Crank No Start That No One Could Fix SBQM Free Video!

2009 GMC Sierra with a crank no start that several techs unable to diagnose but they are sure it's a Crank sensor signalling issue. Looks like they are right.
This video will be available for a limited time here just so the shop can watch the video on this channel- otherwise it will be on my paid content channel at www.schrodingersboxqm.com (Schrodingers Box Quantum Mekanix).
Download our free book while you are there!!
The Diagnosis and Understanding: Ignition Systems video is here: schrodingersboxqm.com/diagnos...

[@erikkirby1]

as a 25 years auto tech i can tell you we learn everyday! if you are willing to!!!

[@SchrodingersBox]

So true my friend!!!

[@502undergroundmedia6]

@@SchrodingersBox this video popped up in my suggestions and I can honestly say that I learned something. New Subscriber!!! Thanks for the tutorial.

[@miraclechikwem4987]

I like your teaching sir God bless you

[@robbieturnbull4253]

@@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 😊

[@valdabromfield2369]

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

[@tinytim9453]

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.

[@SchrodingersBox]

Thank you, that’s what I hope to achieve!! I’m most successful if you can do it!!

[@frankvoynar6427]

I'll certainly agree with Matt that feeling never goes away, solving a complex problem than moving on to the next.

[@riblets1968]

You used your head, applied your knowledge, and fixed the problem. Excellent, sir.

[@SchrodingersBox]

Thanks!! sure beats guessing

[@jamesworsham2312]

Knowledge is the ultimate power. Sometimes we get wrapped up in what we're doing we forget to go back to the basis

[@dougkelley1266]

Your classes have taught me a lot. I figured bad ground before you called it. Thank you for all you teach

[@KG-vr3te]

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

[@chicanobluesaz4191]

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!

[@mlamont9999]

Can you explain better where this is located

[@chicanobluesaz4191]

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.

[@nicklala4982]

Love your logical, rational approach to problem solving. Excellent job!

[@SchrodingersBox]

thank you!!

[@JohnDoesGarage]

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.

[@SchrodingersBox]

Yes I have only seen 3 in almost 10 years

[@cpcoark]

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]

9/10 times that’s exactly how a crank sensor fails though. or a sticking IAC, or a failing fuel pump.

[@sandygrungerson1177]

@@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

[@michaelszczys8316]

@@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.

[@ag1auto588]

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.👍

[@graemer66]

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

[@SchrodingersBox]

Great to hear! “No Worries” lol.

[@MarzNet256]

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.

[@SchrodingersBox]

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.

[@MarzNet256]

@@SchrodingersBox Thanks!

[@tshephokgetjepe3162]

There is a reason why I subscribed to your channel, your methodology of fault finding is top notch....all the way from South Africa 🇿🇦

[@SchrodingersBox]

Thank you my friend!!

[@shepherdguy]

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.

[@SchrodingersBox]

Yeah good thinking on tone wheel- I actually have a video where that was the issue.

[@bludhoun9016]

@@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 ?

[@SchrodingersBox]

What is the CKpS signal voltage showing?

[@rgmeyers66]

Thought provoking intelligent content- delivered in a no fluff no nonsense manner. Logic applied over and over again. Thank you for sharing.

[@TheCowgirlNiamh]

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 👍

[@SchrodingersBox]

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.

[@jviews1]

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..

[@twoshedsjackson6478]

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.

[@23hublock1]

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.

[@SchrodingersBox]

thank you! I have been told this quite often. Maybe a gift.

[@onegurl9]

And hopefully benefit his pocket book too.

[@Kaunas-rx3qv]

Great work Matt. Thanks so much for another excellent diagnosis.

[@spelunkerd]

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.

[@SchrodingersBox]

Thanks Dave!! Great to see you again!

[@spelunkerd]

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.

[@guledmah5872]

You deserve the best technicians award in the USA

[@GreatDataVideos]

Thank you for taking the time to methodically teach us, as you always do.

[@SchrodingersBox]

My pleasure!

[@jazzstarish4186]

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.

[@SchrodingersBox]

You could do that yes. but there also needs to be a 12V on one of the wires. has to be.

[@glennmiller5451]

@@jazzstarish4186 loop l.

[@TheDisgruntledMechanic]

Nice hoodie Matt! Thanks for the shout out. I bet the Pico comes out on this video. Now back to the video.

[@SchrodingersBox]

Hahaha I actually already had it out of the case ready to go but never went that direction!!

[@sheerwillsurvival2064]

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 . 👊🏻

[@gilberthale7777]

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 KZbin 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!

