Hey, awesome! Glad you were able to get it all fixed up! Mike Becker, Senior Technical Instructor

[@quickchrome2012]

I'm back to say 2 years after replacing this sensor the whole pump went bad. Symptoms hard start, after 3 to 4 cranks it would start. New pump came with sensor included. So 2 years with new pump still running good

[@Mauivegan67]

09 Silverado, new ac delco purge valve, new Standard vent control valve, new Gm gas cap. Shop advised to change vent solenoid. Truck sometimes very hard to fill with gas then no problems filling. Vent canister is not plugged. Perplexed. Glad you posted this. I only have a bluedriver but I’m going to check the pressure readings. On live data the pressure fluctuates between -14 to positive while driving.

[@SCRATCHONEMORE]

As Lord Shaxx would say, this is amazing. Just solved my Chevy Silverado P0446 code that the Stealership said was the vent solenoid. Saved 1K+ 🤙

[@nedasher116]

1000 plus 30 part easy in and out

[@ozzstars_cars]

Safety when doing the reach around. Using the sharp edge condom tape was genius Mike! This video went down smoother than the delicious India Pale Ale I was drinking while watching. Great job once again, thumbs up.

[@GoTechTraining]

We, as technicians don't get paid enough to bleed for a living! All about safety! I think anything would go smoother than an IPA...yuk! I prefer something nice and dark, like a nitro stout of some kind. That's one of the best parts about Wisconsin, we have, what seems like a million, small craft breweries making excellent beer! Thanks for watching Glen! Mike Becker, Technical Services Instructor

[@paulmonk7820]

Would plastic door edge trim do the job?

[@Deadbuck73]

Degree in electrical engineering and a mechanic! Awesome job! My mechanic has come to the same diagnosis as you!

[@GoTechTraining]

Awesome Deadbuck73, thanks for watching! Mike Becker, Senior Technical Instructor

[@kevinm9321]

Awesome video! Wish I came upon this sooner...just a shadetree guy...but this is the first video that really explained why I've been chasing my tail so much with evap codes on my 08 Silverado. Thank you very much!

[@GoTechTraining]

Hey Kevin, thanks for watching! Glad this video helped! Mike Becker, Senior Technical Instructor

[@MrGMATech]

found you from South main Auto repair, Excellent info on the old gm evap system. Great Work Mike will be back and telling friends.

[@GoTechTraining]

Great Orlando B, nice to have you here! Tell everyone! :) Mike Becker, Technical Services Instructor

[@baxrok2.]

Outstanding diagnosis, fix, and explanation. Thanks for the lesson!

[@GoTechTraining]

Hey John, thanks! Glad you enjoyed the lesson :) Mike Becker, Technical Services Instructor

[@hjjggktog]

Best teacher I have ever seen! Great job

[@coffeedollsvp]

Informative and professional...not annoying like other quirky videos out there.

[@GoTechTraining]

Thanks for watching! Ryan W, Technical Instructor

[@kyhomegarage3430]

Excellent case study. I really like your diagnostic approach. Thank you sonics for this class. Looking forward for next one. Cheers.

[@GoTechTraining]

Thanks for watching Ramon! Mike Becker, Technical Services Instructor

[@rino75214]

One of the best how too videos I have ever seen.........

[@JOHNSUE28]

Thanks Mike, This is a refresher for me My next job is a P0446 on a 04 suburban flex fuel. Thanks!

[@shawnpierson7672]

Thank you for the video. I've been trying to figure out what sensor tells the computer there's s problem (pressure, vac, flow, ???). I've tested the EVAC systems individual components; they're working properly. I'll be testing that pressure sensor tonight. Troubleshooting and theory. Great video

[@GoTechTraining]

Hey Shawn, thanks for watching! Good luck in your testing. Mike Becker, Senior Technical Instructor

[@johnkimmel2612]

Mike great work here. I came across your site channel today. Oh yes I have subscribed. I am 60 years old and am amazed at your level of talent and dedication.

