Operation and testing coil over plug ignition (4 wire) - Toyota/Lexus

[@joeandgod1]

I remember watching this about 8 years ago. It's one of the videos that started it all for me. I remember that shop noise being a problem, hopefully that's gone. I've been a successful electrical diagnostics technician with my own business. Thank you.

[@arlinreyeschicago]

Eight years later and I am still coming to this video to LEARN! Thanks for all the great videos and excellent content! 🙏

[@kevinpulver4027]

Thank you Paul! Just fixing my own cars.. I bought a Topdon Phoenix plus; and you make me believe I can learn this stuff. I now understand what the 3 or 4 wires are on the injectors. When you start off knowing nothing, it doesn't take long to double and triple your knowledge base! I really appreciate you taking us along as you think out loud, make mistakes occasionally, and figure it out.

[@ScannerDanner]

Great to hear! Thank you

[@ScannerDanner]

You absolutely can learn this stuff! Glad your are here

[@jameswasher3938]

What a great video Paul. You're a gifted teacher and a brilliant technician.

[@ScannerDanner]

Thank you James!

[@chrisfarley6662]

switching the coils around to find out if its bad or not -- brilliant! I have an intermittent problem, so I switched the plug to another spot and the coil to another spot. Now to see which spot the error returns to. You saved me a lot of time and money.

[@tubetime39]

chrisfaley6662; I used to mow lawn at your moms condo association. So after 7 yrs how did this help you,...or not ?

[@chrisfarley6662]

@@tubetime39 You got the wrong guy, sorry.

[@ScannerDanner]

Thank you so much! I really means a lot to hear from a fellow tech. in the field that what I am doing is worthwhile.

[@jimchandler6605]

This is excellent visual evidence of a clear difference in quality of original equipment vs. aftermarket.

[@SuperCarfix]

Very good movie.I hope the air hammer will be nominated for the academy award for the supporting actor and you Paul win the Oscar for lead actor.

[@ring-and-run]

I always liked to refer to the IGT signal from the ECM as the Acronym, “I’m Giving Trigger.” For IGF, the Acronym is “I Got Fire.”

[@vancheeliu6794]

IGF should actually spelling out "I got dwelling, ready to fire" because it is not yet fired until the trailing edge of IGT.

[@ScannerDanner]

I would not argue with that line of thinking one bit. Great point. In fact I tell my students this all the time. "Don't touch it until you test it" I guess I didn't listen to myself on this one. I am however less concerned for "hard faults" if you know what I mean. For intermittent issues, I agree 100%

[@spelunkerd]

Ha ha ha. You didn't know it but that air hammer in the background was Eric O, giggling as he yanked your chain. Brilliant video, this one clarified many of my open questions.

[@shameelali2549]

Yes that makes perfect sense,after around 100hrs of ur normal & premium vids and my had knowledge I can scope and read/diagnose near on anything on a car,the only tricky thing iAm trying to get my head around is interpreting ignition wave forms properly,thumbs up for you sharing your knowledge,your diagnostic book and pico is the BEST tool I have bought for the shop.

[@RotoRCol]

such a good professor I wish I would have had you as my professor at college

[@TANthatMAN]

ok i'm a pretty new tech(just starting my 3rd year in the field). I'm considering buying your e-book as a reference when I get stuck with a hard car to diagnose. I wish I could of had you as a drivability teacher while I was still in school. These videos make sense of everything I've seen in the field and in the classroom. Thank you for these videos and I hope you continue to make more.

[@razyrazak5436]

I am so lucky to watch your vedio I am working as a mechanic. Your teaching style is awesome. I really appreciate your efforts.

[@ScannerDanner]

Thank you! Welcome to my channel

[@sivucit]

Amazing video, you always prove that you are the best in diagnosis and while explaining you talk in simple terms that always make sense. In otherwords you never talk theory that humans wont understand, which is what many others do in theory class. Simply Great.. I also never noticed that u struggle in middle while explaining, you have ur concept very clear and going from there with not struggle, excellent.

