This Silverado Keeps Killing BCMs

This 2008 Silverado came in for what appeared to be a simple bad BCM (Body Control Module) issue, boy was I wrong about it being simple... It's a long video but I wanted to show you my process to find the source of the issue and try to teach you my testing method.
The Stackable Test Leads and Banana Ends for light bulb pigtails can be found on my Amazon page here
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#diagnostics #autorepair #scantool

[@PineHollowAutoDiagnostics]

First? That blew my mind bro. Bummer about the burnt BCMs... That's a tough situation. After the 1st one burnt up I would reach out to the customer and explain the situation. Maybe split the cost of the 2nd BCM 🤔

[@Joe.O_623]

I was thinking the only other person I can think of that would have solved this would be Ivan. Excellent video!

[@Mario-zb1yc]

I agree Ivan. It was a masterpiece of diagnosis. I love to watch your videos .i have the pain of Europe trash Cars everyday.not many US Cars in Berlin to work on it. Thank you all for teaching me. 👍😎

[@jordysandino6577]

I will watch this video 10 times if I have to in order to learn there is not better way to get a free high in class . I feel like I’m in the fron rod chair. Thank you so much sir for thinking about us (the viewer’s)

[@raulpereyra2817]

Thank you for your videos I'm an AWESOME parts changer. However I would like to be a good as efficient in diagnostic and electrical repairs as you and Ivan. As I have used your and Ivan video to guide me or point me in the right direction. As what I can build in skill I'm lacking in confidence. But I feel that with more time learning. I can gain that confidence So PLEASE keep making these IN DEPTH videos as to pass the knowledge for the ones like myself just need a little help. There are PLENTY of parts changing videos. But not that good IN DEPTH DIAGNOSTIC like YOUR and IVAN. Sob THANK YOU and keep up the GREAT CONTENT

[@kyletuttle9064]

Great video cool to watch your thought process.thanks Jake.

[@bobbyshaw9089]

That being the 2nd one in 7 days makes me think that GM has a problem in their harness routing and support. If their field engineers saw enough of them during warranty they’d issue a TSB and possibly a recall. If there was a pending class action they’d definitely do a recall repair with the coil pack fastener and loom support with BCM warranty on a per case basis. If I bought that from GM parts direct or a dealer, I would definitely reach out to the service zone rep to share my findings and see if they’d goodwill the 2nd one. They can only say yes , no , or Hell No….. Anyways great post- you just earned another subscriber!

[@LucasRodrigues-ju2pb]

This has been the best automotive diagnostics channel

[@slimshady23brar]

@@autodiagytany channels you would recommend watching. Interested to see likeminded techs trouble shoot these kind of issues. I mainly watch your channel, south main auto and pine hallow. Definitely learned a lot.

[@cthorn2467]

I agree with the scanner Danner that the customer needs to pay for the diagnostic and the first PCM that frying was part of the diagnostic. I wish I had a competent shop in my area like you that could fix these things .

[@jimyep9971]

Your not the only one.............competent shop in my area

[@josephdavis4201]

Firstly, holy crap you lucked out seeing that flicker on the test light. I was literally amazed how you solved that. I was fixated on this video like it was a blockbuster movie. Secondly, you did your due diligence on testing the harness. I feel the customer should pay for the module. It was a necessary step to achieve the diagnosis. It's the cost of owning that truck. I hope he knows how lucky he is that he found you to fix it. I am beyond impressed. Lastly, thanks for the education. I've gained new territory in my skills from your videos.

[@AAB371]

This is diagnostic Gold. I like this longer video. You have some serious diag skills and have great clarity in explaining and demonstrating. Keep up the good work

[@AutoByteDiagnostics]

Great approach and diag Jake! Thank you for taking the time to record the issue and showing it! I appreciate all the videos you put out that teaches all us novices so much invaluable information. I know you said you were lucky, but I don’t believe luck had anything to do with it. It was your meticulous methods and systematical approach to the issue at hand that ended up fixing the vehicle and not luck.

[@tomhague1162]

I like your perseverance with your troubleshooting. You come across as being "genuine". You have excellent videos, keep them up.

[@spirokattan3655]

What a great case study Jake. Love how you combine a load (light bulbs) along with DVOM to look for unwanted resistance. Your diagnostic approach is amazing. I really hope this customer appreciates all the time and effort you went through and hopefully will compensate you accordingly. Thanks for posting!

