How to Not Fry Your PCM- SBQM Channel Free Video Sample!

This is a sample video from my other channel Schrodinger's Box Quantum Mechanics. The channel is here:
www.schrodingersboxqm.com
This video is the final part in a 4-part series I did on techniques you need to master if you plan to do the PCM controlled component testing you often see me doing without frying the PCM.
If you would like to master this material and be more confident in your PCM electrical testing skills, head over to SBQM and you can finish watching the entire series for free within 2 weeks!

[@labradormcgraw]

This guy is absolutely brilliant. No wonder he's so popular. You wouldn't get this level of tuition at college, let alone on any other KZbin channel. And this is one of his earlier videos - he's only gotten better since!

[@SchrodingersBox]

🙏🏼

[@MarzNet256]

Yes. He is incredible.

[@orionmyth]

We have no excuse not to step up our diagnostic abilities with this kind of (free) content 😎

[@yoyo54314]

30 minutes extremely well expended. and I passed all the tests,. thanks to you of course.

[@stephennichols586]

Been doing air-conditioning and refrigeration for 40 years and now I'm retired and I enjoy working on ars and just learning automobiles and diagnostic but I have always used the troubleshooting any electrical problem source ,path switch , load and sequence of operation to test electrical circuits and don't get overwhelmed with the electrical diagram or schematic ,just knowing what isn't working and only be concerned with that find the component and follow the path backwards to the voltage source .I have enjoyed your videos and I have learned in a few weeks of watching you and your explanation of the sensors and components the ecm and the pcm are controlling and that's what I am looking for thanks for sharing your knowledge and I am going to subscribe to your advanced learning channel. Looking forward to learning and sharing some of my experiences and helping younger students and future technicians

[@vusimuzizondo3623]

Just love this topic, it shows that you've to know and be patient when coming to electronic wire harness and their sensors and modules. Thank you Matt. Great work 😀👍🏽👏🏽

[@emiliomunoz2037]

Thanks for the knowledge, it has improved me tremendously in the diagnostic side. Your a very good teacher.

[@SchrodingersBox]

Gotta love the negative commentors who wouldn't know how to diagnose a dead battery much less a TPS. Am I wrong or would only a fool thumbs down the source of knowledge that would finally make them competent?

[@themountainman2613]

I don't think a smart knot with a balljoint hammer would make them competent-- they know how to cross thread spark plugs. Most of us like to know how to diagnose and (repair). People like to hate what they don't know or understand. Your channel is extremely informative, thanks for taking your time to teach us!

[@SchrodingersBox]

Jeremiah johnson "People hate on what they don't know or understand" Words of wisdom there my friend- that is so true!!!

[@renewedautodiagnostics6525]

+Schrodingers Box I don't think the test done around the 14 minute mark is a good one because if the coil was shorted then you could draw more than 10 amps and blow the meter fuse, your thoughts?

[@schrodingersboxquantummeka2008]

+Nikolay Baranyuk Good point- you're right!

[@SchrodingersBox]

bidoubleo tiwhy Happy thanksgiving to you too my friend. And yes- the comments are gold on this channel. I also learned more from the comments than I have in 7 years of doing this hobby- by far!!

[@abubakarisadiqueibrahim481]

Your explanations goes down soo well. It's very easy to understand you than most of the videos i do watch. Thanks keep it up.

[@SchrodingersBox]

Glad you like them!

[@remotaurog]

Great video,your right about doing this stuff on cars,you can look at diagrams all day long but nothing beats the testing experience.

[@guledmah5872]

The best teacher I have ever seen thanks for your efforts

[@abdelsadinodio7841]

Just awesome and crisp explained. I definitely love your videos man!!!!!

[@stephenhowe5123]

Thankyou for the info.Reading other comments proves your correct that we all learn our own way to diagnose even when they do not know it and turn to negative remarks. Thanks again.

[@jimschiltz5343]

I really enjoy your videos, Matt. Good job!

[@jasonjoncas5998]

Also very important have the the right size terminal to probe the terminal to not overspread it. And to test the drag on the terminal for a good tight contact. In my 30 years experience many problems are caused by other techs spreading the terminals causing additional problems .

