Maybe we diagnosed it wrong! GM 3.6 cam sensor faults. 

Wow that was nuts Keith! But single channel UScope is pretty weaksauce 😅 Break out the 4 channel Pico and compare all 4 cam sensors on one screen! Would be easier for the viewers to see bad vs good pattern 😉

Not sure if this was pointed out but it was critical knowing what the reluctor looked like. Without that key piece of information there wouldn't have been any reason to doubt all the sensors that didn't work and the parts canon would have ensued.

Over the years there have been many instances of cloned aftermarket parts finding their way into oem parts inventory. I remember back in the 70's (yes im old), where there were instances of GM ignition modules in inventory that were cloned parts and reliability was poor.

Sometimes I get petty with issues like this and I’ll file multiple labor claims even if they are only 0.6hrs. If these manufactures don’t have to pay up for their garbage parts or catalog issues they will never correct the issue. Our jobs are hard enough with second guessing our diags because of parts like this.

Parts are a big problem across the board. I have stopped doing A/C work in my shop just because of that. I recently did a BCM in a Monte Carlo, that took 4 aftermarket BCM's from 3 different manufacturers to get a good one. Hours of diagnostic time because I could not conceive of getting 3 bad modules in a row. In the end, I followed the data and the 4th BCM worked like a charm.

Another great video. I just ran into that issue last week. I used the scope to prove it out. I also had to argue with the sales person because they said it came from the dealer so it can't be wrong.

I had a run of 10 bad knock sensors from GM on a 5.3. After the first 4 bad ones the dealer wouldn't sell us any more saying There is no way they were all bad, had to get the others from World Pack and Parts Authority until I found 2 that would work. Used a scope to test them before installing after the first 2 failed so not to keep pulling the intake off to save the shop the labor. All were Delco brand sensors.

Man the parts situation is getting brutal. All this time, replacing new parts with new parts, the giving up and getting used...who pays for it? It won't be long before these cars can not be fixed. By design?

Great video and diagnosis. I guess believing in your data is the hardest thing sometimes.

That sucks. Getting decent parts has become such a gamble

Keith, that case study was quite impressive. Typically, you'll find consolidation of part numbers in the aftermarket rather than in the OE sector. I wonder if the engine was misdiagnosed for that reason?

Holy cow!! You cannot make this stuff up!! Unbelievable what the automotive repair industry is going through. How frustrating? It's so difficult to convey to customers all the variables we're going through AND to CHARGE the customers accordingly. It's unfortunate that the consumers are getting "shafted" due to this whole mess. 😕 Thanks Keith. Always appreciate your knowledge & input. Hope the family is doing well. See you at Super Saturday? 😊🤗🤗

I ran into a similar situation with a Subaru years ago. An oscilloscope saved my a$$. The engine builder company used an inferior crank sprocket for the timing belt and the teeth were 8 thousandths larger than the original. FIX - replaced using the original crank sprocket. 15 hour of diag and a lot of cussing later for a 3 hour fix. Warranty claim only paid for 5 hour. Never used that rebuilder again.

I’m wondering since it is a clocking issue if a newer year model cover might be needed to fix the clocking issue. Would be awesome to see the relationship of the mounting surface on a newer model 3.6 and see if there is a difference.

Yet another way to take used cars off the road. Conspiracy or coincidence?

Lead kits for the pico scope became an essential tool about two years ago. Every dealership should have been shipped them. The problem is we still aren’t trained on scope usage. Granted I haven’t done entry level training in over twenty years but we still aren’t even given scope pattern data to aid in diagnosis.

Thanks for teaching us Keith.keep the videos coming.

Why would a sensor change the pattern on the scope? Also ac delco is an aftermarket supplier. Gm original equipment is OEM.

That's crazy Keith but great information! Thanks for sharing!

Crazy string of multiple sensor issues! Thanks for putting in the determination to getting an answer and sharing it with us for out future knowledge. 👍👍

Great video and very informative. Thanks for the heads up..!

Great video Keith. Love the uscope protector/lead adapter

i didn't know clocking cam sensor would change the pattern . seen when they consolidate # they screwed up

Great great diag and super informative..i love your content 👏 👌 it helped me alot to get better on diags...cheers and thx

Thank you

Wow! That can turn costly fast with that much misdiagnosis. Nice Job Keith!

HELLO THANKS FOR SHARING 🙏👍

story of my life its half the stuff i look at wrong part fitted that look like i might do.. but with out a scope one would never figure it out .. good find by the way

I installed my first defective new dealer part last week. A 2011 volvo xc70 blower resistor. It had mahle printed on part. Had to wiggle connector to make it work.

Solid

Similar thing happened to me last week. Went through 4 AC Delco MAP sensors for a 03 Monte Carlo. The fifth one we used, to fix the issue, was a Standard brand one. Issue? Would not run the EGR and CAT monitor to pass smog. No codes. Was about to quit cuz my boss was being an a$#hole about why it wasn't fix yet. I showed him my diag process but he didn't care. Still thinking about moving on though.

