In this video I have a look at a ladies Jeep Patriot that came in with the engine light on and a customer complaint of "running poorly and stalling." She also told me she had it at another shop that replaced a sensor. Well it doesn't take long to see where they had been. -Enjoy!
If an SMA Video has helped you out please consider giving using "Patreon" to help support us. The videos take real time to create and pull us away from real work that pays our bills. CLICK HERE: https://www.patreon.com/southmainauto
CHECK OUT OUR "SMA SWAG" STORE! Go on Teespring and get your very own SMA merch!
https://teespring.com/stores/the-sma-store
If you don't like Patreon feel free to use the "PayPal Me" link: https://www.paypal.me/SouthMainAuto
The South Main Auto Amazon Store:
https://www.amazon.com/shop/southmainautorepairavoca
AES Wave Automotive Diagnostic Tools: https://www.aeswave.com/cart.php?m=affiliate_go&affiliateID=2525b91fc8e906e8215984074c9d9e8f&go=https://www.aeswave.com/Miscellaneous-p9347.html
Thank you for all the continuing support!
--Eric & Vanessa O.
Feel like sending some swag to SMA because you love the videos but don't know where to send it?
Just ship it here:
South Main Auto Repair
47 S. Main St
PO Box 471
Avoca, NY 14809
Disclaimer:
Due to factors beyond the control of South Main Auto Repair, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. South Main Auto Repair assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. South Main Auto Repair recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of South Main Auto Repair, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained.

Oops, that's too uh. What is it? 2012 jeep patriots got 141k on it uh. The lady left a note here. Let's get this plugged in because it sounds like we're.

Gon na need this little guy, because apparently the car quits can't find the plugger here and runs like poo and rpms drop off, something or other there. Let's see and she writes engine light on well driving stability. Light comes on, rpm's dropping no throttle have to shut off car. Let it sit start again.

Love always. I can't read the name but anyhow sounds like it has some issues: don't we all it runs. So that's a good start. Let me get up in this joint.

Oh she's short little girl we're gon na have to scooch it. Oh she's, the manual see that's good, those ones don't usually break engine light is on passes. The rev up tune up i'll. Let it get hooked up here and we'll see.

Um see what this thing says, what part we need to change and then we'll go from there right, because isn't that what these computers do he's almost done here we go at least it's not all a bunch of codes in here it says we need to replace The crank sensor and we need to replace the torque signal sensor, just kidding folks, uh intermittent crank signal and torque request signal denied, uh abs lights coming on, because the engine lights coming out. That's what that means, but uh crank intermittent that's interesting. So, let's pop back and we're gon na go right into the ecm and see if we have some kind of data there. That would coincide with what she says about the oh.

It just did it just sitting here. Just did, i hope you guys heard it, but i won't touch anything but yeah the rpms dropped right off and um. I was just going to say that would go with what she was saying about the rpms dropping off. So, let's see, i don't know what we just did it again might not even have to drive it.

We might not even have to go, get stranded, crank, cigal, missing faults in sync, that was a great band. Wasn't it not really crank system fault in the olympia? In mode i don't know if we have a uh yeah, i know we can't graph that to catch it. Let's see if we're going to want to bring up the rpms nope, we want engine speed and then run time and then speed okay. So what we'll do we'll set that at zero and put that about six thousand, and then i'm wondering if we should take it for a rip to see if any of this changes, because that would be helpful to know, but it sounds like it probably does.

I don't want to get stranded, but i am going to take it for a little tube just because sometimes you can gather useful information on your tune around town like if it you know, acts up primarily while it's being engine torqued or if it's just completely random. Here we better hit the side streets here we don't want to get stuck downtown with all that traffic huh kind of weird about the wheel, bearings huh, it's pretty noisy all right. Let's see we'll head this way here, go out where we give her some beans wow. This thing does not sound like it has a single wheel, bearing that is any good might be worthy to know.
Oh, it just did a little hitch and it's giddy up. We can see it right there in the rpm display. There's a pigeon got your classic black ice. In case you haven't noticed.