[@SchrodingersBox]

In your 30 years experience you use a noid light set instead of just a test light???

[@prosperandbehealthy]

*Thanks, great video. Like you said in the beginning of the video, if you don't know basic electrical, learn before you start testing. It seams the Auto industry purposely make many sensor's that eventually fail, but what you are saying is that you have to look at the whole picture because it can be different problems. For Example; I just changed my fan resistor and wire connector because my car was overheating. Yes, the resistor and connector wire was burnt, but the radiator was also clogged, and I had to change the radiator, but I had to go much further and change the thermostat and The cheap plastic housing. That finally solved the overheating problem. Thanks!* 😂😂😂

[@shiewaanwyeth5922]

You made my day sir. Your info is just what the doc ordered. Thx.

[@SchrodingersBox]

Thanks you made my day too!

[@chrisdaniels4674]

Thank you for the fuel trim diagnostic information. Really helped me understand something I knew nothing about. This guys a genius

[@johnsippel983]

gotta love them ls engines! I just did an ls1 swap in my thirdgen Camaro one of the hardest things iv done wiring wise but I had to learn it all on my own witch made me much better at it, its so cool seeing you do exactly what I did when wiring my car up

[@tomaszradomski5411]

Great video Matt. At 19:36 you mention that it would be a good idea to use a fused jumper wire which I agree with because there is a small possibility that the underlying problem was an internal short in the injector. That in turn would blow the fuse on the wire supplying it with power thus matching the previous symptom of 0 V coming to the injector. But if we then supply the injector directly the jumper wire might carry enough amperage to blow the pcm. So it would be best to always use protection ;)

[@davidostring7627]

Thank you for posting this video. It was really helpful.

[@NotizLp3]

Best video 👍🏽😱 great instructors! Great brake downs and examples!

[@giftofnile]

Thank You Scroding Box you have a great VEDIO class room instructions solid advise

[@siphomabhena4437]

Thanks for your videos, are much educational and I'm from South Africa

[@Gsxforsale]

For some reason you jumped onto my recommended videos and for that I am thankful. New subscriber.

[@SchrodingersBox]

Thanks for subbing

[@topezful]

Application of fundamental understanding, I have learned alot from your videos , desperate to see complete series.

[@mtrltoolman]

great video , priceless lesson thanks matt .

[@frankminakin1080]

Just found you on KZbin all I can say is simply amazing content also video length is perfect for my treadmill use every morning 👍🏻

[@SchrodingersBox]

Glad you enjoy it!

[@mingovazquez704]

Thank you Master for share your knowledge with us, well explained 👍

[@Derabjee]

Looking forward to your videos on diagnostics with scope. I've been using the picoscope for a while. But it actually doesn't matter. Once you get the basics and realize what you're doing you can work with any scope.

[@John-rz6sp]

Great video. Happy Thanksgiving to you and your family also.

[@SchrodingersBox]

+John B. Kobberstad Thanks John, same to you and your family!

[@dade567]

Great stuff. I thank you for sharing your knowledge. I want to understand concepts and using critical thought in my work.

[@SchrodingersBox]

You are in the right place!!! So far i've only found 80,000 others like is in the whole world so we're not too common in this field!!

[@persadramnath6945]

Very good explanation

[@armandofierro700]

I'm so happy that you were so nice to people who didn't understand why the paper clip was a bad idea, LOL.

[@jonathanrpu]

Enjoyed you and descriptions of other Knowalls but know little....Enjoyable series of videos...all the best and keep well. N.Ire. The U.K retired and love the show.

[@anthonysandyafful7526]

Great job, well done

[@rulebraking]

Awwwwwsommm! Just what I needed not to fry my ECM- signing up for the subscription!

[@lmstuber6044]

Brilliant brilliant video. I'm going to be joining your membership. Iv been a membership of mercanic mindset for about a month now .And watching pine hollow auto diagnostic and subscribed to you for a few years now IV learned a lot about the basics on this one.👍

[@SchrodingersBox]

Thank you! I guarantee you won’t be disappointed!!! It will be the best $3.49 you ever spent I guarantee.

