Duramax LLY - FICM / Injector Trouble / Misfire - Part 1

[Music] [Applause] [Music] their viewers and welcome back to the self-made Auto Channel you guys just never know what I'm gonna drag through the door I've got a little bit of a hard time saying no because you've probably learned at this point looking at all it different things we work on and stuff and you know mentioned before it's all nuts and bolts well let's kind of hope it's the case this time we've got this GMC 4500 or a/c 4500 so a two-wheel drive 4500 it's got the Duramax diesel on it it was well when I was told to he the guy who owns that came from another shop the guy that you know anytime I said came from another shop it's usually one of a couple two or three places but this guy sends me a lot of work he bites he sings and sells them and you know bites all different kinds of stuff so we do a lot of different a lot of work for him you know it's a little beyond what he wants to handle so told me take a look at this he had it too and he knows I don't really care to work on big trucks or you know medium duty trucks or diesels really so much as I do you know like working on gas engines and small vehicles he had this at the wheel caught the GM guy had a GM and or a guy that works for GM something like that I don't really know supposedly he needed a special tool to fix whatever's wrong with it it didn't have the tool and at the dealership you know that he works at they think that somebody stole this tool and whatever so many oh it's our problem now we got to see if we got the tool to fix this whatever's wrong with it but the symptom is I can't drive it's got no plates in it so what he tells me is that it skips it has a misfire dead dead cylinder misfire supposedly the other guy told him that there's no no power at the injector and in order to test you know why you're going to the injector or something like that he needs a special box something I don't know I don't work on you know Diesel's hardly at all not anymore not since I got away from that you know back when I worked in my dad's shop you know I'm like a man tide diesel just because freaks back bad memories but I told we could take a look at it if indeed it is electrical issue I guess I don't care whether it's diesel gas or you know runs on bananas and I guess it doesn't matter you know wires a wire and hopefully in this case it's something like that you know whether it be a module injector or you know Y or whatever but it's mostly the engine lights not on but it does skip so we're gonna it is what we need to so we're gonna plug into it and see if we can see if we can do something so the other thing I don't like about these medium-duty trucks and big trucks and stuff is typically these things you're wired up messes you know cuz municipalities and stuff on them and they have all their lights and you know all the stuff they need to make this truck work and usually usually you look under the dash on these trucks you know and anything that's been outfitted these things are a disaster so we got some miles here rushing low mileage 54 or 487 so we do have a work in check engine light I didn't even pay attention on the way in ya know we just got the daytime running light indicator down there so we'll leave the key on so when you started it sound a little bit rough you know you can you can feel it's shaken and when I pulled it in you know they pretty much had to have it like right till the floor to even make it move good because it was stone cold but so we're gonna see if this thing well I don't think the various supports you know medium duty applications it is a 2005 according to the VIN number so I'm gonna try and see if we can do Auto ID here see if me it does pick it up if not you know assuming this is the same software and everything that the like a one ton runtime maybe we'll just enter in is a you know 3500 and see if we can get the right engine application and kind of take it from there so put it in as an auto ID we'll see what happens here sometimes they can surprise you no it does not support Auto ID well but it read the VIN so v VIN so I got T for 504 which it's gonna be our body which it doesn't have so we'll just pick rear wheel drives here how's that eight then it's a five over four is two so it has that so let's right into this lly 6.6 or to see if we can at least talk to this okay is it automatic just see if we can read data really I think we can I'll be kind of handy alright so we can we can read data what we're good its were thing is so I guess first thing first let's see if we have codes let's go all codes liner we got a p12 29 injector three output circuit well I kind of make sense with what you know what the customer is stating and what he said that the guy at GM found history : what do we get yelled this ignition ok so it's a current code malfunctioning cater service vehicle soon message requests no codes present that's interesting that code doesn't turn the light on even nothing drawn a terrible it's actually 9 ok so it looks like the ticket so I tell you what being over right here let's just go it's our troubleshooter not really is too familiar with these maybe this will give us some direction anyways 12:29 so code sets when computer detects command state an actual state of injector 3 control circuit is not match for less than one second ok so it sounds like we've got a couple pids we can look at maybe command an actual state in the injector it's almost say ok enjoy it will illuminate on second consecutive failure well that's weird then it's not on right now you would think of the drove it here and I've turned it on to bring it in it would not have been on falling one if you'll inject your control code is set open circuit or poor connections most likely cause if groups of 4 injector control circuits suspect shorts short to ground groups are two three five eight one four six seven more than for injector control circuit codes indicate shorts of voltage and a fuel injector and we're just dealing with one so according to the troubleshooter either perhaps we're just dealing with you know a poor connection open circuit something like that okay I