In this video I have a look at a customers GMC Yukon Denali with the big 6.2 that was towed in for a no start not crank. I have seen this enough times it's just as easy to take a guess rather than busting out the tools. Not to mention we already did a video on one of these.
UPDATE: Customer had me bypass the connector and throw away the module and the battery light went out after tightening up the positive terminal. I just had it resting on there when I went out in the lot to bring it in. Now he can go get a sticker on it and get it on the road 🙄
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That folks got us in 2007. It's a GMC it's a Yukon that's the Denali I Assume it's a 5-3 and there could be wrong. Uh, it doesn't run, doesn't crank, it doesn't do anything, and it's got an inspection that's a couple years overdue and it's not even registered on the road. Uh, the guy made the appointment.

There may be a lack of communication on my part. Um, but what I was told is that he put an oil pump in it and since then, uh, it's had electrical trouble and it's stuck in second gear. That's basically all the notes that I have on it when he made the appointment. um, tried calling him to see if this is a new symptom.

I See there's no parental display on the dash was there's a Prindles there, but there's no line under what gear it's in and again, it doesn't crank. it doesn't do anything. Uh, it was out my parking lot. the battery was unhooked I hooked the battery up.

battery seems to have a charge on it. You know you can move the shifter in and out. windows go up and down. horn honks that kind of stuff.

but that's it. so that's all I know. so let's get after it. Give me an idea here.

I come in to hook up the alltail figure I might better show you. um so key on engine off. We do have an engine light which is good. no Prindle display like I say I don't know if we got a I don't see a backup camera.

service, suspension system put open. what else was there? Park assist off but yeah, when I go to try to start it, nothing happens there. Pretty neutral. Nothing happened there like I said yeah we got a horn.

we've got headlights. you know? seems like we have everything like that. You know, power windows go up and down so no clicking? No nothing. what's up Miss though I got you a package.

Perishable, huh? All right. Well thank you I'm trying to let it Auto ID it's not happening. So we're going to type in the VIN number uh manually which this tells us basically that there is. you know, no, it's going to be a no communication situation.

Yeah there we go. Disadvent scan failed which I need so this is a 6.2 I should know him being at was the denial version. Uh so just my big fat guess going into it is the suspension control module is rotted out in the back. that's my big fat guess.

Um so anyways, let's figure it out the right way. So I'm going to let it go through a system scan here. I Think what we'll find is everything on the high speed data Network here is not going to function as we can see it's all grayed out but everything that runs off the class 2 or the low speed here I think it's class two on this is likely going to function and be tattletailing and they can't see. you know stuff on the high speed.

Network So we'll let that finish and then let you guys see what we see. It's all done we're going to go. to report: Skip that uh supplementary passenger presence module erratic loss come with radio past your presence high voltage, low voltage invariable serial data receives that's probably an airbag light on for a while I'm guessing uh, driver's doors problems lost kind of with HVAC All right, Well, we're just going to make note of these. Nothing really to worry about.
A lot of history codes and stuff in here. Those are all history codes like I Say with the battery being unhooked, probably had lots of dead batteries and yeah, because these are all past past all history codes. All right, let's focus on the fact that we have a no com with anything on the high speed. Network I think uh, probably pattern failures and experience is going to help us with this one.

Pop right in here. Pin 6 and 14 is what we want to look at for our high speed can and we can see we have nothing. It's at one and a half volts and just kind of chilling there. I'm on pin 14.

and that's at about I don't know. three quarters of a volt I would guess yeah, about 700 millivolts and then back on pin six and that one's sitting at 1.5 volts. Um, the low speed I Don't know what it is if it's pin two or pin seven I might we might have to look this up. thank you but that that one is talking anyways.

You know what is the J1850 Is that Pin two? No, it's not blinking. There we go. There's Pin One. Okay, so pin one's flashing at us all right and there's where we're communicating on our our low speed Network Um, so just in case you wanted to see that so there is com there.

But when we look at our our regular high speed on pin 6 and 14, nothing's happening. Uh like I say I've seen this enough on these Chevys to know that usually it's just a module that's gone Haywire on us and on the Denalis and the Escalades and stuff. it's typically the suspension module sometimes but not always I Think we did another one of these videos on a Yukon and I don't recall I don't remember what we finally looked back in the video. remember it's a maroon Yukon around the same era I Want to say that I always probably suspension module on that one too.

So let's um, before we dive too deep into this, let's just raise it up in the air, give this thing a visual inspection. It looks super rotted from up here and like say if it's been sitting a couple years. Boy that can that can add 10 years to a car Pretty quick. Welcome to New York baby, that's where your friend belongs.