We put my seat belt stand by all right. Here we go hammer down: oh she's, a little jerky, so yeah you can see a couple of little blips right there. These wheel, bearings are really bad okay, so i don't think we need to go really much further, we'll go up here and turn around. It definitely is acting up and skipping and bucking.

Oh, it's dead right now. Look at that, so the car just died completely shut off on us. So uh are we in limp home mode? True, it says so, let's pull over here in case. We need to call a tow truck.

We got no more power steering hold on folks flip it around don't hit the mud puddle too hard. There we go and there we are at a dead end, how appropriate, let's put it in the park? Oh, don't you don't you'd, be nasty to me. Oh you're, good girl, okay, all right! Well, it did what i had to do. She wasn't lying i'd, want it fixed too yeah this time it stayed running.

So that's interesting, i think we'll go if you can hear me over. The wheel brings we'll go right for the crank sensor and see what we're missing five volts ground signal, something going on. What's its signal? Look like it's. The only thing we can do and then we're gon na have to probably come drive it to make a determination as to what's uh.

What's wrong but yeah. I just did it again, they're just on a ladle now interesting baby. Perhaps the best thing to do is find out a how to open the hood. There's probably some way to do that b.

We need to find out where the sensor lives, i'm sure it's probably been replaced. Typically, before cars end up at my shop they're at other shops and they change the parts that the computer says to uh, whatever we're on c or d, we're gon na have to see if there's any uh service bulletins by chrysler. You know pcm updates anything that pertain to the what we're looking at and then f. If there's not we'll go on with our regular testing methods, just seeing if there was any mice in here or anything, so, let's uh! Well, that's not going to stick back we're going to put a little lube on that we'll leave that up for right now, um, let's find out where uh and we're gon na have to be able to get to the battery negative, i'm sure so we'll take this Thing off, so that's! So let's do that, let's find out where this thing lives.

Let's see if it's new, which it probably is, and then uh visual inspection, service bulletins, things like that and then we'll come up with a plan. This big is gon na need a belt too melting bearings. So as we suspected folks uh, i look back here. Let's see if i can find it for you guys in the mirror uh.

Where is my mirror? You can see so that's the crank center there uh. So i'm looking, you know coming in the engine, looking down past the heater core hoses and we can see the crank sensor there. Now. Typically, we wouldn't be able to see this just using a mirror and a light, because there's a heat shield that covers it, but i can see also in the mirror uh.
This thing probably won't focus on that. You can see, hopefully, that the heat shield there see how it's kind of bent and probably just yank back out of the way so somebody's definitely been in there already, instead of taking the heat shield off, they just you know, yanked it back out of the way. So i assume that the crank sensor has been replaced. Um, it's like it's kind of a pisser to get to it's looking on service data and they were saying to uh.

You know, take the air box off and then to get to that heat shield. But that's why he said i was like well, let's look back there with a mirror, i'm sure it's like somebody's, been there i'd like to get to uh the connector to disconnect it just to make sure the pin fitment's good um, and if it is, then i Guess we're just going to carry on our testing uh, no service bulletins or anything that i saw so folks. I was talking to a customer there. They set this down, didn't want to waste time.

So i was hooking this up. While i was chit chatting uh, i've got a diagram here for the jeep um i've hooked into uh the pcm, because it's easier to get to plus it's the last place. The signal needs to make it uh. We have three wires through wire sensor hall effect sensors.

We have our five volts, our signal and our center ground, and that's where i have these hooked up and i have them running inside into the scope, so we can take it for a shake and just see what's happening, so we should be good now, um. Let's see here so i labeled the channels for you, so our blue is our crank signal. Uh red is our five volt ref and green is our ground. Now uh some people are gon na, be commenting on the the spikes and stuff there pretty common to have noise.

