Wow six years later I re-watch this video for reference and am amazed at how a Great Teaching Moment this video was, once again thanks again Paul !! You Rock ScannerDanner !!
Dear Paul... you have no idea how glad i am, that i came across your channel (thanks to EricTheCarGuy)! Wish there were more teachers like you: teachers who teach "thinking", instead just "doing things". Cheers from Poland! :)
The drawing on the diagram was helpful for me. I'm French i understand each one of your words and the repair in itself but it made "pop" in my head with the drawing. Thank you for sharing the method, the knowledge the effort in the repair and not serving the actual ugly business of throwing things away very quick without using his brain while smiling to the ignorant honnest customer. I learn a lot. And it's free. Thank you. (but don't get the big head) ; ) Greets from Lyon.
I like the principle here of sticking with the problem that you see in front of you. He said the 24x crank sensor issue would not be causing the no-start (having to use starting fluid). But, if you solve that problem, there's a good chance it will lead you to the main issue.
i started following you about six years ago I feel ready to try my ASE and take some tests I need to still buy tools and save up for a good scan tool but in meantime, I am gonna get a good code reader that reads fuel trims and has some bi-directional I see your brother working and that's what a lot of running and working an auto repair and service shop I will be I won't always be hooked up on six channel O-scope diagnosing an intermittent hesitation with a no restart when hot I have a lot to learn I am sure but the knowledge of how those circuits work and the ability to determine if its pull up or pull-down circuitry is crucial to see if the circuit is working right if I can continue to master the basics I may get better as professional automotive technician thank you, Scanner Danner, i pray you stay motivated and inspired as much as me to the work coming up of which some might require special testing and diagnostics my shop name will be Northern Boxer Technologies(TM) it will be my first shop. I will build a 1000 HP boxer and have a motorsport upgrade and engine machine shop with dyno and tuning services THANK YOU, DANNER BROTHERS !!!
Thank you my friend, I promise to stay humble. I can do nothing on my own. All that I have and all that I do is a gift from above. Not to mention there is sooo much that I do not know about my own field! It seems the more I learn, the more I learn I don't know. :-)
I dont mean to be so off topic but does someone know of a way to log back into an Instagram account..? I somehow forgot the account password. I would love any tricks you can give me!
@Santiago Jacoby i really appreciate your reply. I found the site through google and Im waiting for the hacking stuff now. Looks like it's gonna take quite some time so I will get back to you later when my account password hopefully is recovered.
Bought the eBook today, should have a long time ago. Nothing is as clear and well explained. If you're thinking about getting in this field this is your way in. Greetings from Puerto Rico.
This video was AWSOME!!! I had a mechanic tell me that my problem was the crankshaft position sensor due to the p0355 code. I tried to get him to watch this video but he wouldnt listen. Then I fixed it myself and the problem was my wires going to cam sensor were fused together EXACTLY like this video. Just Awesome..
Never stop teaching us Master. You are so great. Thanks to you I have learned how to troubleshoot my car when I have problems. I have you book and watch a lot of your videos. Your book is great . God bless you Mr. Danner.
wow, just wow...awesome troubleshoot and using past experience and knowledge of internal electronic wiring. Love it. I watched this video at 7AM after being up all night watching similar videos. This was by far the best! Bravo Zulu
WORTH EVERY SECOND I SPENT... THANK YOU FOR THE KNOWLEDGE. Having a problem on hard start, Crank sensor DTC. Replaced Crank sensor, still the same. Checked all feeds, all passed. Gonna hunt on whats causing it.
Thanks man, and you are correct, it probably didn't need the sensor, I didn't test the old one after the wiring repair so we will never know. It was in too much of a crappy location not to change it. As for the why the injector still fires, this system was obviously group firing the injectors during a crank or it was "guessing" as to the sequence. I have seen these be no starts with no injection pulse with a bad cam sensor too.
Wow. You are probably the only person who could actually fix my vehicle. Most techs generally can run codes and replace parts, but I doubt they do all this.
Great video! It's been my experience when working with GM's PCM/ECM/VCM/TCM's, finding sensors that are grouped closely together, numerically within the same connector and in the same row, they will typically share a common circuit within the computer, such as what you found. Brilliant deductive reasoning, it took me a little while to figure out the the internal circuitry of these computers before stumbling upon this "silver bullet". It has made life much easier knowing this bit of information.
Here's an interesting one for you all: A Renault Diesel 1.5dCi didn't want to start. It had a cam sensor code. So the mechanic put in a new cam sensor. And it still wasn't starting. However if the cam sensor was removed, it started. Looked very much like a short on the cam sensor wire. But! What really happened is that the serpentine belt split in two, and the inner part of the belt got tangled up in the timing cover in a way, that it was blocking the cam sensor to work properly. I didn't see this, I was told how it happened, since I was curious how is the car. 'Cause I was guessing for a short on the cam sensor wire. Well in the end it was an input error after all. So I was half right, I guess. The story may not be accurately told to me, because they should have seen the problem the first time a new sensor was put in. But it's still an interesting story I think.
Great vid👍. If the problem was on the ground side it would not be uncommon for a computer issue as they generaly use a common sensor ground internaly that i have seen fail time and time again but would give multiple codes with multiple issues. Always suspicuous about cam/ crank sensor sharing feeds or grounds but having said that your wiring and flow chart led you to an ECM and all of us. Info is key to diagnosing anything so you would have done nothing wrong with replacing an ECM(except not fix the problem). This is very frustrating in the field. I pay aprox 4k per year to get this info from a couple of different sources to find there is not enough info or the info is incorrect on quite afew occasions granted they do the best they can. But who wears the cost of time and ECM when the info is what led you there... you trusted your instincs and it payed off wich is great and well done. But if we are accountable for incorrect workmanship when we charge for it. Or a company is accountable for a faulty part. Then with such a difinitive flow chart that would lead anyone who followed it correctly to replace an ECM. Then why do we pay for that info if we are the ones accountable for there mistakes🤔. This make me wonder. I always call the company involved and let them know if there is something not quite right with info given and this all takes alot of time. But i guess we all have to help where we can as the info more often than not is good.. this is a semi rant or not really a rant at all just part of what we do.. keep up the great work SD👍
Awesome vid. I'm an independent tech and this is a very good lesson in doing visual inspections of the offending and related circuits or possible related circuits as u found out...Classic look before you leap scenario
Too bad GM doesn't tell us that both CKP and CMP share the same power feed !!..."proprietary information" they would say !!...this video saved me a while back !!!