[@nicke2307]

this video was an awesome supplement to me doing some ignition waveforms on my sisters 2016 Toyota camry. Same 4 wire coils. The explanation of the 4 wire helped me undersand what is happening. Also I was looking at a diagram on a 2009 Mercedes Benz S550, same design and I scratching my head at that common wire... now I understand. Again I can't stress enough paul your videos are relevant to so many vehicles. These videos are so packed with good info

[@ScannerDanner]

Thanks so much brother

[@ScannerDanner]

Yes, but we want to do this with a test light, not a straight jumper wire. We may even want to add a resistor in series to drop the voltage as the base circuit typically only needs 4v to turn the transistor on. I have used a test light with no issues but it is something to think about,

[@ScannerDanner]

I can do that. Next one I get in with a misfire. Here is the trick, remove the coil housing and run some old spark plug wires to the spark plugs. do all of your tests this way. also, if you have a scope and a low amp probe you can monitor coil firings from the feed wire of the model

[@nestorfresno1]

good explanation Paul,I never understood exactly why use the IGF signal if you already have a trigger signal to the coil ,but it make sense why they do,that is how the pcm determines dwell time... Thanks Paul....

[@matthewbracewell8137]

I love your videos. Your a great teacher and i love how you explain everything so detailed but yet simple. Keep up the great work.

[@ScannerDanner]

Remember there are two coils inside an ignition coil. You can have primary control and no secondary (spark). So technically when we say the coil is "firing", we are usually talking about the secondary spark. I know I am just picking at terms here, but I would say that the coil was not firing, but we had good primary control. This means the coil secondary was shorted or open. The amp ramp shows the primary control of the coil.

[@josealers67]

I use an air hammer 3 or 4 times a week. I HATE USING IT. Your video is still great...Thanks again...

[@johnkimmel2612]

Paul,with all the noise interruptions, I must write that you have the patience of a saint. lol... great instruction thank you.

[@ScannerDanner]

+John Kimmel haha not really, I just know the camera is on me :)

[@johnkimmel2612]

+ScannerDanner I want to thank you for said camera and for what you do.I will be subscribing to your premium channel. I have been in this business forty years now and honestly have been getting by on the seat of my pants.I have always been weak in electrical understanding and that is all my own fault. That being said at my age I can no longer survive on turning wrenches and such. As I have learned much just observing your brother and you, I have a new hunger to be a complete automobile technician.

[@ScannerDanner]

+John Kimmel contact me thru my website and I'll give you a coupon for a free month of my premium channel. Thanks again !

[@amersino]

One more thing: the explanation of the 3rd and 4th wire were excellent. I'm not exactly the "smartest peanut in the turd" (Bloodhound Gang) and so if I get it, I think most people will too.

[@danieljohnson716]

Paul, Thanks for these great videos. I am an ASE master tech with my L1 and 19 years experience. I have been reviewing some fundamentals lately and your videos help tremendously. I share your sentiment that maybe only 5 to 10 percents of techs in the field perform diagnosis properly. I appreciate all the case studies. Thanks again.

[@inkncraig]

i just wanted to thank you for making these videos. I purchased your ebook and reading it everyday. I already impressed the boss with the knowledge that im learning and using it with my diagnostics strageties i really enjoyed this video. They are very easey to understand and apply Again, thank you Paul

[@Baba_Yaga888]

by the way I've learned more from your videos than all the other KZbin videos I've watched combined!! So thank u for that you're an excellent teacher danner

[@ScannerDanner]

Thank you Michael!

[@mr.nobody9630]

Wow, what a video. Two Thumbs Up. You are one hell of a teacher in the classroom.

[@ScannerDanner]

Thanks so much! It's been my passion for the past 18+ years now

[@patrickliverpool6487]

Great job Paul you are a brilliant teacher. I love watching your videos. I learned so much from you I will continue watching your videos. Thanks

[@ScannerDanner]

Thank you!

[@brakedd]

Finally stopped procrastinating and bought your book. I have the theory that our air compressor is hooked up to our telephone system. When the phone is answered, the compressor comes on within 30 seconds.

[@jeffm247]

Another awesome video scannerdanner! Don"t let the shop noise get to you lol, we can still hear you just fine.

