DIY -How To Diagnose No Spark No Start. Bad Crank Sensor? FREE SBQM VIDEO

[@007111]

I am a 60 year old tinkering mechanic, I do not own a scope ,just the tools shown in the video. I’ve learned more in this video than all the rest that I’ve seen!! ❤ Nice! Great Job!

[@SchrodingersBox]

Great to know!! Thanks!!

[@patsuddarth1093]

@@SchrodingersBox , I am having a no crank, no start issue, after I changed my ignition switch. Before I replaced it, it only cranked. Before all this, I had a blown head gasket, my ECU malfunctioned & my BCM. Had to replace & reprogram both modules. I replaced my alternator, starter, battery cables, relays, & all fuses. Even replaced my crankshaft position sensor, still only cranked. But now, since the ignition switch swap, the dashboard only lights up. I was getting that service theft deterrent system, when I put the key in ignition. So, I replaced my malfunctioned aftermarket alarm & got a new key. Still nothing, but I didn't replace the passkey module, that's around the key cylinder. I hooked up my scanner, the module didn't throw any codes. But, for some reason, I still get the P 0633-00, theft deterrent key not programmed, when I program the key with that 30 minute passkey procedure. Do you have any idea why this is happening, when I basically have my van a major tune up. I have new spark plugs, wires, and ignition coils. I think my van is in theft mode, cause of the key code. And, when I put the key in the ignition, the computer shuts my ignition system down. I thought about replacing the park/neutral safety switch, cause my van just stopped cranking, after I replaced the ignition switch. I took the switch back, & exchanged it for another. Same thing, nothing. The brand is, that standard ignition switch.

[@SchrodingersBox]

Just start with the basics- since you changed the ignition switch, what is the control side relay voltage showing with key on vs key off?

[@patsuddarth1093]

@@SchrodingersBox , I only have a volts meter. So, I will have to check it out with that. I just ordered a power probe. Should get that in a few days. I just found the diagram for my van. So, will take probably a day or 2, to study/go over it. Will let you know when I find out.

[@patsuddarth1093]

Hello, I finally got it to crank. I discovered my aftermarket ignition switch was defective. So, grabbed an A Delco, one. Also, I am not getting no spark. Have fuel and compression. However, got the P0118, P0443, P0223, & P0122. However, when I resolve the no spark issue, it should fire up. I already replaced the coolant sensor, but code came back, after I cleared it. Need to get a new throttle body or throttle sensor, & purge valve solenoid. So, what do you think, Sir?

[@jackkitchen1471]

Nothing better than investing in the younger ones. Hats off sir. You explain everything in detail and I watch with intentness. Awesome video

[@rontiemens2553]

I highly doubt that there is a better value on KZbin or the entire internet than SBQM. You Rock, Matt!

[@SchrodingersBox]

Thank you!! what a compliment!!

[@spinology1]

@@SchrodingersBox Hey Matt I’m subscribed to your website but my account needs updating and I can’t contact you on there, it keeps saying ‘error trying to send message. Please try again later’ this is the only other way I can think of to contact you!

[@SchrodingersBox]

No problem. go to the login page and click “contact us”. my admin will fix it for you. this is an issue I am aware of for some users and we will fix it permanently very soon. is your screen name there the same as here?

[@spinology1]

@@SchrodingersBox It won’t let me contact you on there, when I hit submit on your contact us page it says ‘error please try again later’ Thanks Matt

[@SchrodingersBox]

I got ya. Ok email me at [e-mail]. Give me your username and email you use on the site. I’ll get it fixed right away.

[@johnsoper7649]

The relevancy, quantity and quantity of information here meets and exceeds anybody’s wildest expectations for people who value learning and growing in knowledge and discernment, and intuition,. This is coming from a guy 74 years old who is cross training into automotive diagnostics. Matt is a really good model and teacher.

[@mike-vw1zn]

Good to see there is someone like you , who is not a parts replacer, this problem with most mechanics would be in the $500 dollar range with parts and labor . Maybe even more. Having just replaced a crank position sensor on a 2003 silverado it was definitely a challenge to say the least. I got lucky with only replacing a oxygen sensor then the crankshaft sensor which was the problem. Your video was so interesting in your diagnostic testing. Your a smart dude and thanks for sharing your knowledge.

[@angeldavidbustillo243]

Matt you the best

[@Wet_Willys_Wetter_Water]

When the student is ready, the teacher will appear. Subscribed to SBQM a week ago. Been consuming all I possibly can.

[@SchrodingersBox]

Oh great!! I hope you enjoy!!

[@Wet_Willys_Wetter_Water]

@SchrodingersBox is there a way to play the sbqm videos with my phone off?

[@SchrodingersBox]

Not sure I understand your question sorry.

[@labradormcgraw]

There is an absolute plethora of knowledge contained in this one video alone. If you work through all the projects on SBQM, you can equip yourself with enough knowledge to rival a masters degree. Where else can one attain that level of knowledge for less than the price of a pancake each month? You do the math. 💰💰💰

[@SchrodingersBox]

Thanks Andy, as always!!

[@labradormcgraw]

@@SchrodingersBox You're most welcome, as always.

[@joecraigslist9467]

TDC -Top Dead Center sensor. Trigger 4 times per engine cycle. Once at every cylinders top dead center. TDCP -One of the wires for the TDC sensor TDCM -The other wire for the TDC sensor CKP Crankshaft position sensor. Triggers 24 times for every engine rotation. CKPP -One of the wires for the CKP sensor CKPM -The other wire for the CKP sensor CYP -Cylinder Positions Sensor Triggers once every engine cycle at top dead centre of cylinder #3. CYPP -One of the wires for the CYP sensor CYPM -The other wire for the CYP sensor

[@SchrodingersBox]

Looks right to me!!

[@iam1smiley1]

So many acronyms in automotive....my brain is starting to swim 😂 Thank you.

[@legallass9905]

💜💜💜 I love seeing your more detailed videos from the website on the SB KZbin channel. You are always doing something to help others, the repairs, the videos, etc. Love you 😍

[@SchrodingersBox]

Thank you so much baby!!

