I've been in a mentally abusive relationship for 7 years now and been trying to get my truck running for the last 6 months thank you for your video and definitely help me get out of the relationship that I'm in and moved on to a better place❤❤
Great video you remind me of Scanner Danner.. I've been a mechanic for 20 years, & I agree always start with power and grounds,, btw on Chevys is common to have problems with grounds especially with wiring traveling through parts that vibrate or under exhaust manifolds or close to them. My hat goes off to you sir for calling yourself a do it yourselfer, shows humbleness.👍
@@SchrodingersBox admitting your wrong when your wrong is the important thing unlike other people who find out what it really was and say oh I knew that all along you admitted your mistake and that’s very commendable I can see why they would of thought it was a crank or cam sensor your not stupid for not checking the ground first you were just performing tests don’t ever feel stupid for making a mistake we all make mistakes and learn from them peace for now my friend awesome video a lot of people won’t admit their mistakes you did that’s the important thing 😊
That's right we learn everyday...that's good troubleshooting...complex problem(s), simple solution(s); simple problem(s),complex solution(s). Very satisfying and rewarding when you solve the problem(s). Appreciate the vid mate n all comments. Be bless
You know how you can have several teachers that all teach math but you can't pass some teacher's class but there's that one. That's you! It's taught that way. I love to see your videos.
My family buys old (> 20 years old) cars and I ALWAYS clean all ground straps I find as a week 1 checkout. . This is why. GREAT VIDEO. Loved how you came to the problem root cause..
4 місяці тому+3
Over a year ago I had to change the grounding wire clamp to the battery. It was running perfectly before and now been sitting ever since. I was about to sell it for $400 because I did not want to deal with figuring it out. I saw this video and now I got a couple buyers offering me $2000. Thank you so much!!
Two prior crank censors, a cam censor, and you still diagnose it in what I would still call a few minutes. You are Brilliant my friend. I learn something every time I watch your videos.
I knew the problem as soon as I saw the title. Very common issue. Any well versed technician such as yourself should find this issue every time. Good job and great video!
Can you please give me a indication. I have changed my Audi A4 Battery. Same symptoms with the new one. Crank No Start. RPM doesn't move. Right Side Windows don't work. Try to jump start nothing. I'm have codes of lost communication gateway A. Lost communication Cluster Panel. High beams relay clicks hard when I switch it on.
@mattdebeer5289 Sorry but I have no experience with Audi so I have no clue as to where the problem could be. It does sound like you have a communication issue though
@@mattdebeer5289 You'll need to have a bi-directional scan tool and see what data bus is affected and then additionally what modules you can communicate with. You'll also need a good schematic of the communications network
That was beautiful! When it comes to anything electrical, I'm dumber than a box of rocks. But with you, there is something about you that makes it so clear and understanding.
Excellent video. My first thought was a ground and I would of did a temporary ground from neg battery post to engine block to see if the car would start. Great job locating that broken wire. One of the best videos ever produced.
I love those kinds of challenges myself. There is a very good friend of mine who is a factory trained technician with decades of experience and he told me he rarely ever sees a sensor failure. According to him the vast majority of the time it is a wiring issue. Case in point. Thank you for your amazing content.
The first big clue I picked up was the customer stated the no start was intermittent. Then not starting at all. More than likely that would be caused by a bad connection. Temperature affect would be second if it was consistent under hot/cold conditions
@@SchrodingersBox yes i was curious what your initial opinion was on the cause, given the intermettant description, but i would think your diagnostic would work regardless as you would still see the ground/no-ground condition with the light
@@cpcoark bas connections will really mess with you. I have seen a bad battery connection completely imitate a ' last leg and down to dead ' condition when really it was fully charged and good for 100 cranks.
You are the only person that can fix my car. I have a no start for over 3 years. No one can fix it. I tried grounding it just like you did to get it started but it didn't work.
Yes solving a problem can give you much satisfaction and save you money too. Thanks to you I've taken up your tried and tested advise to know how the system works otherwise you do not have an understanding on what you are working on. Over here in Australia I've found a lot of mechanics not interested in working on my 1999 Z28 Camaro but with your video's I have been able to solve most of the issues encounted. Thank you your friend in Australia. Graeme Redman
I've been binge watching your videos and am learning so much, so fast, it's kinda mind blowing. I've been using a DVOM, a knockoff power probe, and the XTool A30D scanner (same as a D7, but with BT and fewer special functions) and practice with it on my 2006 Matrix with 209k miles.
Being a tech brings the money in. I do enjoy the characters I work with and landrover/Jaguar sends me many miles away from home on courses to learn the product. This is easily as good as the courses and I love watching from the comfort of my armchair. He talks perfectly to prompt your own mind thoughts. I love it
You have the rare ability to explain complexity in a way that makes sense and is easy to understand. You would also make for a very good lecturer at a university....even just a few hours a week would benefit so many people.
Thanks for another interesting video. Quite coincidentally, this is the second video in a couple of days I've seen on the same subject. South Main Autos channel had a customer asking for a second opinion on whether he really needed to spend the $4000 being asked the manufacturer's main stealer to replace his entire wiring loom. After diagnostic investigation, he too just needed to replace a corroded earth strap on the underside of the engine.
At the very beginning of the video when you stated the shop had checked and replaced the cam and crank sensors with no luck, I was thinking in my mind you were going to discover a bent or damaged tone wheel, but that thought quickly dissipated when you showed the count and speed. I was not thinking a missing ground. Great information! Love your approach to troubleshooting.
@@SchrodingersBoxreplaced a transmission on 03 Silverado and now crank but no start . No spark from coils and no fuel from fuel pump . Constant ground from (A) and keyed power from pink . Still no start. Wat could this be that’s not allowing truck to start ?
I have to say , I absolutely love your show. Your approach to diagnosis is very logical and definitive. Reminds me of mathematics. It’s either wrong or right no in between. I have the same going on with my 06 navigator. I put headers on it and it just stopped while in traffic. Nothing intermittent. Got it home and went through every electrical test, weather I performed them correctly well learning the three wire and two wire sensors got me headed somewhere it would crank and I thought it was kinda firing nope it combusted randomly but not from spark plug. Dieseling maybe. I’m stuck.
I am so glad you find my videos helpful! If your engine is dieseling it could be high compression due to carbon on the pistons, leaking fuel injectors, Also incorrect ignition timing can do it too.
From earlier on in the video my mind was screaming, "It's a bad ground!" Not just a gut feel, it was more that when you saw the injector signal was firing, and the test light clip on the positive terminal and no test light when you touched the ground circuit wiring, the jig was up. None the less, what a brilliant process, even if you did go to a few more tested areas than "needed." I am glad you did take a longer path to get to your end point, as it gave me a chance to learn more about that GM circuitry. My strength is more in the First Generation Mustangs Shelbys (1966 - 1973), and with Ford systems from the 70s and 80s back when I was working as a Ford tech in SoCal. I can tell you this for sure, your wiring diagrams are superior to the older Ford schematics I had (and still have) to work with, It was not until 1972 that we really began to see fairly decent wiring schematics, and 1973 brought us some even more decent diagrams,. Yet, the wiring schematics you showed are truly superior to the kind of detail I have from my schematics sources (all Ford publications). Anyway, I am a new viewer of your videos. I look forward to seeing more. And, I understand that "rush" when a hard to diagnose problem is finally tracked down and corrected. There was hardly anything more satisfying to me back in the day than figuring out a problem that had gone to so many other technicians, and even other dealerships, before I finally had the problem car come to me. Often the really obscure issues turned out to be ground related. I always enjoyed that logical challenge found in where I chose to begin my diagnostic approach, and why I then chose to go to one "next step" to check as opposed to another one. The logical diagnostic approach I learned in the auto industry served me very well when I went over to the computer industry. I loved solving programming and circuitry issues by applying logic. Now retired, I spend a lot of time sharing things I know about diagnosing and repairing First Generation Mustangs and Shelbys, which are applicable to all older Fords and even other makes. My UA-cam channel has feeble content in comparison to what you have, so far. But, considering my narrow focus I am pleased so many folks have found it to be useful. Anyway, I get why you are sharing your videos, and appreciate your sharing back to the industry we love so much. An aside, I also appreciate when you leave in the goofs and erroneous.needless side trips you take in your diagnostic approach. It lets me get a better feel for where your thinking is. And, it lets me know that indeed it is okay to take a needless side path during a diagnostic approach. Some of my more powerful insights have come from taking needless side trips, where I have a happy discovery I can use at some other time. Anyway, Kudos!
Thanks, and yeah I totally can’t believe I didn’t check the ground while I was checking power but like I said, you can get your well poisoned and also it’s really really distracting when you are also filming. Had I not been filing I’d have tested the power and the ground and then checked signal.
@@SchrodingersBox No matter, you rock! In the end you found the problem, and even demonstrated proof of the error before locating the point of actual cause of the error.. Who cares if a few extra paths were taken in the meanwhile? It will not be me tossing a rock at you! If I had to choose between efficient and effective, I would choose effective every time.