[@PaulysAuto]

I would say that BCM cost should be wrapped up into the total repair/testing charge; because there's no reason you should have to eat the cost... The time it took you to find the problem, as in labor time, is going to far exceed the price of that BCM. Sometimes you just have to bill a customer for what it takes to pinpoint it and it's not as if you were trying to change parts to fix the problem without a thorough testing routine. Unfortunately it's just one of those things that we deal with when the harness is that exposed from age. The total cost out the door will never TRULY pay for your time involved...it's unfortunate that we should be subject to that, but it's no different than struggling with difficult noise concerns when it has already been beaten up by several people and/or other shops. "Well Mr. customer, here's the deal, we had to get a known good BCM in this thing to get it to act up and find out WHY unfortunately; this was an odd problem, that we just don't see on the daily; so therefore, I had to work it into the total cost of repair and diagnosis...it's that simple, hard problems cost money to solve!" In either case don't beat yourself up over it you did an excellent job and I appreciate the time on the video, keep up the great work man!

[@frozenstang3868]

I see it this way. The owner was lucky to find anyone that could actually figure it out, plus its up to him to have the truck checked out before purchase. Anyone else might has burnt up 2 or 3 more lol. Talk to the customer and explain why he has to pay for it. Sometimes you win when you buy a used truck and sometimes you loose. I am sure he got it cheep enough he can afford it.

[@charlesfletcher1629]

Everybody with those trucks needs to PM that loom right there. You’re a hero.

[@Thechuck916]

Sir, first of all, I want to say KUDOS TO YOU FOR FINDING THE MAIN CAUSE!!!!SERIOUSLY, GREAT JOB!!! Not trolling you sir, I am in awe!!!! I too, am a mechanic w/ ASE certifications, and held a CA smog license for ten years. I love trying to solve why it doesn't work, or, how it works and why. (my momma used to call me Dr. Destructo for that reason, you can imagine why) Hence, why I took advanced Auto diagnostics classes. I was tracking on using the test light to check for voltage drops and current flow. My first thought watching your video was, check for loose/ corroded ground wiring and for wire Chafing. This is my first Chevy Truck, first 4x4 truck, so I'm not extremely intimate with the tricks of the trade when it's silverado time. NOW, if it's Toyota Tundra time, its $$$$ !! Needless to say, I too bought a 2010 Silverado (originally from Michigan and lived most of its life there, not Nor-Cal) and am experiencing: intermittent NO Crank, stability control light, key transponder not registering w/ BCM,air bag service light and message, dome lights intermittently working, pwr mirror fuse immediately blows when replaced. I was scrolling thru KZbin and ran into this video, and thank god! I was going to jump down the rabbit hole! Fortunately, you did a lot of leg work for not only me but anyone on any end dealing with, " that bullshit". Definitely saving time for a lot of people. As far as the question you posed, WHO'S PAYING FOR THE BCM'S that were replaced? GM??? The Customer?? The Shop??? MY PERSONAL FEELING IS THE ENGINEERS @ GM. They Designed it that way, flawed, and knew at some point that, stuff like wire chafing was going to happen. And, not only happen but, could've taken preventive measures like, having it routed where that wouldn't happen or, put a protective guard to prevent this (you showed one guard GM did at the end of the video), OR, didn't protect the wiring because, saving stockholders $$$ out weighs things like; durability, dependability, or having a good reputation due to great quality products. 'We'll Save 63 cents on every early 2000's Impala by using cheap window switch contacts, that will total in millions!" said the GM engineer. YOU COULD PUT IT ON THE CUSTOMER TOO...THEIR DUMB ASS, LIKE MY DUMB ASS, BOUGHT A CHEVY SILVERADO. They ultimately came to you to fix the problem. Since you don't charge yourself money to fix your own vehicles etc. etc., It's on the customer. Their Truck, Their invoice to pay. If you wanna be nice, charge cost plus 10-15 percent instead of MSRP. Thank you again for the insight and knowledge! I bought two used BCM's after my initial diagnosis and research brought me to condemning my truck's BCM module. I also knew too that, something made this perfect storm to set off everything ablaze, just had to find the metaphorical kid playing with matches. I'm gonna go find my cause and look everywhere you showed us, Sensei🤣🤣🤣 Sincerely, CHUCK NASTY

[@autodiagyt]

Good luck on your search!

[@scotthow2933]

GM didn't put stud mount harness mounts on any of those coils. I know because I've fixed 3 of them that have rubbed through in the same place. Crazy part is on all 3 of mine it was messing with the a/c high pressure switch wire causing the a/c to go off and on. The first one I had just put a compressor kit on because it was leaking and then vacuum and charge. After 2 hours of scratching my head I finally found that bad wire. Thanks GM !

[@autodiagyt]

So I know they was supposed to have it but I think there might have been 2 different harness suppliers but if you look there my shorts videos i had just diagnosed a different 2008 with the harness rubbing on the stud causing a knock sensor code. The shop I was at that day had a 2007 Tahoe and it's harness had the stud zip tie.