KEITH, AWESOME as Ivan mention break out the 4 channel scope and compare all 4 cam sensors would striate forward to see the difference between each other as always great info thanks for sharing.

Just like the 5.3 knock sensors. On a good note we probably won’t be able to get any factory parts soon

IMO it is usually better to match the part supplier partnr (in this case BOSCH 7 digit) to find a replacement rather than relying on car manufacturers data.

There is no-way that issue can be found without luck or an O scope and knowledge of the sensor pattern. I am an electronics guy first, so when it comes to issues like this, and understanding how that signal is generated in the sensor itself, and then presented to the processing input circuitry catches my attention. With so many swapped out sensors, this is has to be an incompatible electronics part. Most likely a buildup of tolerances. I would bet, dollars to donuts, that the manufacturer of that engine, the test technicians that check each engine, knew this problem also. But what they did was to have a full box of these sensors and just swap them out until they found a sensor that was compatible and i worked. A sensor that didn't work in one engine, would work in another engine, and so on. Then they sent the engine over to install and out the door it goes. Manufacturing Engine Quota Met. Nobody knows the better until the cam codes start popping up in the field.

Grasias

Yes the dealers now have pico leads and an amp clamp. They all got them a year or so ago as essential tools. Now the techs knowing where they are or even wanting to use them is another story.

Confirming unreliable parts should also be a training event all it's own.

Great scientific analysis. What a waste of time for your shop but finding the fault? Golden

What scope is that you are using ? Do you need to buy the leads separately ?

Wow. GM really has their shit together.

That is one reason a lot of shops are closing down and so many techs are leaving the industry what do you do when you’re the only A tech at shop and you keep telling the owner after 4 sensors you still need another one your job would be on the line

I've seen a lot of bad parts from Bosch. This is a Good example of that. The GM High Feature V6 since the beginning have Bosch Motronics and almost all Bosch Sensors, and they fail a lot. Some Saabs that have this engine had the ECM on top of the engine itself, and the Case was the ground ifself instead of a dedicaded ground line. A few monts ago, I Diagnosed a 2011 Acadia Denali with the LLT Engine; the ECM was smoked inside (a big capacitor blew up); wiring was good, no issues with Charging or Battery. Replaced ECM, and it was good as new. Another example, a 2005 Volvo S40 (ME9) that was having 5V codes unexpetedly, and refusing to start; ECM damaged, ECM Replaced and good to go. Bad quality at Bosch is somewhat common nowdays. Not only on Automotive components.

It seems more like a quality control issue. Recently had to go through over 6 knock sensors to get 2 good ones

If its older than 2008, the big bankruptcy gm would just as soon it be salvaged. Expect the same problems with LS knock sensors.

Another example of a hot shot young engineer in the parts department. Same thing happened at Dana Spicer off highway axle division.

Damn! Talking about making a hard job even harder

Interesting

Few years ago I bought a 2014 terrain 2.4 woeh bent intake valves. I repairs the engine and replaced rings pistons cam phasers solenoids and a high pressure fuel pump. All ac Delco parts. The high pressure fuel pump was leaking gas into oil 3500 miles later it spun a rod bearing. Took me replacing the engine and about 5 oil samples to figure out that that new AC Delco fuel pump ruined my engine

L1 automotive training, Keith Perkins 👍 SHREWD L1 Automotive Training, Keith Perkins From Nick Ayivor from London England UK 🇬🇧 ⏰️ 07:09 am Good Morning 🙏 🌄

Great case study. I would have wasted a little time with a visual look; down the sensor hole, looking with a borescope turning the engine over slowly. And then with a scope and sensor in turning engine slowly. Yes, I know the problem followed to the other cam.

I'm curious how so many sensors can misread the phaser. They show they are capable of reading a short pulse so what is happening with that extra wide pulse in the sequence? Perhaps the hall effect chip is slightly out of alignment and reading the inner edge of the phaser wheel. Did you notice if the connector was clocked in the same position in the bracket for all sensors? Wondering if it's a sensor issue or an assembly (into the bracket) issue. Maybe a tweak with some pliers will fix? :P

Did you try to clock the sensor to get the correct pattern? Maybe the only difference is the later model front cover clocks the sensor differently...

i personally think if we would all back up and drive what i have 1994 ram 2500 4wd OBD1 we all would be better off easy diag easy parts swapping life is good

i think i missed something you showed clocking it and the signal got better, so the internals of the sensor is good but the body is not manufactured correctly for it to be clocked correctly when installed, just asking could you clarify thanks

If they chek for corralation if all sensors was the same as the wrong ones would it think its ok then i know it not right but curios if it would work if they matched from bank to bank

i guess what im triyng to understand are you tilting the sensor or rotating the sensor that is causing to get better

👍👍👍

Hey probably a dumb question but wouldn't a malfunctioning phaser that's intermittently not locking show the same pattern..

