Intermittent stall, no start - P0320, P1391 cam, crank sensor testing (Jeep)

Join me and one of my students at RTC as we troubleshoot an intermittent no start problem on a Jeep Grand Cherokee. The procedures shown in this video apply to all Chrysler, Dodge and Jeep electrical systems. In particular, the cam and crank sensor tests that we show.
Symptoms
- intermittent no start, no spark or injector pulse
- check engine light on P0320, P1391 trouble codes
- hesitation and surging
Fix
- replace faulty crank sensor
Tests shown
- how to test for cam and crank signals on scan data
- what scan data Ignition Cycles can be used for
- how to test the cam and crank sensors with a scope
- how sample rate of a scope affects the signal
- why a sensor ground is better to use than battery ground in some circumstances
- how to recreate an intermittent problem
- sensor power and ground tests
Engine Performance Diagnostics chapter 21
Playlist
- (Chapter 21) Ignition inputs, cam and crank sensors
• (Chapter 21) Ignition ...
Related videos
- Picoscope Basics Part 1
• Picoscope Basics Part ...
- Picoscope Basics Part 2
• Picoscope Basics Part ...
- How to test a crank sensor (Chrysler Dodge Jeep)
• How to test a crank se...
- Jeep 4.7 no start from faulty cam sensor (an SD Premium video)
• Jeep 4.7 no start from...
- Faulty cam sensor setting a crank sensor code - P1389, P0320, P0622
• Faulty cam sensor sett...
For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available at www.scannerdanner.com as an eBook or paper book.
Want even more diagnostic training? Whether you are a DIY trying to fix your own car, someone looking to become an auto technician, or a current auto technician that wants to get more into diagnostics, subscribe to ScannerDanner Premium www.scannerdanner.com/join-sc... There is a 14 day free trial.
On ScannerDanner Premium I will bring you right into my classroom at Rosedale Technical College. You will find page for page lectures taken right from my book as well as exclusive classroom type case studies. What is so special about these classroom case studies? I pull live problem vehicles directly into my classroom and we troubleshoot them in real time, using and applying the theory and testing procedures we learn during the classroom lectures. There is no better on-line training of how to troubleshoot automotive electrical and electronics systems anywhere!
Disclaimer:
Due to factors beyond the control of ScannerDanner LLC, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. ScannerDanner LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. ScannerDanner LLC 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 ScannerDanner LLC, 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 in this video is the sole responsibility of the user and not ScannerDanner LLC.

[@snsm6730]

THANK YOU for taking time to post videos like this as many of us drive these vehicles and being able to have an understanding of this issue is important if you are on a budget like many of us are !!

[@b.carroll]

I can't tell you enough how much I have learned from you. When I first met you, I thought I knew how to do pretty much everything I needed to know about auto repairs. I never even thought about engine performance issues and how to properly diag a check engine light. you took me under your wing and everyday after school I would go to all of the shops that couldn't figure out their issues. I did not do it for money. I did it to further my automotive knowledge. I did this all on my own time. You have taught me more after class than I learned from all the other teachers taught me at school. The passion that you have for this field is what made me want to keep learning and bettering myself. You were there at my graduation from RTI and at my Wedding. Words can not express how thankful I am for all that you have done for me. Thank you for everything you have done for me. Keep on making these videos and I'll keep on watching. Brandon Carroll

[@ScannerDanner]

+brandon carroll Brandon! Thanks so much my friend. It's so good to hear from you. I don't always gets the pleasure of seeing or hearing from my students after graduation. I knew when I had you in class that you were going to make it and I was right! The money should be rolling in for you by now and if not very soon. It is students like you that make my job awesome!

[@b.carroll]

I am very happy with the money I am making. Thanks for always pushing me to do my best. I actually enjoy goin to work. Hope all is well with you and your family. Hope to see you around at some point soon.

