Injector Fault 2014 GMC Sierra Part 3... The Conclusion
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- เผยแพร่เมื่อ 14 ต.ค. 2024
- Well I finally solved it! Mostly by luck but a fix is a fix lol. Here is a link to a Google Drive folder where you can dig through the waveforms. Please let me know how you would have approached this issue and if the fix was even on your mind as a possibility because it sure wasn't on my lol.
drive.google.c...
Nice find. An engineer friend of mine once told me, "we don't know what electricity will do, once the circuit is built, we can only theorize."
I've seen a lot of crazy things. This is one of them now. Thank you for being humble enough to share your struggle.
WOW, really Wow. That was CRAZY indeed. Unbelievable! I remember a good saying from Ivan once he said ; be prepared to be humbled in this field. I will NEVER forget this case study.
Thank you very much Jake. No need to put yourself down. We feel your pain and we've all been there. I too am baffled by the issue causing only one injector fault. You load tested the powers and grounds. I'm with you, for future issues scope the powers and grounds while driving conditions cause the issue to occur. Also, keep in mind when doing load testing of powers and grounds with a headlamp bulb use a DVOM to measure the voltages on each wire while lamp is on. I appreciate your videos. Have a blessed Thanksgiving to you and your family.
Jake, loved the injector case study content. I've watched a few of your videos but decided to subscribe to your channel after seeing this. I appreciated your honesty and transparency. It's why I subscribed. Some channels won't show transparency or they edit mistakes.
To me, these weren't mistakes, it was your journey to a proper fix. As in life, we try to learn from mistakes. Your video will help so many in the event we see a similar problem. Thank you. Awesome job man!
I’m a retired technician. These cars and trucks are why we get gray hair 😂. You did a really good job in checking it out
The main thing is, you fixed it. The second thing is you learned something. Schooling isn't cheap. I would still call it a win. You didn't give up, that's important. The other good thing is being able to reflect on the job and see where you went wrong. Good job man!
Thanks so much for posting this video set. Wisdom comes from misadventure, and it's hard to get that from anything other than first hand experience. Scanner Danner likes a test light for ground testing, but when ground-to-ground testing, the light won't glow unless the loaded drop is more than about 4 volts. Better to measure the drop with a multimeter while loading with a bulb to get electrons moving. The tricky thing about ground testing is the way you don't want a testing method to backfeed and overload sensitive electronics. So to protect devices you need to disconnect them, leading to the chance of destroying the very evidence you're trying to find.
Man!! I am baffled by a bad ground causing one injector fault. 🤯🤯 But you did what any good diagnostician would do and then some. You’re good at what you do. Keep the videos coming! 👏🏼👏🏼🫡
What a great case study, for what I see and understand anyone could had missed that bad ground, looks like was good enough to carry 16 amps of current but no more 😮. That was crazy that only 1 injector was giving trouble codes
I went through this on a 12 Impala. Followed TSB and flow chart and replaced injector and ecm according to the flow chart. I finally ran new wires as a test and low and behold it fixed it. I seen wires were brown but never dawned on me that the wires were overheating.
That is flipping insane to me. I'm like you. I have to know why something does or doesn't work, and I waste a ton of time sometimes. You just wouldn't expect that type of fault to come from an engine ground. Thank you for sharing all of this. Huge chance for learning.
Great case study. Recently had a 2016 F150 that would set a CHT sensor code instantly. Fired a sensor at it (circuit integrity good) no joy. Pulling hair my out, fired a PCM at it, that I ended up eating along with the programming. Turned out to be a dirty ground that only affected the CHT. Live and Learn.
My brain was stumped after the last video. I would have never found this issue in a million years. Great Diag. 👍😂
Hi, Man that's was crazy Cause, I worked as as diagnose tech for 30 yrs and never seen a cause like this, so don't feel so bad, the Best things. you did fixed it!! 👍👍😊😊
2 of your videos are life savers. This video and This old ford put me thru the ringer video are countless frustrating hours.From now on im going to purchase a dedicated scope just for powers and grounds.