Our wires are laying right across four ignition coils, so we're gon na see. You know some of these ignition events just being absorbed through our uh through our scope cables. I think at this point we just need to take it for a drive and catch it in the act and see what's happening. Are we losing signal? Are we losing the ground? Are we losing the 5 volt reference, i'm going to put a little more time on the screen.

It makes it easier for me to capture it. So we'll go like this so i'll make sure i can pause it. I can start it. So we're good uh.

I know it looks a little fuzzy and a little messed up right now, but i don't think um. I don't think we need any more than what we have there. I think we're in good shape. So, let's rock and roll all right we'll go out on the big road and we'll hammer down because it seemed to do it around between four and you know: six thousand rpms relatively consistent there.
I don't think we need any scan data so much stupid thing. Probably won't do it now. I did disconnect the connector on the crank and it was nice and clean uh. Nothing looked funky tabs not broke nothing like that.

So i don't hope you guys heard them apart. It did get kind of funky on us just a couple. Three times there i enhanced and hence each time when it did it uh on the picoscope, and i don't see anything funky i mean the our signals, get a little funky uh, almost like the uh, almost like it's putting the crank signal back in through the through The power and ground i mean you can see here it just it just gets funky, i guess for lack of a better term it doesn't, it doesn't just go away. Uh our signal doesn't disappear.

Our five volt and our ground gets a little hatchy there for lack of a better term. That's all it does. I was kind of expecting the signal arc, actual crank signal itself to just disappear. I looked at it in all three spots where it jerked and bucked and that's all it did so.

That's that's interesting. I don't. I guess i don't have an answer for you right now, um. I was half expecting to see the signal disappear, but you can see the discrepancy there.

You know big picture looking at this, so that's kind of bizarre huh. Oh we're not losing ground, we're not losing our five volt uh. The signal gets a little choppy. We know chrysler's in general, are quite fussy with what brand sensor you put in them.

So i don't know if perhaps this is some kind of aftermarket mumbo jumbo that's happening to it. It's kind of weird i'm going to drive it a little bit more. Just because i want to see you know if we can get a big. You know a big event right so far, right now, it's just jerking and bucking like it was uh initial test drive.

So i'm gon na take it for another shake and we'll see, um see if anything changes, but i mean overall just looking at it. I mean everything. Everything looks good when it works good. It seems to be nice square waves, so i don't have an answer for you on that one, but we're gon na we're gon na keep going here for just a little bit and then i'm probably just going to order an oem sensor for it just to be On the safe side, so we know where we're starting.

This is a pretty good one and we sit. She just died on me, uh, i paused it and, oddly enough, so the tack you know i would this speedometer still going. Attack dropped off to nothing and i'm just coasting along, and i still have crank signal right up until the point where i pulled over and then i guess the engine quit rotating. Finally, but i'm gon na.

Let's go back to the moment in which it died. It was jerking and bucking through here, and then i got to the point here where you know we can see uh our noise uh quit. Therefore, you know the injectors quit injecting and the spark quit sparkling in and at that point at that very moment i don't think we lost crank signal. We didn't, we did not lose crank signal.
That is, you know, yeah. There's there is some noise there. Don't don't get too distracted by that, but the crank signal kept cranking all the way, all the way until it didn't. This is the part that kind of perplexes me.

So i mean right here, i'm just coasting you can see. There are no there's, no injectors um kind of enhance on this a little bit see this was another. This here's another moment in time in which it was bucking and you can see it emits the same type of noise on the power and ground uh crank signal looks a little funky. I i don't really have an answer folks.

I do know from experience that chryslers are cray-cray about using oem sensors and i've ran across some anomalies with them on their crank sensors on various chryslers, where i don't have an explanation where i look at the signal and the signal looks mint. You know it looks just as perfect zero to five volt square wave. You know in this case it looks like it's probably a 58 tooth sensor or 58.2 signal minus two teeth and you know you sit there and you look at them. You analyze them and then they look, they look spectacular and you don't have an explanation other than you put an oem in it and all the problems are solved.