wonder one thing I don't know is how these injectors work you know if are they a standard 12 volt injector they like the Fords that you know where they call them the Huey the hydraulic electronic I wonder if we can just go here go to component test see if we can see this thing VIN - right see if we can see how this injector works perhaps I'll see into elf pie under fuel systems they're going check their component information okay objectives are supplied power from the fit come if you want a control module injectors or ground side control so it's a ground side switching jack through 12-volt fed as Quantrill injectors are activated early mechanized fuel control computer uses sensor inputs to calculate injector pulse width and sends commands to fit them to pulse width modulation okay so it's just like a it's just like a car it's like we're gonna have mini man so let's see what we have okay so it looks like the victim has 12 volts and that feeds one four six and seven then we've got a command wire four one four six and seven so then we have 12 volts going to two three five and eight and then command four teeth so let's do B's this should be sent what kind of special tool could we possibly need said Tesla yeah and here's a two wire injector an ism this is gravy train I shouldn't speak before we actually even looking at it I mean listen looks like so if you pop the hood on your c 4500 you can see the air filter and the brake reservoir oh it looks like the power steering cool it I think the engines underneath here somewheres before we looks like these you know these fender liners they populate now so we can work on it we better look up and see what side number three is on I don't know if we have a we have a computer okay so we've got this here this is it looks like a GM ECM so this is probably our engine computer this little fender well comes out well sickly identify anything else I don't know if this this box here is probably our circle maybe let's say anything on it edu common-rail so yeah that's probably our our control module looks like it's got some fresh tape on it so that's always good said no one ever I don't see anything else what else has picked up oh look at this this thing's been cut you never know on these little guys let me tell you got some lawyers or other harness here it's a thing with these diesels you know they can rub it vibrate and corrode sits pretty tight on it inner fender one of those you never know well let's go figure out where number three is and we'll go from there so what we can do is kind of backward we should be able to find the cylinder Bank layout here oh you know what sometimes it's in the guided component tests we were just in fuel system deviation maybe there'll be other injectors no let's see let's go back scanner we'll keep going back here time-savers maybe yeah look at that it's under Ben Cleo okay so passion your side one three five seven driver side two four six eight so it looks like we're going to the passenger side why don't we put a sandal if some things are still a little snug under here so it appears that our injectors are right out here in the open and we can see this is the number three alright is it I'm glad it's not the number one cuz it looks like that's up underneath this module here which has to be our our fuel module the the Pearson fuel hose going to it so let's be thankful that this was our number three it looks like somebody's already cut the wires on it and as you know maybe replace the pigtail maybe there was a bad spot there or something so it's kind of interesting I guess the first thing we can do is will unplug number three let's try the plugs were kind of but we'll get it unplugged and cameras in a way so cannot plug right now with my big meeting magic finger I don't think we have to move you guys I'll get in there and unplug it and then we'll see if we have power we'll see if we're missing a control side power side something's got to be going funky here and take it from there I got our fancy test equipment we're gonna use there I want a front probe into that connecting other connector and I'm head reach in there with a little kick and she slid right off then and we're gonna use one of these front probes I think these are for energy up here so we're gonna put it into the front of that injector it's that little kid I got the ESV I think we just had in a recent video with the Pontiac it's got a lot a lot of different and a lot different here we go got a lot of different banana Jack type connectors these were grateful with the scope little micro piercing probes all kinds of stuff there so we're gonna use this company with a test light I'm just gonna use my test light in there crow bit in there see what we got I'll try to do this with the camera down here we get hooked up to the good ground that's something let's see that's why turns out it seemed to accept that point somebody's been round here by doing the hokey-pokey all right so there's a ground we verify we got a good operating Tesla those things all chewed up to you not a good crowd there we go good grandma okay keys on right now so I assume we're gonna have power on one of these of course we can look back at our diagram I guess watch Parenthood my test it's gonna quit and it did we got to get we got to get a more consistent ground problem in New York oh yeah some good baby laughter now we got a good ground I think let's see that plug in there does come on it's nothing there on that one it's nothing there in that one so I got no light action on either one of those terminals then I verified my tests late does work okay so now what we need to know is this because the truck is not running yeah I got no power on you better run I can see the back of my head I got no power on either one of them just make 100 110 percent that is true where you going to sleep yeah nothing there good testament alright but that's like God start making me upset here you need to find something better nothing folks somebody knows better this is why I use the multimeter there we go nothing airplay Tesla Tesla it's bright okay we have no power at that injector now for the sake of testing I got it