[@zyadkhalid6139]

The last part of the video makes me to love you more than before when you said to the guy that don’t call you Mr. Danner Thank you for the detailed explanation

[@johnchristopherson2718]

Dude you're a freaking rock star, without a doubt you are the best instructor on you tube, oh hell for that matter probably one of the best instructors I've watched anywhere, and I have watched several in real life, and on you tube, and as a former Technician/Instructor for over 30 years I know a good one when I see one. Thanks for sharing your knowledge.

[@willemstreutgers1154]

+John Christopherson Fully agreed !

[@JawnWick215]

I have a 98 jeep GC 4.0 where is the cam sensor located?

[@vincescalise4821]

You are a awesome instructor no question about it, and the comedy is Much appreciated crop dusted LOL

[@roadkill5333]

Oh my! You guys had me rolling! Shane floating an air biscuit! Paul actually having a live being to talk to! Dean had Jerry, Costello had Abbott, now ScanneDanner has Shane the crop duster!! PRICELESS!! Great video, guys! And on top of it all, I still learned from the instructive parts of this vid! Thanks for a great show.

[@wyattoneable]

That was excellent! You make it look simple so I can see where experience helps move things along.

[@trainer2018]

Good to see you still bring your students along Paul, that's the best learning experience by far. Since I've been teaching we have hired one of my former students which is great and I share everything I can with him. Plus at my Full Time job we are bringing in another intern who is also a former student of mine. It has been pretty rewarding Paul watch my former students improve as they progress in their career. You were one of the contributing factors Paul why I became a instructor. My thought about it at the time was if you can take the time to help the next generation of Techs why can't I?

[@josephtucci3666]

Great vid Keep Shane around makes for a great contrast Best of luck Paul

[@int53185]

Great team! Never knew Paul had a sense of humor until now. $! is on it's way.

[@ScannerDanner]

+James Last haha thanks

[@chriscanty8214]

thanks Paul for the video I have purchased a vantage ultra you have given me the courage to continue learning about car electronics

[@davesministry7789]

Excellent, back to science at it's finest . Nothing forgotten, Good work.

[@xerxes456]

Nice when you bring your students with you and it is cool they take the school serious, when I was in school many just went to school because they did not now what else to do. Nice video and many helpful tips.

[@ronvessells1356]

So awesome! to see how you getting along so well with your students. Made the video more enjoyable. I laughed, and I can't remember the last time I laughed watching one of your videos. Great teachers are never forgotten by their students.

[@ScannerDanner]

Thanks man

[@anthonydurantine2292]

thank you for your dedication to our passion. another extremely informative video

[@rockynix7731]

Using my magnifier glass helps see things a lot better when watching on my phone... Nice to see every little detail...

[@mikechiodetti6737]

You guys are comedy relief! Or gas relief!......AND you caught the intermittent when it failed, PROVING the crank SENSOR......NOT the sensor GROUND is bad! FANTASTIC! OR, as I used to say at my previous work place when I caught the problem with the scope, meter, or both......I GOTCHA ! ! ! THAT'S what makes a Great Video!

[@mobilemechman]

I myself didn't find Shane distracting at all. Great video as always. Thanks!

[@kevineinheuser8643]

Just awesome! Danner, you're saving and propelling the industry to the next stage. Keep it going!

[@ScannerDanner]

+Kevin Einheuser thanks Kevin!

[@jordydereus]

love your videos danner. watch them all the time. like your new set up. your great with students. keep them comming. cheers from Holland..

[@bilobicho5317]

Very Infirmative info DR. SD ur a MONSTER TEACHER👍

[@smilingcopycat]

Happy Danner, nice to watch! Thanks...

[@martinguitarhd28]

Excellent as always Paul.Crop dusting lol never heard that saying before.You are a very funny guy and it's good to see the humour with your students.I don't think taking along a student detracts from your teaching !! it's good to see a true master at work.you are the best.Any one reading this if you have not joined Pauls class on his premium channel you are missing out big time.

[@ScannerDanner]

+martinguitarhd28 thank you so much!