[@knock904]

Man you always run into some tough ones..i love learning from you..Great videos thanks

[@exmotorsports]

🤯That's AMAZING Jake, this is now the Third one I've seen do that...but not killing a BCM like that. Wow. The first one was from a diag Paul Danner did like a year ago or so, and the second one was my lucky butt. Lol Yep, except mine was a 2007 Silverado 5.3 and feel lucky that I seen Paul's find and made me look closer at the one I had at hand. 🙃😊 That's a GREAT find bro...👍

[@tzvi-goldenberg]

Wow just wow. It's just crazy how you don't show your frustration in the process. I learned a lot from it. You are great and you deserve all the respect. If I could I would hug you. It's a once in a lifetime thing.

[@r.clydelockley5839]

The Customer should pay for BCM and be thankful it stopped at that. Just think of how many shops he would have paid to troubleshoot and not come up with a solution. Best video ever! You da man!!!!!

[@philfortner1805]

I think using an oscilloscope would make that tracing less intensive by having wave forms to see all the outputs in realtime. Nice work!

[@TnCountryBoy]

Thanks for taking time to walk us thru your very difficult time you've had. I was anxiously waiting for the repair.

[@JoseSilveira-newhandleforYT]

That's a bad one Jake! I would suspect a short of battery power to a lower voltage output on the BCM (still watching, at around 10 mins in). Major gamble you took with the second BCM, even being an educated gamble. Fantastic job of ruling out plug by plug until you found the problem one. Crazy that the fault happened the same way as the previous truck! The first BCM was killed as part of the diagnostic process - it's unfortunate that it's an expensive part, but if it was a fuse, you also might have blown the first you put in, before you could find the cause, and this was a sneaky case. So, you might reach a compromise with customer, to pay half of it, or similar - despite being an unpleasant situation, it's not your fault, and you solved the problem, that others failed!

[@cthorn2467]

That was a great thorough diagnostic and I believe that the customer should take care of both BCM‘s as part of the diagnostic, the customer should be thankful that you found the exact cause and it is now fixed. it looks like no one else could.

[@bobcombs7138]

I had to watch this one twice! I finally understood what you were doing when testing the circuits. To have the knowledge to develop that technique of testing makes you somewhat of a genius! You definitely know how to think outside of the box! Your customers are very lucky to have you!

[@rookiediagnosticsandrepair5956]

That was a crazy one! Thank you for taking us through the whole process.

[@charliegugino8047]

I watched this video a couple weeks ago and I had a similar truck that just came in with a wiring issue is the same spot, took me about two minutes to see the problem thanks to you

[@autodiagyt]

It's a common spot but this has been the only time I've ever seen it burn up a body control module lol

[@charliegugino8047]

@@autodiagyt this was a running issue and the wire was being grounded on the stud

[@kerryandbill]

I admire your patience. Don’t think I could have stuck with it, probably would cut my loses.

[@chuckvoss9344]

This one defies description. A true rabbit-out-of-the-hat trick. Looks like one of those, handheld scope-voltmeter units should start to be used for all troubleshooting. Just reading the voltage may no longer be good enough. Also, watching the BCM before starting the vehicle is an interesting idea. I am afraid I would have just turned the key ... and not learned anything. Thanks for sharing.

[@lupedelacruz4152]

Wow what a great find Jake thanks for sharing

[@fieldsofomagh]

Split the cost is the most honest way forward. Brilliant diag skills and definitely a gold medal 🏅🥇🏅 video you can be proud of.

[@Gilsal89]

🎉that is another level of diagnosis tank you for recording and showing your technic

[@Hybriddiag]

Wow that's crazy...it really boggle my mind...but i really appreciate your persistence and focus...great skills to have in this industry 👏....congratulations on finding out the fault...cheers

[@MiguelOrtiz-pq9gp]

Hi my friend, greetings from Chile. I think the customer must pay. Is not very right thing, but is part of diagnostic. You're a crack. Thanks for sharing videos and you knowledge.

[@richardcranium5839]

11 minutes in and this is EXACTLY what i was commenting on in the last video. no you dont need a caleb. your productions are top notch.

[@chuckmayerchak3071]

As an old retired service manager, Gm would definitely be on the hook for a "defective" BFM. For the price they are charging , a defective unit is already priced in. I would have not charged the customer for the BCM so the only one with deep pockets is the company. I'm sure the dealer has ruined many parts. A good parts manager would want to take care of you in my opinon.