Lady, this thing smoked. unless you ride it boy, gas lines and everything are ready to explode. She is rough. Front brakes are solid.

Rust looks like it got oil sprayed at some point in its life. But wait, can't hardly turn these wheels. She's rough. man.

cross members are running out of there. Thank you. There's our suspension control module. What's left of it? I Just slapped.

Uh, Pin Six here. Pulled up on our scope so we can see if only unplug this if our Network comes back to life. Nice part Bob. He's being all rocking out because uh, the module comes out nice and easy.
Nice and easy. It's got one rat hole through it, so that's usually a pretty tall tale sign. Looks like somebody's been here before though. Hot damn it broke.

Oh listen, bing bing bing. Oh, the whole connector fell apart. Oh yeah, somebody's got this thing jammed rightful. Dielectric Grease and stuff.

Of course. that's what we do. Bingo, Bingo, there's Pin Six. There's Pin 14.

we'll take and get a little more time on your screen here. All right, so we can see we have some data network communications restored. uh, without even looking a wiring diagram. I Do know that up here somewheres I'm as hard as usually is the other half of the resistor that's taped to the harness.

but the truck should probably still start and run without it. I'm just I'm Gonna Pop That connector apart and put this back together just in case we end up leaving this unplugged. Sometimes it's easier to fix a car with experience than it is actually looking. Of course, nobody really learns anything from this, but yeah, boy, they really got that thing.

Patrick Full of grease. Maybe they were trying to fix another problem probably the service suspension light that was coming on and off intermittently would be my guess. I'm pretty sure it wasn't that long ago that we actually did a video on one of these. Nobody ever fixes these.

Oh actually, well, this is where your compressor goes ladies. So yeah, so never mind. so nobody's fixing this one. I was gonna say the compressor is usually routed out and I don't know if we ever put up that video.

We did one of these where I think I mentioned in the video that it was the first time in all self-made Auto history. So we actually fixed the air suspension on one of these vehicles. Typically when these things come to me, they're they're done. It's smoked.

You know? it's like this one frame trotted. It's not worth doing anything with junk. and I think the one that we did in that video I think we just cut the network wires hooked them together. but uh, Anyhow, that was about this.

How about we exit out of here? Oops. Oh oh gosh, come on. Chase Let's go back to our Diagnostics or history and this is the work done. I think it's 07.

it should be able to talk to the high speed now even though that resistor is still unhooked in the back. Let's just go fault scan see if we have communications. Yep, we do. So now our our ECM is back online.

Tcm's back online I've got to wait till I hear from the customer to see what he wants to do. I mean obviously there's no sense in putting this in or you know, getting a new one because the compressor is missing and then there's really no sense in fixing this truck because it's completely rotted out, frame smoked, everything on its junk. But at least I don't have to pull it back outside with a lawnmower. I Guess Well it was littered right, full of no com codes and all kinds of codes in there.
Let's just take him for Grins and Giggles just start it, see if it's got its gears and then that. I've just gotta wait for the guy to call back. All right, we've got our printable display. These six twos are so awesome.

All right. Service suspension system of course we got reavers. hey. ABS Works Battery lights, Huh? Foreign? all right.

Beautiful. It doesn't seem to be stuck in second gear as he was mentioning. All right, Yeah! I Made a shift at least all the way up to Fourth There sounds like there's some Rust flying out of the back stop I Guess that's it. I'm not going to go any further with it.

It's obviously not charging, so wait to hear from this fella. It's kind of a short silly video folks, but it just goes to show that sometimes diagnosing stuff I guess if you will diagnosing we use that term lightly here or guessing at what a problem is can be helpful if you are familiar with some pattern failures of a particular brand or symptom. or you know, however you want to use the word there that I'm not using right? The fact of the matter is, this is probably the eighth or tenth one of these that I've seen come in with the same symptom and the same exact problem. So something like this is pretty easy.

Now if this had a spare tire in it and it was, you know, not a New York car and it wasn't all rotted out, we would approach this a lot different. but being that we'd seen under the hood like oh, this thing looks pretty rotted under the hood it's going to be smoked underneath which we saw, you know, the frames, rotted cross members Rod brakes, gas lines. that's that's junk cars junk So then we could go right for that thing. takes a you know a minute.

you guys seem to unplug it and see if we're right. If it wasn't then we're going to stop right there and do our our diagnosis like we should. Uh, you know the proper way. but sometimes pattern failures really help you and help you not waste a lot of time.