[@mohammedmoaiti4190]

I have never seen an accurate diagnostic video like this before! so I really appreciate that. You did a great job

[@seftonplayer32]

Go and watch Scanner Danner, South main Auto, Pine Hollow Auto diagnostics, Diagnose Dan, Super Mario Diagnostics, Oz Mechanics, New Level Auto and Advanced level diagnostics.

[@briantrueman3505]

The Honda system is known as the P.G.M.F.I. Sequential fuel injection , the ignition module is a very common fault and although it looks quite complicated to check it’s not half as bad as it looks, the fact you had a pulse at the injectors tell you that the cam and crank sensors are ok , I’ve got a detailed breakdown of the system somewhere in my tool box I’ll send you a copy when I come across it, it may help in the future cheers

[@maleko_1237]

Is there a way you can send me the detailed breakdown?

[@cmte.brazinazzo2061]

It doesn't look like.

[@JesusBAlves]

Hi Matt. Thanks your video I solved a big problem with my Old Subaru 2.2 16V 1993. Here in Brazil things are complicated. Lot of mechanics don't work with old car, and leave me with my problem. Your explanation about Fase Sensor was a key. Thank you very much

[@humbertomarquez4497]

This was amazing. I like how you combine the scientific method into the mechanics, going deeper it gave me insight to functionality of electric principles underlying the major components like the distributor in this case. I feel like I understand really well how a distributor works now.

[@SchrodingersBox]

Glad to hear that!!

[@Darren-v5k]

​@@SchrodingersBoxyou are interested in me

[@jmontman]

As an amateur scientist I can fully appreciate you using the SM. I am glad that you are so passionate about going through all the steps. Also I don't know how much you were charging this young man but if you were charging the typical $100-$150/hour wouldn't have been cheaper for him if you ordered a $70 distributor from Amazon and stuck that in? If it didn't fire up then you still are able to run your test. Just a thought. still a great video, you definitely know your stuff.

[@SchrodingersBox]

Thanks for the comment. I don't think it would be cheaper or better to just guess on a distributer for several reasons. First- the only reason we would even think to guess on a $70 distributer is because we only know the distributer was the issue AFTER watching the video. There is every reason otherwise to guess on a $50 fuel pump, or a $5 box of fuses for that matter, or a $25 crankshaft position sensor. The second reason is while I wait two days for the distributer to arrive and the car is taking up my garage space because it won't run AND charging an hour install for the distributer- if the car still didn't start, thats two days lost and $70 I have to swallow plus $100 labor I have to swallow and I am back to square one. So much better to diagnose thoroughly, charge more for a part I can get same day, and the customer gets car back quicker and guaranteed fix while I get paid optimally and maximize my garage space for other revenue generation.

[@InsideOfMyOwnMind]

Nice clean diag. I have done this one before on a friend's Civic but it had NO compression to the point where after getting the ICM installed had to squirt oil into the cylinders to get it to run. There was so much fuel in the engine that the oil was all washed off of the cylinder walls. Once we did get it started it ran fine but told him to change the oil before driving it.

[@Dishsoapdirt1976]

THANK YOU! My 2001 Honda Cr-V has an intermittant Crank but No Start when it's cold outside (below 47F). I've been looking at the same wiring diagram (basically, honda). Tomorrow I'll use this info to crack on. I've really been at a loss. I've thrown way to many parts at this (despite doing my best to diagnose things - also used your videos for fuel system issue). Not sure if it's wiring or PCM issue at this point. The distributor is new & had the issue before. One thing I'm runnning up on is the blk/yel wire from coil to 15A fuse has continuity to ground. Does not when I pull the fuse. Not sure if thats OK - but I''ll use your technique to pull it down. Thanks again!!! Your videos are EVERYTHING!!! So good! I tried using "JustAnswer" auto mechanics "experts". Terrible experience. Very generalized and turned out to be A.I. chatbots anyway. Do you offer a pay-to-ask service? Anyway - keep at it!!! You are amazing!!!!

[@troyburton5303]

You are very thorough when explaining what you are troubleshooting and I appreciate that. I also know you have checked the fuse or ckt breaker LOL. Keep up the white board explanation, that is what I find in my opinion puts you above 90 % of the Instructors found on the internet. There are way to many parts swappers and it drives me nuts when I don't know what the actual problem is before ordering parts. Thanks for all your hard work, I subscribed to you when ever you first started and had very few subscribers.

[@SchrodingersBox]

Thanks so much!! I believe I saw your name before some 8 or 9 years ago.

[@mikeberesford4955]

Wow, love taking time to definitive diagnose. I also hate not knowing,this helps make REAL diagnosticians like you.

[@SchrodingersBox]

Well thank you!!

[@IngeIPI]

Very nice diagnostic demonstration. I take my hat off to you, sir. Wish I had found out about your channel a long time ago, not last week. I had an intermittent ICM failure during 4 months last year on my 99 Honda Accord V6. 2 shops and 3 different electricians couldn't diagnose, until it finally gave out completely. A DIY mechanic friend of mine diagnosed it doing a similar coil test, and ruling out injection or fuel pump. Many videos had led me to believe the main relay was faulty, but again, this friend of mine simply observed if the immobilizer light in the dashboard worked with the relay disconnected, didn't, so he immediately ruled out a bad main relay.

[@MrHernanliom]

You replaced the main relay and it got it fixed ?

[@gregjohnson3619]

P = plus M - Minus Thanks for the great channel!

[@SchrodingersBox]

OMFG how come I didn’t see that hahahahaha!!!!! yeah that’s totally it lol. jeeeez, embarrassing lol!!!

[@lmstuber6044]

Been watching your vids for a few years , I'm a keen diy mercanic just work on my own car ....really really good instructional video

[@SchrodingersBox]

Cool, thanks!

[@yahyagirami2533]

From Afghanistan great experience and explain. We don't have scop in this country but your hand on was a good recipe Thanks.

[@riccilong81]

I have watched SD, Wells Tech, ECG, TCCN, and you explain things in a superior manner with your Dry Erase Board. you really need a new touch screen display but the board is your niche, I get it. Thank you and carry on sir.

[@SchrodingersBox]

Oh wow man thanks for the compliment!!

[@8953147]

As always Matt, love your content! Been busy with other projects so not on KZbin as much, but when I tune in your channel is top.