[@mattnsac]

This is why you do a THOROUGH visual inspection. If I lose more than one module I no is good, Im first checking to make sure I have the correct part number and then Im scouring every inch of the wire harness I can. 20 years of electrical diag and I can guarantee that I've seen everything. Regarding checking correct part numbers, I worked on an F150 that kept destroying AC head units. Took me a week to find out that the truck was salvage and they installed a full IP with harness from a one year newer truck. The AC head units look the same and use the same plugs, but they are wired completely differently. Basically, I was buying correct parts for the truck, not for the wire harness and took checking the burn tags on them to finally figure out that I had a mismatched harness. Got a head unit for the correct year harness wise and everything worked perfect. Diag should ALWAYS start with a visual and check anywhere shorts can occur namely around the engine, around the seats and around where people put their feet or throw stuff.

[@paulburroughs1313]

Charge the customer your cost for the part. Send (or show in person) this video to the regional Rep from GM. If GM will reimburse you for the part then rebate the customer. That standoff that would have kept the harness off the engine appears to me to have been left off at the factory. Unfortunately not an uncommon occurence. Brilliant work here.

[@orlandofernandes4790]

Hello! I'm really amazed by your patience and wisdom. You really have the soul of a good technician. I don't know what to say about the fried BCM

[@Joselle1997]

THis is so helpful and awesome I have a 1999 Chevy s10 and having a few of same problems. thank you

[@christompkins6102]

You're an animal... best video out there....love your process. Customer pay.

[@OzFrog48Z]

It's one thing to diagnose a bad BCM. The real white knuckle moment is plugging in the new one and hoping the same thing doesn't happen again. It's almost impossible to check every circuit that runs through the module, but in a case like this it's necessary. This is a good case to show a customer that thinks you just plug in a scan tool and it tells you what's wrong with the car, and all you have to do is plug in a new part and you're done.

[@niokolabs]

I'd try to warranty it, because it failed because of a bad design by GM. Very interesting diagnostics you did there.

[@stephanecampeau9814]

The customer needs to pay for everything and prove to GM that it is a manufacturing issue if it is not under warranty. If the customer can prove the wiring harness has a missing retainer from day one, maybe GM will make credit for part of the bill. Because the owner of the vehicle is not the original one, it will be difficult to have them pay part of the bill. Most of the shops would just replace the BCM and then send the customer to the dealer to have them warranty the BCM. The dealer will replace the new BCM with a new one and have the same issue. Some shops call me because the customer's car has been sitting for months because the dealer just throwing parts to fix an electrical problem. You just stop that process with your good understanding of how to diagnose electrical problems. This was a good one! Good job! Thanks for sharing your experiences.

[@brucelott3583]

Sometimes the diag labor time seems excessive, but on a job like this, there are no guidelines for time. The bottom line is the root problem was eventually found and fixed. Many times this vehicle would have been to a number of other shops with no resolution and a lot of money spent. If I am the one to finally fix the problem, the customer is usually good with whatever the charge is. Good approach to a strange issue. Subscribed a while back

[@MrAnthonyfym]

Was really cool getting to talk about this at aste today pleasure to meet you

[@Friend_of_the_One-Eyed_Ladies]

Wow you've gotta get your SEO sorted out. Use keywords or something. I ran across your channel the other day, then lost it, and it took me like 3 hours of searching KZbin for every related search term I could think of. Finally found you again.

[@mattlile1738]

Good find. Sometimes were lucky to break even. But you gained experience. Young man thats valuable.

[@mattlile1738]

The only way to have found that is to have done the work Good job.

[@jordysandino6577]

Bro you nailed again just like the other Chevy . What a coincidence brother . Another reason to keep watching your video. Awesome Job . God bless you always.

[@moog2961]

Genius. Best diagnosis video I’ve ever seen.

[@8power0]

I GET IT ,,,,,,,,,,,,,,,,,,,,,,,, IT'S JUST APPLYING A LOAD AND WATCHING THE VOLTAGE . I WILL BE DIGGING OUT MY LOAD PRO JUST SO I CAN SEE IF THERE IS SOMETHING TO LOOK AT ON ANY GIVEN CIRCUIT . THANKS SO MUCH FOR YOUR TIME AND EFFORT !!!!!!!!!!!!!!!!!!!!! 🙏🙏🙏👍👍👍👍👍

[@Ken-1]

Awesome diag process, just subscribed. But I definitely see no issue with charging the customer for 2 BCM's. The way I see it, you are an honest, thorough and hardworking mechanic. And you have overhead. You solved his problem when no one else could. You should not be in the red or breaking even; That is unacceptable, unsustainable and no reward for your honest efforts! This is a hard profession/business to be in when you're honest and have a conscience. But the longer I do this, the more I realize those with good hearts like us sometimes have to put our foot down and REWARD OURSELVES! You cannot always count on customers to care, appreciate or respect you. And the more you do, the more disgruntled you will become.. which does not bode well for you OR your customers. REWARD YOURSELF. GOD knows your heart, and both you and He know your efforts were worth the price of that BCM 5 times over. Keeping your lights on, your pride/passion intact and your customers on the road is NOT a crime. Cheers brother!