Uh, nothing more really saying this. I'm gonna wait till I hear from the guy I assume he's just gonna have us cut the wires Loop them together and you know Adios Muchacho! And I just sent them down the road but I don't know what he's going to do with the truck. probably have to get a look and stick them somewheres somewhere other in my shop. I'll tell you that and then I don't know if he's gonna drive it, but like I say with all the brake lines, gas lines, stuff ready to blow, it's just going to be an endless you know? Money Pit Not to mention the frames are added so that's it.

Comment Section: folks, questions, comments, concerns, see and see the Facebook you know where rat folks. Not a tick tock though jerk and just remember viewers. If I can do it, you can do it. Thanks for watching foreign.

99 thoughts on “Sometimes a lucky guess is way easier than an actual diag”
  1. Avataaar/Circle Created with python_avatars tortoiseandthehare says:

    if anyones looking for a good muscle engine this is it
    part this one out and recoup your loss and make a hunter gatherer buyers day

  2. Avataaar/Circle Created with python_avatars tortoiseandthehare says:

    yea the module came out nice and easy
    surprised it was not hanging loose dragging the ground with dog bite marks on it

  3. Avataaar/Circle Created with python_avatars tortoiseandthehare says:

    how do you know you are in old york
    you aint in kansas no more dorothy
    rust belt buckle usa

  4. Avataaar/Circle Created with python_avatars mark ket says:


  5. Avataaar/Circle Created with python_avatars Matthew Riordan-solid axles are king says:

    How much crap will consumers take before automakers go back to simple vehicles. Old school Throttle bodies and no options

  6. Avataaar/Circle Created with python_avatars Brian Kirkland says:

    What makes a car won't start but on the third try it will crank

  7. Avataaar/Circle Created with python_avatars CJ2007 6.7L says:

    Sell the engine and junk the rest. Those 6.2 bring a nice chunk of change

  8. Avataaar/Circle Created with python_avatars ian 50 BMG says:


  9. Avataaar/Circle Created with python_avatars thermobollocks says:

    If the car's already disassembling itself you don't have to disassemble much. Genius

  10. Avataaar/Circle Created with python_avatars Sam Bell says:

    To me engineers are some retarded knuckleheads why would you put an electronic component at the lowest point under a vehicle so it can soak in water that you’re driving through

  11. Avataaar/Circle Created with python_avatars Joe Boonen says:

    Another awesome video, just blows me away seeing the amount of rot in these newish vehicles. Never see that here in NZ , mind you we dont have salt on the roads either haha. Such a shame.

  12. Avataaar/Circle Created with python_avatars Hoobs Garage says:

    I was having the same problem with my Escalade so I pulled that module and all is fine now. I didnt cut and splice those wires though but it's been driving and acting just fine for months now. Anybody know what happens if you dont do the bypass wire splice thing?

  13. Avataaar/Circle Created with python_avatars D Hyde says:

    I have to say that Pacifica, California may be the Emperor of Rust. I saw a car there with a hole rusted THROUGH the roof. That brine spray off the beach does a number.

  14. Avataaar/Circle Created with python_avatars C Thorn says:

    Past experience is really important I like the fact that Eric verified his diagnosis as he always does.
    My opinion on the
    Frame and body rot is the public needs to be aware That you need to take care of your cars frame, and body when you’re in any states where there is snow and salt is used on the roads.

  15. Avataaar/Circle Created with python_avatars Aaron Schmieman says:

    2012 Sonic LTZ 1.8l hatch, I got traction control, steering system, check engine light and get the same response when turning the key. No codes and I'm up in the PNW so, no corrosion worth mentioning. Any modules or experience with common causes on the sonic? I've cleaned grounds 100-400, all battery wire connectors, starter, alternator. when I reattach the battery, the car makes a single long chime tone and then looses its mind and sounds like a classic bicycle dinger. drains battery down to around 6.3v and I'm trying to get a new one soon.. Is it just a combination of bad brush connection on starter, bad/minimal ground and battery connection, loose terminal on FPCM/TCM connectors and a bad battery slowly overworking itself? Appreciate any thoughts, before I go crazy and DIY battery wires and my harness out of speaker wire and cut up jumper cables. lol

  16. Avataaar/Circle Created with python_avatars Gary Townsend says:

    I enjoy your U Tube channel. I recently subscribed and wanted to communicate. I am new to this so bare with me. I want to ask if you have any experience with BG products. I have an 89 Cadillac Brougham with a 5.0 Y motor and an oil cosumption problem, started out 1 qt at 50 mi. Using various engine flushing products and frequent oil changes l have gotten it up to 1 gt for every 300 mi. Minimal oil leaks, new valve seals and some highway driving is how l got to this point. Do you have any experience with the BG motor flush treatment?