[@israelzunigamascorro9300]

Excellent information. I got the tips for my next car with 4 wires, thank you for all information. GOD bless your family and you too

[@faustogonzalez8397]

Paul, Thanks for reply referencing '86 GT Stang. I'm going to double check all the basic parameters/voltage readings on the coil and the ignition module. Basically the engine dies while in idle, usually takes a few minutes. Especially if run for 10 minutes, turn ignition off and restart immediately. Normal RPMs are about 600 prior to engine stall. She cranks up all the time, during these situations but dies soon after. Compression is about 175 average on cold crank. I have a pressure gauge on the rail and it's 40 PSI rock solid even during the time before it dies. I probed wit a Scope on the computer/ignition module "driver" to the low side of the coil. When the engine starts dying, RPMs dropping, the 12v at the negative coil end increases in time directly coinciding with the drops in RPMs and eventual stall. I think maybe the magnetic pickup in the distributor is acting up and not triggering the coil to discharge and therefore causing the stalling. Once again thanks for the reply, I will recon firm all my parameters and let you know. I do have a video recording of the scope waveform while this problem is occurring. Pete

[@ScannerDanner]

Pete, I believe what you are describing is the ignition dwell time being adjusted by the module due to very low RPM and may be completely normal. Refresh my memory on this ignition system. Does it have a vacuum hose going to the distributor? Is it a magnetic pick-up or hall-effect in the distributor (2 or 3 wire pick-up)?

[@JohnzCarz]

Excellent video Paul. As for the air hammer, just think of it as applause.

[@ScannerDanner]

If cylinders 2 and 3 are on the same coil and only half of the coil has spark, then yes, you have a bad coil. (make sure you replace the plugs and wires too) watch my video on how to do a cylinder drop test. I had a Ford waste spark system with a bad coil that only half of one of them was working and I discuss how this can happen

[@abochavez]

I think the IGF only monitors the primary ignition circuit not the secondary. Great video. I have a 2006 Toyota Rav4 with a misfire coming in tomorrow and I wanted to review this circuit. I think this video also breaks the record for air hammer noise when filming.

[@mrandmissson]

Thanks scannerdanner, with your videos i'm learning how to use a picoscope. I have never use one before

[@bargainspares9531]

Hey Paul, I've watched a few videos of yours, I think your a great lecturer. You really spell out the situation, your diagrams are good and you explain them great, and you scoping exercises are a really good overview of the system working or not. If I had you once upon a time as a mentor I could have saved years and year of working this stuff out on my own. I hope your students appreciate you. And that hammer!! You wanna scream but you gotta laugh. Its a real workshop, and your a real guy with real experience. Thanks for your videos and book.

[@ScannerDannerPremium]

Thank you so much. I really appreciate your kind words and encouragement.

[@natashagoushey9149]

I have a couple known bad waveforms from the exact vehicle if you want me to email them. This car came in, start stall. 2 channel waveform on coil control and fuel injector showed intentional fuel injector shutdown. another waveform on coil control and IGF, showed no IGF signal on #4 coil. And finally another waveform, current ramp and coil control showed no current produced in primary. The shop owner was pretty suprised with a coil fixing a start and stall complaint.

[@theoldwizard998]

Great lecture ! Good explanation of 2 wire, 3 wire and 4 wire COP, Interesting how different manufacturers choose different designs. My swag is IGF is IGnition FEEDBACK, Prior to installing the new coil, I would have guessed that IGF went low when a certain current was exceed and then back high when second current threshold was exceeded. That aftermarket coil sure has a different looking IGF signature and make my theory look incorrect.

[@chrismichaud8204]

would liked to have seen your blood pressure graphed on the scope compared to the square wave signal of the air hammer. Great video as always

[@kevtaylor59]

Nice one Paul, I wondered what that forth wire did and now I know, I bought a Vantage Pro on the strenght of your video's, so now I can check all these wire's, thanks mate.

[@dalenassar9152]

...BEST VIDEO EVER ON THIS!!! A couple of questions: 1) Is the IGT signal compatible with 5V logic (TTL or CMOS) 2) Does the coil fire in the HIGH or LOW pulse (ie is the pulse active high or low)? 3) ...any idea what current is required to hold the pulse active? 4) Will a 12V pulse safely fire the IGT input? Again, thanks so much for the useful information---I LOVE your reactions to the "air hammer" segments!!