[@SchrodingersBox]

Well I hope you get more free time soon!! Much appreciated!

[@ws2664]

Very good presentation, I have been dealing with Honda and Toyota Igniters since the early 80's and I have replaced a million of them over the years, hardly any coils. Just so you know, back then they made really good parts, they don't any more so unless it's original Honda or Beck Arnley it probably won't last so keep that in mind if it quits 6 months from now you might have to do it again so make sure you keep the reciet.

[@SchrodingersBox]

Good to know!!

[@bobbyleach785]

I've just now found you on KZbin! Awesome and really smart I think I'll sign up for your online paid videos. Thanks brother

[@SchrodingersBox]

Thank you! glad you found me!!

[@dannylinc6247]

Hondas have relays before the igniter. The relays I've found on older ones were up in the instrument panel and difficult to access. Cars cranking endlessly without spark out in the field that I've gone to check, needed main relays alot. The internals of the relays looked as though they were poorly soldered. Others had igniter issue. That's a "what has been fixing them?" comment from experience. But fuses are a must check, no brainier. I had a Honda in the pitch black dark for a lady in a parking lot at a shopping center parking lot. No light to see by, and she had three dollars to her name, left for the month. The dollar store was nearby. We took the three dollars and bought a flashlight and batteries. I went to investigate her weird sudden no start. System prechecks are always a must. (Ford factory training) One of her fuses was missing. I think it was a 10 amp? A red ATC. We put one in there. Started and ran. Happy motoring. Where did her fuse go? FIIN. You can't leave a car unattended in some parts of the city. She could have caught a ride and returned to God knows what the next day. This place didn't even have the basic lights to see by in their shopping center. (Democrat run area) Her cars interior lights were also defeated or bulbs had failed. Good thing she still had a few bucks for a basic need in her neighborhood. A light to see with and a spare fuse.

[@whitetiger8652]

Thanks Matt! Great troubleshooting as well as great detailed explanation of the how and why of the issue.

[@SchrodingersBox]

Thanks! Good to hear from you as always!

[@mltndeal5120]

I'm new viewer to your channel. Algorithm from KZbin got me here😂. But I liked your video about the 'no start issue' with the car. I had a better understanding of the ignition problem. I have a 1997 Chevy cavalier which I had given up on, it was parked for 2 years after the diagnostic tool indicated I had bad PCM. So I bought a brand new one from O'Reilly's. Then it was recommended that I get it flashed. I went to two GM dealerships about flashing my car's PCM but they told me my car is obsolete and that it's too old and they only flash (reset) a vehicle's computer for 2000 yr and newer. 🤷. So I went to the junkyard to get a used PCM and my car started. (My car started to have anti-theft activation which I was overriding by doing the 10 minutes intervals 3x, {prior to my breakdown in 2021} until the theft light stops blinking and it was working for awhile until the 'no start happened' no one could figure out what was wrong with my car) One day probably 2 months ago a coworker at my job came over to my house and he tested my fuel pump relay and determined I had a bad wire. So he took out a small section of the bad wire near the firewall. And suddenly my car's fuel pump engaged (but he didn't bypass the fuel pump relay it remain intact). The only thing now is the anti-theft light stays on, but the car runs. Only issue I have is the car has hard starting issue. I suppose it is the fuel injector problem, I do see the leaks in all four fuel injectors. I ordered 4 brand new injectors so I plan to replace them. The car runs good after it starts. Once in awhile the anti-theft activates when I have a starting problem....then I have to wait 10 minutes for the anti-theft light to go off. I did see a KZbin video where they said the anti-theft wire the middle wire can be cut to get rid of the problem for good. What is your take on the anti-theft activation problem? People suggested I put Seafoam in my gas tank because of the stale gasoline... yeah it seems to hv help clean out my fuel system, but I really suspect the fuel injectors are bad. The car runs good when I hit the hwy. The anti-theft situation I have no clue how to fix it. I keep overriding the anti-theft with the 'ignition-on' and waiting 10 minutes...it's a hassle. But most of the time I managed to start the car without activating anti-theft. Yes I felt like pushing my car off a cliff in 2021 after anti-theft system and fuel pump failed to engage. If anyone knows anything about anti-theft problems with 97 cavaliers give me a holler. My cavalier is my commute to work.

[@weldingjunkie]

Great video Matt. Typically it’s always best to ground on the battery vs a sensor ground or any other ground due to possible voltage drop when using an oscilloscope. Thanks for sharing, excellent.

[@SchrodingersBox]

Very true- the reason I did the sensor ground is it lets me test both wires at the same time.

[@weldingjunkie]

@@SchrodingersBox I forgot to channels or kind of talk to do that with. I have the ATS escope where you ground it and all 8ch are free to be used on Powers & grounds. Pico is amazing tho too. Very good scope

[@fernandohood5542]

Crank and Cam position sensors are the key to the control of the engine. Some engine have missing tooth on the crank for a reference to TDC...Once the computer has crank and cam information it knows exactly the position of each cylinder at a specific time and knows what to do in relation to ignition and fuel. I learnt all of this the hard way while designing a knock control system that listens for know only during the power stroke. It also determined which cylinder was knocking.

[@ernestkoranteng2400]

I seriously need your help, I have 2008 Nissan note, this start but unable to accelerate, when I press the accelerator Paddle it does respond, I've change the padle, the ECM and the throttle but it still won't work

[@fernandohood5542]

@@ernestkoranteng2400 Use a scan tool to look at the fuel trims. Look at the o2 voltage at WOT. Check that the 02 sensor oscillates using the graphing function and also read any codes.

[@ritmoalfa6051]

I been working for weeks on a 2000 prelude with a similar problem. Even changing the whole distribuidor and I can’t get a spark from that. When the initial concern on the Honda dealer was the immobilizer control. That what they sold me and they cannot fixed after almost 2 months so I decide to start trying myself. I’m getting a better idea of how. Thanks

[@robertjohnson4401]

I had the same problem on a 96 Civic. I replaced the distributor and that solved the issue. Based on what I see here, it was a rather safe bet. They put everything in there to create the spark.

[@SpokesAndVogues]

What state are you located in sir ? If I may ask ?