sighs just unplug this one here what's that's number five now it was wasn't one three five seven was odd odd numbers in this Bank let's just see ford rinsing angles if we've got power here check our test light that's good just see if one of these its power the way we know what circuit were chasing got no power there got no power there okay so this must not be a key on engine off power supplied unit here I test lights good I'm gonna go ahead and start it up it's such a scene on wiring at that diagram we'll start it up we'll see if we have power if we have power then we'll take our diagnosis from there you guys can see that you're not my class ladies just flickering looks like the pink with a white wire my best light and always guys a little bit of a flicker there where I got nothing that's why it is good listen like that let's just see how this act when it's unplugged that wire doing either one of those must kill the driver or something when we unplug it okay well that test is inconclusive because it appears that when we unplug the number five obviously killed that cylinder you hear the change in the engine but it also you know drop the power to that cylinder so I think it's important that we have a wiring diagram at this point so we can see what the heck we're doing let's just for the heck of it let's see if we generated any other codes by unplugging the number one injector or the number three because that would be helpful you know is it still recognizing the circuit you know is there anything else going on of course we're gonna have a code for number five for sure oh yeah number five injectors circuit problem detector position voltage group control circuit group number two okay I don't know if that's a result of unplugging number five you know I guess possibly so we're gonna do I've plugged number five back in and then shut the car off started to back up and you know it's back we're back to where we started so it obviously reset its reset itself so I'm thinking tests that we do from this point should probably be be back probed or you know current ramp you know I'm thinking that's gonna be the best option so let's go look up a wiring diagram see what we're dealing with alright so we're gonna use this program here Mitchell medium-duty program no five no is the sense of GMC in the GMC somebody at c4 and just like the Corvette baby and this is the Isuzu six six lly that's all of our options we use this or wiring diagrams you should perform at six six all right well I'm gonna dig through these I want to find out where our power and whatnot is originating from for these injectors and then it'll kick the camera back I don't I get some direction here I got some wiring diagram here there is our fuel injectors and we can see we've got it up in here I've got this controls or the others power side here feeds four injectors and then we've got this power wire here that feeds the other four and this is what we're looking at number three so it's the red and white wire that we're looking at it should have power and that comes up and it goes up to our fuel injection control module that's where our power is originated I assume there's no sense of going here and testing it because we know number five injector works it can't work without power so what we need to do I don't know if back probing that would be the best thing that we ought to take just a couple preliminary injector checks obviously there's gonna be some kind of measurable resistance value of this injector we need to check that if we can't find the value we'll just compare it to known good so that'll be a piece of cake and once we have that we can try you know back probing it and checking it for power and we can compare the test results from that you know perhaps number five being that it's right there and we can work on it and then if we find that we have power then obviously we have to check this control site is number three control which is the white with light blue wire you know which also comes up to the control module and see what's going on there come right back over to the various down over here we'll go back to fuel system and the injectors and and we'll do resistance check the resistance should be between a lot points you a zero point four these must be some pretty high amperage drawers here that's almost you know short circuits so really really low resistance any other any injectors with resistance that varies greatly from the other okay other information okay it's a really really low resistance wonder what the current it might be have it probably has some kind of current limiting device yeah they have 22 amps voltage supplied it's 50 volts that's weird why did it why did it tell us and it's a these are 12 volt injectors and then we read that analysis ignition plus I guess it doesn't specify twelve volts from the victim ground site controlled huh ignition positive I mean to me that would mean these things are twelve volts that's kind of weird well supplies up to 50 volts in over 22 amps do not make contact with fuel injector RS ECM or fuel injectors or the ignition on or run position thousand volt gloves Wow warning warning holy crap biscuit extreme caution 24 volt AC what this is talk and AC was it's kind of bizarre thousands psi here we know that this is stating as 24 volts let's see human cost mortgage surge greater than 40 volts DC or 24 volt AC okay maybe just like a general warning like a shot can occur Wow and that's something I'm gonna got slit on this thing like just because you know is it the flyback voltage that's 50 volts I wouldn't and I don't know I would think that we're talking 12 volts here people good thing we didn't blow off huh so what we're gonna do we're just gonna keep on truckin and we're gonna take here we're gonna hook up hook one of these in each sighting injector we're just going to take and check the resistance on that injector see where that's at just kind of start gathering some information we know a little confused on the you know the high voltage applied voltage you know then I got a little Miss information there perhaps they've got a misunderstanding it you know I don't know if when that