Very nice, drawing and all. I just went thru this on an 09 Chevy p/u. The vent solenoid was not working properly, but after I replaced it, it showed that the tank pressure sensor was operating, but slightly off scale. I was getting 6 inches/h2o of vacuum with the cap off. I have been watching your vids for a while, and was able to catch the problem. Otherwise, I would still be scratching my head. Great instructional videos you make. THANKS!!!
Great video Paul and we could tell you was getting pissed from all the background noise Dont worry about it We understand its a working shop. I convinced my wife that I needed a $1300 smoke machine I have had it for 4 months now and haven't needed it. I finally got a job yesterday where I needed it on a leaking intake gasket that I found with carb cleaner, So I put the smoke machine on it and could not see ANY smoke. Maybe I should have listened to her Lol
just got done performing this test on my car. the problem i was having the other day with low feed voltage ended up just being bad ground connection. I scraped off a little rust off a bolt and BAM, the correct numbers showed up. I even manually energized the selonoid with my test light after I verified voltage. Beforehand, I already knew which was the feed and which was the control by printing the wiring diagram off of Mitchell1Diy...long story short. I wouldn't of been able to identify, verify, test..etc. if it wasn't for your instruction via youtube and your book Paul. Now I know that feeling you got after you troubleshooted that no start ford taurus (i believe) that ended up being bad block ground. Keep doing ya thing Paul and I'll be watching. Thanks for the help once again. peace!
Man, my brain just has trouble keeping up with the depth of knowledge in some of these diagnoses even though they are typically and like this one presented quite well. Slow learner on certain things. I keep coming back though. Also completed four classes in a vocational school, all on engines (electrical included). Maybe one of these days enough of the pieces will snap together for feeling ready to begin trying on my own at the level of investigating waveforms and such. I've been looking on eBay and elsewhere for a used scope like the Modis (cheaper than Verus) to at least own a tool for grabbing a bit of hands-on practice, which may and will likely help the process. These videos being available give me hope to find enough patience for keeping on with the education since they require no enrollment, getting to classes on time or anything other than tuning in when wanting to. I am grateful.
+randalusa thanks so much. keep following me, I definitely have the information out there to be able to do this yourself and at your own pace. And when your ready, I have another channel where I bring you into my classroom. Email me through my website and I'll give you a coupon for a free 30 day pass.
thanks for teaching me about emissions paul ,,,, now when i cook red beans and rice with sausage i add baking soda to my cooking ... it keeps the emissions down around the house .
Thank you again for bringing us along. I have your book, I read it cover to cover but these videos are great for understanding some questions I had. I'm back from Germany, work is smooth again so next on the list is ScannerDanner Premium.
Nice video. Another option is to look at the PIDs, specifically FUEL TANK PRESSURE (inH20), to see if there is a change of state when activating the EVAP vent solenoid (since fuel tank pressure is measured in inches of water, when closing the vent there should be a rise in fuel tank pressure). Thanks.
Everything up to the end of this video was a fantastic troubleshooting educational experience! However it would be most helpful if you would have said "These findings (no short circuit or bad ground) conclude that this solenoid valve is stuck open and needs to be replaced!
@@ScannerDanner Thanks for clarifying that. I suspect mine was but who knows without all the diagnostics. I changed mine and got lucky as it was only 34.90 for the part and it solved the problem. Cadillac wants 175.00 to say hello and would charge me at least 150.00 for just the part. I don't begrudge paying a good technician for his skills and work but the cost of parts at the dealership is criminal.
+Isshman Garcia come to think of it...i just replaced that selonoid. its the type that has an included adapter that attaches to the square connector..theres a square and a round connector, but you already know that. ill check it out later. ill let you know. Thanks again.
I have a 08 9c1 impala that has a random P0449. Been trying to hunt it down. CNSTR fuse looks good. Removed connector from solenoid, and tested: Red/white wire has 12v, white wire has 0-0.38v with KO. New GM harness and solenoid. I assume I will need to try to switch it off (as its normally open/on?) somehow through the PCM...I am wondering if this is an issue on the grounding side, or driver? How can we better test the driver/wire length for short?