Fantastic! I also had a feeling the computer wasn't to blame here...rarely is really, unless it's in a bad place and moisture has gotten inside (like in your GMC van video). Great diagnostics, and it's all worth it for that "Eureka" moment when you unplugged the cam sensor harness :) Keep making the awesome videos!
a characteristic of a VRS input is a weak signal at low RPMs. This will be especially pronounced if the sensor is going bad or if there is an air gap problem. but since you switched sensors that rules out a sensor problem. and if it works at higher rpm that suggests wiring is ok too. you need to check these signals at the PCM. They can check good at the sensor and not at the PCM if there is an open in the wiring
3.15.14. Paul, this illustration points up the shortcomings of manuals/trouble shooting sections! I am employed as an industrial Electrician/Instrument Tech, I encounter a huge number of different types & manufacturers of electronic equipment, and with out question the biggest problem is the technical service writing is pretty poor! They don't take the time or hire people with a proper knowledge of how to systematically check the electrical components! You have to know theory & apply it to real world situations. I was taught by a retired German,Dow Electrician to : Test,Don't Guess! This is a superb tutorial!
Thanks Steven! It is a shame you see the same thing in your field. And you are exactly right, "proper knowledge of how to systematically check electrical components" is key! That is what I am trying to do with this channel. Learn the fundamentals and you can handle any system that comes your way.
This is the best there is!!! Thank you all involved in this fix, and Mr. Danner for taking the time to explain computer shared feed circuits! I will have to watch this later again for shorted cam sensor problem, as I learn to troubleshoot issues like this.
Thank you Davil! Join my premium channel if you are serious about this stuff. There is a 14 day free trial so you will know what you are getting before committing. Right now there are about 300 videos on this channel. www.scannerdanner.com/scannerdanner-premium-chapters.html
That is awesome! I should have done that. Snap-On's Troubleshooter is worth its weight in gold. If anyone wants to know why snap-on costs more than other aftermarket scan-tools, this is one of the many reasons why! You get what you pay for.
Excellent video. I just found your videos and subscribed. Also for some people like me that cannot afford a nice scanner tool, etc. As far as checking for shorts in wiring that can be unattached at each end a simple cheap multi-meter & 9v battery with jumper wires and alligator clips can be used to check for direct shorts are broken wires. I know this isn't nothing sophisticated but it's low amperage, so its safe, and it works. Oh, I plan to buy your book ASAP... We can never be to old to learn new and better things.
You do the most amazing testing using knowledge,visual ,and common sense,and experience.Had you put a computer in and had no change most of us would bow out the manufacture gave out incomplete info at our expense. Thanks for sharing your awesome
good question my friend. two different crank sensors on this model the one that wasn't working is only used for misfire monitoring and low speed timing control.
For a long time I have questioned GM quality. This video didn't change my mind. Their engineering sucks, their diagnostics suck and their wiring sucks. Great find Paul..one of your best. We are all getting better out here because of it, thanks.
Great video sir! I happen to have my Solus Pro with me while watching, and I checked the code tips for P0335 on this car. Guess what the first page says? "Internally shorted CMP sensor can pull 12 volt reference circuit low causing DTC to set." Not exactly the case here, but close enough. Your Trailblazer MAP code video showed me the value in checking these code tips, and I've made it part of my diagnostic process. Great work!
Paul - you are the man Brother, awesome trouble shooting. I did not see per the portion of the digram you illustrated, where the power feeds for both sensors actually shared a point. Awesome, we appreciate your work and sharing with us!!
I had the same issue with a 2003 Freaking Montana.But I am not as intelligent as you ,so I replaced the computer with a used one and another used one with a frustrated customer ,I finally after five days find the actual problem and repaid the stupid minivan. I wish that I had you as a co worker man . you rock.
Love your videos! Love your book!Just started learning! Am I the only one who catches this? 19:42 you show wiring diagram for cam sensor, on both crank and cam black is ground, red is power feed and green is signal, so you should be testing brown/white wire from the connector not pink/black. This doesn't change your awesome diagnostics on this car. Obviously you would not find any square wave signal on that brown/white wire as well, also changing the title to a shorted cam sensor wiring harness would be more accurate. Great video! Keep them coming!
I didn't unplug the cam sensor. I unplugged the harness connector before the cam sensor. I couldn't get to the actual sensor connector with the power steering pump in the way. Great question
very nice lesson how flow charts can absorb a lot of time reading them to get to wrong conclusion some time and in your case could be replacing pcm. some time ago I had a sensor problem and after following a flow chart i did all the test and did not get to the root of the problem so I decided to search Google for the fault and cross me to a video in you tube and it was made by you I watch it and I found the exact answer for the fault I was dealing with. I found the fix .
I worked in retail parts sales. From my interaction with the customers, I gathered that their flow chart started with "replace the computer". Then the arguments would start over with "You said (my fault) it was guaranteed!" I later came up with a "pogram" (that is not misspelled) where I would tell the customer I would "rent" the computer to them for test purposes. If it didn't fix their problem, they would pay 75% the cost of the computer and have the satisfaction of knowing the problem was somewhere else. I would then return the computer under warranty. The Standard Motor Parts rep told me that 90% of the computers they get back on warranty claims tested out ok. He also said that 75% of the cores they get in test ok so they clean and buff them up and sell them as rebuilt. Their product used to come with the case anodized and shrink wrapped, but lately not. I opened one box in front of the customer and saw it was not shrink wrapped nor anodized. The case was bare metal and you could see the fingerprints of the person who boxed it. The prints etched the case and the entire palm print corroded into it.