field collapses when that injector fires you know the voltage it sends back you know perhaps I don't know we're gonna proceed with caution this point so I'm hooked in under there to the number three injector it looks like that one is point 1 ohm so plug back into that number 5 injector back there and that too is also point 1 ohm so we can only assume that's a good value I think the according to the varus there was one point to two point four but we know number five isn't known good so we'll stick with that spin out were right here it took the I got the current clamp hooked back there on the number five on the power feed to that because of periods you know obviously we're gonna throw our testing plugged in I think that's where you're gonna get you know if you're gonna get smoked by something it's gonna be when it's plugged in I don't believe these actually send 50 volts - you know - these injectors yeah it could be way off on that but I think it's probably the you know the release of energy when I you know when it fires is what I would assume yeah I could be wrong this isn't electronics 101 but so I've got it hooked up to the varus or any other bears that's at the Vantage here so let's take and start this off and just get a look perhaps that a good current ramp so we can see what we've got here [Music] I held this waveform for us you see her peak voltage there is about 1.46 of what 1.5 volts so every one volt is 10 amps or about 15 amps here it looks like it must be some kind of multi spark system it you know append two double taps that injector there to different peak times and obviously you know we don't see like that you know like that build up like we would on a gas injector or you know like a coil so this if we seen this not regular jagarico injector shorted but this thing has only got 1 ohm resistance so that's what we expect to see it just that you know a huge amperage spike you know holds it then it releases it fires and for spike you know hold it fires how much time is between each one of those events from firing oops cursors don't use this part of this tool a lot what's our time 2.25 milliseconds between the off time of each injector so now we can see that just a little bit of fact so what we can do now we can move our current clamp I don't suspect we're gonna see anything and this one let's number three so our current clamp is but being an injector doesn't appear to be working let's see we gotta get this back to working again so go to run okay we're back live well go ahead and start it up I don't suspect you're gonna see anything but you never know [Music] [Applause] I didn't think we'd see a [Applause] this still leaves us with a couple options you know we're still kind of kind of back to where we started you know power side or control side you know what are we missing we're going to come up a little different testing method because obviously key on engine off we can't check for power at the connectors because we notice that didn't work I wonder if way you know the first thing I'm gonna do first thing I want to do is I want to clear these codes I've seen you know I've seen codes generate on you know different types of coils you know whether it's ignition coil or it's an injector that driver circuit has a problem even a momentary problem shuts it right down that's it usually they come back with key cycles you know like we've seen with a number five you know we unplugged it ran crappy we plugged it back in it didn't work we actually had to cycle the key so but just to be on the safe side let's just clear the codes we know what codes in it see if you know obviously see if the generators right back if it does and we'll kind of take it from there I'm gonna collect some thoughts you have to kind of excuse me for my ignorance on these I don't you know I don't work on this stuff so we're just kind of you know learning as we go but I think we're I think we've got some good good direction ahead anyways I just turn the key on I'll pop back out here over our scanner clear the code smoke another one all right so we got no codes there let me fire it up sounds like it's skipping still baby area all right so this is the next plan of attack that I came up with I've got a back probe in the control side of the number three and what we'll do is we'll hook it to our will hook it to our meter I've got the other end of the meter hooked to a power source so if that control side is working when it's plugged in we should be able to see it on our Vantage here and I think this will give us some direction you know where we looking for we looking for control side problem and we looking for power side problem so here's looking at this that our control side is good because we'd have to convert the number five but look looks pretty pretty dang similar to you know occur you know another Pfizer it's not some good direction there I think what we can do too is we can we can back probe the power side of course I can compare that we compare this to the number five I don't think we have to let's back probe the power side on this injector and see see if we have anything going on there so this is pretty fun right this is making sense rationalized it in my mind I guess paint okay so we're gonna probe into the power side of number three here back probe into that plug that into switch our test leads no it just lead here do that we got trying to find a known good ground here where we had our test laid before these plants you're a little stronger so key on engine off right now we got ten point six five volts I don't know if that's real voltage oops you know I'm saying that could be just straight voltage I guess we can figure that out we have our Lord Pro here beyond you with us we want to hook this to a doing all this on the camera don't whip this to a ground see if our test lyrics does not see all right I gotta sit you guys down for a minute okay so there's that our voltage is going down actually seven it's actually counting down seven something I might just touch it with a test light and of course it goes right to zero so that's just a ghost voltage we proved it using the load program Jory 50 milliamps