[@timgroleau1612]

Well done.

[@davidm3210]

Very special stuff, thanks.

[@SchrodingersBox]

Glad you enjoyed it!

[@stephenfiglewicz2317]

very educational. thank you.

[@joesno406]

Your The BOMB BRO!!!! (Some having a radiater fan not working situation ), I seen people use a paper clip to insert into the coolant temp sensor end that feeds power/signal to the coolant sensor to bypass the sensor to see if fan then works Is this a nono too?

[@elbertmarks5799]

Outstanding.

[@sabergermd]

Another great video on electrical diagnosis. It seems some people were really trying to get your goat below. I see you held your own but you do make it too easy. Trolls will be trolls. The issue with the use of a scope is not so much price but the steep learning curve involved in getting useful results. I recently bought a non-automotive Picoscope (2205A) and have been learning to use it for relative compression, secondary ignition wave forms, current ramps, etc. I have spent hours learning how to set up the software (Picoscope 6) and probes(amp clamp, induction, etc).

[@TheWicklunds25]

YES more on basic electrical please...

[@SchrodingersBox]

Duly noted. My pay channel has LOTS on basic electrical diagnostic procedures. Very step-by-step. Still in process of development but will let you know when it's ready!

[@alrifainidal]

thank you for awesome explanation

[@aminullahfaizy6154]

Thank you sir for all you do for us like you said we need some more video basic electronic diagnostics sir

[@musaalgheriany8917]

yes it was a very useful lesson for me thank you so much

[@roundcornerent]

Matt, you and your videos are just fantastic man .

[@SchrodingersBox]

Wow, thanks!

[@ekimbrough1413]

Thanks Matt! This video was double GOLD! God Bless! Yes, please produce a video on Bi Directional Scan tool! I will be purchasing one in the very near future, and need the tutelage on how to properly use it! You have my thumbs up and subscription! 😃

[@SchrodingersBox]

Awesome, thank you!!

[@ozzstars_cars]

Makes sense to me, good diagnostics

[@charleswilson4598]

I am a retired electronics tech . I am no expert mechanic but I have repaired my cars since my 20's (now 82) and have reasonable mechanical skills. I have rebuilt a couple of engines, but there is a lot I can't do and a lot that I don't know. I drive a 1992 Ford F150 that has three relays. But I have been paying attention to the newer cars too, and have helped troubleshoot a couple of them. That taught me how much I don't know. Right now I am working on my grand daughters 2010 Cadillac srx. I had to get a new scanner and it shows a U0100. From the symptoms I believe the problem probably is a bad ecm, but I am checking the power and grounds to make sure it isn't something else. Anyway, bottom line is that I have decided that modern cars are really computer systems with an engine attached. I find the automotive electronics very interesting and want to learn more so here I am.

[@kamranjalalian4034]

Brilliant demonstrations, even though some people think you go over the top with the explanations! Of course having the right electric wiring diagram is a must. Any idea where your viewers can download the Ford wiring diagrams, preferably for free?Keep up the good work.

[@user-pw8yu7nd7p]

Thanks for your wonderful videos I would like to ask you as a beginner in which order we should see your videos

[@SchrodingersBox]

As a beginner you should probably join my pay channel www.schrodingersboxqm.com

[@TheWicklunds25]

I'm definitely better at the mechanical than the electrical but this crash course is worth its weight in gold.

[@elkarshofyelkarshofy1490]

Excellent

[@Riyad7]

Awesome. That's great

[@bradwettig3441]

Its amazing to me that anyone who owns a computer can't afford 4.50 a month (about 15 cents a day). Most people probably lose that much in spare change every month. There is nowhere else I could find this quality of information for this price. Keep the videos coming!

[@SchrodingersBox]

+brad wettig I like the math reference!! I easily lose 15 cents a day from my pocket digging my car keys out!

[@RADMAGE01]

+brad wettig For just 15c a day, you too can help freezing biologist-mechanics in Colorado warm their garages through all 9 months of winter.

