I'm wondering if the +5V reference is getting dragged down by a green crusty in the wiring somewhere. When you inject more current, you're helping the reference which in turn shows up on other sensors. If the module uses the 5V reference to compare against the battery voltage, that might explain why it's reading high.

Unreal. Incredible patience. Intermittents can make even the strongest tech weep like a little girl....or curse like a drunken sailor. You're doing great work for your customer(s).

The bad CAN waveform looks like the network is stuck in a dominant state, most CAN transceivers have a "dominant timeout" feature, so if the microcontroller they are connected to has it's TX pin stuck active for an implausibly long time, the transceiver will realise something is wrong and let go of the bus to avoid permanently screaming at everyone else on the network. The small spikes on the scope where both CAN H and L go back to idle at 2.5V is probably when this kicks in and there is a brief pause before it starts spamming again. It would be interesting to see if the VCIM is full of water or something to explain that weird behaviour

Years ago i found an old car hop window tray at a yard sale . It's absolutely perfect to put laptop/Pico or scan tool etc on . I don't use it all the time but it comes in handy more than you can imagine.....

Did you check if the sensor 5V isn't shorted by one of the sensors to ground? Excess load on the output of the module could make it misread the battery voltage if it's using that 5V as a reference to measure the supply voltage. Reference is low, voltage measured too high. Could be one of the position sensors causing the short to gnd. Put regulated 5V onto the reference wire with the ESC unplugged and see if it's ok.

This is certainly a strange one! Waiting for the next part Ivan!

So many rabbit holes to go down. Nice job Ivan!

Excellent call on the suspension module Ivan. This case study is very Interesting, your videos never disappoint!! 👍🇨🇦

Genius! Looking forward to this being resolved, hopefully in part 3.

Love these Suburban episodes!!!! 😊

I love the safety sandals! Love your video's. Thank you.

3 parts! Sooupurr! Needless to say, part 2 is a great example of testing, measuring deciding what is wrong. Thanks!

Excellent Ivan: measure twice cut once

Technically you had the lead to go after the VCIM after the first code scan in part 1. I remember that code. But the assumption was that couldn't possibly be causing this issue. I think the lesson is for network issues, never ignore a U code even if the module in question seems to have nothing to do with the vehicle symptom!

good video i like how you use your scope! i pic up some good tech tips. keep them videos coming.

I remember working on the air suspension on 80's model Pontiacs. It was called ERC for Electronic Ride Control. There wasn't a module. The system consisted of the compressor, exhaust valve, relay, and a solid state level sensor. If it had the inflator option there was a 3 way valve and a control panel with an air outlet added to the mix. All the control came from the level sensor and, aside from blown bags, was usually the only thing that would fail. Sometimes the exhaust valve and the compressor would be on simultaneously, sometimes one or both wouldn't energize when needed. It was crazy expensive too. My AWD 6000 had a failed sensor and once I replaced it, I found that the bags were leaking on the discontinued dealer only struts. Luckily there were some still in stock in a GM warehouse. Almost 500 dollars for the pair! Still alot cheaper than some Lincolns that I've repaired before. They use to be around a 1000 each for aftermarket. Cool diag and different from other cases. Great job, looking forward to part 3.

I Love all the cricket noise thru the video !!

Great job Bru

I recently had a "no-crank" condition on my 2005 Ford F-350. At the same time, I noticed that coolant was oozing out from the hose connections, etc. The truck had been running just fine. I go to the "Diesel Stop" website and a responder told me that the radiator cooling fan clutch had been damaged and the engine was slightly overheating causing the coolant issues and the Body Control Module has the ability to "hold-out" the starter circuit when cooling fan circuit issues are detected. Sure enough, the fan clutch has wires that go to it that are held by a plastic conduit. This conduit broke and allowed the wires to make contact with the fan and they were promptly chopped-up. So, after replacing the fan clutch all is well and the starter operates. Great video!