can I get a good say my life here yeah geez okay so we got a good guy let's do this again so all we're gonna do is apply a little load to this you can see if you just got this straight ghost voltage and it goes down too we get a good connection on here we go down to zero zero point zero zero so Appleton there's nothing to be concerned about so we'll get this set up on a waveform see if this voltage comes back when we start it and then what we can do let's assume let's assume it does it what we can do is make sure this is a valid test we'll go on number five which it should be in this portion of it this primary voltage it should look like I'm thinking it's gonna look like you know that I'm a primary voltage kind of like a spark plug a little bit you know we're gonna see that firing event of this coil and you know we're gonna see the you know the voltage spike up I'm assuming or I see something like that so we're doing the wireless pickup it looks like we have our event I should be using barrister that we may we actually may use Pennywise expectancy we're on to number three [Applause] I wonder if this thing or tell now other things skipping her down [Applause] okay so the problem going on here it's crazy I just gotta stop and think for a minute the you know that the power sight test on an injector I guess it doesn't matter for in one or five or you know what the warden we're in because you know obviously on the wiring diagram all the powers are tied together at least on for the injectors so you know this would be you know just like doing you know current ramp testing or anything in the fuse box like on the gas engine we're gonna see each injector we're gonna see for those injector on the power side yeah so we still have no we don't have any current okay so we got no current there but we had we had the you had the control side you know and when we when we were using the advantage there we hooked the power we hooked to the control side you know we could see it you know pulsing that ground mm-hmm this is weird just trying to do some do some thinking I think the test I want to run I guess I'm still indecisive astrologically I think what I want to do you know to make sure that we're definitely missing this event okay so the injector seems fine that's a you know 0.1 ohms so that's that's good what I think we can do is we'll to I guess to verify the power at you know the Keyon running power because the things gonna be running to have power at the injector number three which is our suspect injector I think what we need to do is back probe the power on a number three okay so that's going to give us our you know that's going to give us our waveform and like I mentioned it appears it is just like in the literature that's hooked to the number eight cylinder number five the number three and the two so two three five and eight I believe according to this wiring diagram are on on the same power feed so so if we if we back probe that we should see our our signal there and then I think what we need to do for control so typically we would use like a cylinder identification you know but we're not gonna grab a hold of a spark plug wire on this thing so we'll use a current ramp on another channel too but we're just going to the number five look at that waveform I thinking you know when we do that we should see our missing are missing cylinder we should you know I'm assuming that we will I don't know what this is gonna tell us I think it'll tell us that you know perhaps our our power feed to that injector assuming we see you know a good waveform is good or at least the wire integrity right up to that injector is good I think about it manases uh that's almost 7 o'clock I mean take a break get something in my stomach here and do some thinking but we can do that test real quick see what we got all right so here's how I haven't hooked up we're on the number three injector we're back probed into the power side of it and on the number five there I threw a current clamp on I've got it set up on a dual trace on the lab scope so let's capture this waveform go ahead and start it up here all right so here channel channel 2 is our voltage and this must be so so this kind of proves proof concept we knew this was gonna happen like this this is our current ramp for number five down here on the yellow trace okay so this is our current ramp right here even though I'm probed into the number one cylinder for the number three we're seeing the firing event for the number five right here because all the powers share the same so technically we should see four of these events right in a row or shut it off so that's where we choked to death in here so let's back this out a little and see we can see right now that we're missing an event which we knew so here's cylinder number five here's our missing cylinder then you know whatever other cylinders right here we should see one more firing event here so we're not I don't know for any further ahead than we were but we can obviously see that event is not happening and that could be on the account of the you know control side or the power side I've got to give this a little more thought here I just saw it's kind of a neat waveform bid to capture we can see the fire in event there at number five so I just want to take a second and look at this waveform and I want to try to understand it because we could see that our injector is running and like I don't know 17 volt something like that and there's no no current being passed through it so let's just you know this could be any any volt that any kind of measurable voltage would know current and then all of a sudden we have current draw of oh you know 15 amps or so or even higher kind of spikes up here almost 20 amps but then look look what our voltage just too goes up to like 48 volts ish probably you know just very very briefly and then then it starts to decline you know then we've got this downward slope from around 9 volts down to 5 as the current is being applied or as there's current flow current stops pops back up to our our baseline voltage of 17 or whatever it is and then repeats that process for like this twin firing sequence