[@autodiagyt]

Thanks!

[@عراضي-د4ي]

Thanks for sharing,in my opinion one on the customer and one on technician,because the customer already paid for the new pcm which been installed in truck before. Thank you again gentleman

[@CodycoWeb]

Great thought process on this one. You did your due diligence on testing for issues with the BCM replacement. We are not able to test for every possible cause when replacing modules. I would bill the customer a fair labor charge for the diagnosis then charge him cost for both BCMs that way you don’t loose money outright except for the profit on the BCM. I would caulk it up to a learning experience. Make sure you make enough on diagnostics and wire repair to make it as profitable as you feel it is due. 99% of other shops would have never found this issue so charge accordingly.

[@rwilliam01]

what about charging him your cost for 2 bcm's Make your money on diag and harness repair. I like the logic of your thinking it's easy to follow.

[@jimjam1934]

Charge the customer for both BCM's and diag, no claim against GM but the customer wanted it fixed and you did, great diag

[@grabovg]

Jake, great job. It’s crazy the number of failures I’ve seen online at that same spot. I remember a scannerdanner video that I believe had a shorted CAN bus wire there maybe. As far as charge. You have a business to run and the reason you get these vehicles is because they’ve been burnt before. Your charge holds more value. Charge appropriately.

[@EATSLEEPFARM]

You get the craziest cases 😂 im looking forward to part two of the auction truck

[@fluffyblue4006]

Thank you for the follow-up vid. I like to watch diag processes. The more complicated, the better. And this one was up there, for sure. But I think we missed the real culprit. Your scope capture also showed the start and end of a negative pulse. You might have missed it because your 0V was close to the bottom of the screen. The starter's contactor coil is huge compared to a normal automotive relay's coil. The back-EMF could easily peak to more than -100V. Enough to defeat the protection circuits on the BCM's main 5V power rails and cause random damage. It might even damage the 5V supply itself, causing it to pass the input voltage straight through. The main 12V power supply will then take over and fry the damaged areas until they look like a lightning strike aftermath. It will also kill connected modules that are powered by BCM-supplied 5V. Likely that receiver module. The cost of that 1st replacement BCM that got fried should be billed to the customer, because the customer bought this vehicle 'as is'. Indeed, you could have prevented this by first spending several hours visually inspecting every inch of harness in this car. But that would also cost the customer money. You followed a normal diag flow. There's no blame to you. I'm sure the average dealer would have billed the customer in full for every destroyed BCM. And for a new harness. IF they would ever be able to solve the issue before they'd run out of BCMs, that is.

[@amjadzidaoi4011]

Wow that's was crazy. The first time I have ever seen this. Keep going man, your content is great.

[@MrClipper500]

I stumbled on your video by accident but as have a 2008 GMC Sierra I watched the entire video. My first thought was this is a one in a million thing but the next day I checked the harness on my Sierra where it goes over that Stud on the valve Cover. That stud wore through the plastic casing and was just touching the wires in the harness. You know your stuff. Subscribed today. Sorry you have to eat the cost of the BCM. That Boo Boo was no fault of yours. If I were the customer I would be more than happy to split the cost being you figured out to get his non functioning truck running.

[@autodiagyt]

I would like at the wires and make sure they are not damaged because that stud won’t actually ground(because the valve cover is isolated with rubber gaskets) a wire out it’s when the stud is rubbing 2 wires at the same time you can get issues.

[@MrClipper500]

@@autodiagyt I wrestled my friends makeup mirror from her and you can see that the wires were rubbed. Guess hard plastic wears soft plastic. Glad I checked. Another gm patern failure to watch out for.

[@joedantuono3467]

A likely scenario is that in the past, some parts swapper doing a straight up ignition parts toss for a misfire saw either the loom or harness standoff decided"I ain't got time for that" and grabb ed a roll of tape :) A classic "There's yer problem lady, but it ain't GM's fault so FYPM "!

