Chevy Trailblazer from Hell: P060E (Staten Island Ep 7.8) 

This is the information and scenarios the internet needs. Many forums just have guys asking questions and very little of them want to take the actions to figure it out. Thanks Ivan and Keith for the footage.

There are only a few channels where I watch every video in it's entirety, yours is one of them. That last capture is almost worth framing. I liked the story behind Keith's idea to pull that connector. I can see why this line of work would be so gratifying.

I am the same way, I watch Ivan and Eric O as soon as they come out

Holy mother of $#!, that's some Jedi-level diagnostics. Moral of the story: If the 5V reference is going nuts, consider what other circuitry is connected to it.

Coffee is the solution to complex diagnostic problems.... although if you were drinking tea you would have found it in half the time ;) Great work Keith and Ivan

Wow. What a great case study!! And we get the benefit of those great minds. The five volt reference. And Keith said there is only one regulator in the computer for them. Love this channel!!

As a guy that's done all his auto repairs himself since I started driving, trying to keep up with technology is overwhelming. Learned a bundle of info from you and Eric O. Thanks for the videos. By the way I'm over 70 years old and never been to a mechanic, And I drove many of bombs over the years

Ivan Rocks, Keith Rocks, Pico Rocks, Flappy tape Rocks!!! Awesome guys well done!

Ivan. One of the best part of your videos is the ending the bonus the explanation great video keep up the good work thanks to the two of use

brilliant, the man's a genius! thanks for sharing these videos Ivan, Sandy

Amazing diagnostic skills. Still learning about diagnosis & you guys did great with the help of Duncan donuts. Great job team.

wow! that's the way to chase down intermittent fault excellent video and diagnostic walk through thanks

Wow. That just showed the years of experience that Keith has. Man you are blessed to have him as a mentor. Hopefully he starts releasing some videos of his own soon. As always Ivan another quality video. How the heck did this get 3 dislikes?

Sheer SORCERY! Awesome diagnosis! I'm geeking out over here.

Strange- every time I see a vehicle, with multiple computers, probes- and Technicians with Head lamps and gloves- it reminds me of a Patient on life support, with Surgeons trying to save it. Back in my day- the most you'd see was a huge (comparatively) analyzer called a "Sun Machine". 100% analog. Good 'Ol Days.

i'm loving this GM from hell series with back to back midsize platforms lol

Great detective work.... Had similar issue with 08 Equinox and wheel speed sensor pulling 5 volt reference to ground causing egr and evap faults.

This is why I subscribe to your channel. Awesome find. Sometimes the answer just comes from nowhere. I had a 2010 maxima that would set a crank position sensor code only when the engine hit 5k rpm or higher. The sensor was new OEM 3 months later it lands on my lap. I could see a small amount of noise on the signal with the score. But it ended up being a fault flywheel. Visual inspection of the flywheel showed absolutely no flaws. But the problem was fixed with a new flywheel. Anyway I'm rambling. Good video.

That was a really good problem. Very nice diagnostic work from all involved. I'm going to have to get me a pico scope. I love the data logging abilities(electrical engineer here...).

great video ivan, it shows how much you need a scope to get through the issues and find direction, so for those that think otherwise....take note

Great diagnosis. Am loving the way you do these things. Keep up the good work

Subscribed, been doing heavy line work for too long, tune up is less stressful, as long as you have the equipment and the smarts. "The money shot" you are funny.

Wow Keith! Your mind works in mysterious ways. LOL Ivan I think you would if end up at the coolant fans at one point. But later on your Diagnostic. You were heading the right way. I would if never figure that the fans will be the problem. LOL I had a chance on how Keith mind works. 🤓🤓👍👍👍👍👍 Great video.

Wow A piece of tape that leads you to the fix. Keith must love his coffee.

There's nothing better than putting the cap on a difficult diagnosis. Way to go Ivan and Keith!

Hey Ivan, another one for the books. Damn fine job! Yep this is one of the channels to watch to avoid the parts cannon! Great thinking Keith!

Nice diag! Love your videos. Keith is one smart fella, your lucky to be working with him!