[@juanjuarez7289]

Great to know that you are passing your experience to your student(s)! We all depend on your service to keep our vehicles running well/JJ

[@daddyphatsax304]

Ive seen so many of these on this motor...i likely wouldn't have even hooked a scope to it and just climbed under the truck and swapped the CKP. Rolling the dice on it isn't always the best option...but it's such a quick swap and the part is so cheap...saving myself the 30 minutes in diag is a risk i am willing to take at this point. I've been thru this diag process on this motor a few times but this was a good review and you brought up a couple good points to consider. Thanks for the vid SD...keep up tha good work!

[@northjayhoon9789]

You guys are amazing Thank you for sharing the knowledge with us

[@janregheton]

This is the third night in a row when 2am catches me on this channel. As a DIY-er and a hobby-ist it doesn't make sense for me to subscribe to the premium. I don't think I could ever apply above 20% of that info on my personal car but I would gladly pay that 1$/month for the effort you put in this content. So the idea at the end of this video was not that bad.

[@todayintheshopbanksy5904]

'Crop dusted' is a new to me, classic.

[@eddiemartinez265]

+WhitwellMike B Me to have never got wind of that before ha ha ha.

[@todayintheshopbanksy5904]

lol

[@timelston2152]

@@todayintheshopbanksy5904 ugh hi

[@alejandroruiz3370]

Awesome and informative vid, going to attempt changing my cam sensor since im getting a various codes related to it

[@jimbuford4147]

Good to see a young man that is serious about his training.

[@larryhurst8958]

Great video. Good interaction between you Shane, good break from the technical. Is crop dusting a prerequisite for the class ,lol

[@michaelfrancis3261]

Wow this is like the coolest teacher, thanks for another awesome video. I'm working on a 03 Honda that's starting and stalling, pull the code and it's a camshaft code. I just wish it would run long to do try this on it. again thank you Mr. Danner oh sorry Paul.

[@mikesabin8568]

What do you mean? If it is not running, it should still have the correct waveform on the signal wire? You can literally pull the fuel pump relay out, crank the car, and see the correct waveform with the car just cranking...

[@drivewasher]

Brill video Paul! I think the two person video adds something. It shows what a great well respected guy you are. If I was a bit younger than my 60 years I would defy be trying to get into your classes at Rosedale! Oh by the way the lift on yer truck looks great out at work

[@eddiemartinez265]

+Steve Ashcroft Yes he should do a photo vlog on it like the wheel's.

[@stetto]

Had this exact issue pop up this past week on my 02 TJ 4.0. This saved me a ton of shop fees! I don’t have an O-Scope, but I did test the sensor with a multimeter. Thank you for making this stellar video. Your process is fun to watch!

[@Pablo_Automotive]

Nice diagnostic, you are a good teacher =P

[@pacosoide]

Good comedy routine there, I love it. Educational too!

[@nickayivor8432]

Good Evening Sir ScannerDanner have a great day and take care Sir ScannerDanner. Tutorial great thank you 👏 👌 👍 From Nick Ayivor from London England UK 🇬🇧

[@canifixit3504]

I enjoy watching these video's they really help me to fix my wifes jeep

[@ziyadalshaham1263]

Mr Paul danner you are a great master thank you, my wish in my life to be one of your students

[@ScannerDanner]

+Ziyad Alshaham that would be awesome! However, if you cannot in person, there is always SD Premium. I created that channel for guys like you. Thank you so much!

[@rainbowdiamonds2865]

Good Video , perfect diagnostic.

[@jacobarellano3736]

Great video MR Danner!

[@haywardsautomotive6156]

Nice video Paul! Shane will fit in good in a shop environment.

[@devinsnaples]

thx for the info & the laughs keep'em comin

[@Tedybear315]

Good lord. Crop Dusting and a Bloopers Segment!!! Nice way to start the day!!

[@eddiemartinez265]

Was not to good for paul.