😅Omg I am so glad I watched you you are very smart oh shit man I had my 2012 Chevy Tahoe LDZ I got from friend of my he thought moter was lock up after I bought it from him and brought home and be sitting bout 5 months then I start mess with it found out moter not lock up then I try tester under dash said moter is fine and said sumthing is cross over then took me two months try fill out and brought a New battery and put in then moter turn over then o spray start fuild it vrank up went dead got worse then voltage start drop actually fool then I check all the ground wire and til can't fill out and i thought bout watch Utube then I spot that show is said wooo hooo it doing just like my Tahoe and i am thankful thay show me where the problem is i am get dress then fix jack up i hope i hot it oh man thank lot brother you are the best in ever see i am start watching it show man you so damn good man hell yeah you are the master mind brother
That was awesome. My Challenger cutout i pulled over and the starter was still turning over. I swapped a couple relays. Didn't help. But also when I let off the key fob starter still turning over. It's been in the shop for four days. Still haven't heard anything but it's got gremlins lol. I'm retired plant electrician. Electronics degree but that was first time I saw the explanation of electronic ecm diagram and grnd. Diagrams. It makes me want to take a class. Thnks
Just want to say thank you. I have a truck in the shop and it ran when it came in. I replaced the oil cooler lines on it. I went to start the truck and it was missing really bad. turn the truck off and would not start again. I did the same thing the other tech you talked about. I never thought about the ground. I bumped into your video late on a Friday. Just got in on monday morning and quick checked the injector pulse. It was working. checked the ground on the coils and there was nothing. Thanks for the help. I was really lost on this one.
Absolutely the most in depth video we have seen for problem solving a vehicle. We are definitely going to check our ground wires and see if our vehicle will start. Definitely got us as new subscribers. GREAT JOB!!!
Will do tomorrow. We changed every sensor already and still crank no start😵💫 🤞 it's a ground. Will let you know how it goes. Best UTuber that we ever watched! Subscriber for life!
Stating the obvious, at 10:00, my brain was screaming "You need to check the ground!". That's something I learned back in the late 70's with the advent of computer controlled fuel and ignition. Because some of the manufacturers attached ground wires in stooooopid places like thermostat housing bolts. But, good job. I'm surprised someone didn't catch it before it came to you.
Problem is today, the techs are too young to have been exposed to the daily run down to the last wire of systems they diagnose today. Back in the 80's the automakers were still (sadly) cutting their teeth on EFI and all the wiring logistics that goes with it. I got out the buiz in the mid 2000's and still take the "check all the basics" routine first and foremost while they're relying on the analyzer's leading them to component failure.
Dean, What do you mean “check all the basics”? If you have a P0171 lean condition on a v6 engine what are the basics you use over relying on “misleading analytics?”
@@SchrodingersBox As I've stated I haven't been in this field in well over a decade. When we had codes, we backed up immediately with a multimeter or our 4 ch. Fluke storage scope what the related component's parameters were. We didn't just jump at parts replacement. The meat of my comment was aimed at the chaos of 3 domestic and a plethora of imports all doing their own thing before OBDII standards were in place.
Not sure I follow that. Data is just data, it’s not a direction and certainly not a conclusion on a part. I don’t see how that could happen. Maybe an example of your method vs a young tech method on my 0171 situation I described?
Hi, this is Robert. Excellent diagnosis on the truck ground! I would LOVE to talk to you about a very perplexing No Crank, No Start issue I have with my 2005 Toyota Avalon XLS. Drove it all day the day before, parked it for the night. Next day saw I needed some air in a tire, plugged in a brand new tire pump into the power outlet in my console. It wouldn't start. I put the key in the ignition, turned it...not a sound, click or anything. My windows, moon roof and radio are not working either. I found a blown 15A fuse for the power outlet and replaced it. I plugged the pump into my truck, works perfectly! My car now, only headlights, dash lights and remote key fob to lock/unlock the car and trunk works. I spent 4 days checking all the other fuses, none are blown. Checked power at the starter relay and got power, switched relays with another one, same results... NOTHING! I gave up and took it to a shop almost a month ago now...their electrical guy has no clue at this point either! I have been without my car for a month now, with no light at the end of the tunnel! I don't have a clue why the fuse blew and why it won't start. The one weird thing the guy at the shop did was took out the relay, put a jumper in and it started right up and he drove it around a while! No problems! I don't know if he checked the windows, radio or moon roof though...he takes the jumper out and puts the relay BACK IN and we're back to the no crank, no start issue! What the heck!!??? The guy at the shop ALSO called a friend of his at the Toyota Dealer...still no joy and it blows his mind too!!! What the heck happened, why did the fuse blow and why is my electrical side DEAD? He did however find high resistance in the Neutral Safety Switch and changed that out...still no joy... HELP!!! Sorry this was so long, but that's what happened from start to finish up to this point. He has been looking at schematics he had and from Toyota for over 2 weeks now, trying to see why all these electrical circuits have in common... Geez... PLEASE, if you have any suggestions...I am WIDE OPEN!!! Thanks!
Thx very much for this..I heard "intermittent" at first...that clue made sense as well...now back to my son's 2008 Altima with a new alternator that is not charging the battery...wonderful...
Great demonstration and verbal communication. I’m 74, shade tree type, struggling to keep up with how stuff works. I’m a new subscriber. I also view South Main Auto and Rust belt Auto among a select view. Thanks Schrödinger Box!! I’m a builder/contractor so mine is a much simpler world . Dave in Omaha
Thanks so much! I had the exact same problem on my 2004 Chevy silverado. After watching your video, i was able to troubleshoot and fix the problem. The truck now runs like new. Now, off to the next project, a drivers seat rear motor that won't go up or down. Wish me luck 😊
Great video great job as usual 👊🏻 I remember as a Chevrolet goodwrench technician back in the 70s 80s living in the rust belt those grounds were always a problem. But I never thought that was the problem on this one looks are deceiving . 👊🏻
Just found your channel. Im not a mechanic. I do own my concrete mixer truck and i do most work on it myself with the help of UA-cam. I learn to teach myself the process of diagnosis the way you do because i dont have any fancy scsn tools. All i have is a test light. Lol 😆 unless its a full blown motor, i will try to fix it myself. And because i have the confidence of fixing my 2005 peterbilt, i know i can fix cars as well. So for 2025 i want to buy old problem cars and motorcycles and fix them.
I scored very high on the ASVAB test so I was fortunate enough to be trained in aeronautical electrical and mechanical troubleshooting it’s a skill not easily learned but very easy forgotten when not used. This video is extremely knowledgeable information for anyone learning how modern automotive and equipment work.
How easy it is to overlook the basics. Seems like whoever looked at it before you could not see the forest because of all the trees. Good no nonsense common sense diag there, thanks for sharing
Greetings. I have a 2005 Chevy Zafira 1.8. No spark with new coil. The ignition coil connecter (5 wires 4 go to each one). The 5v reference on each on is around 4 volts. Does it have to have 5v to spark? Can I take a test light on positive battery and supply it to one to spark? 12v is too much. Thank you.
great job. i just went thru a full-on diagnosis (crank-->no start) where current was interrupted and there are so many possible things it coud be. Mine was an older car with a ripped out alarm system and many cut wires. Ultimately it turned out to be an EFI relay that worked, but did not transfer current from pin 87 to 30 and replacing the relay brrought back the check engine light, which did not light up with key on. So solved. interesting and well done video.
I commend this guy for his ability to diagnose and articulate the issues clearly. He makes it easy to understand how the system functions and how to diagnose what to look for and where in the system. Excellent communication skills! I would love to know what scanner system he is using for this video.
Good clip. well done. Eric O had a similar case over on South Main Auto a month or so ago. turned out to be the ground strap between the motor and the firewall completely corroded away. BTY that connector is a called a ring connector, and that one is am “open barrel” design crimp. They take a special die to crimp, but they are better than the barrel type crimp electrically because they have more surface area between the crimp surface and the wire, reducing resistance of the crimp.
Hahaha I was trying to remember the name of the stupid connector lol!! Yes “Ring connector” was what I was looking for but my brain wasn’t working lol. Good to see you back again btw.
@@SchrodingersBox I have shifted to working on marine diesel and boat issues these days. I was very pleased to see that a group of technicians wanted to see this clip as a learning device. I’m out there lurking most days.
Thanx! I had a no spark issue but ground ohm test was good. I checked my G102 anyway and sure enough it fell off with little effort. Corroded. It was dropping out soon as I cranked it, weak ground. Ran new ground and all good. Thanks for this. It was making me nuts
Fantastic work Matt! 👏👏👏 My initial thought was wiring because you said intermittent but I still would have followed your usual method because it really does help give direction 👍
Good call! Yes there are many many many things that can cause an intermittent that eventually becomes consistent. as you said it’s best to just follow the procedure and whatever it is will be found every time.
Spectacular job Matt, good find as well. I had a couple experiences like that as well with my scope on a rope too. Someone a while back spent hours with a buddy trying to figure out why his 89 Chevy truck wasn't starting, they took out the fuel pump and half the top side of the engine apart. Truck still didn't start and they spent a good 6+ hours on it and scratching their heads, like why isn't it starting. The guy calls on me to check it out, go to try and start it, no start, look at the dash, no check engine light, pull out the trusty test light look for ECM fuse, blown fuse. They get a new fuse and put it in, starts right up, told them it may blow again depending on what happened to blow it the first time, but started it up a few more times and let it run and it didn't blow the fuse again. Spent under 10 minutes figuring it out, where the guy and his friend spent over 6 hours and half the truck apart trying to figure out what was wrong. Its thanks to many people like yourself on here that taught others like myself what to do, where to look and stuff. Great job!
Excellent video and another example of how important it is to go back to first principles on such difficult to find faults. I'm in the UK and wanted to say 'thanks' for a great video session.