If there’s any one in automotive that hasn’t had their butt handed to them multiple times either is brand new to the industry or is liar. I often times find myself in rabbit holes as well. That drive to solve the problem at all costs is a great trait to have. Keep up the great work.
Yeah, but you fixed it. When you hit that accelerator pedal, the truck took off and no misfire. I recognized that look on your face.
Happy Thanksgiving.
Thank you for sharing! I never would of guessed a bad ground on a single cylinder problem. You always hear in training to voltage drop grounds and it's the one in a million case like this were you see the value.
This video is got me thinking. I had a Mercedes a couple of months ago doing the exact same thing. One cylinder would misfire and thus that injector would shut off. Very difficult to diagnose because it would only start missing at full throttle. And as soon as it misfires the injector would get turned off. So you had a matter of milliseconds to capture waveforms. And those waveforms would be pretty inconclusive due to such a small window of information. And I also did a comparison to neighboring cylinders. And nothing really stuck out as being faulty. But the one thing I never did think of was the pcm grounds. Like you it never occurred to me that a bad ground would affect one cylinder. If this was my diag I probably would have made the same mistakes. But this is how you learn.
Definitely educational and interesting. This is an example that guides the technician to spend more time on checking the powers and grounds as the fault is happening, like you say, but then again if the technician is not aware of what the ground should look like on this fuel system it is still hard to diagnose it (not having the know goods). I know u down a pcm, injector and what's more important your time and that sucks. I want to thank you for being humble enough to admit we are humans and we have limitations and for sharing this learning experience with us that way we all can learn something. Don't put yourself down! And come up with a funny/original line at the end of the videos lol.
@@autodiagyt I am not lying to you if I tell u I've watch part 1, the explanation after part 1 and part2 5 times each. So yes lol
I recently found your vids. Great persistence-you didn't have to burn it. I'm an old retired owner and operator (37) years.
After the 3 parts video I'm very happy that it's finally done it's very good information Thanks
I can’t imagine how many other parts would have been installed if it hadn’t had you checking it out.
Great job homie.
I will definitely not forget this ☝️ 😊
Cars fixed. Good diag that's tough, wouldn't expect one injector problem from a bad ground.
I have been working on vehicles for over forty years and I've learned some hard lessons just like this one, we all have. You do the testing and follow the results, but sometimes your equipment will deceive you. If a ground tests good you assume it's good, then move on with testing. There are some things I do before I work on any drivability issue because I've been burnt too many times by simple things, fuel filters are an example. Most people don't change filters at all let alone regularly, besides one bad tank of gas can plug a filter. If a car isn't running right, it gets a fuel filter regardless of when it was changed last. I fought with a car for hours and it turned out to be a plugged fuel filter because the owner said he had just changed it. After that fiasco, I change the filter myself so I know what I'm working with. It's easy for keyboard warriors say they always check powers and GROUNDS! If you follow Matt on Schrödinger's Box you'll understand the emphasis. You did that with the load test. As long as you're in this business you're going to get bit in the ass once in awhile, it's just the way it is. Thank you for the great videos.
Holy crap that was a TOUGH TRUCK man. Kudos for winning the battle :)
So the ECM was firing the high side on #1 and #3 together before the repair and not after repair? How did it not affect any of the other injector drivers? Good to know that on GDI systems the ground is even more important since it takes ~20A to open an injector pintle. Really cool case study!
@@autodiagyt I'll ask for his input :) Now I'm really curious what the other 7 injector drivers were doing lol!
@@autodiagyt exactly! One of the weirdest failure modes I've seen on any vehicle...electronics can be unpredictable for sure lol
As always GM re inventing the wheel. It’s crazy how they use capacitors for each injectors. Not even in their “older” GDI engines they used that system (don’t see too many “newer” Chevy trucks, only light cars and SUV). Just discovered your channel Jake and it’s amazing having this crazy issues. Keep it up. You just made another sub :)
What a cool truck! I recently put a motor in one of these and was surprised how many grounds there were on the engine. The one by the vacuum pump(ecm ground good to know) there’s one on the starter side directly to the block then a ground on the back of each cylinder head. 👍
Everything is easier in hindsight. Excellent example of persistence. Thanks for sharing this case study!