[@sammoore1944]

You crop dusted me lol made me laugh.Paul i too like the vids with the students present ,,But then again i love all your vids.Best teacher by a mile !!Anyone on here not part of Paul's class,do your self a favour and join the premium channel !! you will not be dissapointed .

[@ScannerDanner]

+Shaun Moore thanks so much Shaun!

[@Thunderroad8517]

@ 6:55, Dummy Shaft drives the camshaft sensor yes. It is the bridge between the cam and oil pump as well..

[@bigsscore8378]

Very helpfull thank you for the information.

[@nestrac]

Just keep bringing Shane or other students along... It alright

[@eddiemartinez265]

+Carsten Langbo Yes but no gas attack!

[@nigelclark7360]

All good info well explained,excellent.

[@ScannerDanner]

lol two people gave me a dollar. Thanks guys!

[@CL-rf9bm]

Hey Dan i could seriously use a hand... My 97 jeep has been doing weird stuff. Normally it will run fine but lately it will start up run a few seconds and immediately die. Holding the gas does not keep it running and im going nuts here.. After sitting for a few minutes in the past i will hear a click like a relay (sounds like it comes from the fuse block in the cabin) and my gauges will come on and it will then crank/run fine..

[@JamesL-88]

Awesome video

[@stanilastefan1687]

That noise you are picking when you connect the scope at the battery ground it's there because you are making a ground loop. Ground loop noise appear when large and low currents are sharing same path on a circuit. For this reason the PCM has multiple ground pins instead of one.

[@jerrymesser2811]

nice work fellas,love the knowledge,🍺

[@motorcyclesandridingfree2899]

I agree with the snap on leads the ones from AES wave are much better. Snap on needs to fix that as much as they charge

[@JOHNPHUFNAGEL]

Shane is going to do great in this field!! For the KZbin audience check out South Main Auto Eric O has a jeep that fried 2 coils from a bad cam sensor Great video!!

[@ahill007ny]

That video crazy they were smoking!!!

[@roadkill5333]

The first thing I thought of, when he was talking about that!! Eric O and the smoking coils of death!

[@rm1seal]

Great information for a non motor head person like myself.

[@ScannerDanner]

thank you mark!

[@TRYtoHELPyou]

Tks for going over the stuff. I didn't ask for the funny stuff .... But it was good. Like... Just good

[@CRAZY_VIDS07]

Student ID agreeing to everything but body language saying I'm totally lost...lol😂😂😂

[@mr2law]

That was hilarious . Thanks for sharing.

[@oscarcabrera1355]

good video thanks.

[@philh9238]

itd be epic to get you and your bro on one of these mobile calls

[@Adam-bw4lw]

from 16:15 to 16:40 best moment.....i like the new setup :)))

[@jeremystory6981]

Thank good job,

[@amr-50]

you are so funny guys , great video as usual

[@rogerd4559]

HAHAHA! Dude!! you totally crop dusted me!..... PRICELESS!

[@lance1097]

Good infotainment

[@patrickchambers479]

Great 👌 👍 job

[@nestrac]

Eric can definitely relate to the that "it a Chrysler thing"

[@HayabusaRydr]

It was funny :D Subscribed! Haha

[@jasonmushersee]

The way i figured mine out was it would stall the engine @ running temp, then no start with endless starter cranking. Then let engine cool & it starts right up until it stalls again. Got progressively worse over 3 days.

[@colinburdenmc]

What was it?

[@jeffjohnson3195]

YOUR DOLLAR IS IN THE MAIL......, Good info as always

[@courtneysmith4354]

awesome video. i want to be just like you scanner danner. i have watch all your video and red your book.your propell me in becoming a good technician. thanks scannerdanner .

[@ScannerDanner]

+Courtney Smith Thank you Courtney! You've been a long time subscriber and I really appreciate it.

[@srvjediknightsrv750]

guy is brilliant love the vid's ......mobile mechanic ;)

[@ScannerDanner]

Thanks so much

[@avantsautomotive6022]

That shaft is important for oil pressure too as it drives the oil pump !