Magnetized timing wheel? Might make an otherwise good sensors not able to switch reliably.

Planned obsolescence

did you had a hard time to rerunt the factory sensors, at a point did they think you were lying ?

Wow Keith, Ford Fusion ac pressure transducers, and now GM cam sensors? Where are the TSB's? The silence is deafening. C'mon OEM's, get it together. I'm almost embarrassed for you...almost.

This stressed me out 😂

My question is, if you don't know how the reluctor wheel looks like, to have an idea of what you should expect to see on the scope as a good signal, then how do you proceed with the diagnosis?

This is the kind of crap that drives us nuts and reconsider a new career

Is that something that a reflash might cure

Marc miller? Bubba are u in tulsa or sapulpa if so I’d love to send some pcms to u to see if u can fix them for me I’m a local mobile technician

The 3.6 is an international engine is it not ? So it would be interesting to see if the 3.6 used in Holden Commodore (Australia and New Zealand)have the same part numbers and same issues. These motors were dogged with issues with the stretched timing chains, Carbon build up and damage ,regarded as a bad engine where GM Holden tried to fix by attempting to use computer timing adjustment to fix them . Then when the customers had to eventually get them fixed ,it was tremendously expensive,both parts and Labour . Over time one could get cheaper parts from America for the Cadillac using the same engine ,so the distrust of the manufacturer grew even more ,bad customer service and corporate greed . As Eric has proven, dealer tech's aren't trained to question the program,if the computer says it's one thing ,it must be so .

dealer couldn't fix it??? 🤣😂🤣 As a dealer tech, this doesn't surprise me one bit. I work with more parts changers than techs. The scope thing isn't surprising either, I work at a Chrysler dealer and scopes are a fairly recent development, we finally got a pico, called the mopar scope.I have had a Verus for years, and a 2 channel pico, but most of the other guys do all they can to avoid even mentioning a scope.

2023 and the dealership still don't believe in scoping. Not even a single channel Uscope. WTH

Start a cam sensor lemonade stand.

I would have raised the rpm to 1500+ to see if higher oil pressure changed the pattern.

Where is this 'pause' in the video coming from ?

So the signal is inverted? It may be picking up residual magnetism from the steel reluctor causing the signal to invert. Good find 👍

So first check with a scope or just order 20 sensors.😂

Trust the data...no scope = no fix. If as an employee or a mobile tech you were faced with this, would they believe you if you constantly diagnose faulty cam sensors on the same vehicle?

Imagine that, this the type of Shit to make the Costumer, 'Think ', that the Technician doesn't know what they are doing, after having to buy that many parts. Especially in places where they don't take back electrical products

The sensors they Stole probably were bad . . Lol

Sum Dum Fuk , over in china clocked the sensor chip wong. wi getum wit had the day off

A flag swings on front of a sensor, how could pattern change sensor to sensor. Doesn’t compute. It is simply a function of flag present or not in 360 degree rotation. Somehow you are getting ‘scoped’.

so as a flat rate dealer tech, engine diag sucks...

Shit gets nuts and these service managers will destroy a mechanics life over this stuff.I get a work for an '18 Sierra "Replace with reman trans".I didn't diagnose it and an idiot service writer with 3 whole months experience diagnosed it over the phone but done!It comes back 6 weeks later blowing a P0747 SS#1 stuck.I perform the system verification procedures.Clear code and try to reset.I drive it for 1.5 hours but only get paid 3 tenths for a cannot verify complaint because it won't reset.Ship it! It comes back again in another 6 weeks blowing same code and everybody is freaking on me because I didn't test drive it for 6 weeks for free.Time to fire the parts cannon but fuck it I'M OUTTA HERE!2 months later they issue a TSB on this P0747 claiming a software anomaly and engineering was working on a fix.

Have your dealer parts guy call partech....

From what I understand, gm is now out of Mexico. That may be a part of the problem.

It sucks for the tech!!!!!!!!!!!

Object detection sensor in an Escalade.3 different part #s 3 different position revised parts 12 fucking different times equals about 487,000 different combinations.IT'S A GOD DAMNED NUTHOUSE AND MARY BARRA GET ALL THE MONEY!

Did “we” diagnose it wrong? You’re like Eric O saying “we” when something goes wrong!

Nice one. I would of thought it had the wrong reluctor ring after all the sensors said the same thing. Scope save s the day again. Your like a bull dog on these weird ones. AC Delco and Bosch made in China or worse.

who pays for all the extra work for the wrong parts fitting and removal

AC Delco makes none of their parts,rebranded as AC Delco by someone else

This is why I hate new cars, (especially GM); and Delco parts are so crappy!