  17. Avataaar/Circle Created with python_avatars Zedrone says:

    Refreshing to watch a true technician, instead of dealership parts replacing monkeys.

  18. Avataaar/Circle Created with python_avatars Arnold7221 says:

    Again great hands on with experience.

  19. Avataaar/Circle Created with python_avatars Pete M says:

    As a dealership tech you need those pattern failures to make up for time lost on other job .

  20. Avataaar/Circle Created with python_avatars B rabbit says:

    Absolutely agree, experience has been my first option in diags

  21. Avataaar/Circle Created with python_avatars Joe’s Auto Repair says:

    What autel model scan tool do you use in the video

  22. Avataaar/Circle Created with python_avatars Harry L says:

    Trying to keep up but lord it’s hard to – keep ‘em coming Eric! 😂😂.

  23. Avataaar/Circle Created with python_avatars Pablo Velazquez says:

    Not worth fixing

  24. Avataaar/Circle Created with python_avatars L H says:

    Why are manufacturers not required to add some type of bullet proof coating to the frames from day one? It’s ridiculous how quickly that steel can rust through like that. Motor and trans still does its job but rust ends up raping your pocket pretty darn fast.

  25. Avataaar/Circle Created with python_avatars First name Last name says:

    I will never live in a state that uses salt on the road.

  26. Avataaar/Circle Created with python_avatars Scott Farris says:

    This wasn’t a guess. It was a hypothesis based on a diagnostic mind with a wealth of experience

  27. Avataaar/Circle Created with python_avatars Bigdre Dre says:

    Great educated guess

  28. Avataaar/Circle Created with python_avatars Max Jones says:

    That’s a beautiful donor truck! I’m looking for something similar for my 85 k10.

  29. Avataaar/Circle Created with python_avatars Jam Ram says:

    In SW AZ, we’re lost when it comes to rust. We just listen to SMA and follow his lead. He’s the “King of the Crusties” 😅

  30. Avataaar/Circle Created with python_avatars Rob Cohen says:

    I really enjoyed this video. It was great to see how your experience led you straight to the problem. Could you possibly elaborate on how you did the bypass on the wires to the connector allowing you to scrap the module? Thanks again.

  31. Avataaar/Circle Created with python_avatars Hal Weilbrenner says:

    When trouble shooting any electrical problem, an electrician told me to start at the source, in this case: the battery.

  32. Avataaar/Circle Created with python_avatars ` says:

    I don't think it's silly because like you said, time saved. And that means you can start it and that's a big life saver for many.

  33. Avataaar/Circle Created with python_avatars A_ReptileDysfunction says:

    I basically just roll from one lucky guess to the next 😂

  34. Avataaar/Circle Created with python_avatars Daniel Ramsey says:

    I feel sad about any vehicle from the Rust belt. Not worth buying, not worth fixing. A mortal disease.

  35. Avataaar/Circle Created with python_avatars Pew Ski says:

    Prindal display, never heard that phrase before.

  36. Avataaar/Circle Created with python_avatars Dan_LTL_909 says:

    Even though it's a short video and I'd probably never see this issue, it's something I will have in the memory bank now.

  37. Avataaar/Circle Created with python_avatars Michael Rivera says:

    I think he called me a jerk lol. A couple of videos ago I commented if he was on tic tok… I even said I did it to piss him off lol… 😅😅

  38. Avataaar/Circle Created with python_avatars Victor Varsanyi says:

    Educated guesses are not just luck.

  39. Avataaar/Circle Created with python_avatars J Stucki says:

    "the harder you work, the luckier you get" is so true. Thanks for another good one, Eric. My '01 2500 HD with the LB7 was a "desert truck" (eastern Washington) for its first 17 years. The electrical gremlins started surfacing within a couple of years of moving to the north coast of Oregon when I retired in 2018. I still absolutely love this old truck and with you and YouTubes help I'm having much success in keeping it alive.

  40. Avataaar/Circle Created with python_avatars mrlister2000 says:

    Why are is underneath of fairly young cars so bad over there?
    Aren't they undersealed? Are they sent from the factory with bare metal?
    it begs the question why do people buy these cars, knowing the underneath is going to last 5 minutes?

  41. Avataaar/Circle Created with python_avatars Murray Booth says:

    What is the guy going to do with the car now it runs? I don;t get it, is he delusional about it being fixable?

  42. Avataaar/Circle Created with python_avatars Joe Henderson says:

    Wow! As a mechanic myself,I would not touch that vehicle with a 10 foot pole! Remember, once you touch it, it’s your baby!