[@oscarrojas4281]

You are awesomeeeeeeeee

[@kdmq]

Just curious Paul, when you saw the cam sensor problem setting the crank sensor code, was the RPM gauge going nuts?

[@timpeters3895]

My 2004 jeep had start problem.code said crank sensor it was just a dirty connector go in to crank sensor.Its All ways something simple. I sprayed it with c r c no more trouble.

[@SethHarr]

Couldn't stop laughing at the crop dusting. But great info as well.

[@rudysison9010]

Eric tje car guy , I watch his video too, Suscribed and like also dude

[@gregp05]

eric o has a good video on the cam sensor failing and frying the coils. his channel is south main auto. check it out

[@TrimJazz]

+gregp05 great video, chrysler/jeep/dodge should put warning labels on these models.... "dont park your car in your garage, coils may induce fire damage" ohhh the horror!

[@TheRubenTrance]

Hello, Thank you so much for sharing this video... I was wondering if you may shed some light on the problem I have with my 03 Jeep Grand Cherokee 4.0. Initially my car stalled pulling into my garage. Engine was cranking but no start, and gave P0320 on my dash which pointed to the crank sensor. So did replaced my crank sensor with a BWD brand. Engine started & ran but was misfiring and gave another code P0340. which pointed to the Cam sensor this time, & so I went ahead & replaced the cam sensor as well with Mopar OEM. After that still engine misfires/ shakes then gave a different code again P0352 which pointed to Ignition B , so I went ahead & replaced the Ignition coil pack with Delphi brand (close to OEM) . After that replacement, engine ran well & so I took a it for a test drive but after about 15 miles the engine starts to misfire again then eventually stalled on the side of the road. "Checked engine" light was on & this time its P1391 which points to crank/cam intermittent lose. Car had to be towed back home as it wouldn't go anymore. After a good few hours parked at home the car started & ran like normal but eventually misfires yet again when warmed up giving the same problem code P1391. Anyhow, I am quite perplexed by now as you may imagine... I would be grateful to hear your opinion on this matter, if able . Other mechanics on You Tube seem to suggest that the crank sensor must be replaced with OEM Mopar. Do you supposed this is true , & absolutely necessary to do for this particular issue? Thank you so much! Reuben PS. Do these (newly replaced) sensors need reprogramming with car's PCM?

[@Avizponverde]

Ruben L I’m having the same problem right now!!

[@wtbm123]

Good video . Just glad i do not have smell a vision .

[@stevenholcomb2990]

My 2000 Jeep Grand Cherokee 4.0 pulls a p1391 I have replaced both my crank shaft sensor and my cam shaft sensor my can shaft synchronizer(dummy distributor shaft) timing chain and ignition coil and I still get the same code

[@ScannerDanner]

When you replaced the cam synchronizer, are you sure it is aligned properly? I don't remember the procedure on these.

[@adrianornelas6447]

hey man, can a bad cam sensor cause the fuel pump to be constant on when turning the key to the on position

[@matutenoel4833]

good. video. tech

[@trublue2319]

I had a 08 avenger today scoped cam and crank I see the issue I had I was to zoomed in wouldn't of noticed if I was loose ing the pull down to ground

[@NZdiagnostics]

Gidday from down under Paul, have been meaning to ask you and your brother if you have tried a "mooshimeter" before? If you don't know it's a very affordable two channel bluetooth graphing multimeter. I bought one a few weeks ago and find I am using it all the time. Having something that doesn't cost the earth that you can strap under the bonnet and monitor form your phone is super handy, especially if you are working on your own. If you check out their videos they do a neat trick of using a battery cable as a current shunt too. I am in no way affiliated with mooshimeter but had to share with you as I absolutely love mine!

[@ScannerDanner]

+Alex Wills I have never heard of one. Can you post a link? It will go to spam automatically, but I can unspam it when I see it.