or you know I don't really know what to call it not very familiar with these I don't know the terminology but what's weird is you know if we had let's say 17 volts 18 volts whatever whatever this number here is being applied and then all of a sudden our driver turn on so that's what we I can assume at this point here you know when our current goes up that's when our control side is commanded on you'd expect the voltage to drop but in our case the voltage you know spikes really high so must be that that high voltage is must be being applied from the control module at the same time the current is being applied if that makes sense so you know must be the you know the power side is turned on amped up whatever you want to call it the same time that the control side is also being commanded on and then must be a custom at the same time you know that coil saturates up pulls the injector open you know you can see the voltage decreases releases a checker closes then it opens the injector again so I just made that observation I don't know I'm just still trying to think here a little bit so just for the sake of testing I went ahead and I moved our back probe in the number three to the control side now I've got the current clamp still where it is back there number five what I suspect that we will see is the same thing we saw when it was on the power side because that injector is not you know not functioning nice soon we're gonna see the voltage being passed through the you know the 1 ohm resistance of the or the point 1 ohm resistance of the coil and I think we're just gonna see the same waveform to be honest with you so we can take a take a quick peek at that just trying to get a little bit of direction here to be honest oh yeah [Applause] that's the same same thing we were seeing that's kind of what I expected well I don't know think here I guess because I haven't learned anything other than the fact that number three is still not contributing you know we can see it missing we see the current rant missing I don't see any real anomaly there in fact it's missing I hope I'm not way off and my thinking that you know the voltage being applied to the injector at the same time the currents turned on that seems plausible I guess and then you know super super savvy and in this and electrical theory and you know internal components and you know things like that but what kind of the wave form it kind of appears that way so being that we probe the control side and we're just seeing you know the voltage from the number-3 coming through that coil if the victim sends power the same time it sends you know a control signal to give an injector you know we could still have we could still have both both problems here number three you know is it not is it not firing the number three you know sending it's 50 volts or whatever that voltage is to it is it not is it not sending that or is it you know is it also not sending the control to it you know also so then I don't know and we can't really test it control when the plugged in because we're just gonna we're gonna see this voltage you know coming from the other injectors right through that through that coil I don't know if we I guess I don't know unplugging it we I think I think we already had it unplugged but we're using a little Vantage checked in to control the control side of it I don't know if that's a valid test that'll you know what I'm saying let's give it some more thought I think what we can do I wanna grab the winter diagram the control model this thick um they call it it evidently receives its signal to fire the injectors from the ECM then it processes that data and gives us their smoke it has itself let's see if I can find it here injector control number three injector control number three so that comes from the engine computer and then then there's these other wires that go to the number three injector and I'm here they call them injector control also so injector three control so one ghosts actually to our injectors the other one comes from the ECM so what if you know what if this wasn't receiving its signal to you know spray diesel fuel so why don't we just go right to the victim and see what kind of signal that is I don't know if it's you know power side switch ground sight I don't know what kind of signal it sends but I think we can figure it out we can always compare it to a known good to this fickleness right up there looks like connector c12 connector c1 c2 so it's like a couple connectors there so why don't we why don't we go to that next and see we can figure out that's what I did is I took and unplug the lower connector on that Sikkim I used and I found the control wire for a number we're number three and number five just because that's when we've been using we know that we know that song is good and doesn't have any issues there what we'll do is we're good these plugged in I'll get me set up we'll see what that signal looks like get our scope set up here say we're at here [Applause] so you just fired this up so channel 1 or yellow channel here is the number 3 control from the PCM to the vikram so this is what the victim is seen so it looks like we're going from 0 to 5 goals so it must be a pull-up style 5 volt input and then the green trace here is number 5 injector [Applause] rather change our time basis here here we can change the ten bowls know what our scaling is [Applause] a little better definition they've had a good round [Applause] we're gonna have to change our time basis we want to see that other firing oh yeah I guess it's not gonna be in the screen area alright so there there's both of our firing events here's number one ergo I'm sorry number three and that's number five and they look the same so it's going from zero to almost five volts this is going from zero it's just a smidge over five volts I don't know if that's really anything to worry about control sides being drawn a little bit higher I don't know well we can see we've got both both signals for sure I think that kind of eliminates our ECM as being a culprit being that it is appears to be sending the signal to this control module this fuel injection control