In this video I have a look at a customers Jeep Compass with the engine light on and the check gas cap light on with a P0456 for a small EVAP leak. These are pretty simple system once you understand how they work.
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Thank you. It's a Jeep thing. let's see if we can understand. Apparently it has some lights on.

oops not this. Jeep I'm clicking the bind and this one's beeping. Let's go get in this one. I think it's the same thing a compass right? Yep, see if this one has some lights on.

scan towards kind of wet outside today. oops Usually these have Abs track, four-wheel drive and engine lights on. It's like they come from the factory like that. We got the right Jeep Oh we got an engine light anyways so that's good.

check gas cap it's a change gas cap for change, oil check, gas cap, door and jar so that's what it's telling us. Oh boy I can't fit. hang on Oh Daniel Slider survey says uh of course evap problem because like I said we got the gas cap plate. we got the engine light.

uh so evap small leak so maybe perch valve or actual leak or need some switch ABS We've got left rear wheel speed sensor erratic but for tone ring and then of course implausible data from the four Drive model. It's interesting because there are four Drive lights not on. Um, however if it's typical deep fashion turn wipers on here, let's just take a little rip down. Road I'm sure if that speed sensor is missing the magnet like they usually are, our light will come on very quickly.

Anything coming? No sir, let's see what happens, see if anything happens. Thank you graph up here for us. it's an intermittent bomb she was having or something if you're pretty smooth there. usually if the magnets broke, it's wow.

I mean usually I don't throw a light almost immediately so maybe we're just looking on that rear wheel see what it looks like because I thought she said that she had a bunch of lights on. Check with the customer and see I'll take it for a little rip here around the big road. I don't see Natalie's here quite yet? Back to the shop. Uh, nothing bizarre happened with the ABS four-wheel drive lights.

All right. pull up some data here. we're gonna see evap wise if we can get a little bit of data from the driver's seat. So what we expect to see is, well, just what happened.

the easel switch we can't put it on the graph just went closed during a purge cycle. so I was pulling vacuum in the tank. the switch back there closed under under vacuum. This is now the commanded switch.

This is a yes I have vacuum in the tank switch. So what? I Want to see. Get our perch. the kick up there.

Pretty good. gas cap plate is on I'm gonna I don't know what that. I'm just stating facts at this point I Want to see how long it stays close? I mean if there's no leak, it should stay closed for a while so we'll shut the key off key on. Oh, it instantly came back open until there is a pretty big leak in the system.

Uh, because that should have stayed closed. uh for some time. You know I'd say at least you know, 30 seconds to a minute? I Mean it's pretty. damn, it's not freezing cold outside, it's probably in the 40s out it's raining.
But we'll let the uh, let that perch kick on one more time here. It takes it a minute here and then once the purge kicks out. like I said, you should see the switch go closed. If you don't, you either have a really massive leak or you know, possibly a bad switch or a crappy scan tool.

For the longest time Alltel was insanely unreliable on the esome switch or the Nvld switch status on Chryslers It appears to be working now, which is amazing. Uh, so let's see, let's see what we can see. Let's see, we may even just have a bad uh perch valve or we have a gas caps missing or something silly. But yeah, it goes open pretty quick.

So we obviously have a relatively good size leak. so it's a 2016 Jeep Compass I Assume the big two four. Oh yeah, it's got the Dual VVT Whatever that means, it's got it. Um, and it's got the Po456.

So so buttoned up underwear? what's this thing made out of? I Don't know if we need to take that off, but usually you do. Let's find some components. We have a gas line right here so that's good. You need one of them and then We should have a purge valve hanging out here somewhere.

It's probably inaccessible. looks like probably that's the vacuum hose for the booster. Where's the other fuel line here that runs up from the bottom? Let's get a flashlight. let's see if the fuel line runs there.

You take the other one, ran right where that Yes, sir and that goes down around and The Purge valves all the way down here below the booster. Yuck yuck I'd say. And then the hose runs around town over here to the intake somewhere. so not a real greedy job to get to I just wanted to see if it was leaking.

Uh, prior to doing that I guess because that's a little bit more work than I want to put into it. Let's go have a little quick look at the gas cap, not just for friends and giggles. just to make sure I doubt it's it's never the gasket folks. I Can see okay that way we got here, folks.

rust around the cap. Typical. not real terrible though. I Gave the gas cap the old neck polish here.

uh, you know, plug the hole off. use your noodle when you do that you don't want Sparks back there more than likely. Uh I Got the engine speed duty cycle for The Purge and the easel switch. Let's start it up here and see if we made any Improvement before in the eyes.