[@SchrodingersBox]

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.

[@gilberthale7777]

@@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.

[@minamcconnell9932]

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!!!

[@SchrodingersBox]

Glad to hear. Just check for an open ground first. It will save a ton of time.

[@minamcconnell9932]

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!

[@drascretedrascrete3333]

Interesting watching your video, my Nissan NP 200 looses spark and acceleration, sometimes it start and sometimes it doesn't start when you crank the engine, could it be the same problem?

[@SchrodingersBox]

It could be, or it could be one of 100 other possibilities. What data do you have?

[@Ravenshadowson]

Love your videos. I learn so much from your videos

[@konyoha]

I haven't had any problems with grounding either...but you really add to my knowledge in understanding diagnostic problems. Thank you, teacher

[@MasAUS]

Great video, and your ignition video is 1 off the best I’ve ever seen really nice explanation , and the most important think is the way you explain, it is so clear and understanding , you do put 100% effort to make sure others understand.

[@SchrodingersBox]

Thank you very much!

[@BellaRocko]

You are an amazing teacher and diagnostician! You fix cars by THINKING! Thank you thank you thank you for sharing!!!

[@SchrodingersBox]

Wow, thank you!

[@grizz5431]

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.

[@deanb949]

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.

[@SchrodingersBox]

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?”

[@deanb949]

@@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.

[@deanb949]

@@SchrodingersBox Didn't say the analytics were misleading. The techs took the data as a set in stone parts order.

[@SchrodingersBox]

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?

[@simonilett998]

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.👍

[@endurofan9854]

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?

[@simonilett998]

@@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👍🇦🇺

[@SchrodingersBox]

@endurofan9854 correct.

[@foreverwood1963]

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.

[@SchrodingersBox]

I do know what you mean. Thanks for the compliment.

[@robertqman5751]

Great diagnostic skills ... Yes .. Your video's are very helpful. Just found your link recently and glad I did ... 👍.. Thank you for what you do.

[@MagnumOpusSRT]

Excellent diagnosis. It seems many underestimate or overlook grounds. Your methodical approach is appreciated. Thank you

[@SchrodingersBox]

Yes even I overlooked it at first. in 9 years this is the first corroded ground I have ever run into.

[@biglevstergarage]

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!

[@SchrodingersBox]

Great story man!! Thanks for sharing that!!

[@robertbirdsall4571]

The Diagnosis Captain does it again.Well done.I now have a new direction of ingaugment to go..Thanks for your videos, worth every dime. Kalamazoo, Michigan

[@SchrodingersBox]

Thanks Robert good to see you again!

[@carlm2590]

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.

[@SchrodingersBox]

Thank you!! yes I have done a lot of free work lately including this one.

[@johnshinski2994]

An absolutely great lesson. Thanks

[@Briandutoit-sl2nd]

Thanks my man great lesson

[@bchrisl1491]

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.

[@SchrodingersBox]

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.

[@bchrisl1491]

@@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.

[@LinoHart-fr2mj]

I have watched a couple of your videos and not only learned a few things but also entertained. Thank you

[@SchrodingersBox]

Thank you! I try to keep it fun.

[@lanieeve1485]

yes,...it is always helpful and fun to learn from you with your knowledge and your sense of humor thank you very much for taking the time to make things easier...

[@SchrodingersBox]

What a nice comment!!

[@DANNYN224]

Great diagnostic and love learning from you

[@SchrodingersBox]

Glad to hear it!

[@abdul-kabiralegbe5660]

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.

[@ChipperTheChipster]

No one thanked you for this wonderful source of awesome information!!!

[@abdul-kabiralegbe5660]

@@ChipperTheChipster Thanks!😊

[@8307c4]

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.

[@SchrodingersBox]

it works every time!

[@jarrow708]

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.

[@SchrodingersBox]

glad to help!!

[@bernardaflores1720]

Great video. GM cars in the rust belt are known for electrical gremlins caused by bad grounds and grounding straps.

[@at_3831]

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.

[@wyattoneable]

Nice sweat shirt. Mike is a great guy. I smiled when it started. Following a path of solid diagnostics wins every time. Great video Matt.

[@SchrodingersBox]

Couldn't agree more- he is a class act and the sweatshirt is quite comfy hahaha. I wear it whenever I have to crawl under a car in the snowy weather so I don’t ruin my Schrodingers Box sweatshirt hahaha

[@91GT347]

So the ground wire for the test was just hooked into the ground on one of the coils. Then to something that is a good ground spot on the engine ? I have a similar situation with a car someone was halfway through an engine swap on. Found two grounds already not hooked up.