Wow... I have a 1995 Volvo 850 with this crank no start issue... I think I will follow your set of steps in the diagnostic, that was pretty incredible.
That was a great case, I like the way you took us along to follow your thought process. I was a little puzzled by the wiring diagram, because we don't see all of the electronics there. The wiring diagram notwithstanding, it looks like grounding of the primary side is separate from the PCM, triggered by a simple square wave positive input along the signal wire. That would reduce the chance of inductive voltage spikes reflecting back to the PCM.
I went back and looked at the Alldata wiring diagram for my old 2000 Suburban. It doesn't have as much internal detail but they do say that the trigger for firing is a ground signal that turns on and off inside the PCM. So, ground side switched on the signal wire, at least in my old beast.
I had the exact same problem on a Jeep Grand Cherokee. The mechanic, before I purchased the vehicle, worked on it off and on from October to February and couldn't fix it. I stopped and asked about it and he offered it to me CHEAP because he couldn't get it running. I purchased it, had it towed home and a few days later started to investigate. I saw where and what he was working on and went right to the wiring schematic to see what was common to the problem area. It turned out to be an open connection back to the PCM for the engine sensor(s). I opened the first place where the factory spliced the wiring and hooked a jumper wire to it and back probed it to the PCM. Vehicle started right up. Success.
Yes I got asked that a lot. The reason is the brown wire that sends a validation of coil ignition only functions when engine is running. It doesn’t function during cranking. Because this was a crank no start that validation was never a factor so therefore no check engine light.
@@SchrodingersBox Thanks for responding. But you said that the customer concern was that the symptom gradually become worse to the point where the engine would crank but fail to catch and run. I blame the ECU for not being smart enough to detect a faulty ignition circuit. Rock on, S.B.!!!!!! Love your vids!!!
Yep the reason still applies. The issue was with cranking the engine and it not starting. It would happen more and more frequently. When the engine wouldn’t start you won’t get a code for the reasons mentioned. When the engine finally starts you won’t get a code either because now it’s running.
Great video! I read (see bottom) that the Low Reference on those ignition coils was an ECM sourced ground which is a dedicated ground for the coil electronics. The chassis ground is meant to supply a ground for the actual coil windings, but can supply the coil electronics too if the Low Ref is down. This system contrasts with Toyota's 4 wire ignition coil where the fourth wire is the ignition confirmation signal (IGF) telling the ECM that the coil fired. Source: There's a PDF titled "Coil on plug ignition - the wired differences" by Matt Dixon which explains this and more. A quick internet search will show this PDF in its result.
it took 21 minutes and 5 seconds to realize WTF my issue is. Thanks for the info! I pretty much fried my starter and wasted some (to much) time, but this hopefully solves the issue **2009 Ford Escape 3.0L**
I also remember in the 70’s and 80’s that a car seldom made it to 100,000 miles. Now the first tune up is due at that time. No airbags. No antilock brakes. No vehicle stability. No navigation. Good mileage was like 14MPG. Emissions were over 50 times higher than now. Anytime the weather got unusually cold you had to put starter fluid down the carburetor hahahahah. The technology has made cars way way way better and far more reliable.
Hey Matt, love your work mate. I don't believe GM use the brown wire as a confirmation signal like Toyota etc. The brown wire in this design is a common low reference/ground internal to the PCM, shared by each coil igniter transistor, effectively it's a constant path to ground for all of the primary coil windings. The open ground you were chasing is of course the main ground for the secondary coil windings. However, the PCM may still be capable of monitoring this common primary/transistor ground for coil current/over current purposes, and maybe to detect misfires etc.👍
mornin sir, i lack knowledge in this, so i'm pretty curious, so that pattern ow wires on that coil means 2 grounds? one for primary leading to PCM and one for secondary leading tothe battery - terminal/body, and one positive from the battery and one positive fron the PCM aa the trigger for cut-off on primary... did i get it right?
@@endurofan9854 Yep, pretty much spot on mate. One pin (pin D) is a shared positive supply fed via a fuse (one fuse for odd bank, and another fuse for even bank) to power the primary coil and internal coil pack electronics. One pin (pin C) is a square wave switched input from the PCM controlling the primary coil transistor. One pin (pin A) is a shared constant chassis/battery ground, probably for the primary coil transistor to switch to. The last pin (pin B) is a shared constant ground, grounded within the PCM, probably for the internal coil pack electronics to ground to, and maybe the PCM can also monitor this wire for self diagnosis functions etc. Pin A and pin B may actually serve oposite functions to what I've stated above but I'm not 100% sure, but I can confirm they are both constant grounds and can be tested as such. Hope this helps👍🇦🇺
You’re so right about the poisoned well. It’s been my experience that whenever there’s a general consensus about what the problem is yet the vehicle still isn’t working, it’s because everyone is wrong or don’t have any idea what they’re talking about. Go through the process of eliminating potential issues yourself and zero in on the real problem. You’ll waste less time and money and you’ll actually fix the thing. I literally just picked up a 96 Chevy for dirt cheap because it didn’t run. Guy said it was the fuel pump and had a couple other guys tell him it was as well. Ten minutes and an $18 coolant temperature sensor later I was driving away in a truck that runs great and is in pretty decent condition
I truly appreciate this video. I have a 98 dodge ram 1500 5.2. "Stop laughing" 😅 My starter burned up and now. I have this problem unfortunately I knew it had a parasitic draw. I eliminated all of them. At least I thought I had. Most of it was due to a poorly done radio installation. Watching this helps me understand the ground is probably the culprit all this time. Or at least gives me an idea what to look for. Thanks again for the troubleshooting tips. 🎉
On a Toyota can you help. Got a P0335 replaced crankshaft sensor OEM now only got P0336 code condition is Crank but no start condition. If it does start englne light remains on refusing to reset? Replaced camshaft x2 sensors same issue. Stuck nobody can help.... any ideas?
This was a great video! I appreciate the detail you go into, it provokes a great amount of thought with revealing connections so that in turn, I could figure out that I'm having back emf issues with my 73 Mopar 360 causing the plugs not to spark and am missing an engine to chasis ground on the tranny end of the engine!!! I think you just solved me a whole number of intermittent electrical issues I've been having! Thank you!
I use to work with a guy that had a IQ off the Chart, he had Total Recall on everything he read, could resite a Dictionary and carve a Gun stock from a 2x6. This guy could make a couple checks on your engine and tell you what was wrong. I had a recently overhauled engine in my car-one night when we got off from work at 12 midnight, temp/ about 10 degrees, my car would not start, only turn over, he instantly told me that it had jumped Time, I told him that it was just overhauled several months ago-he said well they didn't replace the Timing Chain so he just advanced the plug wires on distributor and engine fired up as it should. He said now go back to the guy that overhauled your engine and tell /ask him why he didn't replace Timing Chain, of course guy denied that he left old chain on my car...
@user-pl1uj5ks4m hah , that the difference experience "brings to the table ". I understood the very thing he was describing about the timing/ plug, ..and it also took me back 30 years when I had to tow a car ,home from far away, because of that that issue. Time jumped.
Thanks for the information. I've literally been dealing with the same type of trouble with my 08 Tahoe and now I'm going to take a look amd i hope i am dealing with the same problem. I'll come back and let you know how it goes.
Great diagnostic. I have a 2010 Silverado 5.3l with a similar issue, except I have a P0340 code. Ive checked wire integrity for the CMP and all is good, replaced CMP, still no start. Spent my whole Sunday trying to figure it out. This evening I`m going to go for fuel and fire. I have crank signal, but not CMP signal on scan tool. Thanks for this video. It gives me another direction to go with my diag.
yes on ANY crank no start I always follow my FASTEC method and it never fails to ultimately find the issue. It is weird though your signal integrity was good on a 0340. what was the reference and signal voltage showing when you tested it?
@@SchrodingersBox reference was 5v. I don’t have a scope so I checked signal with multimeter, showed .150v- .20v while cranking. I’ve got a scope ordered, will have Wednesday, so I’m going to check it and get a waveform to see what it looks like.
@@SchrodingersBox I’ll have to check that. I was hoping to work on it this evening, but didn’t have time. I did do a quick fuel system check with a shot of starting fluid, still didn’t start. I did notice it try to fire one time while I was cranking it. A little background when it started to act up. I do a lot of towing with it. The last week or so I noticed an intermittent loss of power, especially while going up a hill. I did a full health scan Saturday morning to see if there were any pending codes that hasn’t tripped CEL, and only codes I had were for TPMS, which haven’t worked since I’ve had the truck. Saturday afternoon I went to the store and it was running fine except for a short loss of power one time. I shut truck off at the store, came out five minutes later and no start. Checked codes and had the P0340.
@@SchrodingersBox I’ve got 5v on signal. I checked at the sensor and ECM. I checked for fire. Nothing on signal wires at the coils I also just tried another CMP sensor just to be sure I didn’t get a bad one. CKP sensor shows about 180rpm when cranking but CMP shows 0 and also 0 on counter. I don’t have access to my alldata at home so Ive got to go to shop to look everything up. Going there now to get diag procedure for the coils.