[@GoTechTraining]

Thanks John! Welcome to the channel! Feel free to look around and ask any questions you may have! Mike Becker, Technical Services Instructor

[@jasonpeacemaker8218]

Brother, that is a very well done video my friend. I have an ‘12 GMC Sierra quad cab 5.3L with a tad over 167k & just like my motorcycle n’ things, I keep ‘em in great shape. Just yesterday I got this code, so since I don’t even have a basic diagnostic tool, I had Autozone at least pull up what the code was that caused the check engine light, that bein’ P0446 EVAP. I’ve yet gone to school for auto mechanics, but am an aircraft mechanic in the USCG & am able to hold my own bein’ mechanically inclined. Autozone’s results they printed up said that most ASE certified mechanics have typically replaced those fuel pressure sensors on GM vehicles. Gonna take it to Christian Automotive tomorrow here my state Lonestar state of TX n’ have them pinpoint the discrepancy with a better diagnostic system as you have. Again, thanks for the informative video brother! God Bless, Jason

[@GoTechTraining]

Hey Jason, thanks a ton man! Glad you like the video! The list that Autozone gives you is just a list on possible causes. I wouldn't go throwing a pressure sensor in quite yet. A P0446 is most commonly caused by a purge solenoid. I would inspect that first. It's meant to be closed when not powered up. So, if you pull it off and can blow through it then it's failed. Mike Becker, Senior Technical Instructor

[@jasonpeacemaker8218]

Thanks for the heads up bubba. Yeah, done extensive forum research & the techs at my local shop here, honest folk, suggested mainly the vent selenoid & charcoal canister. I actually replaced the vent selenoid today. Noticed the filter for it that clips above fuel fill spout was very accumulated with dust/grime. I’m the 2nd owner now for 3yrs n’ original owner maintained this truck greatly, but drove a lot as a foreman, so probably been down many dusty roads. Had 144k when bought, now at 167k & undercarriage n’ all is emaculate. After installin’, done more research & found out about compressed air blowage to clean all out. Wished I noticed that before puttin’ a new one on haha. If this doesn’t do the trick, I’ll look into the purge unit. But like I said, most of that mileage is highway being just a 6yr old truck. No oil leaks, trans, just spotless. Only major thing I’ve done is replaced my outer tie rod ends last year since boots were all cracked up. This fault code is the only other dicepancy I’ve had thus far. Anyways, you & that South Main Auto guy are very informative gents n’ we all appreciate y’alls honesty. God Bless brother

[@GoTechTraining]

Jason, sounds like you've got yourself a nice truck! Eric from South Main is a great guy! Thanks for watching man! Any questions just let me know. Mike Becker, Senior Technical Instructor

[@johnaclark1]

Excellent video and that's after just coming off of finishing ScannerDanner Premium's full class lecture playlist course. You're definitely up there with the best of them. I really appreciate Wells supporting this channel like this.

[@GoTechTraining]

Hey John! Thank you for the compliment! I really appreciate it. Thanks for watching our channel! Mike Becker, Technical Services Instructor

[@alexscarselli3240]

Great job, nice scan tool to have. Mine started small leak for a few years now Gross leak. GM seems to have different charcoal vapor canisters.Mine has 3 ports. Sites show charcoal gets into the lines. My first thing is to smoke test. 2004 Suburban. Ohm, continuity test purge valve19.4 all good. Will check with 12 volts. You’re too far for my drive. I’m old school, amazing Technology, you explain it well. 👍

[@GoTechTraining]

Hey Alex, Good luck on your diagnosis! Thanks for watching! ~Ryan

[@mikeburton1733]

Great job Mike. Your excellent understanding of the system and critical thinking along the way sure help you make it look easy. But I was right there with you at every step. You just made a lifetime customer with that truck owner. BTW, love rockin' my wellstech "T" shirt. Thanks Mike and looking forward to your next class. It's Thursday the 13th correct?

[@GoTechTraining]

Hey Mike! Glad you were able to follow along! I think I did as well. There is no way this customer is going back to that old shop! Good to hear about the shirt, glad you like it!! See you on Thursday for some Toyota EVAP! Mike Becker, Technical Services Instructor

[@BlksnshN]

I have a VUE that has the po446 right now. Sensor constantly reads 4.2v or higher and shows -13.25 h2o at all times. We pulled the tank and ran the tests and everything looked good. Replaced the sensor and right back to stuck at 4.2v. Figured we got a bad sensor, so we ordered an AC Delco. Still showing over 4 volts. I'm a bit confused on this one.

[@paulkaufman4901]

I'm learning so much from you! Excellent Teaching!