Very, very interesting diagnosis. I want to make a couple of comments on the original problem. First, on the Scanner Graph Display where you mentioned you wish you had your snapshot little ICON, just pull the top of the display down with one finger and you will get a number of options, one of which is to turn on/off the Snapshot feature, which when on you can place anywhere on the screen. I"m sure you likely already know this. The recent OS update seemed to shut it off, I think. If I remember right this was on the ESC diagnostics. Now the comments on the original issue. I know why your method of pulling fuses to effect the CAN bus signals was the method you choose. It is often very difficult, sometimes nearly impossible, to get to the modules to unplug them to see the effect on the CAN Bus, not to mention the time this can take. But, a definitive diagnosis on a CAN bus problem cannot be made by simply pulling one of the fuses. And, on Part 1 you did indeed prove, or it seemed so anyway, pulling one fuse to the Transmission Control Module was correct as you did disconnect the TCM at the TCM and it seemed to show the same thing. As you said, you should verify multiple times to try and be sure. When putting the fuse back in "fixed" the CAN bus, I suspected right then that something else was going on. The reason for this is that how the power is distributed within the module (what each power pin powers inside the module), is unknown. So, if there is more than one fuse and one fuse is pulled the results cannot be predicted. Even if all fuses are pulled to all power pins on a module, one cannot be 100% sure it will not effect the CAN bus. This is because it could cause some output pin to get stuck low which may get sent to the CAN bus by some other module that is powered confusing the CAN bus as one example. I think there is a much better chance that what you have found in Part 2 regarding the first issue, the one in Part 1, is much more likely to be the cause of the problem, but completely unplugging that module should be done as well (if reasonably possible). Unplugging the module, which disconnects it entirely from the CAN bus, is always the best, especially if this is to be a fix. Note, that these are my observations and opinions only and are not any criticisms whatsoever. Thanks, as always, for making these very interesting videos.

You should make up an 8' cable with a fuse plug on one end, so you can stick in whatever fuse your circuit needs, and plug this into the whatever fuse hole, and other end has 1) a SPST toggle, and in parallel, 2) a SPST NC pushbutton switch. Makes this kind of fuse pulling/video making/recording/observing much easier. This is something I use on a pinball machine, for misc diagnosis.

Hello from New Zealand 😂

Interesting diag indeed, those under vehicle modules are always good for corrosion and water intrusion. Always pays to double and triple check controller diagnosis, so easy to get burned.

R u putting the cricket noise in your video for dramatic effect 🙄 🤣

these built-in modules always gets heated in transmission..there was a 2006 toyota ractic with cvt with same symptoms ..disconnect battery and it comes back online so what i did temporarily added a reley on main power supplies to tcm with key on and off to cut its power all the way while key is off it worked for customer untill he found the part..and not easy in affrica find parts..cheers mate

Boy this has been a real head scratcher so far.

Can’t wait for part 3….

Couple weeks ago my 07 duramax classic was telling me service 4wd, battery not charging. I knew both were incorrect warnings. Also my trailer running lights would not work. Long story short, mice were on top of my under hood fuse board peeing and pooping on the fuses. Ended up needing a whole new fuse board. My TCIB fuse would only get 2v at the fuse socket, it needed 12v. But I was thinking of Pine Hollow Auto Diagnostics the whole time I was trouble shooting. Got it fixed the day before I had to pull my 5th wheel camper 1,900 miles round trip. I wish I had a thinktool but my trusty multimeter and 17 years of electrical experience has gotten me by so far

You buy a vehicle with all the bells and whistles you will pay at least twice for it. If you keep it long enough. I always buy a base model every time. It started because I couldn't afford anything else. But turns out it was the right thing to do.

Another short to ground or ground issue, somewhere? Interesting . Just thinking of the one with wire shorted neat trans. Just a guess of course.

Oh the horrors of intermittent problems! As a 12volt tech for over 30 years I've had nightmares about problems I couldn't reptoduce consistently.

Ivan working for Partech now and see a ton of the Vicm modules needing replaced obviously being a module the dealership is going to call in to Partech to make sure they get the right module for the Vin

I’ve seen the same problem with the ride height sensors. I had same problem unplugged rest of height sensors and it was the left front that brought 5 volt ref back after being unplugged

Super interesting how the ESC was reporting higher voltage than the battery. Wonder if there's some capacitor bleed threw or something on the board? IdK. But either way awesome technique on testing those circuits! Really enjoy watching your thought process and troubleshooting skills. Thanks for sharing!

Regarding the active suspension, if the 5V ref line has an external short, depending on the design of the module, it could pull down the regulated power supply in the module. If it didn't trip computer reset inside the module, the reference voltage for the A/D converter could be lowered too. This would make the power input voltage appear to be higher than it really is. I think, to be sure, that I would unplug the module and sensor, then check the wire for a semi-short to ground. The semi-short could also be inside the module. You disconnected the sensor so that is ruled out.

Wow! you really know what to do. repeat a bility key!

The info control module is the dash board alfa display, part of the dash cluster.