So i'm not going to get upside down on this thing just yet. We do have to see if it starts. Let's see what happens here and start up: okay, perfect startup, classic, okay, let's head back to the shop before we get stranded. You know what here, let's check this so right now it's not starting, but it appears to have good crank signal.

So that's pretty bizarre right. It wants a key cycle, so this is definitely uh pcm logic because it doesn't want to start right now so i'll hit. The key again, even though let's pause it, let's just key off, even though we have crank signal, obviously, and we're going to see this amplitude change, because you know because of the starter motor um, so yeah, because now it should start because i shut the key off. So, that's you know some kind of pcm logic that doesn't allow it to restart.

After this event, all right, i think we have enough data. Let's try to make it back here without getting run over. I'm not sure what to tell you i'm going to see if we can get an oem sensor just so we know we're not battling that and that is not based on anything other than experience and previous. You know, failures and repairs here with chrysler, so i'm going to pull it back inside i'm going to go in we're going to call the chrysler dealer see if they have one of these uh crank sensors in stock and then we're called napper see if they go Pick it up for us, because i don't have an explanation, uh right now, uh, perhaps some of you guys have had that problems.

Like you know, the the four leaders were notorious for uh euronius misfires. I've done some videos on them where i've actually taken scope. Captures engine lights sitting there just flashing showing misfires it's going all over the place. We look at the scope capture and it looks exactly like the oem sensor, but for whatever reason the pcm doesn't like it, i'm not a computer guy.
So i don't know uh. You know the whole ins and outs and mumbo jumbo computer garbage as to why it looks good, but it doesn't like it way above my pay grade. I could be barking up the wrong tree, but i don't want to be led astray by some aftermarket sensor. Perhaps the original was bad.

They stuck in a aftermarket and now have this problem that i don't know, but that's what we're gon na do, because we're not gon na get upside down on this. You guys are lucky you get to skip all the weight in uh. Here's the crank sensor i took out of it, it does appear to just be some. You know aftermarket chinese um, i don't know if the numbers mean anything there uh, fortunately, for us, the local chrysler garage should have one echo and medico.

So here's this one. So i'm going to get that in no sense recording it it's kind of a bastard to do you stick your hand down here, and then you use one of these mirror. So you can see where we're at like you can see. You know the crank where it goes, the opening and then to get to the bolt i used.

You know just a long extension, but it is a bit of a pisser. I assume it's probably more difficult irl if somebody hasn't been there because of that shield. That's on there, which, fortunately for us, somebody already smashed it all the way. So i think typically, you would take that heat shield off to make life easy, but we're not doing it that way, because you know somebody already destroyed it.

So that's kind of the nice part about having these vehicles come from. Other shops is, most of them are hacks, and then we, you know we don't have to do the the dirty deed of you know, taking it apart. The right way. Let's see hey, let's see if it runs, hopefully, okay, so it starts and runs the other thing we need to do now.

Let me get you situated, we need to erase codes and i don't know if there's any cam crank correlation relearn. Anything like that that we need to do so, we'll check special functions. Uh, let's see cam crank, relearn. There's that check pcm pen, okay, um! I guess that would be it.

We did change setting cam, please start the engine. Let me see here check. Temperature must be above 70 degrees c we're only at 58 c, so i'll. Let her warm up here, we'll try again.

Everything on this scale still looks the same. You know no change there. So we'll just wait. This warm up.

I don't know if, once it hits 70, if it will automatically start the process. Well, i guess that's good and we'll just make sure that we have no codes which we shouldn't have and then i guess the moment of truth. Let's set that baby down because i don't think we need to see anything data wise. Let me put my seat belt on all right here we go.
Hopefully that was it and we're not some big complicated bag. Nobody likes complicated and hopefully we can sell this. Lady uh, you know four wheel bearings, not that i'm a big upsell guy so far so good it was pretty persistent before so i don't think we're gon na have a problem duplicating and we're not duplicating it ready. Let's hammer down.