module for the diesel injectors I guess we just have to come up with a definitive way you know that thing just not processing the data or you know do we have a you know a wire you know there's a control wire open circuited down to the injector I don't believe it's the power side wire because we can see when we were when we were back probed in our injector we could see the the firing events of the other injectors you know through it you know I think that kind of leads us down to the control side here come up with a definitive way to test that I think we can kind of make a call yeah I just looking at the wider diagram I think the the easiest way to tell perhaps if our wires is broken on the control side to the injector to injector number three is let's test because we've seen our our voltage waveform at at the injector and the control side you know we've seen that you know we've seen out the power side that we've seen on the control side for number three even though you know we didn't see a firing event for number three so why don't we just take and we're number three the number three control here comes out of this out of this victim it comes out of the other connector comes out of connector c1 so it's gonna be the bigger wires why don't we just back probe that if we see our you know all of our other injectors firing event you know coming back down that line then we know our wires good and we know at that point that this control module does not have the ability to control and at that point I think we could say that the control module is toast because there would be no other sense in checking powers and grounds going to it because everything else works we've lost one one circuit so I think I'd be the easiest test to do we can you can check our here now if we check that and we're not getting any voltage up there we're not seeing the other you know the big vaulted the 50 volt voltage spikes you know from the other cylinders then we know we got a broken wire so that's a pretty quick test I think we can do ok just see we're at that's the control module there I just pulled the back cover off the back of that plug I'm in the white looks like a green but it's actually white with light blue so I actually be our number three control side all right and then we'll I'll set up the scope of course we only need one trace now we'll set that up in at 50 volt scale we'll see what that looks like and I gotta assume if we're seen I hope I'm not wrong on this but if we're seeing our you know our voltage feedback from the other injectors then that means our wiring is good and we have no you know the the victim there is not controlling the number three injector boy into that corner well there it is that's a scene same pattern we've seen before at the control module courses and a STONER number three remember this is right here let's see that's we're still going to see the missing event sorry for the shaky camera this easier go record back out now we should still see you see how we're still missing we're still do we've got still a period that we're still missing you know an event that should be right here control modules bad well starting to look to me like this this víctimas van appears to be receiving its command to fire from the ECM of course that was like a smidge higher on the voltage then you know the number 5 you know was like what 5 volts instead of you know 4.8 or something like that you know is that a clue I don't know I would I kind of more suspect I'd have a missing signal and now we've got you know we can see the parade of the other injectors keep on comp coils these will smoke skin to my brain we can see the prey to those up on the control side so you know that tells me the wires intact all the way up to the victim the only thing you know I wonder the you know this victim must it must apply high voltage you know the same time it provides you know making it fire you know the ground side must you know turn on the ground side the control side and then increase the voltage you know which ultimately gives us this big amperage boost and then you know you can see that being drawn now it's kind of neat but I guess shame on me for assuming it was you know just this 12-volt style injector you know like I said I just read on the you know I'm the varus they're like oh yes you know been issued voltage supplied and ground side controlled so yeah I mean they're all willy-nilly my tests like I come to find out of this think it fry your brain there's not a big warning label on there saying don't touch this but live and learn that's why I got my education so here we are I guess one last thing we could do before I make this call on this thing is we can take and unplug it and then we should have our resistance reading of our injector right up here the victim the you know 0.1 ohms you know of course we're gonna have some wire and some connections in a way so maybe you know smidge smidge more resistance than that but I would expect something you know there abouts so why don't we do that and then we'll call it time it I went unplugged it and I use those little terminal probes there out of that we've got from AES wave there and I've got it probe in there to the power feed to the number three injector and number three injector control side I've got our clamp slipped on there we are at 0.3 ohms kind of toggling down arrow point 3.1 I guess to prove that we're hooked to it I can go under there and unplug it and we'll see this reading should go to infinity yeah I got it own up to a mistake but not not a big one hang on here whoa so I was plugged into when we just did our last voltage test wait now I don't plug the injector in the resistance reading stayed the same so I'm like panic so I started double-checking my wires and I said before I was in the white with you know light green well that's actually a real wire color the white with a light blue that we were supposed to be in is actually on the bottom side of that harness it's the kid below it so needless to say I went through and redid our voltage tests they got the same exact result I'm kind of glad I did the you know those old check but needless to say when I