[@SchrodingersBox]

colorado.

[@rosewd2]

I have a 88 mercedes 300se with this problem. You'd stop to get gas and the car wouldn't start. Sometimes some starter fluid would fire it off, then it would run. Finally i saw a video from a mercedes tech with the same car and problem. The crank shaft position sensor would heat soak when the car was shutoff hot. Then the ignition control module would not fire properly or good enough to start the car. I changed the crank sensor after measuring the resistance on the hot sensor like the tech did and replaced it. Engine ran fine after that. I didn't take notice of the tach not working in my car, interesting to note that.

[@derekspaar782]

I love your video 1 million times better than scotty Kilmer click Bait video keep up the good work at least you understand car and how they work unlike other people on KZbin

[@SchrodingersBox]

Thanks you!!! yes I have often been called the “anti-scotty” lol. it’s a compliment.

[@derekspaar782]

Lol I like south main auto he knows his stuff and he like scotty as much as you and me lol

[@brianschumaker5912]

I had a Toyota Camry, roughly the same year as this Honda,that had a similar problem but just had a really bad miss. Investigation showed there was an arc to the distributor shaft from the internal coil. It actually left burn marks on the shaft.

[@SchrodingersBox]

Yep it’s known as “carbon tracking”. You often see it in the plug wire boots- especially on COP systems.

[@pigeonsil240sx]

1:24:00 since continuity tests are not as good as testing under load would it be best to test these wires using a test light and jumping the other end to battery so if we see a nice bright bulb while loaded we have a better test this way instead of doing those unloaded resistance tests?maybe even step up the bulb wattage some?

[@SchrodingersBox]

yes a lot of people do that but I really don’t like relying on the “brightness” of a test light for quantitative measure. in fact I have a video where the testlight seems perfectly same as off battery voltage but there was a 4V drop causing failure of a wiper circuit.

[@nathantechnician2475]

Great video as always, the only videos I like before playing them. The content is amazing Sir

[@SchrodingersBox]

Hahaha I appreciate that. I did notice there are quite a few people who like them within second of release. More interesting though- there are a few people who dislike them within seconds of release. these are people who obviously subscribe, but dislike each video lol. how funny!!

[@boosted_streetz8147]

Awesome video! I'm trying to chase down a gremlin myself on my 2000 honda prelude. Has good compression, fuel, but not getting spark on cylinder 4. Has an obd1 distributor converted to coil on plug. Swapped coils and plugs, still no spark on cyl. 4. I'm leaning towards bad sensors inside the distributor, the cyp sensor

[@SchrodingersBox]

What “sensors” inside the distributer are you suspecting?

[@georgekoulianos2489]

Thank you for your patience and the education that you provide thank you 😊

[@SchrodingersBox]

My pleasure!!

[@Keyooshi]

Will a will a bad crankshaft speed fluctuation sensor (CKF) cause a crank yes but no start on a 2001 Honda CRV? Not the camshaft position sensor in the distributor, the sensor down with the timing belt. I have a mystery crank no start when it stalled half way to work. Original only code was P0108, Manifold Absolute Pressure / Barometric Pressure Circuit High. I replaced the MAP sensor twice, 1 used, 1 new, no luck. I have spark on all 4 (same when swapped with 2 new and 1 used distributers, same issue). Plug wires ohm'd out correctly for length. Cleaned plugs, replaced plugs. Fuel pumps rapidly out of fuel rail inlet. All injectors pulse, removed them and they feed gas to a paper towel, BUT if i pour gas directly in the manifold, it will start and run like crap for about 10 seconds if I rapidly floor and release the throttle. Removed the valve cover gasket and checked timing belt all the way around Belt is good and intake and exhaust line up correctly. No missing teeth or damage. Was considering replacing the CKF sensor and a new timing belt since I would be there anyway.

[@SchrodingersBox]

Yes it could. What’s the voltage on the CKF signal?

[@arthurlull8681]

You have put me in your way I thought not possible

[@owenja7708]

hey matt in Jamaica we Toyota Corsa / Toyota Tercel [1998 ] with the same issue as the Honda in this video. if i allow the car to throttle, it will for about 15 minutes the shuts down, if i change the starter relay it starts immediately otherwise, I'll have to wait about 15 to 20 minutes before it starts again. it uses two coil packs. your thoughts.

[@SchrodingersBox]

When it’s running what does the fuel trim show?

[@owenja7708]

The car doesn't give that info and I don't have a scan tool and mechanic s and techs just want to do some swapping out.

[@SchrodingersBox]

Then don’t use a scan tool. Just use a DVOM and do basic checks.

[@owenja7708]

Doing some further analysis and brain storms and checks myself.​@@SchrodingersBox

[@flex_nyc9885]

I have a 1998 cord explorer that will crank but one start. It was sitting for about 4 years after my father passed. Once I towed it to my house I started with the basics. I replaced the following: Battery Oil/oil filter Fuel pump and old fuel Fuel filter Spark plugs Spark plug wires Ignition coils EGR valve Crank shaft censor Air idle control valve Still no luck. I checked all the fuses under the hood inside the box and the relays. They all passed. I didn’t check the fuses inside the car under the steering wheel. Would any of those fuses cause an issue with the car not starting?

[@SchrodingersBox]

What data do you have?

[@flex_nyc9885]

@@SchrodingersBox today I was able to pin it down to an issue in the fuel system. The fuel pump fuses, relays, fuel pump and fuel filter have been replaced. Now I need to check to see if the fuel lines are bad or the fuel injectors. Waiting on a fuel pressure tester to come in tomorrow.

[@SchrodingersBox]

How do you know it’s a fuel system issue? That’s the data I was asking about.

[@JeffreySchaller-t1e]

Thank you very much I love SB. How do I get copies of wiring diagrams for that particular vehicle because I'm doing the same thing right at the moment and haven't found the issue yet tested coil ICM ignition switch main relay you have given me the idea that I need to check sensors again thank you very much

[@SchrodingersBox]

I use AllData DIY for wiring diagrams.