So we're going to let the purge turn on. eventually. it'll turn on, let's eat some switch, go closed, and then we'll shut the key and we'll let it pull Purge for you know, a minute or so and then we'll shut the key off, turn it back on and see if it can hold any longer. Uh, you know, like I say a returnless system I don't know how much gas? Yeah.

I Instantly went closed. Uh, very quickly. That time through that first turnout closed and it's got almost a full tank. It's got three quarters of tank.

It's highly unusual for somebody dropping their car off at a repair shop. Usually it's not empty or a little bit below. so we'll let this purge for a little bit. Uh, but I Guess what I was getting at is there's not a lot of room in that tank.
So if the fuel is volatile, which it should be a little bit, you know we've been driving around, but it is returning so as that fuel heats up, it's going to displace the vacuum and it's going to go from a negative pressure to a positive pressure. Pretty quick. but you guys seen before when we shut the key, I'll turn it back on. it was switching to go open almost instantly.

purging for a little bit here. Switches closed, cars off, keys on. Oh, look at that. The switch is still closed, so there's still a vacuum in the tank right now.

Key's on, so we're key on engine off and eventually that's going to come back open because like see, the fuel is volatile and it's gonna, you know, heat up and and achieve a pressure. There it goes. So it just opened. Uh, so we definitely made a big change just by cleaning up the gas cap.

I Don't do enough Chryslers or pay attention to enough of them. certainly do enough of them. I Don't pay attention enough of them to know the rate of decay. So I guess we could probably keep going here a little bit.

So if we come underneath it here, we can see right by the front wheel, right up on the sway bar, you see where that hose hooks on. that's the purge valve so we can unhook the hose from it to make sure it doesn't have a a small leak in it, which it's very, very common on. Chryslers Okay, now the lines here are pretty straightforward. They're nice and clean.

I Don't think they use any rubber connections on these anymore and we come back here. And there's your canister. So this white valve over here, that's your Esom switch. Let's eat some stand for emission system Integrity Monitor I Think it is because the Nvld works similar, but that's your natural vacuum leak detection.

This is your ESO switch. These quite often are bad and they're quite inexpensive, so if you're just guessing in even Parts at it, you know heat. one of those things and you'll get it most of the time. Um, do to do yeah, let's just check and see if that purge valve is junk.

uh which they typically are. Usually they're drawing vacuum when they're not supposed to be and that'll cause the Decay you know Kion engine off and then what we can do. If we want to make sure the system's sealed, we can just pinch off the hose here and then hook up the Avoca smoker. I'll set this right here.

I've got our vacuum gauge balancing and they're dangling off here I plugged it in. this will set it right here and we shouldn't have any vacuum on it until you know until it turns that Purge on. So let me just reach in here and start the standby. Just make sure it purges at zero and our backing me to sit at zero.

So that's good. These Chrysler 300 here very temperamental. so it's still a zero and that's still a zero. So I tell this is our first Drake and eventually we're gonna watch.
That should pop right up here as soon as the Uh Purge turns on. I'm going to just turned out starting to build some badge percent All right. So that's good. All right.

Well at least we know it's not leaking. and the other way to know it's not leaking is you know I just shutting the vehicle off. Rather, it maintains the vacuum. you know where it was at.

So I told us our purge valve is good or at least it is in the moment. We have all the smoker follow the hose all the way up here. We just hooked it to the EVAP plane so the line that was hooked to that pert. So now we're filling the whole you know system full of smoke.

which you can see it's starting to drizzle down. Back here, smoke can drizzle. We're gonna pinch off this hose here, so let's go get a pincher. If you're scared to pinch the hose, just unhook the hose and put a cap over it I Like to break as few things as possible working on cars if I can avoid breaking stuff so we're just going to pinch it with a classic pair of pinch off pliers slash needle nose bite scripts and then we're going to let the system.

Oh I think we've got some Smokey up top folks, it's leaking right out of our gas hole. baby. Gosh, we cleaned that sucker. pretty good too.

Must be the cap itself is junk. Well, I'll be dipped. You hardly ever see a bad gas cap. Uh, you know, despite the hundreds that they sell at the Advance Auto I Don't know.

the smoke is slowing down. Maybe the uh I thought the fresh air ended right there. Yeah, maybe it was just some residual. Well, uh, we'll give the evoke a smoker some time here.

Let's see where the floaty ball ends up. It's pretty bouncy right now. We'll see what happens. It's pretty good amount of smoke coming right up here.