This was an incredible piece of trouble shooting in my opinion. When the OEM data points you in the wrong direction, how do you get on the right path? A very challenging trade on a good day, when you can't rely on the manufacturer for good data, you have have to be pretty damn sharp! Thank you for sharing your expertise with us, mere mortals!
Excellent case study. Thanks so much for sharing, and btw it happens to everyone who does any diagnostics regardless of field. My personal record (as a home hobbyist) is buying a battery, a starter solenoid, and a starter all before finding the true cause which was a loose block to body ground…. That one went back on with a fresh star washer, threadlocker, and a lesson learned. I think it’s remarkable that a dodgy ground could result in such a repeatable failure and such an isolated failure. I would have expected random misfires, or different cylinders, or erratic appearance of the fault…. Really appreciate your videos and your perseverance, and your willingness to share with the community.
From Part 1,2,3 from the start to finish loved it tutorial brilliant video Amazing footage thank you very much helpful information video
I WILL NOT GET STUCK IN A RABBIT HOLES
SUBSTANTIAL AUTOMOTIVE DIAGNOSTICS PROGRAMMING
MY TEACHER Automotive Diagnostics Programming
Outstanding tutorial video Brilliant footage thank you very much for sharing your knowledge with us
God has bless you thank you
Enjoy your Holiday with all your family around thank you
SUBSTANTIAL Automotive Diagnostics Programming
Thank you ScannerDanner for sharing what he know about Automotive Diagnostics Programming
From Nick Ayivor from London England UK 🇬🇧
We all have in some way swallowed parts before but don't be hard on yourself. Chop it up as experience and thanks for sharing so others like myself wouldn't make the wrong call.
Heck of a job keeping on going with it. The motoring public is going to have to understand the complexity of new vehicles and the cost that goes along with it.
No one has a problem dropping 2 grand on a lift and a set of tires but can’t stand when they have to pay to fix it.
WOW!!!! Somebody wouldve guessed it I'm sure.. hey my cars misfiring... have you tried cleaning the grounds? I'm telling ya it aint easy!! That known good waveform, night and day difference. You covered your basis. My question is why wasn't it apparent in the waveform. Elevated ground voltage.. or not getting pulled all the way down when the fault code sets.. You were pulling good amperage all throughout as well.. Great case study. Thank you! I wonder what the ground voltage was when it was setting the fault code..
Good final analysis. Sometimes we have to fail in order to win.
Great case study, you have given all of us something to keep in the back of our mines now, please keep your video's coming
Just come across with your channel today and these are the type of channel what i love the most!Man this was a tough one never seen this issue before.
No pain no gain as they say.These are the cases what we can learn the most from.Keep up the fantastic work bro!
Had this happen numerous times painted block and I have taken grounds that are moved far from battery and sources like computers and modules and made extra grounds and bringing back toward the battery sources closer to the main negative ground. I don't get the engineering or electrical design making ground connections yard's from the module when most of them are close to battery. I feel your pain and it is like education and cost shop so much money. I have lost months or year in 40 years of this not charging for lost time but fixed
I agree with you. Bad grounds can cause all kind of problems. I just had 2003 Ford Ranger 2.5L with a jumped timing belt and i was getting misfire on number one cylinder only. Thanks for sharing with us.
I just subscribed your channel, after watching a couple of your videos. This case was a trap from the beginning (from the manufacturer info, to the apparently normal test results) and you made a good call to relate the problem to the remanufactured engine and its painting. That "aluminium" paint is partly conductive when compressed - only a very high load made the ground float, not much, just enough to drive the ECM and you (or anyone else) nuts 🙂 Really enjoyed following your train of thought through this hellish case.