PowerProbe 4 can be used with the PPT5VA current limited 5V Reference Adaptor. This way you can inject 5V Regulated and not 12V Battery. Which I think is safer depending on the Electronic Automotive Module design, but also a little more meaningful in terms of registering a percentage of full scale or a value in volts or a partial divider due to circuit issues in combination with the 5V module output 5V Ref.

"Sleep on it." Sage advice when potentially large decisions arise.

I had to pause the video to see if it was your crickets or my crickets 🦗🦗🦗🤪

Have seen many battery drain issues caused by this module. It would be interesting to see if the vehicle has a small battery drain with the fuse installed.

Not sure on this one, but the VCIM/OnStar on 2000-2006-ish vehicles, even if the owner does not have a subscription, will, in the event of an accident, contact the vehicle to find out if they need assistance, and if there is no response from the occupants, OnStar would contact emergency services and direct them to the location of the accident. Back in the day when I worked for a company that build stereo system interfaces and such for vehicles, we always told our dealers to have a very good disclaimer and have the owner of the vehicle read and sign it for liability reasons.

Excellent! Algorithm boost!

I just repaired a 2003 Chevy van with 4.3 Vortec would shut off randomly no spark no communication. It was the coolant temp sensor two wire shorted internally. Pulled voltage down on system then when cold was fine..once changed runs perfect. Bizarre. I took whole harness and ECM apart all ok. Only a $15 part. Shops wanted to replace module coil ECM $$$$$

I guess it's a waiting game at this point because the network problem was solved by pulling the fuse on the TCM and VCIM. You can not call the VCIM 100% until it's unplugged a few days.

I am only 7 minutes into it, but now I will have to go back and watch the first video. IIRC, pulling the TCM fuse didn't do anything yesterday, it was only after you disconnected it, that the CAN came back to good signal. Then you plugged it back in and it remained good.

Good thing you followed your own advice on recreating the customer complaint. What about the instrument cluster complainant from the customer you had mentioned?

As a dealer technician I have seen several vcim go bad bring down the high speed Network, they are intermittent and hard to diagnose. OnStar data link gets bypassed at back of left ip block

I have a 2011 Silverado with OnStar, and when I disconnected it because I didn’t want it, it made everything freak out. After I reconnected, it all went back to normal.

At the end of the day it could still be only the suspension module causing all the issues by removing the fuse for the info center the small voltage increase could change how the other modules act keep in mind you were running off a low battery. Same as the day before. just a though would hooking up a deep cycle battery in parallel help ?

Not sure I understood the problem with the HSCAN - was the VCIM confirmed the culprit? Anyway, the strange problem with the ESC, turned out to be the module. Let's wait for Part 3 :-)

I had a similar issue in my Chevy cobalt. TCM grounding problem. I had to solder a wire to the TCM module directly and attach it to the engine block ground.

Thinking about it a regular repair shop or even a dealer would either struggle with this Sub or fire parts at it until the customer ran out of money or patience, look stuff fails but it should be clear enough to identify what's failed, this is madness

Here I was thinking I was the only mobile diag tech who wore Sandies (as my kids would call them)

Ivan could you show the proper sensor voltages for the right front after you replace the ESC. I recently messaged you about bypassing the RF ride height sensor and knowing the proper voltage would help greatly. Perfect timing for this video thank you.

Kind of like the carpenter rule measure twice cut once

Try and test main body ground under drivers door. That was my issue with the service warning.

Did you check the connector on the transmission? They leak into the plug and cause all kinds of problems.

Me at 08:00 - "Right, pull every single fuse out!!"

Slobburban ready for the salvage yard....LOL

Hey Ivan on these Chevy Trucks when the Battery voltage shows 0ver 15 volts could it be that the Alternator is bad.

I am glad I am not calling it Ivan. I am still not convinced of what the cause of the CAN signal is. Admittedly I am not there watching you in person or doing the testing myself, so don't know what has not been included in this upload that might be a "light bulb moment" for me. I am looking forward to the final determination. Whatever it is I hope you are correct. While I enjoy these types of video's, tonight I am so frazzled I wish you had something simple, like a nail in a tyre causing the tyre to go flat - ie something obvious!!

Ivan. Could the network problems be in the ESC module? Isn't it providing "its CAN network voltage?" If so, if it is corrupted, wouldn't it kill the CAN Bus? Just a thought.

In Part 1 you unplugged the transmission under the car. Maybe that break in bus continuity reset the VCIM, where pulling the transmission fuse didn't break continuity to the VCIM? Just a thought from someone not fully awake...