[@stevethomas5209]

3 years ago I cut a hatch in the bed over the fuel pump location . My tool box sits on top of it anyway. Now that I have to change this sensor what a dream to have the hatch just lift it up change the sensor and done in 15 minutes. The reason I put the hatch in in the first place was because my research told me fuel pumps and this sensors are problematic in 1998 Chevy's and I needed to change the fuel pump at the time and being that I dont have a lift and I'm too old and fat to crawl under and do this from below I figured cutting a hatch w a grinder would pay off some day and today is payday.

[@GoTechTraining]

Hey Steve, thanks for watching! Sounds like a win for you! Mike Becker, Senior Instructor

[@Whit_Siever]

Thank you for shining some light. Swapped the actual evap valve. $35 oem part and $100 for mobile tech to drop tank. Code didn't clear. Also asked him to swap fuel pump's float sensor since I run out of gas when gauge says I still have 1/8. So now replace FTP and float lever. (2005 Chevrolet Uplander)

[@jray9o]

04 gmc sierra. I had a p0455 changed fuel cap, charcoal canister , vent valve, purge valve and pressure sensor cleared all lines now have a p0446. Not sure where to start.

[@terrencegibson2083]

I have this check engine code. If I replace this sensor will it also help when I pump gas. Right now my truck is very hard to put gas in keeps clicking off I have to hold the nozzle up in the air to fuel up.

[@GoTechTraining]

Hey Terrence, no, this sensor will not have an affect on pumping gas. Chances are, you have a restriction causing the nozzle to click off. Maybe a stuck closed vent solenoid or vent filter. Mike Becker, Senior Instructor

[@derekm9388]

Your trouble fueling at the gas pump is your charcoal canister

[@tonyaxeman4381]

My 2003 Colorado the frame rotted out so bad it almost snapped in half . This truck is not too bad but is on its way to rusting in pieces. Good video it is helping me with my 2003 Aurora . At present it is constantly venting so I am assuming it is the vent valve . I was a auto mechanic for years .

[@ralphreyes2440]

Great video lecture!! I have the same issue on my 2001 isuzu rodeo 3.2 v6 2wd. They replaced the vapor canister and the purge solenoid next to it they performed a smoke test. Also, the purge solenoid in front of the engine plus the 2 vaccum hoses in front of the engine as well. In addition a new fuel pump. But still that pesky check engine light still comes on P0446!!! do you think its the same issue fuel tank pressure sensor? please help? thanks

[@videosenutube]

Evap system has been a mystery to me. But with it being the worst offender when it comes to setting up the MIL light I am glad to have come across you alls Chanel I am sponging up all of this info thanks , can't wait to catch up with the rest of them.subscribed!

[@GoTechTraining]

Hey Jesse! I'm glad you've found us! EVAP is a huge offender in the check engine light work. Enjoy the videos, i'll be watching for more comments. Feel free to ask any questions. Welcome! Mike Becker, Technical Services Instructor

[@norcalzx3]

So, I'm having the opposite reading. My tank pressure is reading full vacuum 4.8v -30.63mmHg (-16.41 inH2o). Is this still possibly the tank pressure sensor?

[@GoTechTraining]

Yes , the sensor can skew both ways vacuum and pressure. ~Ryan

[@jeffkraus1457]

excellent presentation. So the pressure sensor was bad?

[@GoTechTraining]

Hey Jeff, thanks for watching! Yes the fuel tank pressure sensor was faulty on this truck. Mike Becker, Senior Instructor

[@michigansoundwizard]

Well, I tested my MAP and Fuel Pump connections at the harness and I had voltage being fed to both with key on. 4.9v on the MAP & 14v+ on the Fuel Pump plug. (Grand Prix, 3.8L) My code was cleared and hasn’t returned in several days but it returns sometimes. Could be my Vent Solenoid. Maybe.

[@GoTechTraining]

Hey, thanks for watching! The vent solenoid was a pretty common issue on those GP's. Mike Becker, Senior Instructor

[@michigansoundwizard]

@@GoTechTraining Hey Mike, do you think that could be it based upon my test above?