[@Netherlands031]

Long time viewer here, thanks for the content, but I'm wondering about some things. 24:30 you have your test light connected to the switched side of the injector, and the alligator clip of the test light to ground (not shown in your illustration). Aren't you turning on the injector now? Is flooding the cilinder not a problem? Also at 11:24, how much inrush current does that light bulb use, an amp? Isn't there a possibility of frying the pcm/a sensor this way?

[@SchrodingersBox]

great question, actually really great one. no I am not turning the injector on because there is not nearly enough amperage to fire the injector. with my incandescent test light, only 250ma flows and with my LED one I believe it’s only 20ma or so. it requires about an amp to activate the injector solenoid. if I used a jumper wire directly from the injector ground to battery negative, yes then it would operate. IN FACT- that’s a test I will sometimes do to confirm injector operation: I will put a fuel pressure gauge on the rail and prime the rail- then briefly grounding out the injector, I will see a drop in fuel pressure proving the injector not only fired, but it also flowed fuel. also because the PCM is used to an amp of draw, I am not worried about frying it with my testlight. even if I use a jumper wire I wouldn’t fry the PCM because the power comes from a fused source directly from battery and my grounding is after the load. the only way you would fry the PCM is if you, say, jumped the connector with a jumper wire or paper clip or something and then ran the car so the PCM closes ground and you would then put the power directly through the ground with no load in between and it would blow the transistor in the PCM that is making the ground since it is the weakest link. it’s the reason why pcm’s usully do ground side control- much safer.

[@mfreiher]

Hi Matt, was just woundering if you did use a diagnostic tool to see what faults it had?

[@keiththrelkeld5890]

At the beginning of this tutorial you showed that there was no activity from the tach on the honda. If there had been, would it have sent you into a different direction?

[@SchrodingersBox]

Absolutely it would. If I see RPM then I know there must be crank sensor input.

[@tipshikes3682]

Got same problem had problems with it cranking weird not wanting to start and now I’ve put a new battery in that’s not it took it back this definitely helped all have to check this now.

[@johnmwangi6291]

Yes sir... what a blessing you are to us.. thanks 🍻

[@SchrodingersBox]

thank you my friend. You are always one of the first to watch hahahah. By the way another new video coming up monday on SBQM besides this one! that Ford Edge with the alternator issue came back AGAIN!!!

[@rosewd2]

My mercedes since it was 88 was pre obd2, i didnt have the star tool for the mercedes connector. I had an ignition control module - expensive, the crank sensor connected directly to that. Took that to multiple shops snd they were chasing their tail trying to figure it out when the car was running. Apparently the hood had to be shut on a hot car to get the crank sensor in failure mode.

[@johnaclark1]

Nice diag, as usual. Is it possible that with no ignition and injectors firing during all that cranking that it was just cylinder wash in one or more of the cylinders or did this car turn out to have a real compression issue?

[@SchrodingersBox]

oh wow what a great thought!!! ok I admit I never thought of that but indeed I did do a compression test on it and it has a weak cylinder. but damn- I will consider that in the future. that’s absolutely a potential variable. Man I love these comments!!!

[@GripFreak]

That is great thinking!

[@charlesgould8436]

Have you seen the fiat 2.4 with only an exhaust cam and the intake is solenoids? I think the cam was exhaust side for more computer control.

[@FrancesVester-Morrow]

Hello I have a 2011 Buick LaCrosse CXS that will crank, but will not start and I was wondering is that got anything to do with the ground like the video I saw you do on the truck for the mechanics.

[@SchrodingersBox]

no idea. what is the voltage on the ground?

[@jeremyrainwater2175]

Love your videos. Ask you a question. I was trying to figure out why my 2006 Ford Ranger 3.0 would skip after i changed plugs and wires. I thought i wasnt getting a spark and so i pulled out a plug from the coil and it ended up falling from my hand. It landed on the 4 wire hardness! It was sparking all theough that coil harnesses. You think i messed up my computer? Or do you think i need to put all new plugs in and a brand new coil and wires all Motorcraft? My belt also was squilling when it was running. So i 1m just wondering where would you go from here? I havent done anything else just yet. Its hard finding this on youtube!!!! Plesse help me! You are my top online learning mech

[@SchrodingersBox]

I would start with the simplest test first by seeing if there is signal from the PCM to the coil.

[@marcvario]

I heard you say something about adding a new high performance optispark etc. may start throughing p0336 codes

[@SchrodingersBox]

I believe I was saying that lots of people blame the optispark incorrectly for causing codes.

[@arthurlull8681]

Hey Matt...all great 👍I actually had one of those days with that particular system and...distributor ciesed up and broke 😢😳🙄

[@arthurlull8681]

🎉merry Christmas matt❤🤓👍🏻

[@SchrodingersBox]

Thank you!! Merry Christmas as well!!

[@andredwaynewilson6203]

Hi DIY Have your ever done a Gdi Lancer cranking but No spark ⚡️ no engine light

[@SchrodingersBox]

Yes. Same exact procedure. It makes absolutely no difference what car it is.

[@GEricBromley]

I think you nabbed another paid subscription viewer. Well presented , learned a lot. One little comment. Good thing the ICM was not readily available because you seemed to have forgotten your observation of the loosygoosy distributer . Would have been a shame to install a new ICM into a distributor that was heading for the exit. You are now added to my short list. Pine Hollow and South Main are the others.👍

[@SchrodingersBox]

Honored to be considered amongst such great company!!

[@GEricBromley]

@@SchrodingersBox 👍

[@user-2uf2kr2c]

Hello, nice vid. I have a daihatsu sirion 2 with K3-VE engine and it stopped running all of a sudden. It cranks, but no start. I checked all the fuses/relays, they seem good. I checked the crankshaftsensor and it's giving me close to 2000 ohms. So that seems ok. I tested the harness with ignition switched on, no voltage. Any idea what that could be? I still have to check to camshaftsensor though. Regards

[@SchrodingersBox]

Start with the basics - what is the issue why it won’t start- is it fuel, spark or timing? What is the signal voltage from that crankshaft sensor you checked? Ohming it is not useful. You need signal voltage. What’s the ignition signal at the coil showing?