[@acptpf]

1) It is a 0-5V signal. 2) The ramp up of the primary coil starts when the IGT goes from 0 to 3.8V and when the IGT goes back to 0V the secondary coil is fired. 3) If you mean the IGT pulse I would say very low amperage since it is powering a transistor in the COP. 4) A 12V pulse on the IGT input would probably fry the transistor in the COP.

[@oldgeordiegeezer3086]

Brilliant - the look on his face at 9:21 when the air hammer goes off.

[@JD-526]

I have watched this video a few times and thought why am I watching this I have a verus not a pico scope. The procedures you are using here can be used on a verus. Great Video. Who needs T.V. when you have SCANNER DANNER. Got to get book and go premium.

[@ScannerDanner]

Thanks so much JD!

[@mcpooch]

Many modern systems shut off fuel for the misfiring cylinder by not activating the injector. If you are worried your car does not have this, disconnect the coil for a cylinder you know is working and check if the injector is still working. Still, I would only be worried about the oil in that case if the engine has a lot of by-blow, has been driven with misfire for a long time, or it has been too long since the last oil change. When in doubt, oil change is always good! Don't forget the filter!

[@Jay_Dahl]

Thumbs up from me! You talk a lot about aftermarket coil differences in this video. You might want to devote a whole video to the topic of aftermarket parts problems, from your own experience. That's something you won't find in many textbooks.

[@aldrive622]

IGT = IGnition Trigger IGF = IGnition Feedback

[@trublue2319]

First of all Thanks Danner my escope ain't got that much detail, but fast and easy to use

[@rickkaiser8573]

just seeing the current ramp shows for #4 verifies control on that coil. current flow is present therefore the IGF didnt see a problem. i get that. what im not seeing is why this pattern points toward the coil being faulty. the secondary windings were the problem if i understand correctly but based on this pattern alone, couldnt this also be carbon tracing past the boot or the plug insulator? or a dead plug? what am i missing?

[@vusimuzizondo3623]

Nice lesson there Mr Danner even though had a little bit of noise disturbance.

[@fidelgalvan3533]

I have watched your videos, wow youre a great teacher !!

[@Chris-f6o]

Another Awesome video! Seening how the new coil throws spark with the test light would be cool- do any ignitiin coil videos show that?

[@asid731]

2006 sienna. Crank no start. I’m supposed to see 4.5- 5 v on the IGF with key on and I only have ground. Does that mean I have a bad computer?

[@RAFICKDAMISONMOYO]

You are great Teacher, respect to you

[@rdtperformance7829]

Definitely the guy with the air hammer love to interrupt you. Really good Thanks for your help.

[@ScannerDanner]

Thank you Ruben!

[@brianker8455]

Awesome - explanation, Very Good Teacher. - Don't worry bout that Air Hammer Tool. Not a Problem - SPECIALLY as you Stopped & made SURE we all Heard your info. Completely. ' Very Good Value. - #

[@angeliquevanmaanen9753]

Good video , i learnt a lot . Best videos on you tube !!! Thanks , graets from the Netherlands

[@rexluongo6470]

If you had purchased a new aftermarket coil. Then had the same reading but still had a slight misfire on number 4. How would you identify whether the problem was in the new coil if the wavelengths are different. Is there a 100% way to know by waveform if a coil is operating properly? Besides just looking for a difference between the other coils? What if you had issues in multiple coils on a v8. That had a few aftermarket coils? How would you know then? In another video you showed that the ramp was not straight and it was a bad coil as the other coils had straight ramps. I notice these ramps have a negative curve on the original coils just above half way to the top. The other video had a positive curve on one coil only and it was bad. It was near the beginning of the ramp though. Is that the key area? Also, what if a coil has a secondary issue. How do you identify that issue?

[@ScannerDanner]

You cannot see all failures in a waveform. Especially when looking at primary and you have a secondary leakage problem.