I failed auto shop in high school. In my twenties and thirties, I always took my vehicles to a mechanic for everything. At 46 I decided to learn about my truck and wanted to do everything myself. I’m 50 now, and I’ve changed my oil and filter, ignition coils, radiator, brakes, starter, wheel bearings, heater core, fuel filter and lines, wheel hubs,power steering pump👎(that one sucked) And other tune up type stuff. But this!!! This problem with truck has been a pain in my ass for so long I’ve called it a demon… like Christine. Truck would start, sometimes it wouldn’t, when running the electrical system did whatever the heck it wanted to. Always resetting the system, and having to put in the code for radio and security, sometimes the idle was perfect and sometimes there was a slight hesitation… once in a while it would choke out. Even having to push the gas above idle to keep it running and not be stranded. Then it would run perfectly for months… and I run my truck. I’m always off road, in the mud, 4x4 driving( even fixed it when the actuator wouldn’t engage) And pushing 75 down the gravel road in my 2001 Chevy Silverado 2500HD 8 cylinders pumping… and doing donuts around corners… … … then it cuts out at the stop light on The way home… 🤔 After missing work today and troubleshooting it with this time, I concluded it has to be a contact problem. I need one of those testers… man that would help. What I did was, because my truck would loose power completely trying to start it this time, I left the key to on position… and started wiggling wires. I wiggled enough wires I was loosing hope. That’s when I found this one wire under the motor… tucked neatly and hiding for protection… I think? I found that f&@)%#!!! Wire. But first I wanted to listen to a professional before getting ahead of myself. That’s when I saw this videos title. I’m soooooooo glad I did. You helped to answer the “why” and technical terms and how your breakdown/approach for this situation. The moment that you were at a loss, and nothing was making sense… thank you for that. I felt like an idiot because it took me so long to figure this out. Thank you for filling the voids so I can better understand what I’m doing. I’ll finish this book now. I felt damn good and I pumped my arms in the air too, when I figured it out. Not bad, for a journeyman Carpenter/craftsman, that failed auto shop. It was awesome what you pumped your arms in triumph!!! Sooooo cool
GM main engine grounds are on the lower left and right side of the engine block. Below the alternator on the left and on the block next to and behind the ac comp. Also redundant grounds from the left head to the firewall.
Oh connector? Funny name for a ring terminal. Lol, just giving you a hard time. Great diagnosis, practically no parts required. The parts cannon would never have fixed that one. The owners best decision was bringing it to you. Thanks for posting this one 👍🏻
Hahahaha dammit my brain just totally couldn’t recall the name of the stupid connector and of course I thought of it afterwards but it was killing me knowing you guys would surely point that out lol!!!
I live in Denver and spent a good 6 months on and off troubleshooting a no start exactly like this one. When I started I knew nothing. I have spent a multitude of hours learning wiring, signal wires,5 volt square waves, etc.. I have finally narrowed it down to my coils not firing. I bet its a ground issue now that I see this video. Or a control issue. Unless you need a car for your next video I am happy to tow it to you.
Great video. Only i have a Question. Why you Can use a positive pulse for actívate the coil and why and why is it not a negative pulse. I want to learn a little bit . Thanks for sharing your knowledge Teacher
Great question. You have to look at the type of transistor. If it’s a PnP transistor you use a positive. An NPN you provide ground. I can tell you I very very rarely see NPN on any signals for coils.
This is generally cause most technicians think in terms of 12v plus, ignoring ground issues or get lost thinking obout sensors, your aproach is more efficient i loved this video, i work audio systems and a client mentioned a problem with his engine, it turns out another mechanic forgot to reconnect the physical batery ground so the car was taking ground though the engine block wow! i just recconected it and voila! the engine problem went away when other 3 shops couldn't find the problem
I'm definitely subscribing I changed everything and still nothing and now its in the shop and I just paid 600 for a ignition switch that I didn't need so when they fix the ground and it starts we should be even right lol.
Take a bow!!!! Great diagnosis. I liked seeing this. Thanks. One guy I watched thought it was the cam sensor because when he tried to start the engine the rpms needle didn't move. It did turn out to be the cam shaft sensor for him. It didn't look like the rpm needle moved for your situation but did it move when you fixed the ground? Just curious?
Yes it did. Lots of cars do not show a tach movement during cranking - it’s a sensitivity thing. But you will see RPMs on a scantool on all cars which is a more reliable metric for sensor operation.
Thank you so very much for taking the time to explain your process! I never knew the value of a test light. Thank you from Australia! It’s got me thinking. If that system had 2 grounds shown on the diagram how come the second ground didn’t take the load? Are they broken at both spots?
Thanks for watching! As Lambros indicated, it’s one ground. the firewall ground is for the 4.3L which has that ground but not the block ground in the video.
Excellent video! Great detective work! Quick question: On the ground diagram, some wires were represented by solid lines, some by dashed lines. Why was that, what does that mean?
What a great question. On a wire diagram the dashed lines mean there are other connections not shown on that particular page of the diagram. Solid lines mean those shown are your only connections.
Thanks for this video! I have a 1999 Porsche Boxster 986 . It has a crank and No Start . I will start with your direction with locating the ground points of this car. You have enlightened me with how the wires are running, in a general way. Hoping, I can get this problem solved. I do miss driving this car . Thanks again! I definitely will need to sign up for your other channel too! February 2, 2023 Dario Villanueva
I love your videos. I have an 89 chevy that just started dying out. I can put in neutral and will start up again and a couple of times it will die again then run ok. I started looking into the truck and went to pull codes from ECM, but jumped "A" and "B" but not getting a flash check engine stays solid. Maybe an ECM not responding?
ECM must be responding if engine runs even a little. You can verify this by looking for signal input at the distributer. I don’t recall the procedure for jumping to get codes but at the very minimum it will flash 22 if you do it correctly.
You used your head, applied your knowledge, and fixed the problem. Excellent, sir.
Thanks!! sure beats guessing
Knowledge is the ultimate power. Sometimes we get wrapped up in what we're doing we forget to go back to the basis
There is a reason why I subscribed to your channel, your methodology of fault finding is top notch....all the way from South Africa 🇿🇦
Thank you my friend!!
🤝🏽
You deserve the best technicians award in the USA
Absolutely. Every dealership should have a diagnostic expert like this on staff!
I've been in a mentally abusive relationship for 7 years now and been trying to get my truck running for the last 6 months thank you for your video and definitely help me get out of the relationship that I'm in and moved on to a better place❤❤
Well sorry to hear that but glad my video helped!!
If your truck is mentally abusing you, you should definitely sell it, or maybe even donate it to a charity.
Been watching you for a while. Magnificent teaching 😊
Hold Ur head up n get out of there asap
Plz get out of that toxic relationship.
Great video you remind me of Scanner Danner.. I've been a mechanic for 20 years, & I agree always start with power and grounds,, btw on Chevys is common to have problems with grounds especially with wiring traveling through parts that vibrate or under exhaust manifolds or close to them. My hat goes off to you sir for calling yourself a do it yourselfer, shows humbleness.👍
as a 25 years auto tech i can tell you we learn everyday! if you are willing to!!!
So true my friend!!!
@@SchrodingersBox this video popped up in my suggestions and I can honestly say that I learned something. New Subscriber!!! Thanks for the tutorial.
I like your teaching sir God bless you
@@SchrodingersBox admitting your wrong when your wrong is the important thing unlike other people who find out what it really was and say oh I knew that all along you admitted your mistake and that’s very commendable I can see why they would of thought it was a crank or cam sensor your not stupid for not checking the ground first you were just performing tests don’t ever feel stupid for making a mistake we all make mistakes and learn from them peace for now my friend awesome video a lot of people won’t admit their mistakes you did that’s the important thing 😊
That's right we learn everyday...that's good troubleshooting...complex problem(s), simple solution(s); simple problem(s),complex solution(s). Very satisfying and rewarding when you solve the problem(s). Appreciate the vid mate n all comments. Be bless
Your classes have taught me a lot. I figured bad ground before you called it. Thank you for all you teach
You know how you can have several teachers that all teach math but you can't pass some teacher's class but there's that one. That's you! It's taught that way. I love to see your videos.
I do know what you mean. Thanks for the compliment.
My family buys old (> 20 years old) cars and I ALWAYS clean all ground straps I find as a week 1 checkout. . This is why. GREAT VIDEO. Loved how you came to the problem root cause..
Over a year ago I had to change the grounding wire clamp to the battery. It was running perfectly before and now been sitting ever since. I was about to sell it for $400 because I did not want to deal with figuring it out. I saw this video and now I got a couple buyers offering me $2000. Thank you so much!!
Thought provoking intelligent content- delivered in a no fluff no nonsense manner. Logic applied over and over again. Thank you for sharing.
Two prior crank censors, a cam censor, and you still diagnose it in what I would still call a few minutes. You are Brilliant my friend. I learn something every time I watch your videos.
Glad to hear! Thank you!
I knew the problem as soon as I saw the title. Very common issue. Any well versed technician such as yourself should find this issue every time. Good job and great video!
Can you explain better where this is located
Under the driver side exhaust manifold forward of the oil filter adapter, above the oil cooler lines. The ground is bolted to the engine block.
Can you please give me a indication. I have changed my Audi A4 Battery. Same symptoms with the new one. Crank No Start. RPM doesn't move. Right Side Windows don't work.
Try to jump start nothing. I'm have codes of lost communication gateway A. Lost communication Cluster Panel.
High beams relay clicks hard when I switch it on.