You see it coming out of the Uh rear bumper cover. here. you'll see much underneath here. Most everything on these things is plastic, but I'm I think we better sit down and double check the uh, double check the gas hole baby because our fresh air vent just ends right here so there's no other hoses running up there.

so it's pretty much all it can be. You know it's the filler neck itself and or the gas cap because the feeling that could be rotted out of it too. Oh I was gonna say I hear some hissing. Well I'll be dip, look at that when you sit when you know.

huh? Despite the flying job we did cleaning it I pushed down on it I still hear it hissing. Oh look at that. Oh it must be the clicker on its bed. All right.

Well, let's get uh cap from Uh Napper here and we'll go eat some lunch and see if we can fix it that way. Nappers Show it up 703-189 or four tethered gas cap in stock and that we're just trying to record here. Nothing today. comes with a rubber band.
Set that to the side. it's already got the built-in tether right there, gas cap on a string. wiggle that out of there, set it somewheres. Probably the only guy on the internet making a video how to change the gas cap.

Okay, well, let's go get the smoker turned on. Yeah, she's coming through there. Oh there's that's what I'm talking about. boys.

All right, we're good. It's all tethered up smoke machines on it. No more smoke coming out. it's got the cord on it.

Perfect. Let's see where our floaty ball is at all the way to the bottom and then it's turned on. We'll turn it back on. Yep, so floaty balls at the bottom are flow gauge.

So our system is perfectly sealed now. Should be happy. So we'll turn that off and hook all our stuff. Let's unhook that.

Oh man. Yeah, the old the focus smoke took a spill off the car the other day and now she's a little bent up. kind of pulled it apart here a little bit, but it still works so that's good. Now if you guys are wondering how I hooked up to that purge valve hose.

Uh, the Easy Connect kit here. It's the smoke machine. quick connector kit. all right.

I took the red line to make some right? Yeah, red line detection. Uh so I use this one the most and the other one I use the most is when it doesn't come with the kit. it's this size here I don't know what size it is exactly I think it's for Fords because I remember I took a purge valve and I busted it off and then I made my own uh little adapter hose but it comes with quite a few different little adapters for hooking into these Purge systems. Some you know they make it so you can t in I don't know why that would be necessary, but there's four different keys and then of course, uh, four different straight hookups when you include the one I put in there and uh, comes with some rubber caps and stuff but it's a nice little bit of Kit I'm about to put that back in there.

five comes with five different things. four so so there's that and I gotta stick it back in the Box part number is a nine or six. zero, one nine or zero in case you wanna go buy one contact. Okay, everything's hooked back up.

Make sure you get your pliers back. Oh look at that. We left it right on the screen. we needed that away from The Purge to open again.

They should slam our switch shut because we know that works and then we can get an idea of the level of Decay Um, nope, not seeing what I want to see. So I have to give it a minute here. Okay, there we go. I just started to purge I don't know if you guys can see it.

The switch went closed all right, so we'll give that a little bit of time to suck the fumes out of there. Did not know that this system had a fuel tank pressure sensor on it I didn't think I used them on these. Um, so let's see once I wanted it to be negative. foreign switch is closed.

We can watch our decay I don't know what the how many inches of water the eat some switch closes at must be around that You know. negative two: Whatever it was running at there like. well I Guess we can figure it out because we can watch how many inches of water it's at exactly when it opens and we can. we can determine that you can find that in service data.
Also I mean it's not a it's nothing that's hidden. but if I were to go yank the cap off, you know we'd watch it. Oop, you know, pop back up real quick. but we know the system's sealed so hopefully this gives you guys somewhat of an idea.

The court system is always variable depending on how hot the fuel is in the tank, how fast it comes back. But clearly the system is sealed as we already proved with the Avoca smoker. Foreign. Well, I was gonna sit here and wait, we're not gonna.

We can see the system sealed. Uh, its Decay Rate is quite so. Uh, despite only having you know 26 of it into air in there. So oh, that's it.

We're done, show's over, so that's it folks. Uh, not a big lesson on how a Chrysler eats some systems work and how you know that switch back there naturally seals off or seals off the system without any wires. You know it's not a solenoid, it's a pressure differential in weights. It's a very low pressure that it seals the system at and the switch is still closed at negative 0.75 inches of water.

So that's good. So let's spend some time I don't know two or three minutes sitting here and still remain closed. So I think our guy over. Uh, NGK Wells Mike Go Tech garage I think he has some videos as a matter of fact I'm pretty sure I know he does on Chrysler Eason systems and or Nvld systems.