White wire voltage reading plugged in or unplugged? Plugged in, circuit off, should read 12v. Plugged in, circuit on, should read near 0v. Need a scanner to command the solenoid on/off
Sir paul trying to stay with you on fault explanation unable to been having po448 issue with 2006 subie sti . Ill keep it up till hopefully i can figure it out.you have the best test procedure discription out there .
*Chevy Avalanche 2007 LTZ 4WD FlexFuel with LPG* "Tank cap", "Vapor Canister Purge Valve / Solenoid" and "Vapor Canister Vent Valve / Solenoid" have been changed. The latter has 12v and 0.5v when the ignition is switched off. What else can I test?
I wish you could help me out with my Isuzu Trooper. I'm having evap troubles, no leaks just a high pressure gas tank and throwing codes if I don't open my gas cap to release pressure after every trip. My vent solenoid functions but it has an after market wire harness. I wonder if they have the wiring backwards?? If I could somehow find a wiring diagram for DURALAST parts that would be heaven sent.
@scannerdanner Currently when I command vent solenoid to open (venting) i get 12volts. And when i command close (not venting) i get close to 0volts on bidirectional control. Opposite of what your readings are. Would this indicate a failed driver in pcm on control side?
This is a normally open solenoid. So "venting" is electrically off and it would read 12v on the control wire of a ground side switched circuit in the "off" state. What you described is normal
Would this ever prevent the vehicle from starting AT ALL ?...i have an 09 traverse that when turning the key just forward the fuel pump won't even prime...pump does run when I jump it at the fscm but not when I initially turn the key..had a new fscm installed and programmed and nothing
No sir, unless the EVAP vent shorted and blew a fuse and it was the same fuse used for the fuel pump circuit. We can help you on my forum. It is free to join and you will not find a more friendly and helpful community anywhere www.scannerdanner.com/forum/post-your-repair-questions-here.html I hope to see you there!
Could we jump the 2 wires and watch the scan tool go to 12v for circuit integrity and that would be OK because engine computer will not be switched to ground
+Jhn 01 you could do that but, I would never do that with a jumper wire. A test light would work as your jumper wire and will add a buffer just in case. So in your example, the test light would not light, there would be no voltage drop across the bulb and the computer would see 12v.
Hey Paul, I have always enjoyed watching your videos.Two questions, have you ever come across a vent solenoid control circuit high code? How would you go about troubleshooting it if you do? I am pretty sure it can be either from an open solenoid , a short to power in the control wire, a faulty driver and other causes maybe.The way I would test it is to check both wires with the solenoid plugged in. If I get 12 v on both wires, I would disconnect the solenoid and check both wires again. If I get 12 v on both wires , I would assume that the control wire is shorted to power and isolate the circuit and test for the short to voltage by connecting the test light to battery negative and touch on the control wire to confirm the short. If the test light does not light, my focus will now be on the driver. I am not sure with a short to voltage in the control wire, I will be able to bi-directionally test the driver because the pcm will see the 12 v and disable the driver.May be, I would erase the code and check for control with the car running and see if I get control. By the way, with a short to power in the control wire, would you be able to be the computer and ground the control wire and hear the solenoid click?(with a good solenoid)
Just be careful of bias voltage that is coming from the computer on the control wire. I have seen 12v bias that will NOT light a test light. Here, watch this. There is a 12v bias on this fuel pump relay. th-cam.com/video/McnXLcJNVfI/w-d-xo.html
Hello Danner. Is it possible that the PCM does not allow you to bi directionaly turn on the vent valve in the event that the control wire is shorted to power?
A shorted to power control wire on a ground side switched circuit like this one would cook the computer driver. Sometimes the bidirectional tests are disabled by a fault code but no, there would be no protection from this event. The driver would be cooked already before you even got the car into your shop to check it out.