[@johnbriscoejr9738]

I'm confuse @ 18:15! Did you take a jumper wire and connected the 5v ref to fuel tank pressure on the pcm and then you jumped the signal and ground on the connector? If you did I just learned something new, thank you much but will not do it with a 12v, like you said. Also to make sure my pcm is ok can I just back probe the my signal + and - @ the connector then use a multimeter to determine my voltage? If I'm wrong please correct my ignorance? Thank you much

[@iafragosoaf]

Hi Mike, just a big question for you.. l have p0446(1of2)l already changed the gas tank pressure sensor, vent purge selonoid and evap vent selonoid but l can’t fix the problem. This is the first time it has happened, thanks for help god bless you

[@GoTechTraining]

Hi Antonio, P0446 can set when the EVAP system cannot release pressure from having a restricted vent path. I would check for a plugged canister or vent hoses that run to the vent solenoid. I hope this helps Thanks for reaching out! Ryan Wilsing

[@charc.7819]

They are very tuff to get back in!! I did mine 06 gmc! I:don’t feel like ever doing another!!! 💙✝️

[@GoTechTraining]

Hey Charles, yeh it's not the most fun job in the world ;) Mike Becker, Senior Instructor

[@oxygen454]

I have a 2010 Chevy HHR with code P0446 and the readings are always around -12 mmHg and 2.82v tank pressure. Is that a large leak somewhere?

[@GoTechTraining]

Hello, PO446 is set when the system can not vent properly. Sometimes the computer can mistakenly set this code if the Fuel Tank Pressure sensor is faulty. I would watch your pressure reading and remove the fuel cap. If the pressure doesn't go close to 0.00, I would look into a faulty fuel tank pressure sensor. If it does drop to 0, I would check for a restriction in the venting. Ryan W, Technical Instructor

[@КлючарКейси]

Hi nice videos on mine car there is a problem when you open the gas cap you hear whoosh is that normal ? Especaly when its hot checked the purge valve its opening also there is no check engine light

[@GoTechTraining]

What kind of car? Some EVAP systems are pressurized. Mike Becker, Senior Technical Instructor

[@КлючарКейси]

@@GoTechTraining its Suzuki wagon r normal it has purge valve charcoal canister and lines when you open the gas cap there is strong smell of gas and vacumm and when its very cold it starts on first crank but when its normal temperature its starts then dies i think it might be a stuck open purge valve ? Any Clues ?

[@haniyusuf.E46M3]

Thank you very much, and for the innovative way to diagnose faults. I am one of your biggest fans, and I have watched all the videos that you uploaded, and I hope that you will continue to upload more scientific videos, You really are a genius engineer I wish you very good luck👍🏼

[@thomaszavacki5647]

Mike, you said you used a fused jumper wire from the 5 volt ref to the signal wire, what amp fuse did you use?????

[@kylebeach2316]

What could cause my chevy hhr too idle rough when I open the gas cap too refuel, it doesn't throw any codes or stalls

[@chien_1417]

Thanks for the information! I have code p0446 for pontiac grand am. Would it be advisable if I change the fuel tank pressure sensor right away since i dont have a good scanner to test it?

[@GoTechTraining]

Hey Chien, i'd be careful throwing a fuel tank pressure sensor at this one. You'd have to drop the tank down to fix it. You may be better off seeing if you can rent a scan tool. Mike Becker, Senior Instructor

[@richardmueller9565]

on a 2000 impala, charcoal filter is good- the vent clicks and opens. But still fills slow. Maybe pressure silinoid on engine??? OR maybe something on fill hose ( doubt that,) seems like if fill before drive far---will fill with gas pretty well.

[@mrkttrdr2919]

Nice concise clear explanation, ur videos are getting better all the time, anymore colorado videos would be great to see, especially a thermostat change, thanks

[@GoTechTraining]

Thanks Mark! I may have another Colorado video or 2 up my sleeve. They always seem to be breaking haha! Mike Becker, Technical Services Instructor

[@silverado2500wr450]

Hello Mike, im familiar with the EVAP system on these chevy trucks. I have one now, 04 Silverado 1500 4.8. P0446. I have gone through the regular diagnostic, but not coming up with anything conclusive. Aside from smoke testing ( which shows no leaks) i have removed the purge valve and smoke tested it while cycling the valve on and off. Seems to be operating correctly. The fuel tank pressure sensor displays correct voltage and vacuum when performed purge seal test. Can hear vent solenoid when activating. When opening vent solenoid after putting tank in vacuum, voltage and pressure return to normal. Only off thing, is when i open vent after pressurizing with smoke, the voltage goes back to normal, but i dont see any smoke coming out of the solenoid. Could it be a problem with the ECM? Thanks

[@DjGogoLA]

Great video. The fuel pumped was changed but get code P0440 and P0446 and it smells like gas. I would guess that there is some gases escaping and not just the sensor. Any ideas? Suburban 2002, 1500 V8

[@GoTechTraining]

Hey, thanks for watching! Maybe something wasn't hooked back up after changing out the pump? Could be a line off or something? Mike Becker, Senior Technical Instructor

[@DjGogoLA]

@@GoTechTraining I was able to find the issue and you were right. Upon close inspection I did notice that when they took off the gas tank, a wire was yanked snapping it off the Vapor Canister and that is where the fumes were coming from. Thanks for the quick response.