That is an awesome fix, I would have put a computer in this for sure. The current limiting resister and internal computer explanation was very helpful. It goes to show that sometimes code data is wrong too
Okay. So, I thought after seeing 136 videos from you, I thought I'll still be amazed, but my jaws won't drop anymore. And here it is! Video #137 and I'm pickin' up my jaws from the floor. Sheer brilliance! I'm getting lost for words about praising your talant and knowledge, Paul. Keep up the good work, man! :)
after that fix and watching for first time one of your video. it convinced me of buying your book and I have learn a very good techniques of diagnosis thank you, know I became addict to your channel in you tube !!!!
top video , really makes you think about the way you investigate trouble codes. it isnt always what you know that helps you fix a problem its realising that there are things happening that you dont know, and having the ability to look past whats written,to what is not such as your not mentioned shared circuit. thanks for that....
Nicely done as always especially always ending with the engine running. And because of you I changing careers and became an auto mechanic then technician. Thank you.
I would put a new cam sensor before I put a computer, and see what happens next, because sensor is much cheaper than computer, if it works, great if not then computer. But great job I really really love your work, and your troubleshooting, you are the best.
for sure but remember that wasn't even on our radar when we started. we attacked the 24x crank signal right away. there are a lot of things that we could have done different but this is reality in our field isn't it?
awesome video. I stumbled across your channel and have been glued to it every night after work since. (im basically a brake/general service tech right now) lol i cant thank you enough for the knowledge you share through your videos. the best by FAR i have found. i will will def. be looking into this book that you mentioned. thanks again-Pete
Excellent video! I gained more knowledge from this video then I have from hundreds of others I've watched. Your students are very lucky. I hope they know that. I thank you very and have subscribed. Keith
I am not so sure of that my friend. I do not think with low reference voltage that i would have even bothered looking at scan data. I almost blew the call on this one. also i didn't know a P0335 would prevent a P0340. That info certainly wasn't in the flow chart. Thanks for the tip!
Hello Mr Danner. Always enjoy your scientific approach to diagnosing. May I make a suggestion? I know you like your T pins. We both know that there is always the potential to smoke an ECM if they short something. Take your T pins and dip them in liquid plastic / rubber. After it dries, remove about a 1/4 inch of rubber from the tip of the pin shaft. Then remove a small area at the T for your alligator. This will give you the the maneuverability of a T pin, while reducing the chance of a short.
ScannerDanner; great work sir. I always do it the same way, check test and retest again and 9 times out of 10 you'll find out it's just a simple issue with a connection or wiring. I've seen this many times before in working on vehicles and even other types of equipment.
@scannerdanner wow you are honestly a genius....although I learned a lot from my instructor and school and have been doing this since I was 11, I WISH u could've taught me....I sometimes feel as if ive learned more from your youtube videos than I have from 2 years of schooling.....this was AN AWESOME repair, if this vehicle was at my shop, this car would've had a new computer in it....your a genius keep it up Mr. Danner!! your really helping me with my auto repair shop....like a lot
wow Paul, your diagnostic intuition is so good its giving me the creeps, almost as if you've sold your soul to the car gods. I Kid. But seriously its not hard to see that you've really done your homework and have an unrelenting passion for what you do. You my friend are a hero to myself and so many others trying to better themselves by broaden their understanding in an every evolving, perpetually accelerating industry that is auto repair.I immensely enjoyed the well deserved bashing of the FC
Frank Section 2 page 24 in the eBook. I talk about how to Identify an electronic type switch input. Honestly for this video, it really didn't matter about the signal circuit design because we had a feed or reference voltage problem. I misspoke in the video about that.
Manufacturers wiring diagrams often show internal supplies and grounds within the computer modules. Guess this video is a lesson on the limitation of aftermarket wiring diagrams! Great video!
19 was clear codes and retest and 20 was the last one, said to "Are there any DTCs that have no been diagnosed?" End of flow chart. Again, I want to stress, this is NOT Mitchell On Demands issue. It is a manufacturer problem. These flow charts come from the manufacturer and Mitchell On Demand and All Data and other companies get permission to reproduce them.
Great video mister Danner. My opinion is that those two sensor are shared same power feed in computer is just in this case because it is a pull up designed.
Wow! You nailed this one, tracked it down like a hound! I wonder what it would cost to get an honest to goodness diagnosis done like this instead of throwing parts at it? I wonder how many mechanics are even capable of such a diagnosis?
AWESOME VIDEO PAUL.. THERE ARE SOMETIMES WHERE WE HAVE TO THINK ALOT MORE THEN WHAT WE HAVE IN OUR INFORMATION DATABASE ... RIGH !! I HAVE COME A CROSS PROBLEMS LIKE THIS, SPECIALY RELATED TO KNOCK SENSOR CIRCUIT SHORTING VOLTAGE REFERENCES .. KEEP IT UP!!!
I had an 80's Isuzu I-Mark with no check engine light. It had a carburetor, the engine started and ran decently. I smelled a burn in the computer (what was its function in a carb system?) and found it fried when I opened it up. Long story short, someone had put a kit in the carburetor and cut several leads to some solenoids in order to take it apart. All the leads were red...fun.. They wired them back in wrong and fried the computer. This story ties in with the caution you give with replacing a computer without checking for shorts, etc.