If you don't know how they work, they're kind of a, you know, kind of a pain in the neck to uh, you know, to diagnose if you have access to factory service data. uh, Stellanis in this case Salina I think that's how they say it. um, or even back when it was, you know Tech Authority or whatever they Chrysler actually has some good videos on diagnosing these with lots of good tips in there too. I'd show them to you.

but I think it's probably illegal for me to download them and then re-upload them to the general public considering we have to pay, you know, thousands of dollars to get them. But anyhow, they're not a terribly difficult system really. You've got your purge valve, your canister, and your Eason switch. so uh, kind of I think Honda uses a similar system Ford uses a similar system with their natural vacuum leak detection.

They're all kind of the same. but um, yeah, she's still closed at the, you know, half an inch of water there. 0.44 So anyhow, oh, it just opened. It just opened.

There's your magic number. All right. I Think it. maybe it was open when I showed you.

Who knows. but uh, whatever, it's closed or it's open Don't Let's close out this video by you going in that comment section questions, comments, concerns Institute Facebook You guys know what to do and just for my viewers, if I can do it, you can do it. Thanks for watching Foreign.

99 thoughts on “Jeep compass w/ evap trouble”
  1. Avataaar/Circle Created with python_avatars Berth Ljunggren says:

    Should at least be a fairly cheap repair.

  2. Avataaar/Circle Created with python_avatars steve troyer says:

    thanks for watching, your welcome, good man good videos.

  3. Avataaar/Circle Created with python_avatars Scott Farris says:

    Redline would probably like a heads up from a professional such as yourself but that’s not really your responsibility.

  4. Avataaar/Circle Created with python_avatars Scott Farris says:

    What I gathered from this video: Jeeps are generally junk. 😂

  5. Avataaar/Circle Created with python_avatars Larry Ehrlich says:

    I like those flashlights that you use…where can the general public get those flashlights???

  6. Avataaar/Circle Created with python_avatars Courtney Jones says:

    Remember JEEP stands for Just Empty Every Pocket.

  7. Avataaar/Circle Created with python_avatars KingRatt says:

    Sounds like a rod knocking.

  8. Avataaar/Circle Created with python_avatars John Bragg says:

    Wow 6200 red line. Son your gonna drive me to drinking if you dont stop driving that HOT!…ROD!………..Jeep?

  9. Avataaar/Circle Created with python_avatars MikeysHouseofBrakes says:

    Sounds like it has one quart of oil in it.

  10. Avataaar/Circle Created with python_avatars tv says:

    Eric fight the system just upload it just kidding

  11. Avataaar/Circle Created with python_avatars Mark Enloe says:

    Really enjoy your videos…😎

  12. Avataaar/Circle Created with python_avatars Tan Man says:

    just got the evap done under extended warranty 101,000 miles 16' jeep grand cherokee. solid vehicle 👌

  13. Avataaar/Circle Created with python_avatars Cape CodBob says:

    On my 05 Liberty when I had the evap code I change the filter and checked sensor put what fixed it was web advice to put some petroleum jelly on the gas cap "O" ring and did that whenever I changed the oil. Never had evap code again. Put some on the metal neck if it is metal. God those 4 bangers are noisey . I had a Neon back in 95 was never that noisey.

  14. Avataaar/Circle Created with python_avatars Mike Dalton says:

    Great video as always!

  15. Avataaar/Circle Created with python_avatars Leighton Elliott says:

    My Kia just popped a code for bad gas cap. About 3 weeks ago my car was running without the cap fastened at idle, my doing. Pulled a code from AutoZone. I don’t necessarily trust their scan tool. Bought and replaced the cap still have the CEL light. Dealership said it should go out, if not I’m on the hunt to find local mechanic like Eric.😎

  16. Avataaar/Circle Created with python_avatars ToughAncientSpark says:

    I had a 2008 Buick LaCrosse that had to have the gas cap replaced three times.

  17. Avataaar/Circle Created with python_avatars ToughAncientSpark says:

    Avoca smoka:
    Eric's hooka!

  18. Avataaar/Circle Created with python_avatars Eugene Blanchard says:

    My Compass had error code P0456 and it was a dirty gas cap, the rubber O ring was dirty, cleaned it, cleared the code and no problems. Fast forward 2 years later, the code pops up again, I clean the gas cap O ring again and the code pops up again. The O ring looked fine so I coated it with some white grease and now 6 months later no codes.