[@joegenova51]

Good vid very good info do 1 on a cam sencer wireing problem on ground when getting code 340 not cam but on the wireing i think it goes down too tranmission not sure do not want to on rap tape forgot what it is called but some wires have a self ground wire like it has a tin foil rapped around some wireing i no that 6.0 deisol ford f 350 has it i have a f 250 5.4gas hope u can make a vid on the wireing problem or how can i find out were i can get diagram need to no is wire going to injet o thanks

[@joebagofdoe4762]

GREAT VID!!!! Hey what would happen if I did the test light spark test with the test light hooked up to positive side of battery instead of ground?

[@ScannerDanner]

Depends what test. Spark itself jumping to the light? It would still work. Even 12v is essentially a ground when compared to 40kv

[@larsgreefhorst]

Again a sweet video !! Love the airhammer parts hahaha 35 min is so funny Greetings from the netherlands

[@ScannerDanner]

+Lars Greefhorst haha, I hate that tool!

[@dalenassar9152]

@@ScannerDanner ...someone should make an "air hammer" compilation.

[@ScannerDanner]

Thank you for understanding. Feel free to repost it after you remove that part.

[@victor35ma]

Thanks again, super video. Using Verus: there is a IG PID (Ignition Counter PID) along with with Misfire Margin % PID it will address this in seconds. IG counter PID only increments while missfire Monitor is unable. So, if this PID value doesn't change at all, no specific missfire cyl PID will be incremented and no DTC. if IG is not counting not missfire DTC. thats why you need to set up Missfire margin PID. swapping parts will screw up this PIDS. and therefor time spended in diagnost

[@scraiga66]

But can the primary fire without inducing voltage into the secondary coil? Or coils if it is broken in two? My guess is that no secondary spark has to be the result of firing to ground.

[@AutoTechHector]

On your Honda C.O.P example, it reads that you can do a bypass test by touching B+ to the wire that comes from the PCM-coil. On the Toyota this would be the IGT wire (right?). My question to you is how do you know the test light has to be connect to B+, and would it be the same for the Toyota??

[@heathenthatheretic5960]

I have a 94 deville. Lacks power and shakes. I'm guessing it's a spark plug issue . How can I test my theory using a test light? Also no codes are coming up when I manually test it.

[@nickayivor8432]

Good morning ScannerDanner 🙏 🌄 Take care 👍 and have a great day ScannerDanner 👍 Great tutorial thank you 👍 From Nick Ayivor from London England UK 🇬🇧

[@bosaadbosaad6792]

thank you for good explain bro❤ my question is can i check control wire which is green/blue.etc by testlight?

[@ScannerDanner]

Not on ignition coils with the transistor built in (3 and 4 wire designs) as the trigger signal (control wire) is a small 4v signal.

[@Jinglesx]

Paul not going to lie i laughed so hard at that air chisel that was really funny. Again nice video keep em coming ! They Rock

[@nojokeauto]

is it possiable for the coil to send a LGF signal even that the coil never actually fired?

[@diydantex6150]

On a 2011 corolla if you don't have the IGF from one coil it will turn the injector off and not report intermittent faults on other coils. I replaced 1 coil and then had intermittent misfires on other cylinders.

[@ALZWE-LIBYAN-CAR-ELECTRICIAN]

Paul Q: Why Toyota use 2 IGF in V8 engines? Is that mean PCM can't identify which coil not firing when you use 1 IGF. Such as in Toyota V8 4.7L 2UZ-FE engine IGF1 1 4 6 7 IGF2 2 3 5 8

[@acptpf]

Interesting - Each IGF controls ignition firing for 2 set of companion cylinders on each bank. The firing order is 1, 8, 4, 3, 6, 5, 7, 2. 1 8 4 3 6 5 7 2 Companion cylinder's Can't answer why they use 2 IGF's, but curious now.

[@ScannerDanner]

I'm glad you think so. At times it doesn't feel that way to me. :-)

[@dougshaffer854]

I have a question , since the coil is triggered internally and not externally by the ECU would you be able to measure coil primary with a scope or just a current probe?

[@jawojnicki]

Air hammer IS loud as hell, but it has saved my ASS many times. Sorry Danner! Keep up the good work my friend. Love your vids. Awesome instruction.