@mattdebeer5289 Sorry but I have no experience with Audi so I have no clue as to where the problem could be. It does sound like you have a communication issue though
@@mattdebeer5289 You'll need to have a bi-directional scan tool and see what data bus is affected and then additionally what modules you can communicate with. You'll also need a good schematic of the communications network
I’m a Automotive Technician down in CO Springs. I really enjoy watching your channel. Thanks for all the awesome videos man.
Awesome!! Thanks for watching!! Love the springs!! Western Omelette my favorite breakfast place hahahaha
That was beautiful! When it comes to anything electrical, I'm dumber than a box of rocks. But with you, there is something about you that makes it so clear and understanding.
Thank you, that’s what I hope to achieve!! I’m most successful if you can do it!!
Excellent video. My first thought was a ground and I would of did a temporary ground from neg battery post to engine block to see if the car would start.
Great job locating that broken wire.
One of the best videos ever produced.
I love those kinds of challenges myself. There is a very good friend of mine who is a factory trained technician with decades of experience and he told me he rarely ever sees a sensor failure. According to him the vast majority of the time it is a wiring issue. Case in point. Thank you for your amazing content.
Yes I have only seen 3 in almost 10 years
The first big clue I picked up was the customer stated the no start was intermittent. Then not starting at all. More than likely that would be caused by a bad connection. Temperature affect would be second if it was consistent under hot/cold conditions
9/10 times that’s exactly how a crank sensor fails though. or a sticking IAC, or a failing fuel pump.
@@SchrodingersBox yes i was curious what your initial opinion was on the cause, given the intermettant description, but i would think your diagnostic would work regardless as you would still see the ground/no-ground condition with the light
@@cpcoark bas connections will really mess with you.
I have seen a bad battery connection completely imitate a ' last leg and down to dead ' condition when really it was fully charged and good for 100 cranks.
You are the only person that can fix my car. I have a no start for over 3 years. No one can fix it. I tried grounding it just like you did to get it started but it didn't work.
What was the voltage on the ground before you grounded it? How did you know the ground was the problem?
Do u hear the fuel pump turn on? Also have u changed the canister purge valve
Yes solving a problem can give you much satisfaction and save you money too. Thanks to you I've taken up your tried and tested advise to know how the system works otherwise you do not have an understanding on what you are working on. Over here in Australia I've found a lot of mechanics not interested in working on my 1999 Z28 Camaro but with your video's I have been able to solve most of the issues encounted. Thank you your friend in Australia.
Graeme Redman
Great to hear! “No Worries” lol.
Totally glad you left this one up, I’ve got an 06 f150 CNS that nobody has been able to diagnose, I think you’ve got it. I’ll let you know.
I've been binge watching your videos and am learning so much, so fast, it's kinda mind blowing. I've been using a DVOM, a knockoff power probe, and the XTool A30D scanner (same as a D7, but with BT and fewer special functions) and practice with it on my 2006 Matrix with 209k miles.
Great to hear! You will definitely be able to get the most out of those tools for sure. that setup is pretty similar to all I use in 90% of my videos.
@@SchrodingersBox Thanks!
Being a tech brings the money in. I do enjoy the characters I work with and landrover/Jaguar sends me many miles away from home on courses to learn the product. This is easily as good as the courses and I love watching from the comfort of my armchair. He talks perfectly to prompt your own mind thoughts. I love it
You have the rare ability to explain complexity in a way that makes sense and is easy to understand. You would also make for a very good lecturer at a university....even just a few hours a week would benefit so many people.
thank you! I have been told this quite often. Maybe a gift.
And hopefully benefit his pocket book too.
Thanks for another interesting video. Quite coincidentally, this is the second video in a couple of days I've seen on the same subject. South Main Autos channel had a customer asking for a second opinion on whether he really needed to spend the $4000 being asked the manufacturer's main stealer to replace his entire wiring loom. After diagnostic investigation, he too just needed to replace a corroded earth strap on the underside of the engine.
At the very beginning of the video when you stated the shop had checked and replaced the cam and crank sensors with no luck, I was thinking in my mind you were going to discover a bent or damaged tone wheel, but that thought quickly dissipated when you showed the count and speed. I was not thinking a missing ground. Great information! Love your approach to troubleshooting.
Yeah good thinking on tone wheel- I actually have a video where that was the issue.
@@SchrodingersBoxreplaced a transmission on 03 Silverado and now crank but no start . No spark from coils and no fuel from fuel pump . Constant ground from (A) and keyed power from pink . Still no start. Wat could this be that’s not allowing truck to start ?
What is the CKpS signal voltage showing?
I have to say , I absolutely love your show. Your approach to diagnosis is very logical and definitive. Reminds me of mathematics. It’s either wrong or right no in between. I have the same going on with my 06 navigator. I put headers on it and it just stopped while in traffic. Nothing intermittent. Got it home and went through every electrical test, weather I performed them correctly well learning the three wire and two wire sensors got me headed somewhere it would crank and I thought it was kinda firing nope it combusted randomly but not from spark plug. Dieseling maybe. I’m stuck.
I am so glad you find my videos helpful! If your engine is dieseling it could be high compression due to carbon on the pistons, leaking fuel injectors, Also incorrect ignition timing can do it too.
From earlier on in the video my mind was screaming, "It's a bad ground!" Not just a gut feel, it was more that when you saw the injector signal was firing, and the test light clip on the positive terminal and no test light when you touched the ground circuit wiring, the jig was up. None the less, what a brilliant process, even if you did go to a few more tested areas than "needed." I am glad you did take a longer path to get to your end point, as it gave me a chance to learn more about that GM circuitry. My strength is more in the First Generation Mustangs Shelbys (1966 - 1973), and with Ford systems from the 70s and 80s back when I was working as a Ford tech in SoCal. I can tell you this for sure, your wiring diagrams are superior to the older Ford schematics I had (and still have) to work with, It was not until 1972 that we really began to see fairly decent wiring schematics, and 1973 brought us some even more decent diagrams,. Yet, the wiring schematics you showed are truly superior to the kind of detail I have from my schematics sources (all Ford publications).
Anyway, I am a new viewer of your videos. I look forward to seeing more. And, I understand that "rush" when a hard to diagnose problem is finally tracked down and corrected. There was hardly anything more satisfying to me back in the day than figuring out a problem that had gone to so many other technicians, and even other dealerships, before I finally had the problem car come to me. Often the really obscure issues turned out to be ground related. I always enjoyed that logical challenge found in where I chose to begin my diagnostic approach, and why I then chose to go to one "next step" to check as opposed to another one. The logical diagnostic approach I learned in the auto industry served me very well when I went over to the computer industry. I loved solving programming and circuitry issues by applying logic. Now retired, I spend a lot of time sharing things I know about diagnosing and repairing First Generation Mustangs and Shelbys, which are applicable to all older Fords and even other makes. My UA-cam channel has feeble content in comparison to what you have, so far. But, considering my narrow focus I am pleased so many folks have found it to be useful.
Anyway, I get why you are sharing your videos, and appreciate your sharing back to the industry we love so much. An aside, I also appreciate when you leave in the goofs and erroneous.needless side trips you take in your diagnostic approach. It lets me get a better feel for where your thinking is. And, it lets me know that indeed it is okay to take a needless side path during a diagnostic approach. Some of my more powerful insights have come from taking needless side trips, where I have a happy discovery I can use at some other time.
Anyway, Kudos!
Thanks, and yeah I totally can’t believe I didn’t check the ground while I was checking power but like I said, you can get your well poisoned and also it’s really really distracting when you are also filming. Had I not been filing I’d have tested the power and the ground and then checked signal.
@@SchrodingersBox No matter, you rock! In the end you found the problem, and even demonstrated proof of the error before locating the point of actual cause of the error.. Who cares if a few extra paths were taken in the meanwhile? It will not be me tossing a rock at you! If I had to choose between efficient and effective, I would choose effective every time.
😅Omg I am so glad I watched you you are very smart oh shit man I had my 2012 Chevy Tahoe LDZ I got from friend of my he thought moter was lock up after I bought it from him and brought home and be sitting bout 5 months then I start mess with it found out moter not lock up then I try tester under dash said moter is fine and said sumthing is cross over then took me two months try fill out and brought a New battery and put in then moter turn over then o spray start fuild it vrank up went dead got worse then voltage start drop actually fool then I check all the ground wire and til can't fill out and i thought bout watch Utube then I spot that show is said wooo hooo it doing just like my Tahoe and i am thankful thay show me where the problem is i am get dress then fix jack up i hope i hot it oh man thank lot brother you are the best in ever see i am start watching it show man you so damn good man hell yeah you are the master mind brother
That was awesome. My Challenger cutout i pulled over and the starter was still turning over. I swapped a couple relays. Didn't help. But also when I let off the key fob starter still turning over. It's been in the shop for four days. Still haven't heard anything but it's got gremlins lol. I'm retired plant electrician. Electronics degree but that was first time I saw the explanation of electronic ecm diagram and grnd. Diagrams. It makes me want to take a class. Thnks
Great video. GM cars in the rust belt are known for electrical gremlins caused by bad grounds and grounding straps.
Just want to say thank you. I have a truck in the shop and it ran when it came in. I replaced the oil cooler lines on it. I went to start the truck and it was missing really bad. turn the truck off and would not start again. I did the same thing the other tech you talked about. I never thought about the ground. I bumped into your video late on a Friday. Just got in on monday morning and quick checked the injector pulse. It was working. checked the ground on the coils and there was nothing. Thanks for the help. I was really lost on this one.
glad to help!!