[@jesuslara3175]

Thanks for sharing Good video It's good to learn more about Electric car problems Very professional teaching. 🤗🤗

[@GoTechTraining]

Hey Jesus, thanks for watching! Glad you enjoyed the video :) Mike Becker, Senior Technical Instructor

[@mikecont9742]

Great diagnosis video. Thanks for taking time.

[@GoTechTraining]

Thanks Mike! Mike Becker, Senior Technical Instructor

[@jimflynn8364]

I wonder if you could cut a hole above the sensor in the bed,and use a patch panel afterwords. Just in case of later on if you would have to change the regulator ?

[@GoTechTraining]

Hey Jim, you could....but I don't recommend it. Cutting a hole in the bed is a permanent thing. Removing bolts or whatever is not. Mike Becker, Senior Technical Instructor

[@jimflynn8364]

I could call it the secondary fuel door for removal and install for fuel pump... Anyway it's my old truck and I don't think I'll get too much money when I sell it anyway. Thanks for getting back to me. I told the smog guy about you and he was impressed that I learned so much from you. I have been chasing the code for a long time. I thought I could sneak a smog in today (cleared the codes and unhooked the battery) but failed so now I have 30 days to fix it. (different shop from the smog guy) Now I have 5 pending codes to clear.

[@GoTechTraining]

Hey Jim, clearing codes resets the monitors. The truck would need to be driven for a while to reset all of them. Mike Becker, Senior Technical Services Instructor

[@bluewave3417]

Had this code (P0446) on my 2004 Silverado. Turned out to be the fuel pressure sensor. I should have watched this video first. I changed the EVAP Vent solenoid. Check engine light didn't budge. I then changed the purge valve in the top of the engine. Check engine light still on. I had to unbolt the truck bed and lift it partially to get to the fuel pressure sensor. But that did the trick. It's been a few weeks and the check engine light has stayed off. And I was able to pass smog. Hopefully it doesn't come back on.

[@EzMDr]

Is it a good idea to replace the whole fuel pump assembly as a preventative maintenance since, the pressure sensor comes with it? I do have a running pump that's at least 10 years old but I dont know if I just do the whole assembly or just the sensor for P0446 code?

[@gadasavideos8564]

Wonder if can swap on 02 s10 without dropping the tank

[@davidd8435]

So a P0446 is it a component trouble or a EVAP leak you could find with a smoke machine? I do not have access to a high end diagnostic scan tool, would be the best way to trouble shoot this trouble code?

[@GoTechTraining]

David, first thing I would do is attempt to run the component with a scanner and verify it has power and ground. From there, as long as the valve is in good shape, it's time to grab the smoke machine and pressurize the system and inspect for leaks. Mike Becker, Senior Instructor

[@Fulmer27]

Might want to grab a cheap endoscopic camera so you can watch where you're going with both hands free. Great video and advice. Thank You

[@patrickmurphy8619]

I have a truck reading the same thing a GMC Canyon Vent system performance. I replaced the vent valve solenoid. when I hook the truck up to my big scanner it says that there's vacuum all the time even when the truck isn't running in the gas cap is off. There's so much vacuum It won't even let me perform an evap self test. I'm just wondering is it the purge valve on the engine stuck open but since it's doing it not running is it just the same thing the tank pressure sensor reading the opposite too much vacuum

[@GoTechTraining]

Patrick, really quick confirmation is to pull the gas cap, does it still read vacuum? If so, then you have an issue. It's possible the vent could plug up and keep the tank in vacuum but a stuck open purge would only read a very very slight vacuum and only when running. Mike Becker, Senior Technical Instructor

[@patrickmurphy8619]

@@GoTechTraining appreciate the response I already fixed it It was the tank pressure sensor just like in the video but instead of reading high pressure it was reading negative pressure now when I adjust the vent valve solenoid and the purge valve the pressures go up and down like they should. Good video though definitely helped me out

[@davidd8435]

So there are multiple components that can cause this code, not just the vent solenoid? I have this code that happens intermittently on a 2000 Chevy Silverado, I only have a code reader, when I clear the code a month maybe two it comes back. I already installed a new gas cap, so where do I go from here?