+Erick LWS most likely a wiring issue, usually right at the solenoid connector. For more help post your issues here www.scannerdanner.com/forum/post-your-repair-questions-here.html
@@ScannerDanner no problem thanks last year I had took it a mechanic he did smoke test and change the vent control valve 6 months later code re appear it's a 2006 Nissan Sentra 66K miles
+lolz larkin you are. I had my receiver in my front pocket and the mic right next to it. One of my first videos with my new camera and wireless mic. Sorry about that
+Isshman Garcia yes, but again, having power to the solenoid does not mean it is energized. In this case the computer switches the ground to energize it
Pretty sure I showed it? Broken wire at the connector right? Was it the control wire? Then yes, the control is a switched ground, so yeah, a broken ground you could call it. Its just not always a ground, to be clear
@@ScannerDanner yes it is. 2005 suburban 2500 6.0L gas. And the light has been on for a year however since I need inspection I have to replace it. Wiring is good so just need to replace.
You can buy a bi-directional scan tool (Topdon Topscan Pro) for $100 There is no excuse to not have one these days. You can get one here. www.aeswave.com/scannerdanner (affiliate earned) The only other way to make that driver turn on is to meet the conditions for the PCM to run an EVAP test on itself and good luck with that.
gm electrical problem on wheel I say all there cars not dependable electrical conextion burn short out lost of head lights emission control monitor incomplete still no check engine code for bad part electrical problems on wheel pass the word around
Wrong channel if your just looking for a silver bullet. If you want to actually learn how to troubleshoot this stuff, then welcome! You just want to fix your car? This isn't the place for you.
![BABYMONSTER - 'DRIP' M/V REACTION [WAS NOT EXPECTING THIS!!!]](http://i.ytimg.com/vi/t0Lpgr1jo3Y/mqdefault.jpg)
Your TH-cam channel along with your website and your class is truly help me thanks
Thanks so much!
Very nice, drawing and all. I just went thru this on an 09 Chevy p/u. The vent solenoid was not working properly, but after I replaced it, it showed that the tank pressure sensor was operating, but slightly off scale. I was getting 6 inches/h2o of vacuum with the cap off. I have been watching your vids for a while, and was able to catch the problem. Otherwise, I would still be scratching my head. Great instructional videos you make. THANKS!!!
roadkill5333 hi may I ask what was your problem?
Great knowledge and always enjoy your no nonsense diagnostic procedure .
Great video Paul and we could tell you was getting pissed from all the background noise Dont worry about it We understand its a working shop.
I convinced my wife that I needed a $1300 smoke machine I have had it for 4 months now and haven't needed it. I finally got a job yesterday where I needed it on a leaking intake gasket that I found with carb cleaner, So I put the smoke machine on it and could not see ANY smoke. Maybe I should have listened to her Lol
just got done performing this test on my car. the problem i was having the other day with low feed voltage ended up just being bad ground connection. I scraped off a little rust off a bolt and BAM, the correct numbers showed up. I even manually energized the selonoid with my test light after I verified voltage. Beforehand, I already knew which was the feed and which was the control by printing the wiring diagram off of Mitchell1Diy...long story short. I wouldn't of been able to identify, verify, test..etc. if it wasn't for your instruction via youtube and your book Paul. Now I know that feeling you got after you troubleshooted that no start ford taurus (i believe) that ended up being bad block ground. Keep doing ya thing Paul and I'll be watching. Thanks for the help once again. peace!
+Isshman Garcia awesome, thank you so much! Keep up the good work.
+ScannerDanner Thanks again Paul.
Man, my brain just has trouble keeping up with the depth of knowledge in some of these diagnoses even though they are typically and like this one presented quite well. Slow learner on certain things. I keep coming back though. Also completed four classes in a vocational school, all on engines (electrical included). Maybe one of these days enough of the pieces will snap together for feeling ready to begin trying on my own at the level of investigating waveforms and such.
I've been looking on eBay and elsewhere for a used scope like the Modis (cheaper than Verus) to at least own a tool for grabbing a bit of hands-on practice, which may and will likely help the process. These videos being available give me hope to find enough patience for keeping on with the education since they require no enrollment, getting to classes on time or anything other than tuning in when wanting to. I am grateful.