I'll certainly agree with Matt that feeling never goes away, solving a complex problem than moving on to the next.
I agree as an electrician
Absolutely the most in depth video we have seen for problem solving a vehicle. We are definitely going to check our ground wires and see if our vehicle will start. Definitely got us as new subscribers.
GREAT JOB!!!
Glad to hear. Just check for an open ground first. It will save a ton of time.
Will do tomorrow. We changed every sensor already and still crank no start😵💫 🤞 it's a ground. Will let you know how it goes.
Best UTuber that we ever watched! Subscriber for life!
Stating the obvious, at 10:00, my brain was screaming "You need to check the ground!". That's something I learned back in the late 70's with the advent of computer controlled fuel and ignition. Because some of the manufacturers attached ground wires in stooooopid places like thermostat housing bolts. But, good job. I'm surprised someone didn't catch it before it came to you.
Problem is today, the techs are too young to have been exposed to the daily run down to the last wire of systems they diagnose today. Back in the 80's the automakers were still (sadly) cutting their teeth on EFI and all the wiring logistics that goes with it. I got out the buiz in the mid 2000's and still take the "check all the basics" routine first and foremost while they're relying on the analyzer's leading them to component failure.
Dean, What do you mean “check all the basics”? If you have a P0171 lean condition on a v6 engine what are the basics you use over relying on “misleading analytics?”
@@SchrodingersBox
As I've stated I haven't been in this field in well over a decade.
When we had codes, we backed up immediately with a multimeter or our 4 ch. Fluke storage scope what the related component's parameters were. We didn't just jump at parts replacement.
The meat of my comment was aimed at the chaos of 3 domestic and a plethora of imports all doing their own thing before OBDII standards were in place.
@@SchrodingersBox
Didn't say the analytics were misleading.
The techs took the data as a set in stone parts order.
Not sure I follow that. Data is just data, it’s not a direction and certainly not a conclusion on a part. I don’t see how that could happen. Maybe an example of your method vs a young tech method on my 0171 situation I described?
Man you’re amazing at what you do u make it look so easy and the way you explain things is at another level man ! God bless you and thank you!
I appreciate that! Thanks for commenting!
Love your logical, rational approach to problem solving. Excellent job!
thank you!!
Hi, this is Robert. Excellent diagnosis on the truck ground! I would LOVE to talk to you about a very perplexing No Crank, No Start issue I have with my 2005 Toyota Avalon XLS. Drove it all day the day before, parked it for the night. Next day saw I needed some air in a tire, plugged in a brand new tire pump into the power outlet in my console. It wouldn't start. I put the key in the ignition, turned it...not a sound, click or anything. My windows, moon roof and radio are not working either. I found a blown 15A fuse for the power outlet and replaced it. I plugged the pump into my truck, works perfectly! My car now, only headlights, dash lights and remote key fob to lock/unlock the car and trunk works. I spent 4 days checking all the other fuses, none are blown. Checked power at the starter relay and got power, switched relays with another one, same results... NOTHING! I gave up and took it to a shop almost a month ago now...their electrical guy has no clue at this point either! I have been without my car for a month now, with no light at the end of the tunnel! I don't have a clue why the fuse blew and why it won't start. The one weird thing the guy at the shop did was took out the relay, put a jumper in and it started right up and he drove it around a while! No problems! I don't know if he checked the windows, radio or moon roof though...he takes the jumper out and puts the relay BACK IN and we're back to the no crank, no start issue! What the heck!!??? The guy at the shop ALSO called a friend of his at the Toyota Dealer...still no joy and it blows his mind too!!! What the heck happened, why did the fuse blow and why is my electrical side DEAD? He did however find high resistance in the Neutral Safety Switch and changed that out...still no joy... HELP!!! Sorry this was so long, but that's what happened from start to finish up to this point. He has been looking at schematics he had and from Toyota for over 2 weeks now, trying to see why all these electrical circuits have in common... Geez... PLEASE, if you have any suggestions...I am WIDE OPEN!!! Thanks!
Huh! I was wrong! no Pico. But to diagnose with basic tools is awesome! It was the hoodie you were wearing that helped you diagnose this!
it did help or I’d have frozen to death!!
The hoodie always helps.And if you have the baseball cap underneath it even better.
Nothing beats a good vehicle like a bad ground !!!!!! Thank you for taking the time to do this .......
Nice hoodie Matt! Thanks for the shout out. I bet the Pico comes out on this video. Now back to the video.
Hahaha I actually already had it out of the case ready to go but never went that direction!!
Thx very much for this..I heard "intermittent" at first...that clue made sense as well...now back to my son's 2008 Altima with a new alternator that is not charging the battery...wonderful...
Love your videos. I learn so much from your videos
Great demonstration and verbal communication. I’m 74, shade tree type, struggling to keep up with how stuff works. I’m a new subscriber. I also view South Main Auto and Rust belt Auto among a select view. Thanks Schrödinger Box!! I’m a builder/contractor so mine is a much simpler world . Dave in Omaha
I haven't had any problems with grounding either...but you really add to my knowledge in understanding diagnostic problems. Thank you, teacher
Thanks so much! I had the exact same problem on my 2004 Chevy silverado. After watching your video, i was able to troubleshoot and fix the problem. The truck now runs like new. Now, off to the next project, a drivers seat rear motor that won't go up or down. Wish me luck 😊
Great video great job as usual 👊🏻 I remember as a Chevrolet goodwrench technician back in the 70s 80s living in the rust belt those grounds were always a problem. But I never thought that was the problem on this one looks are deceiving . 👊🏻
Just found your channel. Im not a mechanic. I do own my concrete mixer truck and i do most work on it myself with the help of UA-cam. I learn to teach myself the process of diagnosis the way you do because i dont have any fancy scsn tools. All i have is a test light. Lol 😆 unless its a full blown motor, i will try to fix it myself. And because i have the confidence of fixing my 2005 peterbilt, i know i can fix cars as well. So for 2025 i want to buy old problem cars and motorcycles and fix them.
Glad you joined. Heck I have a lot of subscribers who don’t work on cars at all- they just like watching the mysteries get solved lol.
I scored very high on the ASVAB test so I was fortunate enough to be trained in aeronautical electrical and mechanical troubleshooting it’s a skill not easily learned but very easy forgotten when not used. This video is extremely knowledgeable information for anyone learning how modern automotive and equipment work.
How easy it is to overlook the basics. Seems like whoever looked at it before you could not see the forest because of all the trees. Good no nonsense common sense diag there, thanks for sharing
Thank you for taking the time to methodically teach us, as you always do.
My pleasure!
Greetings. I have a 2005 Chevy Zafira 1.8. No spark with new coil. The ignition coil connecter (5 wires 4 go to each one). The 5v reference on each on is around 4 volts. Does it have to have 5v to spark? Can I take a test light on positive battery and supply it to one to spark? 12v is too much. Thank you.
You could do that yes. but there also needs to be a 12V on one of the wires. has to be.
@@jazzstarish4186 loop l.
great job. i just went thru a full-on diagnosis (crank-->no start) where current was interrupted and there are so many possible things it coud be. Mine was an older car with a ripped out alarm system and many cut wires. Ultimately it turned out to be an EFI relay that worked, but did not transfer current from pin 87 to 30 and replacing the relay brrought back the check engine light, which did not light up with key on. So solved.
interesting and well done video.
Excellent diagnosis. It seems many underestimate or overlook grounds. Your methodical approach is appreciated. Thank you
Yes even I overlooked it at first. in 9 years this is the first corroded ground I have ever run into.
I commend this guy for his ability to diagnose and articulate the issues clearly. He makes it easy to understand how the system functions and how to diagnose what to look for and where in the system. Excellent communication skills! I would love to know what scanner system he is using for this video.
Thanka so much. in this video i used an Autel MS909 scanner.
Good clip. well done. Eric O had a similar case over on South Main Auto a month or so ago. turned out to be the ground strap between the motor and the firewall completely corroded away.
BTY that connector is a called a ring connector, and that one is am “open barrel” design crimp. They take a special die to crimp, but they are better than the barrel type crimp electrically because they have more surface area between the crimp surface and the wire, reducing resistance of the crimp.
Hahaha I was trying to remember the name of the stupid connector lol!! Yes “Ring connector” was what I was looking for but my brain wasn’t working lol.
Good to see you back again btw.
@@SchrodingersBox I have shifted to working on marine diesel and boat issues these days. I was very pleased to see that a group of technicians wanted to see this clip as a learning device. I’m out there lurking most days.
Thanx! I had a no spark issue but ground ohm test was good. I checked my G102 anyway and sure enough it fell off with little effort. Corroded. It was dropping out soon as I cranked it, weak ground. Ran new ground and all good. Thanks for this. It was making me nuts
Fantastic work Matt! 👏👏👏 My initial thought was wiring because you said intermittent but I still would have followed your usual method because it really does help give direction 👍
Good call! Yes there are many many many things that can cause an intermittent that eventually becomes consistent. as you said it’s best to just follow the procedure and whatever it is will be found every time.
My 2008 Nissan Maxima is doing the same thing I wonder if that can be the problem
It could be. Or could be 1000 other things that can cause same symptoms. Diagnose it to be sure.