[@ScannerDanner]

thanks man

[@johnnymalicoat754]

So the only way to check and see if the coil is getting a signal is to put a scope on the signal wire right? That sucks that you cant test it with a dvom,node, or test light.

[@davidallen6685]

Hi Paul, what software are you using on the smart board, love the way you highlight things

[@estrelladelnorte1308]

i think the IGF is "triggered" when amp draw happens inside the coil, to me is looking at amp draw since they dont care about having them all in the same wire, but i am not sure , I would say to your question is impossible , are you thinking on a worst case scenario when computer ecm diagnostics fail or get false information?

[@ScannerDanner]

:-) I was laughing during the editing too. figured a good laugh for others would be welcome, and I guess I figured right huh? thanks again for the video on the wideband O2!

[@SS-U23]

Thank you, it is another great video. I need to know how to find something similar to a labor guide, yet it's used to charge for diagnosis tasks. I looked around but found nothing like that.

[@ScannerDanner]

Here you go eautorepair.adtrk.biz/?a=10817&c=24&p=r&s1= Labor guides are offered as well as service information for individual cars. Same program I use at a professional level that costs a lot of money is being offered to the DIYer for a fraction of the cost!

[@SS-U23]

​@@ScannerDanner Thank you so much. God bless you.

[@Jacobtaylor1775]

2008 Volvo xc90 V8 Sport I have a P0356 Ignition Coil 6 Primary/ Secondary circuit code. I tested the coil with a test light for spark and have a good spark. The plug is fouled. I replaced the plug and after a day or so I get the code again and the plug is fouled...again. I'm thinking injector? I'm not sure. Great Video! I wondered why there were two commons on the diagram. Now I know!

[@ScannerDanner]

could be, or you have a compression issue with that cylinder? Have you swapped that coil to another cylinder? I would do that too

[@nickayivor8432]

God has bless you thank you Sir ScannerDanner PROFICIENT Sir ScannerDanner From Nick Ayivor from London England 🇬🇧

[@dalenassar9152]

On a page from your book: "2007 Honda C.O.P" there is a note indicating that it is OK to touch a test light from +12V to fire the IGT transistor base, thus getting a spark. What concerns me a bit is this: It looks like the square wave from the PCM may be from a 5V-TTL logic processor output port in normal use. Will applying 12V to the IGT digital input possibly harm the digitally controlled switch in the ignition coil? I have an incandescent 12V test light and want to try it with IGF pulled low. I am also afraid of letting INPUT ports "float" (especially CMOS) which may, at times, cause oscillating (due to high impedance) and overheating. I do not know if that input port is pulled down in the ignition coil itself to prevent this HI-Z The pulldown resister may be in the PCM only. In the worst case, the input port is floating 5V CMOS logic. BUT, I really think it is built more robust. Thanks again for the best video I have seen on this coil.

[@ScannerDanner]

Use an LED test light for this test. Yes an incandescent can overload that base circuit. Ask me how I know lol It is one of the only times I will ever recommend and LED type test light

[@dalenassar9152]

@@ScannerDanner I bought an incandescent tester for that...glad I put a 1K resistor in series first! It fired. I DID NOTICE ONE STRANGE THING...The spark ALWAYS seem to fire when IGT went HIGH. I blamed it on contact bounce, but even if I held the base high for a second, upon release--NO SPARK! I am fairly certain that it fires upon release, but I guess I will have to set up a digital bounce-free input to ever see it?

[@ScannerDanner]

@@dalenassar9152 can't answer that my friend, spark definitely occurs when the coil primary current stops, on all systems, in all years. Now, who is to say what the electronics are inside of that coil. A base circuit turn ON signal may stop coil primary current? There is more inside of that coil than you think

[@juancarlosvelasquezx5950]

I have a 2003 Nissan sentra 1.8 and I replaced the spark plugs, coils, air filter, and cleaned the air sensor and mtmy engine is still shaking. what can i do to check if it's my sensor or injector? And when I put my vehicle in drive, it kinda shakes still.

[@GRUSSNewton]

Ordering a low amps probe for my VP on payday! Great video!