[@JohnSmith-pb1dd]

Thank you, amazing video, you are a great teacher 👏

[@SchrodingersBox]

Glad you think so!

[@mechanic_marky]

Nice find. I also love being able to fix problems that multiple others were unable to find. Keep it simple.

[@SchrodingersBox]

That's the plan!

[@dbayboyds409]

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?

[@Lambros_Stefaneas]

probably, this car has only the one ground. it will be kind of a different model/engine etc.i

[@SchrodingersBox]

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.

[@Lambros_Stefaneas]

@@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 😀

[@user-sn2lj1jp6q]

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

[@TheDisgruntledMechanic]

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!

[@SchrodingersBox]

it did help or I’d have frozen to death!!

[@InsideOfMyOwnMind]

The hoodie always helps.And if you have the baseball cap underneath it even better.

[@randybeard6040]

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...

[@KWAHU93]

@@user-pl1uj5ks4mgoogle advancing a distributor.

[@SuperReznative]

@@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.

[@nickspua1096]

Mate, I am non technician but also have learned so much from you. Thanks.

[@SchrodingersBox]

Cool, thanks!! Always appreciate the DIY's since that's who we are!!

[@Back2dkicks]

Man, I truly appreciate you for making this video.

[@SchrodingersBox]

Glad you enjoyed it!!

[@kartamap]

The Disgruntled Mechanic-subscribed !

[@TheDisgruntledMechanic]

TY!

[@j.1294]

Thank you for this great video! If I may ask: Do I understand correctly that you did use 12V on the signal wire of the coil? If so: Is this always safe or may there be coils that run on e. g. 5V on the signal line? Best regards

[@SchrodingersBox]

Yes I did but I used low amperage. it’s the amperage that prevents damaging the circuit.

[@Sera-Chelle]

You really seem like u know how to diagnose engie troubles. Just found this & wanted to ask how close this is to a '94 Chevy Cheyenne? My dad just had a new fuel tank & fuel pump put on his big green machine. It ran for the drive home, maybe one more day or 2, and now it completely won't start. He's been a mechanic for decades too. He replaced the fuel pump, again, replaced the MAP sensor, & she still won't turn over. Poor guy's about over the thing! Is this similar for him to troubleshoot with, or any ideas of where to find a list to run through for troubleshooting? Any help advice is greatly appreciated! Thx in advance!

[@SchrodingersBox]

I would totally start with that MAP sensor. What was the data he had that indicated the MAP sensor was bad? What was the MAP voltage showing? That abnormal MAP data he saw would be the main clue for sure.

[@paulgarcia1040]

Thank you so much. I'm checking the ground on my 99 gmc 5.7. The way you explained this is 2nd to none. Everett Garcia Wichita Kansas USA

[@grenvillephillips6998]

Great to share in Matt's total chuffedness - I always enjoy a happy ending!

[@SchrodingersBox]

That sounds dirty lol

[@grenvillephillips6998]

@@SchrodingersBox To be chuffed is a British expression meaning delighted. I wasn't sure whether it was used in common parlance in the bars of Benson, Arizona. But soon maybe?

[@davidbradley7770]

would that be a problem on a 1995 chevy silverado 350 with tbi 5.7? I have a no start and its getting fuel sometimes it will start and sometimes it wont.

[@SchrodingersBox]

it’s possible. but hundreds of things can cause a no start- however there’s only a few categories that can cause it which would be fuel, spark, timing or compression.

[@lielyncher755]

Beautiful, I think most 2 wire coils switches the ground ckt. in the PCM. What happened to the open primary ckt. code?.

[@kennethkristensen5537]

I love you video. When you test the coil with supply on the signal wire. From battery positive in series with test lamp. How do you know that you not excid the 5 volt I guess that 5 volt is the signal voltage. How big resistor do you need for not fry the PCM. Will it be possible to use VOM in volt mode instead or is the internal Resistor in VOM to big?

[@sergiorivera8170]

Very comprehensive analysis of the possibly causes of the issue. THANK YOU.

[@syedmuzakkir7130]

Hi, I came across your video, it was great, and the way you demonstrated it is appreciable. I have Mitsubishi Galant 2.4 ES 2008. it has performance issues. it will not speed up when I push the accelerator. it runs a little fine in the morning but after driving for 30 Km it starts to jerk, Missfire. I changed the fuel pump and cleaned the fuel filter, but no luck. Please guide me on what might be the possible reason. I have a code of P0300. Is it Crankshaft or EGR valve or something else? Many thanks.