[@user-2uf2kr2c]

I don't think it's fuel, cause i sprayed carbcleaner into the inlet and cranked it but nothing happened. I unplugged the harness at the crankshaftsensor and measured the sensor. It gave me almost 2k ohm, but then when i meassured the harness with the ignition switched on/no cranking there was no voltage at all. It's a 2-wire sensor. i bought the car almost a year ago and it started well/rn decent. The only problem i had was that it didn't really pull through the revs. I measured the voltage at the vvti-harness and it only gave 3,6 volts, according to the manual it should give close to battery voltage(12v). So i had to look into that, other than that it drove quite well. Then about a week ago while driving it jerked once and then about half an hour later it totally stopped and wouldn't start. The coolant light was strangely flashing green all of a sudden, although the engine had already warmed up I had to tow it home. I have a good obd-tool for OPel, but I don't have an obd tool for daihatsu/toyota. I have a cheap elm327 and torque. I'm gonna try that. Regards@@SchrodingersBox

[@andreclarke291]

Next time you leave the distributor plugged in on the power connector remove the 3 Bolts use to secure distributor to cylinder head with a 12 spanner. To diagnose coil turn the distributor cam by hand you will get spark that way.

[@SchrodingersBox]

Good idea!! I can vouch that this works because I remember shocking myself before doing that by accident ahahaha!!

[@thomashernandez-s2w]

THIS COMMENT DESERVES A MILLION LIKES

[@marka.2715]

Around the 24 minute mark when your talking about where you back probed your test light, you didn't say where you had the other end connected. That test light doesn't come on with only one end connected. So where did you clip on the flexible wire end of the probe?

[@SchrodingersBox]

it depends on what you are trying to do. when I am grounding a circuit I just use a chassis ground point. If I am creating an input signal then I will normally either use battery voltage or a 5 V reference bypass to signal.

[@marka.2715]

@@SchrodingersBox You were testing the 0 volt signal to the injector. Where did you clip on the other end of the test light?

[@SchrodingersBox]

well I’m not sure what mean by “zero volt signal to injector” -there is no signal to a fuel injector. But in looking at control, again it depends on where you are testing and what design it is on the control. if the control is ground side switched and you are testing control then you want to be on a feed. if you are looking on the power side then obviously you would want it grounded. If you are working on a pull-up design then obviously this would be reversed. It depends on the design so you don’t possibly blow the PCM. Since I verified this is a ground side switched circuit and I verified the switching and power I know the only possible failure must be injector continuity. Make sense, right?

[@marka.2715]

@@SchrodingersBox ground would be 0 volts. Ground side switched to the injector you were testing. In order for the test light to light up, the other end had to be connected somewhere. I was asking where you had the other end connected to. Battery +?

[@SchrodingersBox]

The ground side of the injector is not always zero volts. remember- it is only zero volts during the ground side switching when you have voltage drop across the injector- it will read 12V when the switch is off because you have no voltage drop.

[@Tony-rl2fr]

I get a kick out of you getting wrangled by idiotic comments. Every shadetree, backwoods dipshit knows better or has a better way, yet you don't see them with a successful channel. Excellent presentation, technique, and information, thanks Matt! 👍🏻

[@SchrodingersBox]

Hahahaha. I would have to say though- scotty has like 2M viewers lol.

[@Tony-rl2fr]

@@SchrodingersBox Rev your engines! Lol, I used to watch him purely for entertainment, I can't imagine anyone taking him seriously. Your channel is on a completely different level. I've been out of the auto repair business for years now but I still find your videos to be top notch. Starting to sound like a fan boi I know, lol. Anyway, keep up the awesome work! (I used to have a nice PicoScope rig years ago but it got ripped off. It's amazing what you can learn and diagnose with a decent scope). Cheers!

[@SchrodingersBox]

Thank so much. this comment made my day!! Yea you are so right about the scope. Once I got a scope my electrical diagnostics skills grew exponentially. at first I though you needed mad skills to use a scope- but now I realize a scope gives you mad skills.

[@mikesabin8568]

Awesome video as usual. Excellent explanation and demonstration of concepts.

[@SchrodingersBox]

Glad you liked it!

[@alexmessina3383]

So Matt, at the point where the ign input didn't trigger the coil, could we have ohmed out the primary on this system ,, not clear if you could get to the ground side?

[@SchrodingersBox]

Yes that could be done by removing the rotor and cover and accessing coil. it can’t be done from outside the distributer though. it would be a fair test for sure!!

[@alexmessina3383]

@@SchrodingersBox I love the detail Matt because that’s where the learning happens ... ohming the coil is never definitive, especially the often break down under high demand, but short cutting the process in this case also shortcuts the learning

[@SchrodingersBox]

extremely well said my friend. I agree 100%

[@harleyclair98]

My 97 civic has a po336 I am wondering if I need to replace my crankshaft position sensor in the distributor in that case get a new distributor the runs and drives but it's intermittent when it pops the po336 code I be driving down the road and i have to clear the code and it and runs find for a bit some days it doesn't even do it.

[@SchrodingersBox]

i don’t know. what is the signal voltage reading?

[@kabirkhan5344]

Mitsubishi Pajero 2008 model car V6 does not get current in four flags, does it come in two?

[@billsmith2212]

Matt : If you want to spend some money , the ATS E Scan Elite will do a relative compression test at the OBD 2 connector , in seconds , also a Volumetric Efficiency Test ( clogged cat , bad MAF ) and a number of other tests . I am sure you have seen Bernie Thompson use it in his videos . However , at $ 1800.00 , a DIY could not justify the expense . And there may be a cost to update . But it's there if you can use it . I see it's all about using diagnostics instead of the parts cannon .

[@SchrodingersBox]

never heard of that. how does it do relative compression through the ALDL? I can’t think that I have ever seen a pid for starter amperage.

[@GustavoHernandez-s9q]

Oh ok im confuse when you test the injector to see if it was ground side or power side did you had your test light connected to ground or did you just backprobe it without connecting to ground and then the computer completed the ground ?

[@SchrodingersBox]

The computer completed the ground.

[@jriversford]

Hat Matt, I have a 2012 Ford Fusion SEL that had a bad fuel pump after replacing the bad fuel pump with a new fuel pump a ran for less than a month the car started losing fuel pressure had to cut the car off and restart again to keep the car running this morning it cranks but will not start so what should I do to get it running again?