Hey Paul I have an 05 F150 Lariat that back in March of this year my instrument cluster started going screwy, lights flashing on and off yet the truck ran fine. Brought it into a shop and they replaced the cluster, but didn't fix the problem as to what caused the cluster to go bad. After a week of driving the same thing happens, so I bring the truck back to the shop. They send the truck out to a electrical specialists who finds a short in a wire ruunning along the drivers side floor under a panel. That gets fixed a a cost to me twice cause the cluster was was replaced twice. Mechanics didn't hesitate on charging me again for their lack of knowledge. Fast forward now to summer time and I go to turn on my A.C and it doesn't work. It worked last year, I bring it back to the shop he brings it to his cousins shop and they think it might be the pcm that is not allowing the ac to turn on. I checked my ac pressures there good, I'm able to jumper out the ac clutch relay and get the ac to turn on. The relay is good, the high pressure and low pressure switches are good and on my Autel scan tool I see on the data screen that ac is allowed. I refuse to bring it to another garage or dealer and decided on replacing the pcm my self at a cost of 140 bucks from Flagship one. I don't want to be a parts changer but I am at a loss. I have been told that if that part of the pcm that controls the ac is no good that the truck could still run fine with no issues. I have read that faulty coil packs could cause a pcm problem, and I did have a misfire on cylinder 8 back in Jan 2020 so I changed out all the coil packs with oem ones and the problem went away. I figured why replace only one when they were all 15 years old, so I ordered 8 new ones. Any thoughts or suggestions?
To help Nandor understand your reply. The 7x signal can ID which pair of cylinders is at TDC for coil firing and the injectors can be fired as bank fire to allow the owner to drive the car to get home and in for service. HTH
1st time responding to your videos, let me know if I'm over stepping my bounds. Need to know if you checked with GM, or any other services out there if they may have different flowcharts avail to help us techs, and if so who they may be. Our shop also uses Mitchell as the main info source, and yes I have heard where they simply reprint what is supplied to them. In a nutshell, info like this does nothing for my bank account, and drives my sanity 'OL'. Your teaching techniques are the best
By far the best video I can definitely relate too ..I also am dealing with something similar....it all makes sense now ....I have learned to somewhat read circuits..thanks to Yu u make it so clear.....
@@ScannerDanner your so welcome pleas keep on preaching your knowledge I need every bit of it...btw finally got me an amp clamp..now I have to watch your videos to really get to know how to use it
@@nutsandbolts7407 spend some time in my chapter 1 playlist right here on YT on relative compression testing. Then look up some misfire stuff in my chapter 22 playlist. Both of them have a lot of amp probe testing in them
ps- this is why a really good approach sometimes with these cars, is change all the sensors, like changing spark plugs/points/condenser/cap/rotor on the old car, because otherwise you are running into one sensor at a time and wasting a lot of effort and time fixing each and every one, over the life of the car. and you don't need expensive test equipment. a cam sensor is very cheap to change.
omg thank you so much was pulling my hair out on this one i did put a used computer in that we had on hand but didn't program it checked still had only .08 volts went thru everything u did im like wtf finnaly did search found ur video thank you again
Wow Dan, You startet youtube before it was Cool!!. So you really know all about scanning/Mobilizing cars...and also RUclips as well!... Bravo!!!.. Thank you for all you do!
the camshaft sprockets can be installed backwards, i believe it says 2.4 on one side & 2.0 on other, i think... been a minute, but i remeber somthing distinct to tell which way they go... also they can be tricky to time in the car because of strut tower location. should be able to use ruler and all 4 marks should be in a straight line, you may have to manipulate the cams a bit so there straight when the belt is tight.
Thanks man. I'm still learning too. The longer we do this the more we see similarities between circuits and designs. We can then plug in our past experience to a new problem. Check out my Honda Element video I just did with a shorted 5v ref. circuit. This condition was on my mind as I went through this crank sensor fault.
ScannerDanner hi friend I have 4.6 reference voltage from ecu to the crank sensor and when I plug the sensor it's drawn to 0 volt I tray new sensor and it's same can you help me please
Truthfully, I don't think there is much of a drop at all on this resistor as long as the circuit is working as designed. I know that there would be no measurable amount of current flow on the hall effect reference (or what I called feed in the video). I'll have to try to measure current on one sometime. I'm pretty sure you cannot with conventional equipment.
Wow six years later I re-watch this video for reference and am amazed at how a Great Teaching Moment this video was, once again thanks again Paul !! You Rock ScannerDanner !!
It really was man, i still remember it. Thank you!
I wish I had an instructor like you. I'm near retirement & still learning. Thanks for your help.
Dear Paul... you have no idea how glad i am, that i came across your channel (thanks to EricTheCarGuy)! Wish there were more teachers like you: teachers who teach "thinking", instead just "doing things". Cheers from Poland! :)
those flow charts seem to mislead people you are a born teacher
Brilliant as always Paul, amazing how the cam sensor circuit - the actual culprit - didn't set an error code. Thx buddy :-)
The drawing on the diagram was helpful for me.
I'm French i understand each one of your words and the repair in itself but it made "pop" in my head with the drawing.
Thank you for sharing the method, the knowledge the effort in the repair and not serving the actual ugly business of throwing things away very quick without using his brain while smiling to the ignorant honnest customer.
I learn a lot.
And it's free.
Thank you.
(but don't get the big head) ; )
Greets from Lyon.
I like the principle here of sticking with the problem that you see in front of you. He said the 24x crank sensor issue would not be causing the no-start (having to use starting fluid). But, if you solve that problem, there's a good chance it will lead you to the main issue.
i started following you about six years ago I feel ready to try my ASE and take some tests I need to still buy tools and save up for a good scan tool but in meantime, I am gonna get a good code reader that reads fuel trims and has some bi-directional I see your brother working and that's what a lot of running and working an auto repair and service shop I will be I won't always be hooked up on six channel O-scope diagnosing an intermittent hesitation with a no restart when hot I have a lot to learn I am sure but the knowledge of how those circuits work and the ability to determine if its pull up or pull-down circuitry is crucial to see if the circuit is working right if I can continue to master the basics I may get better as professional automotive technician thank you, Scanner Danner, i pray you stay motivated and inspired as much as me to the work coming up of which some might require special testing and diagnostics my shop name will be Northern Boxer Technologies(TM) it will be my first shop. I will build a 1000 HP boxer and have a motorsport upgrade and engine machine shop with dyno and tuning services THANK YOU, DANNER BROTHERS !!!