Holy Crap a bad ground lol, Well i never saw that coming,I agree with you the dynamic testing would of shown you that bad ground. But 1 injector only crapping out how do you get from one to the other. Something Ivan said a while ago stuck with me. Education isn't free it costs time money or both. You got some education from this one brother nice job.😄
Thank you for sharing your struggles
I think when you get a car with a known engine swap, installation errors or year to year compatibility should immediately go to the top of the list of suspicion. You live and you learn, at least you got the sucker 🤜
I am a huge believer in gathering data and waveforms from known good vehicles, when something is in the shop, plug into it. YES, we cannot always give time and of course, we cannot always check every system on that vehicle so what I do is create a list of waveforms to gather on each vehicle, some have systems that their sister vehicle does not have based on the trim level so need to get something different from that trim and get it first as a priority. Simply looking up the schematic is a lesson in itself, we are constantly in the learning process and we will never know it all with the added experience that we go out of our way to gain on a daily basis, if only for 30 minutes to learn or gather something new that we did not have in our brain or better yet, our library database. NO, we do not have time to do it right, label it and file it away, if we ever need to retrieve that data in the future, label it properly, annotate it properly and use it quickly for the third time and beyond as most problems will be seen again in the future, this truck may be on the road for the next 10 years and many like it, different truck, same engine.
Now in video, typically when I have to do work for a body shop, the first place I look is painted grounds, WHAT A FIND Brother, you are the man, a known painted engine, my fix from 30 years ago is these sharp star washers and no need to clean the paint but if the area is very accessible, go for the cleaning.
You must learn to clear codes please, on newer vehicles, a code will kill that cylinder and it will never work with a code. I see techs also not checking codes enough to know when a code set that does not have a tell-tale sign of activation in another module that does not illuminate the MIL. The problem with your test drive here is YOU DID NOT FOLLOW YOUR OWN RULE, in previous videos you cleared codes, set up your scanner to monitor code activation, and the SO set the codes live. Another problem with techs, we are human when we need to work like robots, create a system, and a strategy and stick to it every time, until we improve our strategy, then stick to that new version, EVERY SINGLE TIME Brother. Laziness is the problem, being tired, being brought down by the scenario at hand, being confused, OK, it's a learning process. You have a new SUBer, this is the type of channel I love the most, scanner, scope, schematics, theory of operation, service info, etc. Thank you.
Watch IVAN on Pine Hollow Auto Diagnostics, he load tests up to 5 amps, depending on the circuit, go back to training 30 years ago, a test light with 350mA is not a load tester, TST Seminars TH-cam, G. Truglia, I went to his class around 2002 and been a paying member of iATN since 2000, training is a must and this was a simple one, would you have found a Voltage Drop of value, we will never know.
Bernie Thompson, ATS, TH-cam, monitor every pin on a component somewhere in the circuit during your test drive just as you mentioned, would you have found the bad ground for this injector as a visible and legit voltage drop?
Great case study, you did everything right, you fix it, no matter how much time you spend on it and weird thing is that bad ground didn't act up somewhere else on the system.
What a ride thanks for your time...the whole process was so encouraging for me 🍻
Man what an amazing case study! Or case beat down i should say.loool but seriously I know it was painful for you. But thats how it goes some times and thats why we love it.
Nice find👍. I can guarantee that even tho you lost your ass on this particular one, it will pay for itself over and over from now on. It made you a better tech and it’ll never bite you again. As a hvac tech that has gotten pretty good with intermittent/silly hard to find issues every one I get makes the next one easier and quicker.
Great case study and video set. Your honesty and diagnostic process is awesome! I know it sucks to put parts in a vehicle and not fix the issue but you had reasoning behind it. You analyzed the data and came to a conclusion based off the data. Data driven diagnostics is what I learnt from Bernie and it is what you were doing. You would have seen a higher voltage on that ground during the fault before you cleaned it correct? Ever starnge to only effect one injector.... grounds usually have more wide range effect..Thanks for the video I learnt alot from it!
@@autodiagyt who would've thought a ground would only effect that one I injector though. Your whole process had reasoning and logic to it I wouldn't beat yourself up too bad my friend. Amazing work . Great video. You are helping more people than you realise !!