This is where it left us walking before without a mess. So that's good and we'll slow down again, we'll give her the beans one more time like say it was pretty persistent. Well, you guys are with me. You know, okay, we'll hammer on it again.

The case of the i don't knows, folks, i'm not going to have an answer for you at the end of this video. Some people are going to want to know how i knew what to do. That's because i've been burned come on, cbt just hold together for us one more time. Well, she's working like a charm folks, i'm confident with it.

I'm gon na bother driving anymore. It was pretty persistent from the get-go, so i think this lady will be happy. I'm happy you're. Happy happy happy happy.

So that's really that folks, i don't have any explanation for you as far as why does the oem work when the aftermarket doesn't i don't know, but what i do know is i've been burned on it in the past, and i remember my first time coming across Something like this and i learned you know my experience from somebody else's experience uh, who originally got burned by an aftermarket, crank sensor on a chrysler. Well, we may never know, but somebody did they shared their experience. You put it in your vault and you don't forget it because there's times like this, when you just know that's the answer, but you don't know why i could. I know.

In the past i've taken chrysler, crank, sensors, i've taken the image of the aftermarket. I've made a copy of it, made an overlay image and i've stuck it right over top of the oem, and i see no difference, it's not biased a certain amount off from ground. They are from zero to five volts. Almost precisely the aftermarkets are also uh.

When you do like some of the hondas, i know they'll be biased, almost a half, a volt or 300 millivolts three to four hundred millivolts roughly on the oem sensor, but the aftermarket goes all the way to ground. Is that the difference? I don't know, but that's what i see these i've never been able to tell i'm not a i'm, not the electrical wizard of how internal sensor things work uh. Why does one hall effect work and the other one? Doesn't i don't know, i don't care um, but that's that's all. It is put an oem sensor in it call it a day and uh.

You know move on with life and uh. That's what i got ta do. I got ta move on with life. We got a bunch of junk out there, a bunch of chevrolets that need to be fixed.
So, let's move on you move on in that comment, section the questions, the comments, the instinct, the facebook and just from our viewers. If i can do it, you can do it thanks for watching.

By EricO

13 thoughts on “Jeep patriot: p0339 bucks, tach quits then dies?”
  1. Avataaar/Circle Created with python_avatars Tim Harmer says:

    Good evening..always good to see a new video from SMA!

  2. Avataaar/Circle Created with python_avatars William Holcombe says:

    Opps there its is , first view again .Thanks for the videos and dropping some true professional repairs.

  3. Avataaar/Circle Created with python_avatars Jason says:

    Happy Easter Eric!

  4. Avataaar/Circle Created with python_avatars Mike says:

    I miss read that title. Thought it said tech quits then dies 😁

  5. Avataaar/Circle Created with python_avatars Steve Walker says:

    Another video! Excellent!

  6. Avataaar/Circle Created with python_avatars Baddrivercam says:

    Never been this early

  7. Avataaar/Circle Created with python_avatars XXX Do Cat Cat XXX says:

    Another piece of cheese

  8. Avataaar/Circle Created with python_avatars Joseph Furey says:

    Nothing better than a SMA video after a day of work.

  9. Avataaar/Circle Created with python_avatars tobykenobe says:

    Good afternoon

  10. Avataaar/Circle Created with python_avatars John 44070 says:

    First!

  11. Avataaar/Circle Created with python_avatars Gabriel Merza says:

    Good evening Eric.

  12. Avataaar/Circle Created with python_avatars kj bunnyboiler6353 says:

    Evening Eric

  13. Avataaar/Circle Created with python_avatars Steven says:

    19 seconds ago gang

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.