Thank you my friend, I promise to stay humble. I can do nothing on my own. All that I have and all that I do is a gift from above.
Not to mention there is sooo much that I do not know about my own field! It seems the more I learn, the more I learn I don't know. :-)
You doing great Paul, one should never loose the desire to learn, even though we learn all our lives and we still die "stupid"
I dont mean to be so off topic but does someone know of a way to log back into an Instagram account..?
I somehow forgot the account password. I would love any tricks you can give me!
@Gannon Nathan Instablaster ;)
@Santiago Jacoby i really appreciate your reply. I found the site through google and Im waiting for the hacking stuff now.
Looks like it's gonna take quite some time so I will get back to you later when my account password hopefully is recovered.
@Santiago Jacoby It worked and I finally got access to my account again. I'm so happy:D
Thank you so much, you saved my account !
Bought the eBook today, should have a long time ago. Nothing is as clear and well explained. If you're thinking about getting in this field this is your way in. Greetings from Puerto Rico.
This video was AWSOME!!! I had a mechanic tell me that my problem was the crankshaft position sensor due to the p0355 code. I tried to get him to watch this video but he wouldnt listen. Then I fixed it myself and the problem was my wires going to cam sensor were fused together EXACTLY like this video. Just Awesome..
Sweet! Thanks man
Never stop teaching us Master.
You are so great.
Thanks to you I have learned how to troubleshoot my car when I have problems.
I have you book and watch a lot of your videos.
Your book is great .
God bless you Mr. Danner.
wow, just wow...awesome troubleshoot and using past experience and knowledge of internal electronic wiring. Love it. I watched this video at 7AM after being up all night watching similar videos. This was by far the best! Bravo Zulu
Thanks so much! Glad you enjoyed it.
WORTH EVERY SECOND I SPENT... THANK YOU FOR THE KNOWLEDGE.
Having a problem on hard start, Crank sensor DTC. Replaced Crank sensor, still the same. Checked all feeds, all passed.
Gonna hunt on whats causing it.
Thanks man, and you are correct, it probably didn't need the sensor, I didn't test the old one after the wiring repair so we will never know. It was in too much of a crappy location not to change it.
As for the why the injector still fires, this system was obviously group firing the injectors during a crank or it was "guessing" as to the sequence. I have seen these be no starts with no injection pulse with a bad cam sensor too.
Wow. You are probably the only person who could actually fix my vehicle. Most techs generally can run codes and replace parts, but I doubt they do all this.
Great video! It's been my experience when working with GM's PCM/ECM/VCM/TCM's, finding sensors that are grouped closely together, numerically within the same connector and in the same row, they will typically share a common circuit within the computer, such as what you found. Brilliant deductive reasoning, it took me a little while to figure out the the internal circuitry of these computers before stumbling upon this "silver bullet". It has made life much easier knowing this bit of information.
I have come across a few excellent teachers, you are certainly one of them.
Thanks for sharing your knowledge, great video Paul.
Wow, thanks!
Here's an interesting one for you all:
A Renault Diesel 1.5dCi didn't want to start. It had a cam sensor code. So the mechanic put in a new cam sensor. And it still wasn't starting. However if the cam sensor was removed, it started. Looked very much like a short on the cam sensor wire. But! What really happened is that the serpentine belt split in two, and the inner part of the belt got tangled up in the timing cover in a way, that it was blocking the cam sensor to work properly. I didn't see this, I was told how it happened, since I was curious how is the car. 'Cause I was guessing for a short on the cam sensor wire. Well in the end it was an input error after all. So I was half right, I guess. The story may not be accurately told to me, because they should have seen the problem the first time a new sensor was put in. But it's still an interesting story I think.
Great vid👍. If the problem was on the ground side it would not be uncommon for a computer issue as they generaly use a common sensor ground internaly that i have seen fail time and time again but would give multiple codes with multiple issues. Always suspicuous about cam/ crank sensor sharing feeds or grounds but having said that your wiring and flow chart led you to an ECM and all of us. Info is key to diagnosing anything so you would have done nothing wrong with replacing an ECM(except not fix the problem). This is very frustrating in the field. I pay aprox 4k per year to get this info from a couple of different sources to find there is not enough info or the info is incorrect on quite afew occasions granted they do the best they can. But who wears the cost of time and ECM when the info is what led you there... you trusted your instincs and it payed off wich is great and well done. But if we are accountable for incorrect workmanship when we charge for it. Or a company is accountable for a faulty part. Then with such a difinitive flow chart that would lead anyone who followed it correctly to replace an ECM. Then why do we pay for that info if we are the ones accountable for there mistakes🤔. This make me wonder. I always call the company involved and let them know if there is something not quite right with info given and this all takes alot of time. But i guess we all have to help where we can as the info more often than not is good.. this is a semi rant or not really a rant at all just part of what we do.. keep up the great work SD👍
Awesome vid. I'm an independent tech and this is a very good lesson in doing visual inspections of the offending and related circuits or possible related circuits as u found out...Classic look before you leap scenario
Too bad GM doesn't tell us that both CKP and CMP share the same power feed !!..."proprietary information" they would say !!...this video saved me a while back !!!
Fantastic! I also had a feeling the computer wasn't to blame here...rarely is really, unless it's in a bad place and moisture has gotten inside (like in your GMC van video). Great diagnostics, and it's all worth it for that "Eureka" moment when you unplugged the cam sensor harness :) Keep making the awesome videos!
a characteristic of a VRS input is a weak signal at low RPMs. This will be especially pronounced if the sensor is going bad or if there is an air gap problem. but since you switched sensors that rules out a sensor problem. and if it works at higher rpm that suggests wiring is ok too. you need to check these signals at the PCM. They can check good at the sensor and not at the PCM if there is an open in the wiring
3.15.14. Paul, this illustration points up the shortcomings of manuals/trouble shooting sections! I am employed as an industrial Electrician/Instrument Tech, I encounter a huge number of different types & manufacturers of electronic equipment, and with out question the biggest problem is the technical service writing is pretty poor! They don't take the time or hire people with a proper knowledge of how to systematically check the electrical components! You have to know theory & apply it to real world situations. I was taught by a retired German,Dow Electrician to : Test,Don't Guess! This is a superb tutorial!