[@SchrodingersBox]

I always start with a fuel trim analysis as the first step so I can get a basic direction to start with. that’s always the first step as it prevents you from just randomly guessing at the 100000 things that can cause a 0300 code.

[@infinitelyblessed359]

Help! My 94 cV8 amaro that has a hard start issue. This all began right after the kid next door put in my new starter and used the old bolts along with a ton of washers to keep it in place. I think the washers are the issue, what do you think? Being an old lady I dont know much about cars but I do know that when you replace parts, you're suppose to use all he right parts during installation. Thank you for your time.

[@SchrodingersBox]

Hard to say but maybe the starter isn't aligned properly with the driveplate

[@infinitelyblessed359]

@@SchrodingersBox ok thank you so much I'll let a real mechanic look into that for me.

[@Mr2004MCSS]

Nice video. I was expecting you to check grounds after checking the power and was surprised when you didn't. I just subscribed to your channel so that I can see all of your info and videos.

[@SchrodingersBox]

Thanks 👍. Yep I absolutely would check grounds but as I mentioned I think I was so set on a CKPS issue I just forgot to do it!

[@raycook1503]

Such an awesome video. Shows that other areas can cause problems thatcwere never thought about. Also some ignition systems are hot at all times, and the ground is turned off/on to fire coils and injectors as needed.

[@user-pg8kh1pm2o]

I have a 2002 Chevy trailblazer. It just died. All of a sudden I change the fuel pump fuel filter, coil, packs spark plugs starter oxygen sensor fuel regulator, still cranks no start I am I just don’t know what it could be

[@SchrodingersBox]

What data do you have?

[@xj31]

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

[@mintyperfectionable]

LOVE the videos. I’m not trained at all, but I do all of my own work until it gets to the really complicated or sensitive replacements, and these videos are insanely helpful. Side note, at least half of the time while you’re talking, your voice sounds to me like crispin glover 😅

[@SchrodingersBox]

Hahaha someone else mentioned that before too lol. I don’t see the similarity hahaha

[@davidmedley9652]

Great logic and clarity, thanks for another great video.

[@SchrodingersBox]

Thanks again!

[@Ottonic6]

You always have great content. I need to subscribe to your premium channel so when you refer to the content I can watch and understand... For the price of a gallon of gas (well maybe not), even if I only chime in a few times a month it's still a win... On this diagnosis, Powers & grounds. A lot of times that's one of your first tests. Thanks Matt!

[@SchrodingersBox]

thank you! just a point though-Powers and grounds comes after you know what system is at fault. if you want to Check powers and grounds then you are going to have a long day because there are 400 on this car and many are shared.

[@luiscardonapcardona5243]

Hello Sr. First of all thank you for all your amazing teaching. I’m working on my 2010 Mercedes B200 which has a crank no start situation. When I disconnect the crank sensor the engine starts, but when I reconnect it the engine doesn’t start. The code is P0336 (crankshaft position sensor no signal. What do you think of this situation ? Thank you for your input.

[@SchrodingersBox]

Interesting. I would say it sounds like you may have a signal wire issue. I would try a crank sensor bypass and see if it causes a spark

[@luiscardonapcardona5243]

Thank you for your prompt response. My powerprobe reads aprox 2.17 v. In a range of -1v and 6v. Does that make sense ? Thank you again for your time.

[@SchrodingersBox]

It might. I don’t know the values for a BMW. You need to first measure the reference voltage. I don’t know if BMW uses 5V, 9v or 12V but you need to see what the reference voltage is. Then you have to see if you get an output of that reference voltage to the signal when the engine is cranking. So if the reference is 5V then while cranking the signal should show alternating 0 and 5V. On a power probe this will show as between 2-3V because it’s going to take an average reading. Now all this is at the sensor. If this is what you see then you have to do the next step which is to measure that signal voltage at the PCM. If that voltage is not reaching the PCM that would be the cause of the problem and actually it’s what I suspect the issue is.

[@luiscardonapcardona5243]

Thank you very much Sr.

[@jocelynantoinette4108]

Thank you sir for the video. I enjoy wathing you too from France. I was just wondering how did the pcm missed that and throw MIL and fault codes?

[@SchrodingersBox]

Good question! I believe it’s because the coil fire detection only operates with engine running, not during cranking.

[@jocelynantoinette4108]

@@SchrodingersBox Thank you sir for taking your time to answer.