That VCIM was just in a major identity crisis and it tried to put Ethernet frames on a CAN bus. (In all reality: Module is probably borked... possible water ingress through a clogged roof drain?)

Nice work! Does the pass-through act as a security gateway? Will this pass-through work for my 2018 Chrysler Town and Country if the need ever arises? Thanks Ivan!

So the vcim is the network killer that was restored when pulling the Tcm fuse in the engine bay. How many 5v references are shared with the esc? Or is the fuse box intermittent?

I was and still am a little skeptical on the TCM being our culprit. I think it was just a fluke when you pulled the fuse on it the first time. And now focus has shifted to the ESC that's misreading data. What are the odds of that failing ESC module back feeding the network and causing the prindle to malfunction? Is that even possible?

🌷🌷👍👍

Is that an aftermarket radio? If so to get one to work, you need an interface between the radio and factory harness. Maybe this bad and is causing issues. Or maybe someone cut the factory harness up to get radio to work.

I DON'T KNOW HOW YOU KEEP YOUR SANITY ? One day vehicle shows this, next day shows SOMETHING TOTALLY DIFFERENT. I look at your SCAN TOOLS KRAZY LINES & IT MEANS JACK TOO ME, THEN YOU SAY " CAN IS BACK " OK ? I GUESS, LOL. I guess it's like you say ( IF YOU KNOW WHAT YOUR DOING ) TEST, TEST, TEST & RETEST TOO MAKE SURE IT'S THE RIGHT CALL. That's what THE STEALERSHIP & MOST GARAGES DON'T DO BECAUSE TIME IS MONEY. THANKS FOR THE ENTERTAINMENT, SIR IVAN & MAGA.

Ivan, you dodged eating the s*it sandwich on the TCM.

There will be a capacitor from the 5v ref to ground, but the capacitor has a semi short. That's why the test light can use it as a semi ground. Very common for smd capacitors to go short. If it was a junk car i would feed it with 5 volts via a 10 amp supply (blow the cap open). Yes i am evil :)

I think I have this problem. What happens if you just unplugged the module and left it unplugged? I dont care if I have a service light I just dont want the crazy lights and going into limp mode

What about parasitic draw in that 5V reference?

Wow, TCM then is not then it's the ESC? Something is going on with network!! I wonder if that causes the network bring down? Kinda bit confused on that. I'll see what happens part 3.

in part one you pulled fuses with the missing fuse in part 2 you pulled fuses with the missing fuse in place so could the missing fuses in place be back feeding any of the fuses or circuits you pulled in some way

👋👍

Ok. Now you've got something. Did you disconnect the on-star module and check CAN the next day to verify proper signals? What happens when you wet the outside of the truck AND the undercarriage? CAN still good?

I see yhat the fuse display coverare different .The left side is gas and the right sideis diesel.And the fuses are in different places.

Question Ivan, where does the high speed CAN com from, the PCM, the BCM or do all the modules give out the CAN bus signal? As i understand it all the modules associated with the Cam bus all generate a CAN bus signal and they all talk to each other....

How did you learn the wave forms in the beginning

Can't watch part 3, after suffering through the first two your repair is to leave a fuse out?

That many miles should replace transmission?

That On Star System wouldn't work anyway as the cellular networks it needs don't exist anymore

Isn't there an antenna module the fails in these and takes down the CANBUS? Pretty sure Samcrac diag'ed one of these....

Battery voltage 16.2v ???? - has the alternator spiking/noisy?? fried some electronics?

Vehicles need more modules.....lol

Interesting suspension module acting flakey. With the module unplugged and on star fuse in did the network still look like garbage. Just curious.

😎😎😎😎😎😎😎😎😎😎😎😎😎

Have you checked the LGBT control module for the transmission problem?

DIY automotive electrical testing tools you can build yourself: kzfaq.info/get/bejne/rdGFesh3vrLLn6M.html

Failing terminating resistor

At 4:23 in the video you stick your head inside and say do we have a PRNDM you say nope but in the video I can clearly see that PRNDM is there and illuminated? It has an OnStar button right on the rear view mirror!

you didnt fix it before untill you pulled the tcm connector off the module it didnt fix it self when you pulled the tcm fuse

I do hate those "sophisticate"cars with those mass stuffed electronics gadgets

Broken ground

Think your scan tool is having issues. Try another scan tool. Other than that I'm suspecting green crusties as another viewer mentioned.

how are the grounds on that suburban???

I bet your subs would go up if you incorporated some cat fights.