+randalusa thanks so much. keep following me, I definitely have the information out there to be able to do this yourself and at your own pace. And when your ready, I have another channel where I bring you into my classroom. Email me through my website and I'll give you a coupon for a free 30 day pass.
thanks for teaching me about emissions paul ,,,, now when i cook red beans and rice with sausage i add baking soda to my cooking ... it keeps the emissions down around the house .
oh i don't have to worry about rich conditions anymore so i did not have to take the cat off the exhaust system .
Very good. Very simple when you know what your doing.
Nice video. Once you go wireless you'll never go back! It's great not being attached to the car!
Testing and explanation well done for such a common failure.
nice job. Quality scanner must have for a quality diagnosis
Thank you again for bringing us along. I have your book, I read it cover to cover but these videos are great for understanding some questions I had. I'm back from Germany, work is smooth again so next on the list is ScannerDanner Premium.
Nice video. Another option is to look at the PIDs, specifically FUEL TANK PRESSURE (inH20), to see if there is a change of state
when activating the EVAP vent solenoid (since fuel tank pressure is measured in inches of water, when closing the vent there should be a rise in fuel tank pressure). Thanks.
As always just perfect,just professional..Keep doing these great lectures Paul.THANK YOU.
Everything up to the end of this video was a fantastic troubleshooting educational experience! However it would be most helpful if you would have said "These findings (no short circuit or bad ground) conclude that this solenoid valve is stuck open and needs to be replaced!
Thanks for the comment.
Just want to clarify this wasn't a "stuck open" solenoid. This was an open in the electrical winding of the solenoid.
@@ScannerDanner Thanks for clarifying that. I suspect mine was but who knows without all the diagnostics. I changed mine and got lucky as it was only 34.90 for the part and it solved the problem. Cadillac wants 175.00 to say hello and would charge me at least 150.00 for just the part. I don't begrudge paying a good technician for his skills and work but the cost of parts at the dealership is criminal.
Well that was sure easer than a lift kit!!!Great vid. my friend!
just what i needed as well. i have 2004 chevy monte LS 3.4. with evap code. Thanks Paul.
+Isshman Garcia for sure! Thank you
+ScannerDanner i get 5v at the feed..so obviously that is an issue. i was thinking it was a 5v ref. back to square 1.
+Isshman Garcia on the feed to the vent solenoid? tug on wires near the connector, the feed wire will most likely break
+ScannerDanner yes to the vent selonoid. ill tug later. im at work enjoying a scanner danner lunch break. thanks for the assist.
+Isshman Garcia come to think of it...i just replaced that selonoid. its the type that has an included adapter that attaches to the square connector..theres a square and a round connector, but you already know that. ill check it out later. ill let you know. Thanks again.
I use noid lights for those vent circuit codes too :)
Great video & explanation as usual! Just purchased your book. Look forward to gaining more knowledge! Thanks for all your hard work. Best wishes!
Thank you so much!
I have a 08 9c1 impala that has a random P0449. Been trying to hunt it down. CNSTR fuse looks good. Removed connector from solenoid, and tested: Red/white wire has 12v, white wire has 0-0.38v with KO. New GM harness and solenoid. I assume I will need to try to switch it off (as its normally open/on?) somehow through the PCM...I am wondering if this is an issue on the grounding side, or driver? How can we better test the driver/wire length for short?
White wire voltage reading plugged in or unplugged?
Plugged in, circuit off, should read 12v.
Plugged in, circuit on, should read near 0v.
Need a scanner to command the solenoid on/off
Sir paul trying to stay with you on fault explanation unable to been having po448 issue with 2006 subie sti . Ill keep it up till hopefully i can figure it out.you have the best test procedure discription out there .
*Chevy Avalanche 2007 LTZ 4WD FlexFuel with LPG*
"Tank cap", "Vapor Canister Purge Valve / Solenoid" and "Vapor Canister Vent Valve / Solenoid" have been changed.
The latter has 12v and 0.5v when the ignition is switched off.
What else can I test?
Great !!! Have learned a lot from you Paul. Thank you!!