[@jordysandino6577]

Hello sir . Great video as always and please never give up explanations cuz people like me who wants to learned do not want to miss any second out of it . Thank you so much sir

[@jordysandino6577]

I have a question mister jake or any who can answer please. if the bcm was getting burn why didn’t blow any fuse ? I just trying to learn

[@jordysandino6577]

By the way I don’t think that is your responsibility to buy the bcm it happens it wasn’t your fault you didn’t do anything wrong though. I agreed to it Ivan phd

[@paulspooner-q6k]

im not as smart as he is but research on line about a 5v regulator and how it works will help you. i self studied electronics years ago and back in the late 80s i could make repairs on modules not now. if i understand the problem right it was being fed source voltage back thru that 5v ref not a short to ground may have to look back at the beginning hope this helps. computers do have current limiting on their hi current out puts like injectors to protect itself but not on the 5 volt and their is a resistor usually involved with that so no current to speak of to cause a failure . keep seeking knowledge i still do at 67 and love knowledge of all types not just mechanics. if i can figure out how to reach you maybe we can converse some, im not above the you tube celeberties just a guy like you always seeking truth and knowledge@@jordysandino6577

[@blademan7671]

I can’t speak to BCM cost, just a interested DIYer here. But I will say this: you, and Ivan at Pine Hollow, and Diagnose Dan, and others are focusing on the future: electrical. All modern cars are full off electrics, wiring, modules, and thorough understanding of the same systems will be key to solving auto problems going forward. Chin up, and I’m drinking one for you today.

[@johnmeyer6537]

You didn't tell us if it was 100% fixed. Did you check the battery sensor to make sure it didn't get fried as well. Billing would be hard. I think I would eat the cost of the first BCM and bill for all man hours spent. Then I would put up a big sign. (2008 Silverado's CHECK WIRING HARNESS). (Ha Ha). Its hard to tell a customer that its goin to cost $600 + to fix a dome light. There are not many Techs out there that could have found that. It makes you wonder how many BCMs the last guy installed just to get it to run again. I'm a retired tech/plant manager and it always sucked having 30 people stand there wait for you to fix it so I really try to stay right there with you as you work thru the problems. Knowing what type of voltage drops you should have on each wire and taking the time to do the checks most techs won't do. Love your videos and the detail you provide us.

[@atichargr]

Very well done. Love watching and hearing your thought process. Still have not found that high impedance test light. When you first cranked it and the test light flickered, the flicker was definitely lined up With the starter cadence. Was my thought but had to watch to see how it was tied in. Awesome job

[@fluffyblue4006]

You can DIY a high impedance test light like that: Get a normal test light and a 12V 0.6W mini bulb.

[@alanw5879]

another great video, this is the summer of GM BCMs. I cant believe how many of the same ole.. another Silverado, and another and another. We have seen so many this summer, I have folders filled with these trucks. You definitely should not take loss on this. GM has to pay for all the junk they sell. A dealership would have thrown at least a few BCMs at this before even going after a short like that. Ill be watching for that harness section now on every one. Thanks for the video Jake,,

[@windward2818]

One key point in the video, before troubleshooting a vehicle you have to address any main power customer/technician hacks, corrosion or damage. The message to the customer is a simple one, I can't troubleshoot a vehicle that has main power (starting, charging, etc.) issues. These have to be repaired before proceeding. The go to tool for inspecting the PCB circuitry is a stereo zoom microscope. You can back out a lot of the circuitry by looking at the BCM top and bottom trace layers. This is because of cost reasons the BCM usually does not have any internal signal layers, internal layers are usually reserved for power and power return (+5V, +3.3, Signal Ground, Digital Ground, etc.). So, the process is to look at that origin of the failure, the blown resistor and trace back in the circuitry what feeds this device. Then by looking at the IC pin traces see what signal originate at the connector, they may go through a simple RC filter and then to the IC, and based on the module pin function you can then determine what the IC does in the circuit. After this you can confirm if the I/O to this IC is working properly. Properly in this context is made simpler from the fact that the IC has failed and is drawing a lot of current (high heat). So, what on the I/O (connector and circuits) can fail this IC? Really not many because the IC has a lot of protection for basic I/O failures like short to ground or power. However, if you overload a 5V VREF with +12V you could take out the regulator and/or short the Microcontroller internally (the logic chip getting hot). As in the video a key tool to use on this type of problem is a thermal imaging camera, preferably one that you can save the images for the customer as repair documentation. When the plastic loom was shown as being completely missing in the video, with just wires remaining on or near the engine, means you can see real crazy problems like in the video. The engine wire must be protected from overheating and shorting out by having a plastic or friction taped wrapped high temp wire plastic loom. If the loom is missing, the wires have to be inspected for damage, repaired if needed, and the loom replaced and tape wrapped. The reason the failure doesn't happen on every crank, is because the engine does not move the same on every start, and the problem is related to how the engine moves on its mounts.

[@johnmitchell8925]

This situation is exactly why I started working for the County on fleet vehicles with an hourly wage

[@ZoomAutoDiag]

Finally got to watch it. Stayed up late to see what the fault was. Nice find dude. Great idea changing the stud out 🤘🏻 ~Jeremiah

[@roxanneabbott8424]

That was awesome Jake!! What a gift you have in electronics, thank you. GM should pay for at least one BCM.