Crazy case indeed! Thank you for sharing.
I would have got beat on that one too!! I have a hard time pulling the trigger on ecm pcm anymore!! Good video ty
@@autodiagyt happens to the best of us.. your better for it look what u learned and what u taught us.. ty
Thanks for the waveforms (google drive). I am sure you were relief after finding out what was wrong with the vehicle. Schooling/Experience is not cheap. Hopefully you can make up the loss on your next project. :)
all i can say is you got it and that is all that matters ok unnecessary cost and time but a learning experience
Really enjoyed the diagnosis on this one great job. The only thing I'm wondering or that I usually do differently when i dont know what a known good looks like is check another injector on the vehicle. Did you ever compare the waveform to another cylinder on the truck that was not setting a fault code? I would be curious if they were picking up voltage feedback from other cylinders like number 1 was.
i watch a lot of South Main Auto Eric most of the time uses a headlamp bulb to load test grounds.. what did you use just wonder. great video glad you shared
I guess the ground was decent enough for most of the pcm circuits to work but with the injectors being 60 plus volts it was enough to cause issues with them. When you deal with enough crazy problems like some of us you’re bound to find yourself in a rabbit hole from time to time. It’s just the name of the game and we learn from it. No need to beat yourself up about it.
Nice work Sir Jake! I applaud your professionalism and persistence. I guess it would have been good to compare other cylinders to see if there was a difference (don’t remember seeing that and not sure I would have done it being in your shoes). I wonder if the non firing injector has a path to ground for the boost capacitor for the injector that’s not firing as a way of regulating voltage and current to the injector that’s firing. I don’t thing the ground for the injector that fired could have been affected because the current actually went up. Maybe current went up because the bleed off voltage couldn’t bleed off as much as it was supposed to because of a bad ground. I like a previous comment of AC voltage may have an affect but I can’t think of an explanation for it. Just my thoughts. I don’t know how that built the ECM so I can’t say for sure.
Great find!! I knew early on it had to be human introduced. This to me is why its good to load test circuits.I wonder if this wouldve showed up if during your power and ground test at the pcm you loaded it with a 4 amp test light?
Edit
You said this later own in the video 👍
Amazing sir...the nice video..i alif from malaysia.kelantan state...
You checked the computer grounds with a bulb and they were good. That's crazy. I figured they screwed up the reman install. Nothing like having a known good. That ground is so hard to get to on a 5.3 I usually bolt it on before I drop the engine in.
Great video! thank you for putting this case study together.
yay, you figured it out. great info for us all.
Great job brother … from Iraq
You may have encountered an issue with ground reference impedance on that ground to the ECM. One clue is that the issue occurs when the firing rate of the injector control system was high! I am suspecting the AC bandwidth of that ground was improved when the connection was cleaned offering more surface area of contact and thus improving the ground performance that the ECM needs to perform correctly.
Yea, this is where I ended up too. It can carry starter current but not the injector frequency.
i had a older pontiac that if you adjusted the seat and it went to the stop would shut off engine, if you raise a window part way ok but if you raise all the way to the top or bottom would shut of engine. i worked and worked everything worked great ran great unless you did the seat or the window then engine would die. got on you tube there is a ground bar under the carpet driver side where all the grounds connect was corroded carpet was wet and it was sitting basically in water cleaned and all is good
I think the major red flag for this strange problem was the engine swap. This is major engine work, so as a technician you have to recheck and verify all connections before even starting the vehicle.
In doing an engine swap you should really make sure all of the block grounds (which would include the starter ground return to the battery) and wiring are good (not corroded) and terminals clean. Not all engines swaps scrutinize the condition of the major block ground, or any of the wiring unless the technician knows what to look for. With an engine swap you should also check the charging and starting connections and wiring. We can see that in reassembling the truck a rear injector connector mount was broken but not address, which was a mistake. Not a big deal, but the connector should have been at lease tie wrapped to the post so the bare signal wires are not sitting on the engine.