[@SchrodingersBox]

John Ris Hahahaha OMG please dont send Sally Struthers over here- I don't nearly have enough food for her

[@donniejohnson7499]

Another great video. Your a great technician an I did scream a few times.

[@thanoongiravi4892]

Please do make a video on how to use a scan tool. That would be helpful. Thanks

[@tomclark3592]

Matt I am going to subscribe to your pay site tomorrow. Loved this video!!!

[@SchrodingersBox]

Thank you!! You will love it I guarantee!!

[@stephenmccann3621]

fantastic

[@SchrodingersBox]

Thank you so much 😀

[@simonashley8914]

what a great youtuber you are sir thank you and take a bow lol

[@Viper81766]

Your videos are excellent and you have one bad ass Pontiac .

[@SchrodingersBox]

No argument here lol! Thanks!!

[@waiting4aliens]

thank you.

[@Pablo_Automotive]

Hi Matt. very good tips. =) When you measure this type a measure i recomend use the Multimeter VRMS es more exact because the multimeter VRMS cant measure voltage out 50Hz. But if you have a osciloscope not is necesary. A big Hello from Spain.

[@carpro2406]

I love you sir thank you so much

[@shayrhussain9188]

Awesome explanation sir, I found this video related to my recent Honda Element issue. I replaced the TPS sensor and during calibration, I feel possibly I fried my ECM because when I used the volt meter I mistakenly connected the black lead to Battery + and the red lead to the signal wire or 5v wire accidentally or both together, I heard a sparking sound but I thought it can be a relay or fuse noise. Well, when I tried to start the car it was cranking but no start. The fuel pump stopped priming on the ignition key in position. The next day I noticed the immobilizer green key flashing in the inst. cluster along with Check Engine Light and oil pressure. Also, DLC or OBD2 connector showed a linking error earlier that was working perfectly. Because of the check engine light, I am still hopeful ECM is good but in some forums, I saw ECU can still be bad. Kindly guide me in light of your best experience for possible reasons and fix. I checked all the fuses and relays are good along with the power and grounds.

[@preetdhillon764]

Thanks sir

[@JH-bh5lm]

Now that I have gone through this video about 10 times I have one question. The test no.6 looked very similar to the last test you did, except in the test no.6 when you tested the fuel injector you did not use a DVM in amps mode you simply just took the power directly from the battery. I understand that DVM in amps mode does not provide a load but I didn't see the reason for using DVM especially because you have a scan tool where you can clearly confirm the work of a MAF sensor. Is this assumption correct or am I missing something? Thank you

[@johnnymalicoat754]

On the last question. Could he possibly blow the fuse in his meter if the ckt draws more than 10 amps seeing the maf is fused at 20 amp?

[@armandofierro700]

This guy at times can be bit of a smart ass but can you imagine the comments he has to read. On the other hand I learn everyday. This guy is great!!!!

[@SchrodingersBox]

Thanks- yes I do bite back in the comments lol!

[@mertvak]

thanks a lot!!!!!!!!!!

[@likezdislike]

Superb video!!! 26:30 makes me laugh that's always happen to me 😄

[@anyheck]

And thanks for the interesting exam :)

[@patrickmoran6004]

You do do some brilliant videos. Could you do one on why I do not get a battery dashboard light when my ignition is turned on. The alternator is charging the battery at 14 volts.? Any ideas?

[@SchrodingersBox]

There is a wire from the alternator to the dashboard- either its disconnected from the alternator, its broken on the way to the dashboard, its disconnected at the dashboard or there is a failure on the IP circuit board.

[@Partytime1excellent]

not bad at all! i would of thought putting jumper wires with the plug undone to sig/ground and the power feed from battery straight to the 12v pin, bit more mucking around though

[@joesno406]

Now if I praticed your current test (16:00) with black and red test leads switched But in same sequence Would I get same result? Not sure if I can remember sequence in test lead colors!!

[@micheller8014]

A thumbs down does not mean it is bad content. Sometimes it is the way it is delivered.