[@JoelAutomotiveInaction]

In theory yes gm should pay for it but who? The dealers is just a store that buys Part from manufacturers. So in real life they will pay nothing

[@mrbigvanlife7130]

Outstanding diagnostic! The charge to the customer is interesting. I think they should expect to pay the second unit fee and also then they can take both BCMs back under warranty for refund. Root cause is manufacture error?

[@kkoz1023]

Not how that works dude! He’s gonna have to bump up his diag/labor time and take it out of that He will still make money but not nearly as much

[@raymondmetcalf9110]

great diagnosis and diligence that was really interesting not many techs would have worked so methodically finding their way to the end prognosis ,as for the billing you never had a chance with the first module on cranking . Whatever it may have been more costly had he taken it to another shop , plus its a reliable repair and he will get his truck back if you want reliable repair you have to pay. Great video thank s for your time .CHEERS Jake.

[@rvnzil]

one of the best diag video i ever seen , thank you very much

[@Nemesis-yn5wv]

This might help simplify it for some people. All of the voltage is needed to overcome the resistance in the circuit. Resistance comes in many forms. The only big resistance should be the item the circuit powers or operates aka “the load” which is i.e light bulb/electric motor etc. There is small amounts of resistance at connectors plug sockets etc but they are negligible. If unwanted resistance is within a circuit then some of the circuit voltage is required to overcome this. The greater the unwanted resistance the more volts are required to overcome it. So when a light bulb for example is lit only dimly then we know that somewhere within the bulbs circuit is unwanted high resistance which is stealing some of the voltage the bulbs needs to light brightly. The test method in the video he is using is to look for signs of high resistance within the bcm’s connected circuits using a bulb of which he observes the brightness and also a volt meter to see if all or only some of the voltage is being used by his test lamp. Depending what the circuit he is testing is actually used for he will know whether the test result shows good or bad.

[@ourtexasfamilyvideos62]

I love watching your Sherlock Holmes detective work.

[@michaelfalter6200]

I hear your compassion and commiseration. Any of us who deals with the public knows this. However. Your business has only one thing to sell. Your skill, care, and judgement. The hard costs such as the burned up BCM are just like the other hard costs (utilities, rent, etc.). The customer pays for hard costs, as a given. Without them you would close your doors. Then the customer pays for your wisdom, experience, intelligence on top of that. The customer expects to pay, they do not arrive at the grocery check out expecting to NOT pay. Shorting yourself is unfair to your next customer. Having said that, there are occasions where it is reasonable to pay tuition. If you feel this cost was tuition, then that is your choice.

[@fredautos]

Woaw, i was actually looking forward to see the root cause of this problem.. thank So much fo sharing Nice info!❤

[@ws2664]

That was a good one, Well, you can try splitting the cost with the customer, you can add some more labor if that fails, if you have a working one, you can sell it in future on another job or keep it and use it for a test module.

[@adamking6419]

Nice find Jake 👌

[@jareddeitch9121]

Thanks for your help!

[@richardjones3112]

Great video.👍You shouldn’t just be breaking even on that repair.

[@carmo9693]

That is a tough one time and testing for such a repair you cannot discount the time at all, with that and the repair of the harness, and the programming and don't forget the standard diag hook up for your test equipment and to erase all the codes. As you said you may break out even but it is the right thing to do. If the customer feels your pain they will tip you accordingly for such a job. Gm is not going to warranty, and customer should pay for 1. If you could have fixed the module that would have been an acceptable fix as long as all worded as designed. Keep up the great work.

[@GroundedDiagnostics]

Superb😌Be nice if customer paid half and the rest is the price of education and business👍👍 HERO Truck lol

[@bartscave]

Great to watch your diagnostic process! Thanks

[@sheerwillsurvival2064]

Was so glad I got that test light way back when you showed it . I got the last one from Freedom Racing online

[@FixthisCD]

Nice find. Wow that will test your patience

[@ericorta8196]

Awesome Diagnostic’s man , that’s on us as a tech , unfortunately

[@autodiagyt]

It definitely should not be on the tech. There isnt a logical way for a tech to have diagnosed that issue with the symptoms that was presented with the customers concern. Now if the customer had said that they had a BCM go bad, replaced it, and it went bad right way, then you as a tech could dig in a little deeper. But it's still very unlikely you would find it without replacing the BCM 1 time.

[@RipCityBassWorks]

That was insane, I doubt very many people could have found that.