So the ECM needs a good block ground to operate injection properly, but why? If we analyze the injection circuit we should ask the question, do any injection currents return through the block as part of normal operation, or does the a bad block ground effect circuit bias? It depends on how the ECM circuit and injectors are designed. Any faulty connections should result in a DTC, but which DTC?
What ECM currents would be effected by high block ground resistance during a heavy tip in to inhibit only one injection channel? Maybe you could look at the ECM block ground return currents with a current clamp to see what the current is doing during the heavy tip in.
Perhaps the GM troubleshooting flow charts only apply to factory assembled vehicles and not a rebuild, like an engine swap.
I hv a important question u said iv got 10 to 12 hours in this truck. But 10 minute grnd clean. How and how much did u end up charging? Important because I'm on my own as well
It's electronics. It can be tricky at times and time consuming! Just the way it is but many customers don't understand that!
I don't know if someone said this but if I remember right each side has the own fuse for coils and injectors meaning bank one has a fuse and bank 2 on an other so useing an amp clamp with a fuse loop you may have seen it that way. I'm not sure but one day if I come across this problem I'll try it.
That would be for a non gdi engine. With GDI the injectors take a much higher voltage to open so the power and ground are both switched inside the ECM. The only way to get an accurate current reading for multiple cylinders is to undo the harness and separate out the individual wires and clamp around them.
thanks you!
Any circuit code for an output I will always load test the circuit lines + -. cause of this series..
Wow! Crazy
Like a breath of fresh air man, just sticking it out until the end and not sending it somewhere else says it all. I think bad ecm grounds cause so many more issues on vehicles, or even just grounds being in the wrong place. You did a great job, they should have known better than leaving the grounds painted. That heavier current flow was taking another path, not making it through the paint. Maybe the place that did the reman engine should pay for some of that time, its really their fault. Engine builder that doesnt know better about painting grounds?!?
Thanks for the last video,, I was waitin all week for this one.. =) you owe yourself a few beers
@@autodiagyt oh ok,, I thought it had been from a reman shop, people think spray painting everything to make it pretty is such a great idea,. But you have much greater patience than me, I would have been adding a few gray hairs to my head on that one. Really, this just goes to show people how difficult this business is some days, or weeks. That and trying to keep up with technology when you work on every make...
@@autodiagyt I blame grey hair on vehicles completely..lol Its a great excuse..
I have had buses not start even after replacing the battery and starter -nothing. Then clean the battery to frame to engine then computer ground, now wow it starts!!
I am curious if it only affects cylinder because of how the traces are ran in ecm. Like something is able to jump traces when the ground gets more voltage than it likes
Edit either way man you did a wonderful job it's alot more than knowing how to take a nut and bolt off these days
These are the worst. Hindsight is 20/20. At least YOU found it and not someone else. Maybe then you could feel bad. How many amp bulb did you load test the ground with originally?
Wow amazing
Question I’m getting code p0201 I’ve change the injector out and it is still dumping fuel constantly….. my block is also painted … wiring seems to be okay but I could always check it again would it be possible to get a check list of things to do ? My trucking is literally dumping fuel out the exhaust and misfiring
That would need to have power and ground sent to the injector at all times. Unplug the injector and substitute a test light, then troubleshoot the circuits.
👍
How did you come up with that ground
1000 subscribers 😁👍
My truck is doing exactly the same thing, but on cylinder number 5, i will check the ground.
14:14 I'm right...loose connection.
Yaho
Damn.. It doesn't make sense
Expecting someone to chase a ghost on an engine swap, is asking a lot. There is a snake under every rock. And in this case, you got sucker punched by some kind of crud that caused a bad connection. A brutal situation for sure. Watch some of the stuff Eirc O. over at SMA has to put up with and you'll have a new appreciation for chasing down bad grounds. GM trucks in upstate NY have their frames half rusted away after just 10 years, causing shorts and bad grounds all over the place. I know you'll conquer the next challenging situation with ease.
One for the memory bank.
Jake this reman was done by a Nissan dealer. Lol....😮
Voltage drop...scope between batt(-) and block ground... Who's talking on the ground?