[@SchrodingersBox]

Yes, there are some people who are too stupid to realize the content is all that matters

[@donaldwarren190]

Can the last test inform me of coil pack connection from coil to fuse???

[@nandanalal5072]

Thanks

[@SchrodingersBox]

Welcome as always!!

[@jamesbailey7785]

I have to admit I am struggling. Thanks for your help.

[@trainer2018]

Matt good job. I have something I would like to add. When you were checking battery positive supply at the injector connector unplugged that test is not totally valid. That test is only telling you if you have a open circuit or not, you are reading static voltage. You have to load the circuit to see an actual representation of the voltage at that wire. So hooking up a test lamp or using a substitute load rated the same amperage the injector is would be a better test. Or use a Loadpro which is what I would use.

[@SchrodingersBox]

+busjockey1 I was not testing for voltage drop at that time but I do check voltage drop through amperage measurement later

[@trainer2018]

+Schrodingers Box Alright so you were just checking to see if you had static Voltage? Sorry that just threw me off because you said that was a valid test. For checking for a open circuit yes. I understand your process here but you might want to clarify the difference between a Static Voltage Test and a Loaded Voltage Test: Voltage Drop. Someone new to doing this type of work could get confused and in effect not do these measurements properly.

[@schrodingersboxquantummeka2008]

+busjockey1 Yes remember this video is part of a whole 4 part series where I talk about all this stuff. I also talk about static vs loaded voltages in my video on voltage drop on this channel.

[@trainer2018]

I figured you did it's just at that part in the video on how you did that test I think it would have been a good idea to clarify this difference between the static and Loaded Voltage. Not trying to be a pain at all it's just I want everyone to understand the difference between these two readings. Keep up the good work.

[@trainer2018]

I will check out your premium channel, looks interesting.

[@dancin4]

What scope/probe do think is the most useful? Are there any features to look for...I had a Heathkit!!!

[@schrodingersboxquantummeka2008]

+Dan Sisulak I have a video called "introduction to oscilloscope" that covers this

[@GripFreak]

This video is a great example for anyone considering joining the SQM community to go for it. This is a final video in a series on the SQM channel. The prior videos teaches you what he is summarizing in this video. Can't recommend the paid channel enough.

[@SchrodingersBox]

Thank you my friend!! Glad you finally got access!!

[@RADMAGE01]

FINE MATT.... FINE! I'll go do my free trial of your new channel. But, somewhere deep down I know this is going to be like taking the free hit from the heroin dealer. Pretty soon I'm gonna be pawning stolen sneakers for a SBQM fix. Damn you! Actually I have just been waiting for a nice long weekend to start the trial. So good job on the timely reminder.

[@schrodingersboxquantummeka2008]

+John Ris Hahahahaha all part of my master plan lol. Big difference between what I'm doing and a drug dealer though- I purposely target schools lol.

[@ScorpionRegent]

+John Ris Not a fair comparison. Heroin just makes you feel good, this stuff allows you to improve your life. If only all knowledge was that addictive. I know that SBQM is going to be a valid monthly expense for me. It will easily pay for itself.

[@Z14kt12timandjes1]

Can a picoscope oscilloscope probe with a positive and negative alligator lead fry my computer if I probed a wire with the wrong clip attached to the battery or does it have built-in protection similar to a test light?

[@SchrodingersBox]

if you measured current incorrectly it would fry the scope but not your laptop. Test lights don’t have built in protection. they are just low amperage. Measure a 50mA computerized circuit with your 250mA testlight and you’ll fry the circuit all the same.

[@robmut1357]

Great video and very instructive. (I passed, by the way. Yay!) A minor question on the four cylinder remark at around 12:15: Why would the events happen faster? An injector on a four cylinder engine would fire at the same rate as a six or eight cylinder engine at the same RPM, correct? You get one fuel spritz per cylinder for every two crank revolutions on any four stroke engine. Only revving it up would make the events faster. Also, on an unrelated subject, is all that white cable sheathing stock or did you add it?

[@SchrodingersBox]

+Rob Mut True at the same RPM- I guess I was thinking how usually smaller engines rev faster but correct at Idle there would be no difference. The white wire sheathing was actually blue but it turned white within a few weeks because it was cheap crap lol.