[@ableblessed6117]

Hello thanks for doing what u do on u tube it helps immensely for a paint and body tech with just minimal mechanical skills. I have a 08 maxima in which code was crank sensor I replaced a few already an to include have checked resistance on sensor it is at spec. What I have come down to is I have no spark I checked a couple plugs and am sure that's not my problem . But I have no idea at this point I've spent well over 20 to 30 hours trying to diagnose this but am at a dead end . I am also located Directly in the city of Denver as well could u please give me some advice. Thank you.

[@SchrodingersBox]

You need to check reference and signal on the sensor. Did you do that?

[@frontlinemedia4270]

I found this helpful. But do you have a video on a diesel that the injectors use 2 wires? I am assuming one is the signal from the ecu and the other a common ground. Yes, I am still working on the sprinter. I discovered that sometimes when I turn the key to start, it stops. Then sometimes turn the key and nothing. So I held the key on, and it was a delayed crank. I then found the relay involved and felt the delayed click. Then I would shake the relay and it would start. So I am still not sure where the issue is. I have been unable to get a gray relay thus far, so I can not just swap it out. If it's not the relay, it might be a common ground failure

[@kinglangren]

ThTs so true about bad or certain information. I was looking at my friends truck and he said his fan wouldn’t turn on and it was overheating. Spent too much time looking at the fan , which it turned out to be a bad water pump and the fan was fine. If he hadn’t told me about the fan I would have found the bad water pump issue fairly quickly.

[@yosshuagutierrezvillanueva3892]

Hello Matt Is there any possible way if you can tell me the diagnostic tools you used in this video

[@agold3765]

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.

[@geovanybonilla2244]

Hello mat, good diagnosis, I would like to know the name of the software you are using? Thanks

[@SchrodingersBox]

Autoenginuity is what I used in this video.

[@BryTrapStar-op8sy]

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.

[@johnmorse5617]

Thank you for taking your time to educate me. I found you a good teacher, a vary human one . Thanks again sir .

[@SchrodingersBox]

Wow, thanks!!

[@richardbizzoco624]

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.

[@miked1372]

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

[@dstich1164]

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?

[@SchrodingersBox]

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.

[@johndeloach503]

I have a 97 mustang, when it's cold outside and I start it up the wipers come for a cycle. any idea what could fix that? everything else is great.

[@daquilema2011]

Thank You Math, for post this video from your paid channel . Heats off

[@JonalistTwitMe]

Perhaps you have solved the S-10 'Crank No Start' issue on this 2001 LS Pickup truck 4.3 L. We have replaced the starter, it went bad when its ground disconnected and were back at cranking right now.

[@skoff1214]

Im into the same issue, crank but hard starting at cold start. thank you for this content and i will try this as reference.

[@danieltenorio3559]

I have replaced my fuel pump (in the Honda civic 2012 the filter is built in) bec of long crank to start, but sometimes I still get a long crank ? Is there any help?

[@SchrodingersBox]

What data showed the fuel pump was causing the long crank? What was the decay pressure showing?

[@danieltenorio3559]

@@SchrodingersBox nvm I solved the issue from what it looks , I didn’t install the lid right . But another bad news my gas mileage and level is frozen smh

[@danieltenorio3559]

@@SchrodingersBox I might check Tomrrow after , if the arm is bended in there or what

[@SchrodingersBox]

Need some data. Nothing to go on here man.

[@danieltenorio3559]

@@SchrodingersBox in short : I changed my fuel pump , the day after I tighten it in bec it was loose ; completed new fuel pump installed. So then I drove it to the gas station and seen my gas level dictator is stuck on what the level had before (didn’t update to level full ), which is odd considering I just filled it up . Hope this clears up my situation

[@oliverthemechanic8532]

Mate very nice video 😉 help me a lot 😉 just want to ask where you get your wiring diagram for a different brand of car? Thanks in advance for the reply 😉

[@SchrodingersBox]

Normally I google them but if I can’t find one I use Mitchell DIY

[@eliuddvillanueva4576]

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

[@SchrodingersBox]

Thank you. I am sure you will solve the issue with your car.

[@tonyb1968]

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 👍🏻

[@SchrodingersBox]

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!!!

[@pureonyx5090]

Great video And thank you for sharing your knowledge with us all

[@SchrodingersBox]

Glad you enjoyed it!

[@baltazar0007]

GREAT video´s . i will sub right away..... QUESTION ...where do you get your wire diagrams from :) need one for my fiat qubo diesel mjt from 2012, .

[@SchrodingersBox]

Usually I just google them.