[@GoTechTraining]

David, next step is going to be to test out the components and see what isn't working. A smoke machine may be required. Mike Becker, Senior Technical Instructor

[@davidd8435]

NGK Technical Training if the system has a leak would it not be a different code like small or large EVAP leak?

[@drs4649]

Excellent presentation!! Well Done! Thanks.

[@GoTechTraining]

Thank you very much David! Mike Becker, Senior Instructor

[@troubledsoul764]

Is the fuel tank pressure sensor built into a fuel pump or is it separate? Just had a fuel pump put in so I'm curious. Had a gross leak prior, tried the ol fuel cap switcheroo. Replaced fuel pump due to a rusted out line. Wanting to get to the problem instead of throwing parts at it. I do have trouble filling up with gas. The code is the same code as this. I no longer have the gross leak code.

[@GoTechTraining]

Hey, many times the FTP is part of the fuel pump assembly. If you are having issues fueling the vehicle you'll want to look for a restriction in the vent path or vent solenoid. Mike Becker, Senior Technical Instructor

[@erjio983]

@@GoTechTraining Hey, I have the same issue. I changed out my fuel pump assembly on my 2012 Sierra because of rotted fittings and now I have the 446 code and issues with refueling. The part I don't grasp is how a bad pressure sensor causes venting issues. Does it cause the PCM to close the vent solenoid even when the vehicle is turned off?

[@elkskiutah8204]

can you replace the fuel tan sensor on a 04 yukon without pulling tank?

[@claudiawilliford8381]

If the sensor is bad can it be driven without any detrimental effects on the vehicle? Will it affect the gas mileage or anything else? And going at highway speeds will it damage anything further? We have a 2005 Chevy Silverado.

[@GoTechTraining]

Hi Claudia, in 99% of situations a faulty fuel tank pressure sensor will not cause any driveability problems. You probably will not notice and difference in the way the truck drives or the fuel economy it gets. It also will not cause anything to be damaged. The vehicle simply will not run the EVAP emissions test. This means your vehicle isn't being tested on board to make sure it falls within emissions compliance. Mike Becker, Senior Technical Instructor

[@tommydelahorne5802]

Thanks for the video. Super job ! I’ve noticed most of the diag videos I’ve seen always include a wiring diagram that you guys just “pull up” . Is there a website or is it one of those $2000 a year subscription things. I’ve always had to go get a vehicle specific manual for whatever I was working on. I don’t do it for a living but I help a lot of people in my community and at work. Keep up the good instructional videos as I am learning a lot. Thanks!

[@GoTechTraining]

Hey Tommy, thanks for watching! The website that most of us use are all "pay to play" such as Alldata, Mitchell, or Identifix. Yes, they are costly, but when you do this for a living they become a necessity. Mike Becker, Senior Technical Instructor

[@paulmonk7820]

BBB Industries has free diagrams, probably what you need

[@josephdavis8074]

Can an EVAP ISSUE cause the truck to lose gas pedal and starting capability? Truck died towed it home wont start so I charged the battery. Changed the alternator. Turns over wont start. I got an OBD scan tool it told me P0446 I found a hose disconnected from my EVAP CANISTER could that cause me to lose gas power and pull over then no start?

[@GoTechTraining]

Hey Jospeh, I don't think the evap issue is going to be the cause of your no-start situation. Mike Becker, Senior Insturctor

[@cleapatra82]

would this same technique of not dropping the tank apply to a 04 yukon slt?

[@GoTechTraining]

Hey, pretty sure they are about the same setup. Not sure on the clearance though, may not be able to sneak your hand up in there. Mike Becker, Senior Instructor

[@cleapatra82]

@@GoTechTraining i just wanted to confirm,no there is no clearance for ones hand on the 04 yukon with 5.3L and awd. perhaps this will help someone else out.

[@felixmoran627]

Have same code p0446 on 2007 impala flexfuel.... vent and solenoid have been replaced... code returns after short drive

[@GoTechTraining]

Hey Felix, have you checked for power and ground at the vent solenoid? Mike Becker, Senior Instructor

[@germanescobar9659]

I have a 2005 silverado 5.3 and mine popped up the p0446 code but mine says evaporative emission system vent control circuit can i get some help? It also took out another code recently p0300 for a random-multiple misfire please help

[@carolinem.9800]

in the 07 chevy express 3500 s gm supposedly added a mouse hole so you can access the FTPressure sensor thru a hole in the side of center storage drop down compartment .