[@billsigsbury4680]

@@SchrodingersBox That is Funny. I thought you used white because it was "cooler" than black reflecting heat away protecting Wires and Hoses from intense heat cycles! ;)

[@jeroenkortooms3959]

Hi Matt, I'm still new on this stuff and I find your videos very instructive. I was just wondering if that last test could impose a risk. Would it be theoretically possible that there was a a short in the MAF sensor itself? Wouldn't that blow up your meter at best and at worse the pcm?

[@SchrodingersBox]

No because the last test did not test for amperage in series with a potentiall faulty component.

[@jeroenkortooms3959]

But at 25.03 you set the meter to AMP mode. If the fuse on the first part of the circuit is blown, wouldn't it be drawing the current thought the meter?

[@DonJuanRicoSuave]

where is your Patreon??

[@garyc134]

On these tests, how about the noid light tests?

[@SchrodingersBox]

+gc Yes a noid light is always safe- it cannot cause damage because it is a load between the power and PCM. A testlight is exactly the same thing as a noid light but I think it's way easier to hook up a noid light since it just plugs right into the connector.

[@octavebourgeois5101]

in this video dated 2015 you close with an announcement of doing a video on scan tool operation. Is that video currently on youtube? Thank you,

[@SchrodingersBox]

yes it is on my channel at www.schrodingersboxqm.com

[@3134902]

hey great video i did screamed

[@johnnyappleseed7400]

Looking to some classes in auto mechanic. I would really like to learn from your classes. How can I get in touch with you?

[@SchrodingersBox]

thanks but I just do this as a hobby. I am not in the automotive field therefore I don’t teach classes.

[@user-yg6vq1kf7c]

U said u get 9v because d injector is on ,how could it b when d hernace is disconnect an your dvom lead is on d hernace

[@m.b.smoshitoa8325]

HI MART, I LIKE YOUR VIDEOS BECAUSE IN MANY CASES YOU TRY TO USE DVOM WHICH MOST OF US HAVE YOU USE SOMETHING ELSE WHERE IS NECCESSARY. THANKS FOR THAT LET ME ASK THIS. I THINK DVOM ON CONTINUITY HAS VERY LITTLE RESISTANCE. AND I HAVE SEEN YOU ON ANOTHER VIDEO TRYING TO FIND WHICH WIRE WAS NEGATIVE. YOUR DVOM WAS ON CONTINUITY AND THE CAR WAS ON BUT ENGINE OFF. THEN YOU PUT ONE LEAD ON NEGATIVE AND THE OTHER PROBE ON ONE OF THE WIRES ON THE HARNESS. FORTUNATELY IT BEEPED AT FIRST ATTEMPT AND YOU SAID MMMM THIS IS MY -VE. BUT I WISHED TO SEE WHAT WOULD HAVE HAPPENED IF THAT WIRE WAS NOT GROUND BUT FROM PCM. WOULD`NT YOU HAVE FRYIED YOUR PCM? AS I BELIEVE DVOM IS JUST LIKE JUMPER WIRE IF IS ON CONTINUTY I USE TO FEAR TO DO THAT. M.B.S MOSHITOA (SOUTH AFRICA)

[@thnkbg]

So if a component on a circuit shorts, its just like not having a component at all & therefor its not considered a load? A shorted component is not considered a load on a circuit? therefor my PCM can burnout?

[@SchrodingersBox]

A short is the opposite of a load.

[@arthurlull8681]

Thank-U-matt&UR-VEWERS💥💫

[@SchrodingersBox]

Yes the viewers are the ones who make it all possible!!!

[@elisahachiles634]

In a fuel injector what is a normal amperage one injertor in four cylinder engine thanks

[@SchrodingersBox]

About an amp. My preference is to test the counterelectromotive force ramp pattern to look for a short in the winding however- the current itself is basically not informative unless the circuit is open.

[@Quantumoprh]

Mother of God. That was fun.

[@mahdijoumazadeh996]

ok thanks mn