+Freddy Soto thank you!
I wish you could help me out with my Isuzu Trooper. I'm having evap troubles, no leaks just a high pressure gas tank and throwing codes if I don't open my gas cap to release pressure after every trip. My vent solenoid functions but it has an after market wire harness. I wonder if they have the wiring backwards?? If I could somehow find a wiring diagram for DURALAST parts that would be heaven sent.
@scannerdanner Currently when I command vent solenoid to open (venting) i get 12volts. And when i command close (not venting) i get close to 0volts on bidirectional control. Opposite of what your readings are. Would this indicate a failed driver in pcm on control side?
This is a normally open solenoid. So "venting" is electrically off and it would read 12v on the control wire of a ground side switched circuit in the "off" state.
What you described is normal
Nice explanation and well detailed what kind of scanner do you use ?
Do you ever work on any diesel systems Paul? would love to see some diesel diagnostics.
Just did one of these the other day at my shop on an 06 chevy equinox. The control wire was actually broken on that one though.
Great information Paul.
See you feel better now that you have you scanner in your hand. Hey paul did you put the new tires on the truck yet?
I am having po449 code but also having problems with the electrical like gauges and headlights not working. Please help
Nice ;-) drawing ok, no problem there!
Nice and fantastic work, thanks for share this video =P
+Pablo A thank you!
Would this solenoid make the click sound if forced on/off? If you had it off the car could you test it by adding removing 12v?
+mharradine57 Yes, if the solenoid was good. And yes, off car testing can be done with two jumper wires.
Hey could someone explain what section of the Snapon scanner where you access the data pid that indicates "Evap Circuit Staus". Thanks.
I have a 2002 Buick rendezvous with a p0449 and the car wont start will a bad vent cause no start?
No sir, completely separate problem
Would this ever prevent the vehicle from starting AT ALL ?...i have an 09 traverse that when turning the key just forward the fuel pump won't even prime...pump does run when I jump it at the fscm but not when I initially turn the key..had a new fscm installed and programmed and nothing
No sir, unless the EVAP vent shorted and blew a fuse and it was the same fuse used for the fuel pump circuit. We can help you on my forum. It is free to join and you will not find a more friendly and helpful community anywhere www.scannerdanner.com/forum/post-your-repair-questions-here.html I hope to see you there!
Could we jump the 2 wires and watch the scan tool go to 12v for circuit integrity and that would be OK because engine computer will not be switched to ground
+Jhn 01 you could do that but, I would never do that with a jumper wire. A test light would work as your jumper wire and will add a buffer just in case. So in your example, the test light would not light, there would be no voltage drop across the bulb and the computer would see 12v.
+ScannerDanner would that fry the pcm because it would now be getting a straight 12v???
Hey Paul, I have always enjoyed watching your videos.Two questions, have you ever come across a vent solenoid control circuit high code? How would you go about troubleshooting it if you do? I am pretty sure it can be either from an open solenoid , a short to power in the control wire, a faulty driver and other causes maybe.The way I would test it is to check both wires with the solenoid plugged in. If I get 12 v on both wires, I would disconnect the solenoid and check both wires again. If I get 12 v on both wires , I would assume that the control wire is shorted to power and isolate the circuit and test for the short to voltage by connecting the test light to battery negative and touch on the control wire to confirm the short. If the test light does not light, my focus will now be on the driver. I am not sure with a short to voltage in the control wire, I will be able to bi-directionally test the driver because the pcm will see the 12 v and disable the driver.May be, I would erase the code and check for control with the car running and see if I get control. By the way, with a short to power in the control wire, would you be able to be the computer and ground the control wire and hear the solenoid click?(with a good solenoid)
Just be careful of bias voltage that is coming from the computer on the control wire. I have seen 12v bias that will NOT light a test light. Here, watch this. There is a 12v bias on this fuel pump relay.
th-cam.com/video/McnXLcJNVfI/w-d-xo.html
Thank you, Paul.
Hello Danner. Is it possible that the PCM does not allow you to bi directionaly turn on the vent valve in the event that the control wire is shorted to power?