You saved the best for last. Great video, diagnosis and Pico scope work. This job will drive you crazy on intermittent issues but so satisfying when you finally get it to screw up and capture it. Keith looked like the cat that just ate the canary at the end of the video...great thought process. Great series Ivan and I always look forward to watching your videos especially the ones with Kieth...they always have some twist. Nice job & keep them coming!

Wow..This one is one of the best so far... Great job guys..

Excellent! Another suspect to check on the Envoy. Thank you guys for the technical help in these videos.

5V ref. is very important. Scanner Danner always refer to check to see if there is a 5v ref. getting pull to ground by some other sensor on the net work, Especially when there is intermitment noise in the signal ... this can also play a big culpric on CAN BUS NETWork. Bus link.. I usually first check to see how may modules is on the net work.... and who is misbehaving on the net work causing turbulence disrupting every one else on the net work. Good Job....You guys are terrific ..

Nice job coach D.! Nice job scope master Ivan! Epic save PicoScope! Thanks all!

Wow! The shop really fired the parts cannon at this car before you got to it! Great video, Ivan!

You are the first Russian I have seen in dashcam video that is going under 150 MPH in whiteout conditions!

Great video guys. One heck of a good one to catch on film.

Looks like Keith picked the wrong week to quit drinkin' coffee...

That is an excellent point. I have been scratching my head wondering why no-one use the scope to do what it is well suited to do, checking for noise in sensor circuits and signal quality. In wired LAN it is kind af a basic checks, but rarely in automotive. 12V relay with a faulty flyback diode can send a voltage spike and cause a fault code in a poorly designed schematic.

"all we gotta do is pray", no wonder he wasnt able to fix it lmao.

awesom finding and very strange problem thanks for sharing IVAN, subscribed to keths channel. cheeeeeers

similar experience with a 90s buick century..... ac signal from a cooling fan motor disrupting the ignition signal at the module. rolled in with a intermittent stumble off idle, left with a new cooling fan motor.....and after two dealerships later threw the parts cannon at it. good 1 ivan and keith.

That is crazy that you guys found that, what on earth made him unplug fan, that one is definitely going in the back of my head good job

Totally crazy! Never would have figured out that one.

that's awesome real world diagnostic work there.

First off, that was a brilliant display of Shop-Fu. Your tenacity found something concrete that could warrant a design change or proactive fix - something the 'parts cannon' wouldn't reveal. While the culprit was found I couldn't help but notice something in the scope traces at 23:31 - 24:00. The pulse width of the interference rises and decays in a harmonic fashion. The need for the engine and the fan motor to be at certain speeds suggests that only when the vibrations of the two were resonating and boosting each other, a beat frequency occurred that was strong enough to cause or reveal shorting of internal fan conductors. I think the speed sensor was framed! :) It would have been interesting to see if a current trace of the fan motor (like you would do with a fuel pump) would show any corresponding anomalies. Great work guys!

Ivan you know what Eric O. would tell you to do with that flow chart!! LOL

Ivan, extra footage!!!!!lol. great work

As a owner of 5 trailblazers I can tell you that those fan speed sensors have caused a lot of grief in TB owners. Weird shifting,low power mode,you name it. I remove those fans,replace with electric fan (make sure to beef up the battery cables to ground and alternator to avoid power dips) and have the ecm programmed to delete the fan speed sensor.

Good diagnosis, sometimes it's not by the book and thank goodness for DunKin Donuts coffee!

I have a 2002 TrailBlazer with 200K miles. It's been a fantastic vehicle for me, never leaving me stranded, but that stupid electro viscous clutch has been a nightmare for most owners. They have a very high failure rate, never seem to kick engage quickly enough to assist quickly in cooling or A/C. I appreciate the attempt to gain 1/10th of a MPG by trying to better regulate the fan. It's no wonder GM switched these to conventional thermostatic fans for the last year of production.