[@nasirkamal6333]

can not we test the base of the transistor by using a test light to see if we get an off/on signal?

[@ishmael-zq4vl]

wouldn't switching the coils also tell you if there's a problem with the circuit control? If the misfire condition stays on the same cylinder doesn't that prove it's either a wiring or computer problem?

[@dalenassar9152]

At timestamp 39:36 it looks like IGF is immediately triggered by IGT?

[@dalenassar9152]

Hello...SCANNERDANNER!!! Can you tell me what the average IGT pulse-width's are that you have seen on COP's?? THANKS MUCH!! --dAlE

[@ScannerDanner]

Do you mean how long the coil primary is energized? Under 5ms typically

[@dalenassar9152]

Actually, I needed to know when the HV output arrived WRT the IGT waveform. I want to use this pulse to activate a logic input that must turn on when the COP spark starts or is still happening...yes, an unusual application. I am guessing that maybe trigger my input on the 'falling' edge of IGT may work...or perhaps a small delay 'after' the rising edge. I don't think anyone else could give a better answer! THANKS SOOO MUCH!!!!@@ScannerDanner

[@ScannerDanner]

The falling edge of the IGT is where spark occurs. 😊

[@dalenassar9152]

Really MUCH thanks Danner!!! This gives me a valuable piece of info. I was thinking...If the HV spark occurs on the falling edge of IGT (which I am assuming to be a normally low signal), then it follows that a confirmation signal of the spark, IGF, would have to occur when the IGT pulse is back low, or, nearly so....unless there is some kind of internal sensor (Hall?) that is doing something via coupling, from within. ...still catching up on your videos...wish I had found them sooner than I did!! --dAlE @@ScannerDanner

[@ScannerDanner]

​@dalenassar9152 the igf circuit is supposed to be triggered by the collapse of the primary coil winding magnetic field, but i don't know the internal circuit any more than that, I'm sorry.

[@TANthatMAN]

can you use an amp clamp connected to a dmm? or would I have to purchase some type of oscilloscope

[@greenlanelandroversgllr9092]

Great Video thanks! What I would have been intrested to see is would that new coil look the same on say cylinder No1 or No2 just to see if the old coil had caused a more long term issue with the PCM?

[@VladGoro25]

If we look at IGF and current signal, IGF signal already starts when coil still charging up. Isn't that strange? FIRE confirmation occurs BEFORE actual FIRE.

[@dalenassar9152]

Hello again, I have mu coil firing on the bench, but I need to add some additional external control which requires firing an EXternal custom circuit just when the high voltage spark starts. This means I need to use the digital I/O with my custom circuit. My source of confusion is at timestamp 33:25 WHAT IS TRIGGERING IGF?? Is some sort of time delay with respect to IGT happening here? Or maybe IGF is triggering on a certain CURRENT level (range) through the primary ramp??? There seems to be a contradiction at timestamp range 17:00 to 17:25

[@ScannerDanner]

What triggers the IGF circuit exactly? Can't answer that other than to say when the coil fires, it uses that event to create the signal. Service info says the high voltage spike from the collapse of the primary winding is the trigger, but I believe we saw something that didn't quite match that here.

[@Fudwwwaaaawaaqqqqqqq]

what about the rpm drops on the 4 Cyl. could be on the injectors

[@dalenassar9152]

Hello again...just a quick question: Why does the ignition coil secondary (I'm actually thinking of the black"can" type) NOT fire any time during which the primary coil field is still building UP? There is sure a lot of fast flux interaction from primary through secondary during that time interval.

[@ScannerDanner]

Good question! Yes, voltage is being created during this period where current is flowing in the primary and the magnetic field is moving and building, but it is not enough voltage (few hundred volts maybe) to overcome the air gap of the spark plug. Average kv to overcome the air gap on compression, is about 10kv

[@Z14kt12timandjes1]

I love the credits at the end of this video, "starring a very annoying air hammer!" 😂

[@ScannerDanner]

it's called a shield wire

[@Metal_Mechanic]

The air hammer is one of my favorite tools because it means I’m done playing and something is about to get my frustrations taken out on it 😂 . But yeah I can see how you would hate it in this setting while trying to teach a class.