[@NZdiagnostics]

+ScannerDanner Sure can, check them out here moosh.im/ also if you search mooshimeter on youtube they have a couple of great videos where they test it out on a Honda using the battery ground as a current shunt. I have found it fantastic for working on my own and also find the speed and convienience really good. The software isn't perfect, but I have a vantage and vantage pro (bought on your recommendation) as well, so no biggie. Great to support a US startup company too!

[@jat-justamaturetech-philpj8285]

That'll be $637.50 please! $100 for the comedy routine and $10 for the air biscuits! 🤣

[@Johnsmith-dz2mj]

Danner, I want to buy your book, do you have sell it. good information thanks danner

[@billyr9840]

Paul, I think the hash that the scope was detecting in the signal might have been emanating out of Shane's A** ! LOL ! Great vid !

[@ScannerDanner]

+Billy R haha yep

[@miltonscornertobylove5068]

Cool vid, but I notice that towards the end when the crank signal was craping out how come the cam signal was still good(nice square waves) ?

[@ScannerDanner]

2 completely separate sensors

[@steveallen5496]

Another troublesome Jeep. Are they all defective? It needs a lift kit, that will make it look good even it it won't run. Good on you Shane for pursuing knowledge.

[@DENicholsAutoBravado]

+Steve Allen LOL. I know I've told a similar joke before. :)

[@IMFDB]

i've had a crank sensor drop out on a 97 saturn sl2 intermittently and cause stalling. unfortunately did not set any trouble codes and was really hard to duplicate and prove it even was a crank sensor. when it did stall out. it cranked and didn't start. the no rpm while cranking pointed me towards crank sensor. i didn't have a oscilloscope to prove it. i wish i did. i told the customer you have a 50/50 chance it's a bad sensor or a warped crank reluctor wheel. put a sensor in it. ran it for 3 hours, haven't seen it since. the old cars that don't have engine computers smart enough to store bad sensor history data can be real frustrating to narrow the cause for intermittent concerns.

[@eddiemartinez265]

PAUL i am on the floor going nut's when you started talking about crop dusting with a fart hahaha.

[@ScannerDanner]

+Eddie Martinez :-) thanks Eddie

[@willemstreutgers1154]

This reminds me of a movie called Dumb and Dumberer. The most important one learned here is Check the way you lay down your leads. Thanks for the added fun part.LOL

[@ScannerDanner]

+Willem Streutgers for sure!

[@rxracer]

For $10k. I'd hope it have a camera. And I love that those are windows based

[@zacatecano1986]

Man i should of attended rosedale tech instead of uti damn !!!! Must be a blast bieng around scannerdanner

[@ScannerDanner]

+zacatecano1986 It's never too late my friend. I would love to have you

[@derwinrandle2682]

hey Paul I have a 03 grand prix 3.1. code po336 I have fuel pressure,spark at each coil,but no injector pulse.I changed crank sensor in block now it starts somtime and somtime it doesn't the wire is not broken or short,at first it would not start at all,do you think I bought a bad sensor

[@josephpingel2553]

My engine light goes on and off and returns a code about intermittently losing cam and crank sensors. It doesn't die but misfires sitting at a stoplight. Seems to drive okay on the highway. The problem turned out to be an oily mess (probably from a leaky trans) getting on the crank sensor. It appears the magnetic signal is affected when there's oil on the sensor, but obviously it's getting through, so I'm wondering how bad the problem actually is; whether I can drive it without worry until I get something else or budget a costly repair to fix the oil leak.?

[@lukekujawski]

how do you test if you do not have a fancy tester and codes was cleared 6 mos ago I know it had a O2 senor error but ran fine all of sudden died and would not restart and a jeep mech said not worth it vechal is a 2002 Jeep grand Cherokee with the high output engine v8

[@nandor690]

I always love how danner says “I’m not gonna worry about it, I’m not gonna do it” 5 seconds later, “You know what, we are here and talking about it. I’m gonna go ahead and do it” 😂😂 I understand why you always decide to change your mind but it is funny to see