[@mudvayne0330]

Any advice for a person who tired removing the sensor and now has the 90 degree portion of it stuck in the original housing for the fuel pump?

[@GoTechTraining]

Hey, that's no good! A small screwdriver maybe? Try to wiggle and pry it out? Unfortunately you may need to drop the tank :( Mike Becker, Senior Technical Instructor

[@danmarklesr6260]

Push it down into the tank, clean, lube & install new.

[@shawnschultz4096]

Hey Mike, I trying to replace the fuel tank pressure sensor on my 2010 GMC Sierra. Any tips? I’m having a hard time getting either connector off and I am not able to pull the sensor out. It’s a pretty tight space.

[@teddriver4739]

Very thorough, Mike you're wizard...just curious once you saw the connectors and determined clip style other than needing a free hand, when you placed flashlight did you realize you pointed it at an area that you were blindly disconnecting by touch only. Actually had a StarWars feel to me, let the force guide you luke..oops Mike. Diag guru. You're awesome 💪👀💪

[@jimflynn8364]

If everything is correct and wiring is OK and the light still stays on,do you think that re-flashing the PCM to stock would eliminate light?

[@GoTechTraining]

Hey Jim, I suppose it's possible....I would be willing to bet that everything is not correct though. Maybe you are chasing an intermittent problem? Mike Becker, Senior Technical Instructor

[@elvisvaldez3168]

I have a -33.6 mmhg and 4.5v any advice?

[@adamUDavies]

What if you get a reading of 3.62 from the back of the plugged in sensor. I got 5volts from the unplugged wiring ?

[@GoTechTraining]

Tom, 3.62 seems high. Either you have pressure/vacuum in the tank or you have a skewed sensor. Mike Becker, Senior Technical Services

[@adamUDavies]

@@GoTechTraining okay , thanks for your fast response !

[@GoTechTraining]

You're welcome! Hope you are able to get it all fixed up! Mike Becker, Senior Technical Instructor

[@jonathancoleman3074]

I have an 03 s10 4.3 and I am at a loss this is the only code it shows is a po446 and the truck began to have poor performance real sluggish and slow about acceleration just wondering if this could cause my problem

[@GoTechTraining]

Hey Jonathan, have your taken a look at the purge solenoid? Maybe it's stuck open causing the truck to run poor? Mike Becker, Senior Technical Instructor

[@richardmueller9565]

Can ya test a fuel tank pressure sensor??

[@brandonpaolinetti09]

Great video. Got a question also. I’ve got a 01 Silverado 1500 5.3 pulling same code. I’ve changed out vent valve an solenoid. Code still comes up. But only pops up when driving around town. When reset the code an drive 250 miles non stop code never comes on. Do u know why that is ?

[@GoTechTraining]

Brandon, the code has nothing to do with the length of the drive or anything like that. The EVAP monitor has VERY particular setting conditions that usually involves at least 2 cold starts and full warm up cycles. Drive 250 miles non-stop only gives you one warm up cycle. Mike Becker, Senior Technical Instructor

[@aw.dutton]

@@GoTechTraining an absolutely under rated comment. Very informative.

[@bridgetterose7607]

What type of scanner are you using?

[@GoTechTraining]

Hey Bridgette, The scanner used in this video is a Launch X-41 Thanks for watching! Ryan Wilsing, Technical Instructor

[@bridgetterose7607]

@@GoTechTraining awesome video well said.

[@mikegodfrey9552]

Great Video, helped me fix my 03 Silverado, Thank you!

[@GoTechTraining]

Hey Mike, Great!!! Glad I could help :) Mike Becker, Senior Technical Instructor

[@davisbrown1559]

If it doesnt make the "whoosh" sound, does that mean the vent valve is bad?

[@hooknbook911]

Extremely badass vid bro love ur style had my attention throughout the whole thing looking forward to doin this test on my 04' colorado..p0446 just popped up smh..

[@GoTechTraining]

Hey, thanks man! Good luck with your testing. If you need any further help don't hesitate to reach out! Mike Becker, Senior Technical Services Instructor

[@edlozano8694]

excellent video. Thank you for all your help.

[@wyattoneable]

Very well explained and your camera work is excellent.