Thanks Steven! It is a shame you see the same thing in your field. And you are exactly right, "proper knowledge of how to systematically check electrical components" is key! That is what I am trying to do with this channel. Learn the fundamentals and you can handle any system that comes your way.
I was told that electricity always runs downhill (ground) and that if I stayed above the wires I would never get shocked.
This is the best there is!!! Thank you all involved in this fix, and Mr. Danner for taking the time to explain computer shared feed circuits! I will have to watch this later again for shorted cam sensor problem, as I learn to troubleshoot issues like this.
Thank you Davil! Join my premium channel if you are serious about this stuff. There is a 14 day free trial so you will know what you are getting before committing. Right now there are about 300 videos on this channel.
www.scannerdanner.com/scannerdanner-premium-chapters.html
That is awesome! I should have done that. Snap-On's Troubleshooter is worth its weight in gold. If anyone wants to know why snap-on costs more than other aftermarket scan-tools, this is one of the many reasons why! You get what you pay for.
I have a stalling issue with a 2003 Impala, same engine. This was great, at 3am watching this and getting excited to do so.. Well Done Sir.!
Excellent video. I just found your videos and subscribed. Also for some people like me that cannot afford a nice scanner tool, etc. As far as checking for shorts in wiring that can be unattached at each end a simple cheap multi-meter & 9v battery with jumper wires and alligator clips can be used to check for direct shorts are broken wires. I know this isn't nothing sophisticated but it's low amperage, so its safe, and it works. Oh, I plan to buy your book ASAP... We can never be to old to learn new and better things.
So what do you do clip the 9v to sensor end and check for voltage on pcm pin?
You do the most amazing testing using knowledge,visual ,and common sense,and experience.Had you put a computer in and had no change most of us would bow out the manufacture gave out incomplete info at our expense. Thanks for sharing your awesome
good question my friend. two different crank sensors on this model the one that wasn't working is only used for misfire monitoring and low speed timing control.
For a long time I have questioned GM quality. This video didn't change my mind. Their engineering sucks, their diagnostics suck and their wiring sucks. Great find Paul..one of your best. We are all getting better out here because of it, thanks.
Great video sir! I happen to have my Solus Pro with me while watching, and I checked the code tips for P0335 on this car. Guess what the first page says?
"Internally shorted CMP sensor can pull 12 volt reference circuit low causing DTC to set."
Not exactly the case here, but close enough. Your Trailblazer MAP code video showed me the value in checking these code tips, and I've made it part of my diagnostic process. Great work!
Paul - you are the man Brother, awesome trouble shooting. I did not see per the portion of the digram you illustrated, where the power feeds for both sensors actually shared a point.
Awesome, we appreciate your work and sharing with us!!
I had the same issue with a 2003 Freaking Montana.But I am not as intelligent as you ,so I replaced the computer with a used one and another used one with a frustrated customer ,I finally after five days find the actual problem and repaid the stupid minivan. I wish that I had you as a co worker man . you rock.
Love your videos! Love your book!Just started learning! Am I the only one who catches this? 19:42 you show wiring diagram for cam sensor, on both crank and cam black is ground, red is power feed and green is signal, so you should be testing brown/white wire from the connector not pink/black. This doesn't change your awesome diagnostics on this car. Obviously you would not find any square wave signal on that brown/white wire as well, also changing the title to a shorted cam sensor wiring harness would be more accurate. Great video! Keep them coming!
I have an 05 with the 3800 and some bad wiring, which caused a short. This is a huge help.
I didn't unplug the cam sensor. I unplugged the harness connector before the cam sensor. I couldn't get to the actual sensor connector with the power steering pump in the way.
Great question
very nice lesson how flow charts can absorb a lot of time reading them to get to wrong conclusion some time and in your case could be replacing pcm. some time ago I had a sensor problem and after following a flow chart i did all the test and did not get to the root of the problem so I decided to search Google for the fault and cross me to a video in you tube and it was made by you I watch it and I found the exact answer for the fault I was dealing with. I found the fix .
I worked in retail parts sales. From my interaction with the customers, I gathered that their flow chart started with "replace the computer". Then the arguments would start over with "You said (my fault) it was guaranteed!" I later came up with a "pogram" (that is not misspelled) where I would tell the customer I would "rent" the computer to them for test purposes. If it didn't fix their problem, they would pay 75% the cost of the computer and have the satisfaction of knowing the problem was somewhere else. I would then return the computer under warranty. The Standard Motor Parts rep told me that 90% of the computers they get back on warranty claims tested out ok. He also said that 75% of the cores they get in test ok so they clean and buff them up and sell them as rebuilt. Their product used to come with the case anodized and shrink wrapped, but lately not. I opened one box in front of the customer and saw it was not shrink wrapped nor anodized. The case was bare metal and you could see the fingerprints of the person who boxed it. The prints etched the case and the entire palm print corroded into it.
That is an awesome fix, I would have put a computer in this for sure. The current limiting resister and internal computer explanation was very helpful. It goes to show that sometimes code data is wrong too
Okay. So, I thought after seeing 136 videos from you, I thought I'll still be amazed, but my jaws won't drop anymore. And here it is! Video #137 and I'm pickin' up my jaws from the floor. Sheer brilliance! I'm getting lost for words about praising your talant and knowledge, Paul. Keep up the good work, man! :)
This is information the manufacturer needs to share. Think of the time lost or wrong diagnosis. Thank you for this it is burned into my brain
Good one to burn into your brain! This is a common occurrence on many systems today that share reference voltage and com lines
after that fix and watching for first time one of your video. it convinced me of buying your book and I have learn a very good techniques of diagnosis thank you, know I became addict to your channel in you tube !!!!
top video , really makes you think about the way you investigate trouble codes. it isnt always what you know that helps you fix a problem its realising that there are things happening that you dont know, and having the ability to look past whats written,to what is not such as your not mentioned shared circuit. thanks for that....