was home checking the right wires you know I still had the point three ohms or resistance on plugged in then I went to infinity and beyond and then like I said I read the de volta check so we're still good so I'm gonna make the same call but hand me a little nervous there for a minute so I guess at this point we're gonna leave it at that I mean unless I'm you know blatantly missing something because the lack of knowledge of the system I'm working on it appears that that control module the fuel injection control module it just isn't controlling you know here's our nYSSA's is good you know it's not stepping up the voltage nor is it turning on the control side of it that I guess well we wouldn't really know that because we don't have any you know applied voltage to it so you looking at that waveform and that current ramp if it was turning on the control side you would think that let me show you coming up and going off is here where we can see what the heck we're doing yes I guess you guys can see that okay so this is our waveform we captured you know just real quick I want to see this for a I had to go through and read caches because I didn't save it last time we'll just yeah this is like I remember what it is I'll come back and fix it leave here we knew that you all that okay so it's gonna be our current ramp a number five and then our control side we're probing the control side of the number three oops let's pick out an event here so what I guess I guess my thought is I guess where I was going on my train of thought is if if the control side of our injector was still working so we can see we have this baseline voltage of whatever so what what is that voltage let's see here it's eighteen point seven volts 1819 volts okay so we have this 1819 volts here in between firing events and that's number five firing I would think if the control wire I'm number three injector was turning on even the control side it would take this and pull this right now it would take our 1819 volt here they drop right down to zero we'd have like a little dependent how much current this could carry which I assume this is some kind of bias voltage or something on there to detect you know whatever it detects maybe open circuits stuff like that you know so I assume this is some kind of bias voltage goes volt or something because it's obvious to me you know maybe what you're wrong on this but I think what it looks like is that you know at the moment this coil is commanded to fire so right there that exact time you know our current draws up the the voltage is turn applied to that injector that's the only thing to me that kind of makes sense and you know we see a big spike in current you see a big spike in voltage you know that it's kind of you know holding it open it appears for its for its cycle you know I I assume that pin hole opens at this point and inject you know the injection process begins and then you know it's closed and then you know reintroduced again here just moments later you know a few milliseconds later let's see here so start to start we're looking at two point one nine milliseconds I hope about what I'm saying makes sense you know just ramble and babbling a bunch of crap here but okay say if that control side worked you know independent of the power turning on I would assume that's waveform a drop rate to zero you know we'd see we'd see a big glitch here and then then we know that we may know that okay you know our power wires broke but I I'm pretty sure we've got a bad control module that's that's my final answer I guess one more observation this shows that good on that screen I just sitting here is getting ready to go home so when it when it does its ignition initial peak here you know as this current builds up and you know this panel the injector goes open let's see if we're carrying a steady current but it appears that you know these oscillations here you know it's the thick I'm controlling the voltage you know if that's dropping down to zero volts and then back up to ten obviously still carrying current you know across this path is it you know is that Duty site must duty cycle that and a you know just kind of something I observed there before it you know finally cuts it back to essentially turning it off no current flow and back to this bias voltage so I didn't know if everybody saw that I think before when I first captured these waveforms I may have had the filter turned on so we might not have seen that deep that level of detail right there so I just something I thought was kind of kind of neat worthy of looking at I think that's it I just called the guy who owns it and told them so I think he says he has a he perhaps has a another der max on there with that this lly engine in it is what they refer to us that must be to our peel code of this engine and you know maybe we can take the fit come off of that and you know swap it on here just for verification and then you know they don't have a truck and they'll pick them well yeah I think I'm pretty happy with my test results and it appears that the victim is receiving its signal they're two fighter and it's just not doing anything with it and you know we appear that we've got a continuous loop all the way down through our injector and our ejector is good so I think I made the right call so we'll find out when we get a new one right or wrong I'm wrong I'm at doing my research but a little shame that I didn't pay you know didn't do a little digging on this injector before I went and did the Hokey Pokey to be honest with you I don't know if it could have got stupid or not but it didn't so another day maybe there's no day folks so check us out on Facebook and Google+ and all that business and subscribe to our channel if you haven't done that and you want to stay up to date with all of our repair videos we roll out here each and every day you know a couple times a week anyways and just remember viewers if I can do it you can do it thanks for watching [Music]

Channel: South Main Auto Repair LLC

Views: 536,686

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Id: 4k-G1dMgFUo

Length: 71min 59sec (4319 seconds)

Published: Thu Jun 16 2016