[@GoTechTraining]

Hey thanks for watching Wyatt. I have been practicing :) Mike Becker, Technical Services Instructor

[@spelunkerd]

Well done, what a professional video! When you jump the 5V ref to the signal wire, would it ever be wise to add in a resistor, maybe 5k ohms, in line with the fuse so that any current through that wire would be negligible?

[@GoTechTraining]

Hey Spelunkerd, thank you!!! Being that this is a PCM driven 5v circuit there already is a resistance built in, inside of the PCM. It will/(should) current limit itself. If you are ever hooking directly to the battery you will want to be much more careful. That magic smoke is hard to get back into the PCM once it's escaped :) Mike Becker, Technical Services Instructor

[@rodneynelson6164]

so what if you don't get the wosh from taking the gas cap off , and you already replaced the entire fuel pump and pressure sensor but the check engine light only comes on intermittently not every time , you start or run the truck

[@JW318is]

Same question here. Trying to diagnose this P0446, already replaced the vent solenoid and trying to dig deeper using a Tech2 tool. Pull vacuum, open fuel cap, no "woosh" or pressure change.

[@Someguy3.8]

What type of grease did you use on that FPS O-ring?

[@ehw1615e]

Well Done Video!!Question: Can I replace the Fuel Tank Pressure Sensor on a 2007 Avalanche without removing the Gas Tank as well?Or should I remove the Tank? Also, would it have been better to connect the wire before installing the new sensor ?

[@GoTechTraining]

Hey, thanks for watching! By the book, you're supposed to remove the fuel tank. You may be able to sneak your arm up in there though and get to it. I prefer to not have the connector plugged in. I don't want it getting in the way when i'm trying to install the sensor. Mike Becker, Senior Technical Instructor

[@nickcampbell7198]

I have an 05 silverado 2500hd 6.0. And started getting the same code. So hopefully it's just the sensor or it could be the evap canister.

[@rileyworrells472]

Just did this Fuel pressure sensor replacement on my 04 Silverado 5.3 now the truck wont start at all. Was running fine before hand with just the P0446 code with no symptoms. Help?

[@GoTechTraining]

Riley, did the fuel pump maybe get accidentally unplugged? Mike Becker, Senior Technical Instructor

[@rileyworrells472]

@@GoTechTraining I've checked every wire and connection at the pump and everything seems to be in place. I do not hear the fuel pump turn on with ignition though, I hear the click with the relay under the hood but not a sound at the actual pump. Could I have possible pulled a different connection loose?

[@amtpdb1]

I have a 2004 f150. The scanner says 2.4 volts, but at times goes from 1.9 to 2.5. I pulled the plug and the scanner now says 5.0 volts! I checked the 3 pins while disconnected and get 5 volts on the 2 outside and 0 on the middle wire. Thoughts or suggestions?

[@GoTechTraining]

Hey there, you are referring to the fuel tank pressure sensor right? Pin 1 should be 5 volts, pin 2 ground and pin 3 is the signal wire. Seems odd that you have 5 volts on 2 wires. Something doesn't sounds right here. Mike Becker, Senior Technical Services Instructor

[@amtpdb1]

Wells Vehicle Electronics Thanks for answering. I couldn't get to it to back probes it. As I put it back together I noticed that the scanner values changed to .2 then .4 then back to 2.4. I guess I will have to drop the tank to get a better view. Thanks again for answering. Don

[@GoTechTraining]

Good luck Don! Mike Becker, Senior Technical Services Instructor

[@hanskramer9874]

From this I learned that a bad fuel pressure sensor in the gas tank will damage the entire EVAP system but there is no engine code for it. Purge and vent valves are doing what when the fuel pressure sensor is bad? What is the air flow in the charcoal canister?

[@GoTechTraining]

Hey Hans, thanks for watching. It depends on the design of the system...the system may still try to test but fail due to the FTP being out of range. There is a good chance the system will purge though. Mike Becker, Senior Instructor

[@shannonrichardson3934]

06 Chevy trailblazer LS 4.2 Check engine lite on High purg And hard to restart (excessive cranking) after fueling Rough idle while fueling Where would you suggest I start looking

[@GoTechTraining]

Hey Shannon, sounds to me like a stuck open purge solenoid. If you take it off, unplug it and can blow through it, it's bad. It should be sealed unless the computer commands it open. Thanks for watching! Mike Becker, Senior Technical Services Instructor