  19. Avataaar/Circle Created with python_avatars johnhufnagel says:

    ironic I'm watching this today after looking at mom's PT Cruiser, which threw a P0441 recently. used my autel to toggle the vent between its duty cycle settings, so i'm pretty sure the valve is good. will see if it comes back on her.

  20. Avataaar/Circle Created with python_avatars Bryan Krall says:

    Is the ECU really on top of the Air box? WTF

  21. Avataaar/Circle Created with python_avatars Gordon G says:

    My old 07 Dodge Caravan usually trips the gas cap light every 2 years. I take the cap off, lube up the O-ring with petroleum jelly and away she goes for another two years. I do find that every 4 years the o-ring starts to crack. I aways carry a new cap with me because the stupid light bothers me when it cilcks on and 'dings'. lol

  22. Avataaar/Circle Created with python_avatars Richard says:

    Great information. I don't think most people realize the expense that mechanics have to get information.

  23. Avataaar/Circle Created with python_avatars Matt Simms says:

    Great video man

  24. Avataaar/Circle Created with python_avatars Universal Associates says:

    Based on my own experience with my two old Volvo's, I guessed at the gas cap right away. Also by reading the message on the dash!

  25. Avataaar/Circle Created with python_avatars CAM NEILSEN says:

    Is there no JEEP THUNDER! ???

  26. Avataaar/Circle Created with python_avatars Wes Hawkins says:

    It was a good lesson because I learned something I didn’t know.

  27. Avataaar/Circle Created with python_avatars Pinoi_Cowboi says:

    LOL…Yeeps come from the Factory with the dash lites on…!!

  28. Avataaar/Circle Created with python_avatars Iain Kinsella says:

    ESIM Aluminum

  29. Avataaar/Circle Created with python_avatars Lepus Malignis says:

    This is oddly appropriate for me. I've had a "GASCAP" dash alert since I got the evap canister ripped off in a high speed water splash. I've ignored it b/c I don't really care, anymore. It's 15 years old, so the list of minor "quirks" is getting longer & longer. 🙂

  30. Avataaar/Circle Created with python_avatars Chris West says:

    Sometimes it really is simple. Too bad it isn't always!

  31. Avataaar/Circle Created with python_avatars john whan says:

    My Versa throws a code if I leave it loose every time.

  32. Avataaar/Circle Created with python_avatars BILL UPSTATE NY says:

    Never mistreat the Avoca Smoka, after all you have been through together, & never let you down 🇺🇸🗽

  33. Avataaar/Circle Created with python_avatars jim jab says:

    Those compass' magnets have always been twitchy . There is a reason why the dealer is way backed up. Suppose quality cars being made

  34. Avataaar/Circle Created with python_avatars Paul Dubetsky says:

    Eric has been spending to much time watching Diesel Creek. Contact..

  35. Avataaar/Circle Created with python_avatars Pontificus Vascillious says:

    does it have a 'get another car' light (on)?

  36. Avataaar/Circle Created with python_avatars E Vincent says:

    I remember the old days our smoke machine was another tech who smoked way before all this new stuff LOL! puff and blow it in LOL! I miss those days…..

  37. Avataaar/Circle Created with python_avatars Brad Snyder says:

    Love the jokes today! Working a Grand Caravan evap leak now. Very helpful. Need to check the gas cap…

  38. Avataaar/Circle Created with python_avatars Richard R says:

    " I think they come from the factory like that ", you totally cracked me up Eric ! 😅😅

  39. Avataaar/Circle Created with python_avatars Charles Mitchell says:

    Excellent as usual

  40. Avataaar/Circle Created with python_avatars Jeff Compton says:

    Evaporative System Intergrity Monitor.

    Not the Emissions system. Evap is just one of many systems in the entire Emissions control system right

  41. Avataaar/Circle Created with python_avatars James Cunningham says:

    “Contact” 😂😂😂

  42. Avataaar/Circle Created with python_avatars S C says:

    I see a pattern of vehicles in your shop…

  43. Avataaar/Circle Created with python_avatars Fred Salter says:

    Great vid, again. And thanks for plugging WellsTech. They also produce some fantastic diag vids! Rock on, Eric!

  44. Avataaar/Circle Created with python_avatars THE US CONSTITUTION says:

    Why do we need all these eve app lines boxes sensors? The stuff is going to do one of two things and you can’t stop it it’s going to evaporate or it’s going to burn these eve app systems are probably 30 or 40% of your service calls imagine if we just get away with all that garbage and ran one line from the gas tank? They’re not stopping anything they’re not changing the world or there wet dream of climate change? You can’t fix what ain’t there