Spectacular job Matt, good find as well. I had a couple experiences like that as well with my scope on a rope too. Someone a while back spent hours with a buddy trying to figure out why his 89 Chevy truck wasn't starting, they took out the fuel pump and half the top side of the engine apart. Truck still didn't start and they spent a good 6+ hours on it and scratching their heads, like why isn't it starting. The guy calls on me to check it out, go to try and start it, no start, look at the dash, no check engine light, pull out the trusty test light look for ECM fuse, blown fuse. They get a new fuse and put it in, starts right up, told them it may blow again depending on what happened to blow it the first time, but started it up a few more times and let it run and it didn't blow the fuse again. Spent under 10 minutes figuring it out, where the guy and his friend spent over 6 hours and half the truck apart trying to figure out what was wrong. Its thanks to many people like yourself on here that taught others like myself what to do, where to look and stuff. Great job!
Great story man!! Thanks for sharing that!!
Excellent video and another example of how important it is to go back to first principles on such difficult to find faults.
I'm in the UK and wanted to say 'thanks' for a great video session.
Thanks for taking time to write!
Because you helped the poor with their auto repair I thumbs up every video you publish. God bless you. 👍 and I’ll subscribe to your pay content.
Thank you!! yes I have done a lot of free work lately including this one.
Wow... I have a 1995 Volvo 850 with this crank no start issue... I think I will follow your set of steps in the diagnostic, that was pretty incredible.
it works every time!
Great work Matt. Thanks so much for another excellent diagnosis.
Im into the same issue, crank but hard starting at cold start. thank you for this content and i will try this as reference.
That was a great case, I like the way you took us along to follow your thought process. I was a little puzzled by the wiring diagram, because we don't see all of the electronics there. The wiring diagram notwithstanding, it looks like grounding of the primary side is separate from the PCM, triggered by a simple square wave positive input along the signal wire. That would reduce the chance of inductive voltage spikes reflecting back to the PCM.
Thanks Dave!! Great to see you again!
I went back and looked at the Alldata wiring diagram for my old 2000 Suburban. It doesn't have as much internal detail but they do say that the trigger for firing is a ground signal that turns on and off inside the PCM. So, ground side switched on the signal wire, at least in my old beast.
I had the exact same problem on a Jeep Grand Cherokee. The mechanic, before I purchased the vehicle, worked on it off and on from October to February and couldn't fix it. I stopped and asked about it and he offered it to me CHEAP because he couldn't get it running. I purchased it, had it towed home and a few days later started to investigate. I saw where and what he was working on and went right to the wiring schematic to see what was common to the problem area. It turned out to be an open connection back to the PCM for the engine sensor(s). I opened the first place where the factory spliced the wiring and hooked a jumper wire to it and back probed it to the PCM. Vehicle started right up. Success.
An absolutely great lesson. Thanks
Thanks my man great lesson
Great vid, sir. I wonder why a DTC wasn't set for the coil failing to fire. Thanks for posting this vid for free!
Yes I got asked that a lot. The reason is the brown wire that sends a validation of coil ignition only functions when engine is running. It doesn’t function during cranking. Because this was a crank no start that validation was never a factor so therefore no check engine light.
@@SchrodingersBox Thanks for responding. But you said that the customer concern was that the symptom gradually become worse to the point where the engine would crank but fail to catch and run. I blame the ECU for not being smart enough to detect a faulty ignition circuit. Rock on, S.B.!!!!!! Love your vids!!!
Yep the reason still applies. The issue was with cranking the engine and it not starting. It would happen more and more frequently. When the engine wouldn’t start you won’t get a code for the reasons mentioned. When the engine finally starts you won’t get a code either because now it’s running.
Great diagnostic and love learning from you
Glad to hear it!
So on the 5.3 there will be a gound on firewall and on the block by the exhaust manifold
Great video! I read (see bottom) that the Low Reference on those ignition coils was an ECM sourced ground which is a dedicated ground for the coil electronics. The chassis ground is meant to supply a ground for the actual coil windings, but can supply the coil electronics too if the Low Ref is down. This system contrasts with Toyota's 4 wire ignition coil where the fourth wire is the ignition confirmation signal (IGF) telling the ECM that the coil fired.
Source: There's a PDF titled "Coil on plug ignition - the wired differences" by Matt Dixon which explains this and more. A quick internet search will show this PDF in its result.
No one thanked you for this wonderful source of awesome information!!!
@@ChipperTheChipster Thanks!😊
it took 21 minutes and 5 seconds to realize WTF my issue is. Thanks for the info! I pretty much fried my starter and wasted some (to much) time, but this hopefully solves the issue **2009 Ford Escape 3.0L**
Remember the late 60,s and 70;s v8 motors that were so basic. Now you have to be a mini Einstein to diagnose cars.
I also remember in the 70’s and 80’s that a car seldom made it to 100,000 miles. Now the first tune up is due at that time. No airbags. No antilock brakes. No vehicle stability. No navigation. Good mileage was like 14MPG. Emissions were over 50 times higher than now. Anytime the weather got unusually cold you had to put starter fluid down the carburetor hahahahah.
The technology has made cars way way way better and far more reliable.
What point with all that if the car dosent start 😂@@SchrodingersBox
You are an amazing teacher and diagnostician! You fix cars by THINKING! Thank you thank you thank you for sharing!!!
Wow, thank you!
Hey Matt, love your work mate.
I don't believe GM use the brown wire as a confirmation signal like Toyota etc.
The brown wire in this design is a common low reference/ground internal to the PCM, shared by each coil igniter transistor, effectively it's a constant path to ground for all of the primary coil windings.
The open ground you were chasing is of course the main ground for the secondary coil windings.
However, the PCM may still be capable of monitoring this common primary/transistor ground for coil current/over current purposes, and maybe to detect misfires etc.👍
mornin sir,
i lack knowledge in this,
so i'm pretty curious,
so that pattern ow wires on that coil means 2 grounds?
one for primary leading to PCM and one for secondary leading tothe battery - terminal/body,
and one positive from the battery
and one positive fron the PCM aa the trigger for cut-off on primary...
did i get it right?
@@endurofan9854 Yep, pretty much spot on mate.
One pin (pin D) is a shared positive supply fed via a fuse (one fuse for odd bank, and another fuse for even bank) to power the primary coil and internal coil pack electronics.
One pin (pin C) is a square wave switched input from the PCM controlling the primary coil transistor.
One pin (pin A) is a shared constant chassis/battery ground, probably for the primary coil transistor to switch to.
The last pin (pin B) is a shared constant ground, grounded within the PCM, probably for the internal coil pack electronics to ground to, and maybe the PCM can also monitor this wire for self diagnosis functions etc.
Pin A and pin B may actually serve oposite functions to what I've stated above but I'm not 100% sure, but I can confirm they are both constant grounds and can be tested as such.
Hope this helps👍🇦🇺
@endurofan9854 correct.
You’re so right about the poisoned well. It’s been my experience that whenever there’s a general consensus about what the problem is yet the vehicle still isn’t working, it’s because everyone is wrong or don’t have any idea what they’re talking about. Go through the process of eliminating potential issues yourself and zero in on the real problem. You’ll waste less time and money and you’ll actually fix the thing. I literally just picked up a 96 Chevy for dirt cheap because it didn’t run. Guy said it was the fuel pump and had a couple other guys tell him it was as well. Ten minutes and an $18 coolant temperature sensor later I was driving away in a truck that runs great and is in pretty decent condition
Thank you, amazing video, you are a great teacher 👏
Glad you think so!
I truly appreciate this video. I have a 98 dodge ram 1500 5.2. "Stop laughing" 😅
My starter burned up and now. I have this problem unfortunately I knew it had a parasitic draw. I eliminated all of them. At least I thought I had. Most of it was due to a poorly done radio installation.
Watching this helps me understand the ground is probably the culprit all this time. Or at least gives me an idea what to look for. Thanks again for the troubleshooting tips. 🎉
Excellent!!! You are approaching it correctly for sure. You'll get it soon and its so satisfying when you solve it!
Nice find. I also love being able to fix problems that multiple others were unable to find. Keep it simple.
That's the plan!
On a Toyota can you help.
Got a P0335 replaced crankshaft sensor OEM
now only got P0336 code condition is Crank but no start condition. If it does start englne light remains on refusing to reset?
Replaced camshaft x2 sensors same issue.
Stuck nobody can help.... any ideas?
What are your reference and signal voltages? Have you tried a crank sensor bypass?
With Ignition on unplugged the power/plugs for the (Crank & Cam)sending a 5v signal
Wait- how can the crank sensor send a 5V signal??? That doesn’t make sense.
Crank plug thats reading 5v is that not correct?
Clearly dont know what to do now.
Out of interest where you located?
& thanks for yr responses
The Disgruntled Mechanic-subscribed !
TY!
This was a great video! I appreciate the detail you go into, it provokes a great amount of thought with revealing connections so that in turn, I could figure out that I'm having back emf issues with my 73 Mopar 360 causing the plugs not to spark and am missing an engine to chasis ground on the tranny end of the engine!!!
I think you just solved me a whole number of intermittent electrical issues I've been having! Thank you!
I use to work with a guy that had a IQ off the Chart, he had Total Recall on everything he read, could resite a Dictionary and carve a Gun stock from a 2x6. This guy could make a couple checks on your engine and tell you what was wrong. I had a recently overhauled engine in my car-one night when we got off from work at 12 midnight, temp/ about 10 degrees, my car would not start, only turn over, he instantly told me that it had jumped Time, I told him that it was just overhauled several months ago-he said well they didn't replace the Timing Chain so he just advanced the plug wires on distributor and engine fired up as it should. He said now go back to the guy that overhauled your engine and tell /ask him why he didn't replace Timing Chain, of course guy denied that he left old chain on my car...