Nicely done as always especially always ending with the engine running. And
because of you I changing careers and became an auto mechanic then technician.
Thank you.
I would put a new cam sensor before I put a computer, and see what happens next, because sensor is much cheaper than computer, if it works, great if not then computer. But great job I really really love your work, and your troubleshooting, you are the best.
for sure but remember that wasn't even on our radar when we started. we attacked the 24x crank signal right away.
there are a lot of things that we could have done different but this is reality in our field isn't it?
awesome video. I stumbled across your channel and have been glued to it every night after work since. (im basically a brake/general service tech right now) lol i cant thank you enough for the knowledge you share through your videos. the best by FAR i have found. i will will def. be looking into this book that you mentioned. thanks again-Pete
This is a few years old but may have just saved my 6. This will be my next check and hopefully my final fix as well. Thank you SIR!
+ibbeach09 cool! hope it helps you
it's a good trait to be sceptical of the flow chart quality. it makes you wonder if the flow chart can be trusted at all.
most of the time, no
Excellent video! I gained more knowledge from this video then I have from hundreds of others I've watched. Your students are very lucky. I hope they know that. I thank you very and have subscribed. Keith
I am not so sure of that my friend. I do not think with low reference voltage that i would have even bothered looking at scan data. I almost blew the call on this one. also i didn't know a P0335 would prevent a P0340. That info certainly wasn't in the flow chart. Thanks for the tip!
Hello Mr Danner. Always enjoy your scientific approach to diagnosing. May I make a suggestion? I know you like your T pins. We both know that there is always the potential to smoke an ECM if they short something. Take your T pins and dip them in liquid plastic / rubber. After it dries, remove about a 1/4 inch of rubber from the tip of the pin shaft. Then remove a small area at the T for your alligator. This will give you the the maneuverability of a T pin, while reducing the chance of a short.
:-) thank you for the awesome comment
Job well done,without changing parts.All brain work and you are a gifted person.
Thanks brother
ScannerDanner; great work sir. I always do it the same way, check test and retest again and 9 times out of 10 you'll find out it's just a simple issue with a connection or wiring. I've seen this many times before in working on vehicles and even other types of equipment.
@scannerdanner wow you are honestly a genius....although I learned a lot from my instructor and school and have been doing this since I was 11, I WISH u could've taught me....I sometimes feel as if ive learned more from your youtube videos than I have from 2 years of schooling.....this was AN AWESOME repair, if this vehicle was at my shop, this car would've had a new computer in it....your a genius keep it up Mr. Danner!! your really helping me with my auto repair shop....like a lot
wow Paul, your diagnostic intuition is so good its giving me the creeps, almost as if you've sold your soul to the car gods. I Kid. But seriously its not hard to see that you've really done your homework and have an unrelenting passion for what you do. You my friend are a hero to myself and so many others trying to better themselves by broaden their understanding in an every evolving, perpetually accelerating industry that is auto repair.I immensely enjoyed the well deserved bashing of the FC
Frank
Section 2 page 24 in the eBook. I talk about how to Identify an electronic type switch input.
Honestly for this video, it really didn't matter about the signal circuit design because we had a feed or reference voltage problem. I misspoke in the video about that.
Manufacturers wiring diagrams often show internal supplies and grounds within the computer modules. Guess this video is a lesson on the limitation of aftermarket wiring diagrams! Great video!
19 was clear codes and retest and 20 was the last one, said to "Are there any DTCs that have no been diagnosed?"
End of flow chart. Again, I want to stress, this is NOT Mitchell On Demands issue. It is a manufacturer problem. These flow charts come from the manufacturer and Mitchell On Demand and All Data and other companies get permission to reproduce them.
I can't believe I just found your channel now wow . Dude you explain everything to the t! Great stuff
Thank you! Glad you're here
Great video mister Danner. My opinion is that those two sensor are shared same power feed in computer is just in this case because it is a pull up designed.
Wow! You nailed this one, tracked it down like a hound!
I wonder what it would cost to get an honest to goodness diagnosis done like this instead of throwing parts at it?
I wonder how many mechanics are even capable of such a diagnosis?
unfortunately not many of my peers do this type of stuff properly
AWESOME VIDEO PAUL.. THERE ARE SOMETIMES WHERE WE HAVE TO THINK ALOT MORE THEN WHAT WE HAVE IN OUR INFORMATION DATABASE ... RIGH !!
I HAVE COME A CROSS PROBLEMS LIKE THIS, SPECIALY RELATED TO KNOCK SENSOR CIRCUIT SHORTING VOLTAGE REFERENCES .. KEEP IT UP!!!
It's pple like you that makes the Mechanic world a better place!!!!
Thanks so much!
now would this be also related to a P0336...
Excellent lesson on being thorough.
thank you!
This is a great case study, and good call suspecting the cam sensor, excellent work.
Awesome 😊👍👍👍👍👍👍 ur way of diagnosing is another level , u proved again....
Great video. I'm learning a lot about computerised cars...Now I just need to win the lottery to buy the scan tools....
@ScannerDanner A+ as usual ... an the importance of doing visual checks before swapping parts,
this guy is the best!!! for some reason i got really excited when you found out it wasn't the computer. haha great video!
Paul - Nice video. I would like to point out that a quick look at scan data would have showed a problem with the CMP on that vehicle.
Hi I wish I had you as a teacher when I was young
I had an 80's Isuzu I-Mark with no check engine light. It had a carburetor, the engine started and ran decently. I smelled a burn in the computer (what was its function in a carb system?) and found it fried when I opened it up. Long story short, someone had put a kit in the carburetor and cut several leads to some solenoids in order to take it apart. All the leads were red...fun.. They wired them back in wrong and fried the computer. This story ties in with the caution you give with replacing a computer without checking for shorts, etc.