A shorted to power control wire on a ground side switched circuit like this one would cook the computer driver. Sometimes the bidirectional tests are disabled by a fault code but no, there would be no protection from this event. The driver would be cooked already before you even got the car into your shop to check it out.
Thank you very much, Paul.
stupid question after all this time ,but when you say "not energized" when u test voltage on feed wire does that mean with the key off or with key on?
+Isshman Garcia not energized, simply means no current flow. Whether you are missing a power or a ground.
+ScannerDanner thanks
great video from a great tech, keep it up A+++++++++++++
what do you do if you replace the vent culinoid and engine light keeps throwing that code? computer module replacement?
+Erick LWS most likely a wiring issue, usually right at the solenoid connector.
For more help post your issues here
www.scannerdanner.com/forum/post-your-repair-questions-here.html
Thanks!
Good video
Nice 👍👍
Can you do a video on p0448?
Same exact checks for the 448 (shorted) code. Report what you have after doing these tests and I can guide you further
@@ScannerDanner no problem thanks last year I had took it a mechanic he did smoke test and change the vent control valve 6 months later code re appear it's a 2006 Nissan Sentra 66K miles
It could also have been corrosion in the plug too, but just backprobing it would have made the control voltage jump around.
good video teacher best
where exactly is the device? Under that panel; above the tire on the outside of the car?
What if it doesn't have no voltage
sounds like im hearing your lav mic and the camera audio together. somethings sounds odd. pro diagnosis as usual though.
+lolz larkin you are. I had my receiver in my front pocket and the mic right next to it. One of my first videos with my new camera and wireless mic.
Sorry about that
+ScannerDanner no need to apologize. most people aren't the audio nerds that I am. can still hear what you are saying which is the main thing.
+lolz larkin haha that's okay. good ear bro
awesome
When you say feed wire what do you mean?
sorry, power supply (12v)
So my question is: what needs to be done to get it fixed ? So the code can be cleared and won't come back
you clearly did not watch the video if you are asking that question. It had a bad vent solenoid (open in the winding of the solenoid)
i assume that the key needs to be to "on" so the battery sends the power to the selonoid. KOEO..key on engine off?
+Isshman Garcia yes, but again, having power to the solenoid does not mean it is energized. In this case the computer switches the ground to energize it
+ScannerDanner great reply, just what I needed for my notes. Thanks for the reply.
+Isshman Garcia and great question!
What was the problem a bad grown
Pretty sure I showed it? Broken wire at the connector right? Was it the control wire? Then yes, the control is a switched ground, so yeah, a broken ground you could call it. Its just not always a ground, to be clear
But what does one do to fix the issue? Just replace the soleniod?
Or there is a wiring problem right at the connector and if this is a GM we're talking about
@@ScannerDanner yes it is. 2005 suburban 2500 6.0L gas. And the light has been on for a year however since I need inspection I have to replace it. Wiring is good so just need to replace.
Ok thanks
good
Could this not be the gas cap
nope, we have a circuit code for the EVAP vent solenoid
Not everybody has bidirectional scan tool there's got to be some other way of explaining this
You can buy a bi-directional scan tool (Topdon Topscan Pro) for $100
There is no excuse to not have one these days. You can get one here.
www.aeswave.com/scannerdanner (affiliate earned)
The only other way to make that driver turn on is to meet the conditions for the PCM to run an EVAP test on itself and good luck with that.
gm electrical problem on wheel I say all there cars not dependable electrical conextion burn short out lost of head lights emission control monitor incomplete still no check engine code for bad part electrical problems on wheel pass the word around
rolling shorts on wheels
check your fuse first
Then what? Fuse is fine.
No help at all, just go straight to the point
Wrong channel if your just looking for a silver bullet. If you want to actually learn how to troubleshoot this stuff, then welcome! You just want to fix your car? This isn't the place for you.
I am getting po449 code but also having electical issues gauges and headlights not working. Please help
where to get service info for your car eautorepair.adtrk.biz/?a=10817&c=24&p=r&s1=