@user-pl1uj5ks4mgoogle advancing a distributor.
@user-pl1uj5ks4m hah , that the difference experience "brings to the table ". I understood the very thing he was describing about the timing/ plug, ..and it also took me back 30 years when I had to tow a car ,home from far away, because of that that issue. Time jumped.
Thanks for the information. I've literally been dealing with the same type of trouble with my 08 Tahoe and now I'm going to take a look amd i hope i am dealing with the same problem. I'll come back and let you know how it goes.
Great diagnostic. I have a 2010 Silverado 5.3l with a similar issue, except I have a P0340 code. Ive checked wire integrity for the CMP and all is good, replaced CMP, still no start. Spent my whole Sunday trying to figure it out. This evening I`m going to go for fuel and fire. I have crank signal, but not CMP signal on scan tool. Thanks for this video. It gives me another direction to go with my diag.
yes on ANY crank no start I always follow my FASTEC method and it never fails to ultimately find the issue.
It is weird though your signal integrity was good on a 0340. what was the reference and signal voltage showing when you tested it?
@@SchrodingersBox reference was 5v. I don’t have a scope so I checked signal with multimeter, showed .150v- .20v while cranking. I’ve got a scope ordered, will have Wednesday, so I’m going to check it and get a waveform to see what it looks like.
You don’t need a scope you just need a basic DVom. Of course the reference is 5V- what’s the signal voltage showing when you ground it?
@@SchrodingersBox I’ll have to check that. I was hoping to work on it this evening, but didn’t have time. I did do a quick fuel system check with a shot of starting fluid, still didn’t start. I did notice it try to fire one time while I was cranking it.
A little background when it started to act up. I do a lot of towing with it. The last week or so I noticed an intermittent loss of power, especially while going up a hill. I did a full health scan Saturday morning to see if there were any pending codes that hasn’t tripped CEL, and only codes I had were for TPMS, which haven’t worked since I’ve had the truck. Saturday afternoon I went to the store and it was running fine except for a short loss of power one time. I shut truck off at the store, came out five minutes later and no start. Checked codes and had the P0340.
@@SchrodingersBox I’ve got 5v on signal. I checked at the sensor and ECM. I checked for fire. Nothing on signal wires at the coils I also just tried another CMP sensor just to be sure I didn’t get a bad one. CKP sensor shows about 180rpm when cranking but CMP shows 0 and also 0 on counter. I don’t have access to my alldata at home so Ive got to go to shop to look everything up. Going there now to get diag procedure for the coils.
I failed auto shop in high school. In my twenties and thirties, I always took my vehicles to a mechanic for everything.
At 46 I decided to learn about my truck and wanted to do everything myself. I’m 50 now, and I’ve changed my oil and filter, ignition coils, radiator, brakes, starter, wheel bearings, heater core, fuel filter and lines, wheel hubs,power steering pump👎(that one sucked)
And other tune up type stuff.
But this!!! This problem with truck has been a pain in my ass for so long I’ve called it a demon… like Christine.
Truck would start, sometimes it wouldn’t, when running the electrical system did whatever the heck it wanted to. Always resetting the system, and having to put in the code for radio and security, sometimes the idle was perfect and sometimes there was a slight hesitation… once in a while it would choke out. Even having to push the gas above idle to keep it running and not be stranded. Then it would run perfectly for months… and I run my truck. I’m always off road, in the mud, 4x4 driving( even fixed it when the actuator wouldn’t engage)
And pushing 75 down the gravel road in my 2001 Chevy Silverado 2500HD 8 cylinders pumping… and doing donuts around corners… … … then it cuts out at the stop light on The way home… 🤔
After missing work today and troubleshooting it with this time, I concluded it has to be a contact problem. I need one of those testers… man that would help. What I did was, because my truck would loose power completely trying to start it this time, I left the key to on position… and started wiggling wires. I wiggled enough wires I was loosing hope.
That’s when I found this one wire under the motor… tucked neatly and hiding for protection… I think?
I found that f&@)%#!!! Wire.
But first I wanted to listen to a professional before getting ahead of myself. That’s when I saw this videos title. I’m soooooooo glad I did. You helped to answer the “why” and technical terms and how your breakdown/approach for this situation. The moment that you were at a loss, and nothing was making sense… thank you for that. I felt like an idiot because it took me so long to figure this out. Thank you for filling the voids so I can better understand what I’m doing.
I’ll finish this book now.
I felt damn good and I pumped my arms in the air too, when I figured it out. Not bad, for a journeyman
Carpenter/craftsman, that failed auto shop.
It was awesome what you pumped your arms in triumph!!! Sooooo cool
GM main engine grounds are on the lower left and right side of the engine block. Below the alternator on the left and on the block next to and behind the ac comp. Also redundant grounds from the left head to the firewall.
As in my trade, a broken neutral is the arch nemesis! This explained my truck issue, Thanks!
Oh connector? Funny name for a ring terminal. Lol, just giving you a hard time. Great diagnosis, practically no parts required.
The parts cannon would never have fixed that one. The owners best decision was bringing it to you.
Thanks for posting this one 👍🏻
Hahahaha dammit my brain just totally couldn’t recall the name of the stupid connector and of course I thought of it afterwards but it was killing me knowing you guys would surely point that out lol!!!
I live in Denver and spent a good 6 months on and off troubleshooting a no start exactly like this one. When I started I knew nothing. I have spent a multitude of hours learning wiring, signal wires,5 volt square waves, etc.. I have finally narrowed it down to my coils not firing. I bet its a ground issue now that I see this video. Or a control issue. Unless you need a car for your next video I am happy to tow it to you.
I’ll take it!!! Email me at Schrodingers_box@yahoo.com.
i yelled at the screen when you checked for 12v input and skipped streight to signal checking lol great video my brother
Great video.
Only i have a Question.
Why you Can use a positive pulse for actívate the coil and why and why is it not a negative pulse. I want to learn a little bit .
Thanks for sharing your knowledge Teacher
Great question. You have to look at the type of transistor. If it’s a PnP transistor you use a positive. An NPN you provide ground. I can tell you I very very rarely see NPN on any signals for coils.
@@SchrodingersBox omggg thanks for sharing that little secret. The electronic and electric is awesome. Greats for Chile!
This is generally cause most technicians think in terms of 12v plus, ignoring ground issues or get lost thinking obout sensors, your aproach is more efficient i loved this video, i work audio systems and a client mentioned a problem with his engine, it turns out another mechanic forgot to reconnect the physical batery ground so the car was taking ground though the engine block wow! i just recconected it and voila! the engine problem went away when other 3 shops couldn't find the problem
Beautiful, I think most 2 wire coils switches the ground ckt. in the PCM. What happened to the open primary ckt. code?.
I'm definitely subscribing I changed everything and still nothing and now its in the shop and I just paid 600 for a ignition switch that I didn't need so when they fix the ground and it starts we should be even right lol.
Take a bow!!!! Great diagnosis. I liked seeing this. Thanks. One guy I watched thought it was the cam sensor because when he tried to start the engine the rpms needle didn't move. It did turn out to be the cam shaft sensor for him. It didn't look like the rpm needle moved for your situation but did it move when you fixed the ground? Just curious?
Yes it did. Lots of cars do not show a tach movement during cranking - it’s a sensitivity thing. But you will see RPMs on a scantool on all cars which is a more reliable metric for sensor operation.
Thank you so very much for taking the time to explain your process! I never knew the value of a test light. Thank you from Australia!
It’s got me thinking. If that system had 2 grounds shown on the diagram how come the second ground didn’t take the load? Are they broken at both spots?
probably, this car has only the one ground. it will be kind of a different model/engine etc.i
Thanks for watching! As Lambros indicated, it’s one ground. the firewall ground is for the 4.3L which has that ground but not the block ground in the video.
@@SchrodingersBox
Thanks man, for all the awesome videos that you are sharing with us.soon ,I will come and be part of the Q-group 😀
I have watched a couple of your videos and not only learned a few things but also entertained. Thank you
Thank you! I try to keep it fun.
Thank You Math, for post this video from your paid channel . Heats off
Excellent video! Great detective work! Quick question: On the ground diagram, some wires were represented by solid lines, some by dashed lines. Why was that, what does that mean?
What a great question. On a wire diagram the dashed lines mean there are other connections not shown on that particular page of the diagram. Solid lines mean those shown are your only connections.
@@SchrodingersBox Thank you for the rapid response! Good to know!
Thanks for this video! I have a 1999 Porsche Boxster 986 . It has a crank and No Start . I will start with your direction with locating the ground points of this car. You have enlightened me with how the wires are running, in a general way. Hoping, I can get this problem solved. I do miss driving this car . Thanks again! I definitely will need to sign up for your other channel too!
February 2, 2023
Dario Villanueva
Thank you. I am sure you will solve the issue with your car.
I love your videos. I have an 89 chevy that just started dying out. I can put in neutral and will start up again and a couple of times it will die again then run ok. I started looking into the truck and went to pull codes from ECM, but jumped "A" and "B" but not getting a flash check engine stays solid. Maybe an ECM not responding?
ECM must be responding if engine runs even a little. You can verify this by looking for signal input at the distributer.
I don’t recall the procedure for jumping to get codes but at the very minimum it will flash 22 if you do it correctly.