Great case study. The deductions were really cool. Lot of knowledge to put in the bank!
Hey Paul I have an 05 F150 Lariat that back in March of this year my instrument cluster started going screwy, lights flashing on and off yet the truck ran fine. Brought it into a shop and they replaced the cluster, but didn't fix the problem as to what caused the cluster to go bad. After a week of driving the same thing happens, so I bring the truck back to the shop. They send the truck out to a electrical specialists who finds a short in a wire ruunning along the drivers side floor under a panel. That gets fixed a a cost to me twice cause the cluster was was replaced twice. Mechanics didn't hesitate on charging me again for their lack of knowledge. Fast forward now to summer time and I go to turn on my A.C and it doesn't work. It worked last year, I bring it back to the shop he brings it to his cousins shop and they think it might be the pcm that is not allowing the ac to turn on. I checked my ac pressures there good, I'm able to jumper out the ac clutch relay and get the ac to turn on. The relay is good, the high pressure and low pressure switches are good and on my Autel scan tool I see on the data screen that ac is allowed. I refuse to bring it to another garage or dealer and decided on replacing the pcm my self at a cost of 140 bucks from Flagship one. I don't want to be a parts changer but I am at a loss. I have been told that if that part of the pcm that controls the ac is no good that the truck could still run fine with no issues. I have read that faulty coil packs could cause a pcm problem, and I did have a misfire on cylinder 8 back in Jan 2020 so I changed out all the coil packs with oem ones and the problem went away. I figured why replace only one when they were all 15 years old, so I ordered 8 new ones. Any thoughts or suggestions?
To help Nandor understand your reply. The 7x signal can ID which pair of cylinders is at TDC for coil firing and the injectors can be fired as bank fire to allow the owner to drive the car to get home and in for service. HTH
1st time responding to your videos, let me know if I'm over stepping my bounds. Need to know if you checked with GM, or any other services out there if they may have different flowcharts avail to help us techs, and if so who they may be. Our shop also uses Mitchell as the main info source, and yes I have heard where they simply reprint what is supplied to them. In a nutshell, info like this does nothing for my bank account, and drives my sanity 'OL'. Your teaching techniques are the best
Nice catch Paul, a little bit of Chrysler thinking on a GM ;)
Keep up the good work keep uploading those case studies!!!
By far the best video I can definitely relate too ..I also am dealing with something similar....it all makes sense now ....I have learned to somewhat read circuits..thanks to Yu u make it so clear.....
so good to hear this type of feedback. Thank you!
@@ScannerDanner your so welcome pleas keep on preaching your knowledge I need every bit of it...btw finally got me an amp clamp..now I have to watch your videos to really get to know how to use it
@@nutsandbolts7407 spend some time in my chapter 1 playlist right here on YT on relative compression testing. Then look up some misfire stuff in my chapter 22 playlist. Both of them have a lot of amp probe testing in them
@@ScannerDanner awesome I will !!
That was impressive... This one will really stick with me. Very glad you were able to show this one!
And The Whole World Has To Answer Right Now Just To Tell You Once Again, Who's Bad !! What up guru! This truly higher learning !!
Yet another insightful and educational video. Well done on this one Paul... ;-))
ps- this is why a really good approach sometimes with these cars, is change all the sensors, like changing spark plugs/points/condenser/cap/rotor on the old car, because otherwise you are running into one sensor at a time and wasting a lot of effort and time fixing each and every one, over the life of the car. and you don't need expensive test equipment. a cam sensor is very cheap to change.
Good Evening Sir ScannerDanner take care and have a great day 👍
Great tutorial thank you 🙏 👍
From Nick Ayivor from London England UK 🇬🇧
omg thank you so much was pulling my hair out on this one i did put a used computer in that we had on hand but didn't program it checked still had only .08 volts went thru everything u did im like wtf finnaly did search found ur video thank you again
Fantastic diagnosis Dr. Danner!
Wow Dan, You startet youtube before it was Cool!!. So you really know all about scanning/Mobilizing cars...and also RUclips as well!... Bravo!!!.. Thank you for all you do!
My name is Paul Danner :-)
@@ScannerDanner Hence: scannerDanner… nice... Keep up the good work!!
the camshaft sprockets can be installed backwards, i believe it says 2.4 on one side & 2.0 on other, i think... been a minute, but i remeber somthing distinct to tell which way they go... also they can be tricky to time in the car because of strut tower location. should be able to use ruler and all 4 marks should be in a straight line, you may have to manipulate the cams a bit so there straight when the belt is tight.
Thank you , very good job .i wish all the best for you and your family ,
Great video, excellent demonstration of thinking outside the box to cover all the bases..experience comes through
23:25 best feeling in the world at that moment in time Paul? I've had a few of those. Great video... As always!
I love this stuff I just bought a Snapon MODIS ULTRA after years of just multi meter testing, l wish I knew as much as you,
Thanks man. I'm still learning too. The longer we do this the more we see similarities between circuits and designs. We can then plug in our past experience to a new problem. Check out my Honda Element video I just did with a shorted 5v ref. circuit. This condition was on my mind as I went through this crank sensor fault.
ScannerDanner hi friend I have 4.6 reference voltage from ecu to the crank sensor and when I plug the sensor it's drawn to 0 volt I tray new sensor and it's same can you help me please
@@carslover3509 you have a broken wires or corosion is my opinion did you ever figure it out if so what was the problem
Man these videos are awesome. I'm learning so much got my eyes glued to the screen haha
Welcome Zach and thanks so much!
Well done beyond flow charts deep knowledge in practice in real world application
Brilliant. I only hope I can get to your level. I'm saving money for your ebook. Sheer genius.
Truthfully, I don't think there is much of a drop at all on this resistor as long as the circuit is working as designed.
I know that there would be no measurable amount of current flow on the hall effect reference (or what I called feed in the video).
I'll have to try to measure current on one sometime. I'm pretty sure you cannot with conventional equipment.
This is experience. Great job bro.