[@SchrodingersBox]

Usually this is from sediment in the gas tank that clogs the new pump. Did you clean the gas tank before replacing pump?

[@barneygordon2585]

in how many instances does light on with power and light on with bad ground happen?

[@arvindracing]

Would you have the wiring diagram for 2004 0:36 Toyota RAV4

[@arvindracing]

I want to know where does the Pin 4 get it’s earth from and why is it not connected to chasis ground

[@skunqly]

You are the best on here omg 👏👏👏👏👏 every single of them is very helpful

[@SchrodingersBox]

Glad you think so!

[@skunqly]

What I meant was not only here the way you are explaining is perfect and very professional you know what you are doing not everyone is like you you are very talented that’s all very professional bravo that’s all I can say

[@nickluckleek2445]

Hi mate you have replied about p0336 you said the pcm what is that please thanks 👍

[@danthemanofthelegend9793]

My truck cranks but foesnt start. Starts with the starting fluid and runs well after but if i shutoff, will need starting fluid again to start it... what to do?

[@SchrodingersBox]

You 100% have a fuel problem. Check fuel pressure next.

[@andymasiddo8180]

You’re the BEST! Thanks for sharing your knowledge!

[@SchrodingersBox]

I appreciate that!

[@regaladov95]

Where I can find the compression issue video??

[@arvindracing]

Hi, I need your urgent help to diagnose and fix a crank no start on a 2004 Toyota RAV4 in Fiji Islands. After scanning with a Launch scanner I got the following codes : b1800, b1801, c0246, and c1244. Also note the battery charge light does not come on when ignition is turned on. What I also found out was the there was no continuity between pin 4 of DLC connector and the chasis ground on the right hand side kick panel ( white black stripe wire) however when I put a test lamp on Batt ( pin 16) an pin 4 (chasis ground) the the test lamp comes on. What could be the problem

[@SchrodingersBox]

Sounds like a module problem. I don’t think this car uses CAN yet so I would look at individual module communication but you can’t do it through termination resistance.

[@teejayu.767]

Did you explain how to test the icm? I thought you did briefly. I can’t remember

[@SchrodingersBox]

yes there are several ways. First you check for reference and ground from the PCM. once established you input a signal to to the PCM and see that it is processed by outputting an RPM signal. if all those work the PCM is fine.

[@teejayu.767]

Thanks for the reply! I’ll try that tomorrow. The issue I’m having is there’s power to distributor but I’m getting no spark. The distributor is brand new because I just swapped my d16y8 out for a b18c. The engine is obd1 and my car is obd2a. I’ve kinda checked the signal for the icm I do have voltage at the ecu going up and then I have voltage coming from the under dash fuse box to the driver side pillar. But from the harness side connector c101 I believe. I have a drastic voltage drop. We jump the wire with alligator clips and a new wire and It still only would crank. Didn’t have spark still. I’ve tried my best to diagnose each possibility before taking it to a shop. Still cant figure it out though. I mean is it likely that a new distributor would fail. Could I have fried the icm and coil some how idk. I did test the coil my test light didn’t come on while I was manually trying to get spark but the screw sparked every time. Now take it I done I’m the test light during the day so I may not of seen it. But thanks I enjoyed learning thing during the video. Very knowledgeable and easy to understand!

[@SchrodingersBox]

The distributer still needs ignition signal. Seems it’s missing that.

[@mrfrenzy.]

Maybe you would get a better spark on the testlight if you ground the secondary/body on your coil.

[@jimmym9929]

I have an 02 Silverado which has a intermittent no start but starts on the 2nd sometimes 4th try I sometimes have to feather the gas peddle when starting so it’ll catch. I have no idea what this problem could be and it’s driving me crazy I have replaced pcv valve, fuel regulator, fuel pump, fuel filter, purge valve, cleaned throttle body, and cleaned Maf sensor. All I have done is make noticeable change for the better of the vehicle but this intermittent no start is so random it happens cold start warm starts after reverse parking after driving all day and sitting a little awhile even sitting for a day and me just moving it back or forth 5feet and starting it back up. So I am at a loss and does it 2 to 4 times a week or sometimes goes days or weeks without doing it.

[@SchrodingersBox]

ok what data do you have?

[@charlesgould8436]

The electrical and fuel trims are my fav.!

[@andywrites2141]

Probably doesnt make a difference in the final diagnosis but on the wite diagram and white board you show 9 wires going to the distributor. Earlier you said it was a 8 wite connector on the car. Did i miss something? Thanks

[@SchrodingersBox]

one of the wires was actually internal in the distributer. nice catch.

[@-g.k.4389]

Mines started but still keeps stalling fuel psi 43 on start 35 psi with engine on and at idle my rpms are also high at park and goes normal when I drive 1993 Buick regal 3100

[@SchrodingersBox]

sounds like it’s not fuel then.

[@joemerlongcob9492]

Sir pls do explain the distributor with 7 wire in nissan..thank you so much..i have no spark issue..

[@mcdanielgarageroadservice1045]

can you put in a link for the Cam/crank lesson you talk about in this video. Thank you

[@SchrodingersBox]

Yes it is on www.schrodingersboxqm.com "Cam and Crank Sensor Basics"

[@BrandonSalas-us8mm]

There are 3 sensors they run dizzy to ecu two wires each tdc crank and cam i think

[@hpelisr]

Putting a new distributor is the best choice, why? because of the play in shaft. compression ratio's can vary, as long as it is mechanically sound, and not below minimal standards.

[@SchrodingersBox]

how can a bad distributer cause variation in COMPRESSION?? it will change the timing but how can it change the compression????

[@hpelisr]

@@SchrodingersBox A bad distributer won't make a variation in the compression. I was talking about the variation between cylinders compression. A motor can have different compression between cylinders and still run. play in the shaft of the distributer may make a difference in the spark timing.

[@SchrodingersBox]

yes of course there will be variability in cylinder compression- up to 20% is tolerable in fact. I didn’t understand how a loose distributer can cause any effect on cylinder compression though. The play in a distributer shaft is completely irrelevant to compression. It’s relevant only to timing.