WOW great find........Not guess work either.........A considered approach.......Good old smoko break eh, I couldn't tell you how many time I've thought over a cuppa tea then BOOM you get it. Thanks for shearing

Ivan thank u so much for your videos and especially this one in particular you really help your viewers think outside the box lol im so grateful for you, eric o, scanner danner and etcg yall really make it interesting. thanks and u have my support

This is call: "work experience"... I have this always when I'm called of my shift apprentice to just have look ;) GOOD JOB GUYS

I got the same problem with this vehicle the same one thank you for the video very smart guy thanks

lol @ when you had the camera turned on yourself and Keith was gradually trying to gtfo of the shot

great video way to think outside the flow chart thanks guys

Let's be honest here. Keith so soooo good, he's a just a little scary. A good scary though. Thanks for sharing.

Great case study, really enjoy your content. I'd really like to get a decent scope just to mess around on my own vehicles with, maybe someday. LOL at the boss trying to get out of the shot at the end.

The harnesses that go to the fan clutch are notorious for rubbing through on the fan itself. I'd bet the wires are getting rubbed through causing some interference.

You need to hand customers an information sheet asking things like (10) When was windshield last replaced? (2) How often do you notice water leaking from under dash area and or notice wet carpets and/or a mildew smell? (3) Last time body work was done, and when and for what? (4) Copies of all service records (5) When was problem first noticed? How many shops have tried to fix it?

What is it with you that run into all those weird diagnostic hells? It isn't half this weird when I'm with Keith! Great case study! All in Asy's place.

So the moral of the story is it's good to leave comments below,,,,, but in the auto / diagnosis field "feedback" is a bad thing. Great job Ivan and Keith ! 👍👍

Great case! Glad it didn't happen to my car. Why have speed feedback on a cooling fan; infinite control is not necessary?

Crazy azzz video I’m dealing with a 2005 Colorado with a app sensor code that just wont act up

Very good, complicated . So what was the Fix ? Thanks

a great video that show why not even a flow chart has all the answers. weird shit just happens.

awesome diagnosis guys

I love how you got Shalamar playing in the background that's my music there

I think everybody knows a "Keith". My "Keith" is a Serbian gentleman named Predrag, who literally knows everything about power supplies. I've learned so much from that guy. Coincidentally, he also solves problems after having a cup of coffee or two...

Wow impressive work thanks I'm having same code on 06 gmc 5.3 envoy

I loved the diagnoses but I couldn't hear squat when the TB was running. I'm not sure what you could do to remedy this, in reality probably my hearing issues not yours.

This video made me realize Keith is not human! He's a robot telepathically communicating with cars! Great work guys! Ps: was there a shared reference involved?

I would never have guessed it, but I can see how the fan power leads running through the wiring harness in the same bundle with the TPS sensor wiring could cause a lot of AC induction into the TPS wiring due to abruptness of the on-off impulses in the fan power circuit. A very abrupt on-off can induce a big voltage spike. The two sets of wires running alongside each other are like a primitive transformer, with the fan power circuit being the primary and the TPS wiring the secondary. Or it could be RF overload on the TPS circuit wiring. Since the kind of interference that the fan motor creates is very broadbanded, RF frequency-wise, it might be that the TPS circuit wiring happens to be resonant somewhere within the frequency spectrum of the transmitted interference, so you get a strong RF standing wave on the TPS wiring.

That's a awesome find for sure. Just think of all those that may have come across this code and all the money spent trying to fix it.

Boy, how many places would have found that? Good job guys!

This is a well known issue on the forums. Anytime someone has a problem or code for the throttle system, first thing we tell them is to disconnect the fan, which accounts for 90% of these issues. Then we go into heavy diagnostics if that's not it.

We love all your videos Ivan

Lol 😁, KEITH, is trying to get away from the CAMERA - - SHOT!, "KEITH" is a MASTER - - NINJA!!, I hope maybe one of these days he could break out of his camera shyness, lolo, 😁😂😄. great video Ivan, but see if you can get a microphone with " Noise Cancellation" --- too much engine noise, can barely hear you guys talking, OK see ya in the Next Vid...