[@stevemazzarella7212]

Wow that’s amazing!!! I think Ivan is right split the cost.. awesome fix!!! 50:43

[@bobbywarthan5173]

I feel it is a cost of repair at the end of the day it's the customers vehicle that makes it the customers problem

[@daviddasilva4897]

Wicked,cant beleive it,for the bcm i would try to get it waranty by the dealer,or else i would eat it,but that is a long diag,maybe you will be able to get it back,your patience pay out,love it,those are the diags that i love to hate,nice work jake,cant wait for monday for the ending of the case studie of the pick up hit by lightning

[@Bikerman42]

Great video. I would say split the cost of the second BCM like Ivan suggested. But full labor on the diag part with all the headaches you had to deal with.

[@danceswithtrees]

First time watching any of your videos and I just wanted to point out a couple places where I disagree with you. At 17:54 "I know, this video is probably going to be terrible." No, this was awesome. And at 37:40 "I basically got very, very lucky." After working methodically and diligently. That was not luck good sir. Maybe in the sense that chance favors the prepared? Subscribed.

[@autodiagyt]

Well thanks 😊 glad you liked it

[@dougowens2686]

As a customer and a electronic tech that with similar experience. I would pay your cost for both modules knowing how much hair lost and that you save my ass from being stuck on a dark road in the middle of know were.

[@JohnDoesGarage]

You did your due diligence, so smoking the BCM you put in actually attributed to you finding the problem. There is no way you would have known to do all the tests you did to find the problem had the BCM not fry when starting the truck. I equate it to blowing a fuse, an expensive fuse, but a fuse nonetheless. You should not have to eat that expense. Obviously nobody else could figure it out and they smoked a BCM in the process as well. Who knows how many they fried before they fenced the truck. The cause of the problem is a GM issue, but they'll tell you to get bent. Ultimately the owner of the truck should be responsible for the cost of repairs. He bought the truck knowing it had issues. He took a gamble and it was an expensive one. Maybe he got a good deal on the truck so the expense of the repair won't leave him spending more than the truck is worth. I've bought vehicles where there was a potential that it could be an easy fix or one that would be more involve, but I try to buy them at a price where I won't lose money if it is the worse case scenario. The car I drive now was advertised as possibly needing a transmission. My gut told me that wasn't the problem, but I bought the car factoring in a new transmission. It turned out my gut was right, it was a $3.00 axle seal that was leaking and the transmission was just low on fluid. Once in awhile I get lucky, but I've lost as well, this guy lost on this one. Hopefully he got a good deal. I own my own shop as well and I understand wanting to do right by your customers, but you did not make any mistakes. If I screw something up because I did something wrong, I eat it, as I should, but you did nothing wrong. Maybe give him one BCM at cost and retail on the other one. Average it out on the bill so they appear to be the same price, but you have to make a profit to stay in business. LIke I said, it's obvious somebody else tried to fix it and they couldn't, but you did, and that is worth something. Thanks for another great video.

[@suryaprihadi2258]

Awesome troubleshooting as always Jake. Wow, the way the main wiring harness in engine bay is routed , that is so bad at design level. Longitudinal engine position and yet the wiring harness is coming in from perpendicular side, the engine highest movement angle with such wide body vehicle.

[@stevemazzarella7212]

Not many ppl would be able to repair that issue, hope it all works out..

[@r.weaver3769]

Chevy Thunder... I remember having one where the door locks did that on off thing a long time ago. Customer stated, "Yeah it does that, dealer can't seem to fix it."

[@DJ-tn7vj]

Jake where do you get these kinda of case study bro. You and Pine hollow have all the fun.

[@txdm9383]

I think that stud has been the source of many headaches for people that don't know about it (I remember getting my butt kicked the first time I ran into one that had the harness shorting out there (had random stalling issues and would set random sensor codes), now I check every one that comes in and either replace that stud with a bolt or put a piece of heater hose around the harness to keep it from rubbing out), it seems that some never got the harness retainer installed at the factory because I see many with it but also quite a few that don't have it. I haven't yet seen one fry a module because of it though, that was nuts.

[@cullenmiller8170]

Amazing case study and skill. I guess knowing common failure points does help too. Obviously, not knowing the history about the previous BCM failure didn’t help your diagnosis. I guess as long as the customer pays all your diag and harness repair time you are on the hook for the BCM. It doesn’t seem right, but I don’t think there is really a way to bill it since customer brought vehicle for diagnosis.

[@JoelAutomotiveInaction]

In my opinion the burn bcm is part of the diagnostic, now you discover why the bcm is gutting cooked , I little bit of engine torxion could make the fault to be at all time , intermitently or no present , so who do you predict what circuit will have the isuue where you have 200 wires , plus the Right conditions for the fault to appear ,cranking