[@barneygordon2585]

what if you tried one long piece of paper or blue paper toweling over all of the injectors at one time>?

[@randycook7184]

I could use some help on this 2010 chevy traverse no body has been able to figure it out I was driving AND battery saver mode light came on and the truck shut off a mechanic checked it out and said that it would need a new motor so I ordered one he put it in and truck Crunk and ran good for a few minutes and then it cuts off and it keeps kicking off a crank position sensor code changed it 3 times and it is still not working it still keeps popping up the crank position sensor code and won't even crank now any suggestions on what it may be I paid $5,700 for the truck now have $12,000 in the truck (motor n shop bills and it is not running

[@nainarkumar]

I would like to know about FET with horn circuit bum how is working FET instead horn relay

[@SchrodingersBox]

Not familiar with that. possible future video!!

[@therealspixycat]

The reason why they switching the ground is because they can use a simple N channel mosfet and switch that mosfet with signal of about 6 volts on the gate of that mosfer. The other way around to switch the 12 volt means they need 12 plus 6 volt which is 18 volt they have to generate specificly for only driving these mosfets. The could use a P channel mosfet but these are less efficient.

[@mikemiller3565]

It would be beneficial to show the other lead of your test light or meter when discussing voltage present on a broken ground.

[@SchrodingersBox]

The other lead goes to ground as mentioned.

[@mikemiller3565]

@SchrodingersBox understood but not shown on your drawings. It is the only way that meter would read, so I thought it needed clarification. I'm not sure if i missed hearing it. Good demo

[@ShowenAlnardoMethjulianVanWyk]

Hi. I think i have a crankshaft position sensor problem. Because at first i thought it was my coilpack that was faulty but i replaced it and i still have no spark at all coming from my coilpack. I have a mazda 121 Soho 1998 1.4. and I took it to mechanics but no one can fix it. I have power going to the crankshaft position wires but nothing happens..please help me with advice

[@SchrodingersBox]

Start with the basics. What is the signal voltage from the crank sensor?

[@ShowenAlnardoMethjulianVanWyk]

@@SchrodingersBox i checked there is no voltage. Only the ground wire is working then i checked the ecu pin and the ecu pin is working but not sending voltage through.

[@ShowenAlnardoMethjulianVanWyk]

Sorry i meant to say the pins that go into the ecu i checked those for continuity and they have

[@SchrodingersBox]

Ok if you have no signal voltage then that’s your issue. Either you have an open ground or open reference. Whats your reference voltage?

[@ShowenAlnardoMethjulianVanWyk]

@@SchrodingersBox i got it to work. The Ecu was faulty. But now it is giving spark And fuel but still not starting. When i crank it ,it doesn't turn over and my battery goes flat quickly and then the starter motor doesn't even turn. And i have a new battery.

[@cesargonzalez6828]

My x5 bmw only starts when the weather is warm it seems like . Battery is charged and ok . Should I go with starting relay or alternator

[@SchrodingersBox]

What is the voltage from the alternator?

[@cesargonzalez6828]

@ alternator voltage 14.2 when AC ON

[@SchrodingersBox]

Ok provided that voltage is reaching the battery you either have a bad battery or loose electrical connection or bad starter. Check voltage drop at starter as next step.

[@cesargonzalez6828]

@@SchrodingersBox good battery good starter says autozone

[@cesargonzalez6828]

@@SchrodingersBox voltage when to 14.2

[@Boooo-id1vt]

Hi schro! I have a Lexus is300 with a no spark but fuel and great compression situation, I followed most of the procedures but I can’t help but to realize my ignition system is ran by an igniter would you possibly know how to check that? I have all of the possible tools needed

[@SchrodingersBox]

I am not familiar with that system off the top of my head. What year is it and I get a chance I’ll look at a wire diagram this weekend and see what would explain that.

[@Boooo-id1vt]

@@SchrodingersBox your awesome! That would be great! I’m so glad you replied I felt I had no luck! it’s a 2004 Lexus is300, a little more detail is : all of the relays and fuses work, my 2 prong ignition coil harness’s are getting its full 12 volts and ground, my crank sensor’s ohms are within speck. The crank sensor harness is getting perfect ground but not receiving any signs of voltage of some sort don’t know if that’s normal. Ecu is in great condition seems to function properly. My only go to is my ignition coils, but I’m not buying them because ima follow your rule to thoroughly inspect and find the issue before buying😁.

[@SchrodingersBox]

Well wait wait- how it possible you have no spark if the coils are two wire but you have power and ground? Those are ground side controlled. Always. Are you saying they have constant ground? If so then that’s exactly the issue. Are are you saying they have ground side control? How are you testing that?

[@Boooo-id1vt]

@@SchrodingersBox well it’s not consistent ground one wire is having voltage to prevent from grounding completely. I’m using a handy dandy test light to verify that on my run position both of my leads are getting voltage.

[@Boooo-id1vt]

@@SchrodingersBox and I’m also using a multimeter, on my multimeter one prong is having its full 12 volts and the other( which is ground) is only having 6 just a little amount to level and keep from grounding completely.

[@carcasscruncher9354]

you sir know your stuff and I am subbing even though I only work on my own vehicle. I have a 2002 chevy astro with a 4.3 in it. I let it sit for 4 days and now it won't start. I have done the armchair mechanic thing and changed out a bunch of parts "because it needed it anyway," lmao, low and behold nothing has worked yet. I am wondering about the camshaft sensor now. I noticed rust on it on the top and all the sides of the sensor. im gonna remove that rust and see what happens, since it is enough rust to throw the sensor off thinking it is reading a distributor rotor. ever seen that be the problem before? thx

[@SchrodingersBox]

does the sensor have ground, signal and reference? that’s all that matters.

[@carcasscruncher9354]

@@SchrodingersBox idk. Any vids on that specific issue?

[@SchrodingersBox]

yes- this one. I used the testlight and dvom to test each.

[@efrensaclolo7021]

I replaced my fuel pump but my fuel pump gauge is not accurate, I have 28 gallon tank but then when I gas up it will only takes 20 gallon max,so there is Still 8 gallons in the tank but my fuel warning light illuminates and the needle is in Empty I gas ⛽ up but it will only take 20 gallons.How can I fix this?