Nice work guys Ivan u are awesome my man does Keith have a RU-vid channel also

AWESOME< But what did you replace? E.V. fan clutch?? Is that parallel circuitry with several sensors that was having mass interruptions, due to the "noise" from fan clutch?thanks in advance

un freakin' believable ....!! great job as always .. :)

My 2019 xt5 3.6 had a P0128 my scan tool graph mode showed erratic signals on the temp sensor. I disconnected the sensor plug at the sensor and did a pin fit. Tightened and applied dielectric grease and reassembled. No parts needed.

Amazing as always! Great video!

Great diagnostic, love it

You did good as well Ivan.🤓

There is a common thread between this problem and the GMC no crank issue in your other video and that is a pirate voltage or ground sourcing through a faulty component and upsetting other systems sharing the common supply or ground circuit. Here the TPP and the APP were effectively showing exactly the same trace so the diagnostic take home clue here is that if you see several systems with parallel responses check to see on a wiring diagram how they might be collecting signal from a common fault . I do not think that this could be tackled without a scope unless you effectively follow Keith's example of simply unplugging systems one after another on the shared circuit until the faulty symptoms stop; a bit like clamping off vacuum lines to the intake manifold when looking for a suspect vacuum leak. Here is good example of huge cost and inconvenience to the owner not because the cooling fan motor was broken but that the speed sensor monitoring its performance was temperamental.

Nice job Keith. I saw the capture and thought interference myself, just didn't know where,lol. First thought was checking battery and charging system for excessive ripple because as rpm increased it got worse. But when I saw you go toward the fan and unplug it I knew what you were thinking,lol. That was real cool.🤓 This is the reason why I love Pico Scope so much. I can put a long screen on that bad boy, drive the vehicle if I have to or check stuff in the bay and I don't have to watch it all the time. I can just go back and look at the data. Or in this case it's great for action and reaction testing. Was only 1 five volt reference driver affected or all of them? Was curious about that.🤓

often 5 v reference(s) set by Lm-309 regulator(s) in ecm module -often buried in LSI module BUT I found ADDED tantalum capacitor (10 mfd at 35 v) on flaky 5 v output helps stabilize high frequency noise on signal so less susceptable to noises-wierd problems often goes away,since 5v feed stable never use electrolytic capacitors-tantalum ONLY

Very nice and educational exploration,I did have a similarly case on a Ram 3500 6.7l kill the engine when it passed 3500Rpm the fan clutch speed axe sensor get the 5v reference to grown random to 0 or 3v some times...team work is always better

likely nothing wrong with the sensor circuit itself and caused by other fan controller component failure, like "capacitors" degraded and low to no RFI filtering/excessive back EMF. if you scoped the fan power and ground, it should be going nuts too. A failing alternator can produce major ripple and with the different voltage/signal wires bundled it could wreak havoc :)

Hey, have you made a video explaining why you do service calls/strange hard to solve issues? Since most guys work in a shop doing the regular stuff. You know, how you got into this doing work on your own for other shops and stuff.

so what was the takeaway from this video all i heard was the motor running three quarters of the video

talk about finding a needle in a haystack. thats an incredible diagnosis.

The sound of the engine running put me to sleep 😴😩

Great find! Now how do you sell a cooling fan to a customer who has already been sold all of those other parts for an intermittent low power mode? It seems like a customer who knows just a little bit would say "yeah right."

freaking awesome video!!!!! wow !!!! i am a tech and thank you for these videos!!!

Well, that escalated quickly.

Again, WHAT IS THE FIX? All the diagnostics were great, but you didn't tell us what the fix is. It sort of is suggested that the fan speed sensor was the problem, but not conclusively. It could be some interaction that is not necessarily a faulty fan sensor. I have this exact same issue.

I wish I could of been there. Maybe I could of been a part of the hero clan. Had several of these Trailblazers that came in no start. Un plug the fan, Walla instant hero. Pulls the 5v completely down.

talk about off the wall bs......... and basically if it wasn't for having a 4 channel scope it might be unverifiable. miss the day ya could pull a matchbook out from under the 8 track to use it to set your points.

Fantastic! !! how does a speed sensor affect the computer ? so what you're telling me is that the 5-volt reference signal from the computer can be contaminated by an external noise source. How did Keith know WHERE to look ?