Chevy Traverse: O2 Sensor Problems

In this video I look at a 2009 Chevrolet Traverse that came in with some O2 sensor problems. The customer and a friend of his have been struggling to get this thing fixed. Ends up ultimately it needs a PCM but with an addition of a substitute ground and replacing the front O2 he was able to get his drive cycle done so he could take it in and get a sticker. -Enjoy!
If an SMA Video has helped you out please consider giving using "Patreon" to help support us. The videos take real time to create and pull us away from real work that pays our bills. CLICK HERE: / southmainauto
THANKS A MILLION!!
--Eric O.
If you don't like Patreon feel free to use the "PayPal Me" link: www.paypal.me/SouthMainAuto
The South Main Auto Amazon Store: www.amazon.com/shop/southmain...
AES Wave Automotive Diagnostic Tools: www.aeswave.com/cart.php?m=af...
Feel like sending some swag to SMA because you love the videos but don't know where to send it?
Just ship it here:
South Main Auto Repair
47 S. Main St
PO Box 471
Avoca, NY 14809
Disclaimer:
Due to factors beyond the control of South Main Auto Repair, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. South Main Auto Repair assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. South Main Auto Repair recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of South Main Auto Repair, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not South Main Auto Repair.

[@SouthMainAuto]

Sorry so long between posts folks. Kind of a really crazy week at the shop that set me way behind! Trying to play catch up this week and get things back to "normal." What ever that is 🥴

[@Bobbyjwmwb]

Hi

[@chrisfreemesser5707]

No problems Mr. O...crazy seems to be the new normal these days ;)

[@Dratchev241]

Normal is 10 viewers calling 9 Rusted bolts 8 dead brand new parts 7 Jerry's Jerried 6 hacked up wires 5 trouble codes 4 bald tires 3 faulty brakes 2 dead wipers and a dead pcm for you.

[@marathonfreak67]

Whatever Mrs. O says it is!

[@chrismechanic2000]

interesting video, strange that it is putting out a live supply, must have cooked a switching transistor or something like that.

[@WatchWesWork]

I guess Jerry also has a welder...

[@JeffCounsil-rp4qv]

🤣🤣

[@HouseCallAutoRepair]

That weld was too good for Jerry...

[@JeffCounsil-rp4qv]

@@HouseCallAutoRepair Nope. Notice how it "screws" around and overlaps and is "oops, gotta try that again"?. 🤣🤣

[@JeffCounsil-rp4qv]

@Jerry P 🤣🤣

[@bigkat1919]

looks like a flux core from "The Freight"

[@robpeabo509]

There is no need to aplogise Eric. Us viewers benefit way more than we could express. You have to earn an income to pay all your bills, wages and support your family. Somewhere in there you are a husband and parent and your dogs need you too! I am thankful you take the time to put out the videos. You and Mrs O are champions!!

[@cgmoog]

18:56 - "I don't know all the electrical mumbo jumbo that happens in there" best definition of a "black box"

[@gary00832]

Yea he does. He's just pulling your leg

[@loz11968]

Hey Mr O I’m sure I’m not the only person who would rather have a video where you point the camera at the screen than no video because you don’t have time to mess around... I certainly appreciate the fact that you do take time to do videos from a working shop and a busy one at that.. keep up the great work

[@VBshredder]

Agreed, honestly the video looks fine 2nd hand, almost prefer it - for the "authenticity"

[@BuceGar]

Yeah, it looks fine to me. I can see everything, not sure why anyone would complain.

[@bismarcksandiego6539]

100% agree !! Thanks for taking the time to show us. You did however have some beard hairs out of place, gotta knock you on that. sorry.

[@emkayusa]

That guy not only had a parts cannon, he had some leftover pipe and a welder. “Flex pipe? Who needs that”

[@markh.6687]

Maybe he needed the flex pipe for the Parts Cannon. I mean, you have to conduct the plasma burst to the projectors somehow....

[@DAZ_SR]

The owner of that Traverse over the first bump.

[@throttlebottle5906]

@@DAZ_SR it's there to allow engine torque load movement, now it will likely break the exhaust manifold flange gaskets up and start leaking or break the gasket downstream.

[@crazyedo9979]

Yeah! You dam'n right. Spare parts are totally overrated. Better look on the goodie pile first😁

[@ajfurnari2448]

Guarantee you that that nice, convenient 02 sensor bung right next to the welding area made one heck of a good place to attach a ground clamp.

[@RS-qp4bp]

That's right and both O2 sensors were replaced. Eric should get a court order to have the O2 sensors exhumed so that he can do a post mortem on them. LOL 🤣 Good catch AJ

[@pfsenterprisesllchill2695]

Your common sense approach has stimulated my thinking and problem solving on several occasions. Thank you from an old mechanic.

[@cowfrank]

The analyzing of this type of problem is so important. It has become common place to just bring out the parts cannon at most repair facilities..

[@richardbambenek2601]

Your troubleshooting and deductive skills are something to behold. I'm sure if they handed you a schematic for the ECM you could figure out which IC was bad and what junction was shorted. Watching you work is like watching a good who done it movie.

[@dnprall]

Different brand, doesn't make the noise. Love it!

[@SimplyDiagnostics]

Josh was working hard on the audio today 😂 great troubleshooting video mate - you're awesome 🏆

[@sdgelectronics]

5V on that line suggests it's conducting through a body diode in one of the semiconductors. The welding likely blew out the 0V/GND switching element to the 02 sensor. It's a good idea to always use two ground clamps when welding - one either side of the joint!

[@andreavico6198]

In my opinion the input is differential and the "signal ground" is not a ground otherwise you can't get 4,62V out of if. In case you're right the body diode short and the track on the pcb burn and open. As I did write in my opinion the input is differential (also suggest by the draw in the wiring diagram) and the signal reference is not at 0V. This beacause of the high impedance of the output of an O2 sensor output is more sensitive to external EM noise. A good test would be measure the other O2 sensor signal reference if they are a 0V or not. The original problem could be anyway in the ECU.

[@sdgelectronics]

@@andreavico6198 I think it's likely the ground element was damaged during the welding, so now the only path is through that internal ESD diode. The wiring diagram showed that the ground to the sensor was not a true ground, it was switched in some way - presumably to protect itself if it was shorted to some other rail.

[@andreavico6198]

@@sdgelectronics another test to proof your theory is measure if the signal reference is short or isolate from the metallic case of the O2 sensor.

[@throttlebottle5906]

@@sdgelectronics or the a ground trace is blown and there's other things tied to it, which are now raised above ground and back feeding!

[@SIGINT007]

After 24 hours of live ranching, this is a perfect Sunday morning video

[@wdobni]

all things considered, you probably have the best youtube channel on the internet .....you could have made it big in hollywood but you would have had a miserable life there .... a man of many natural talents ....not very common any more

[@htownblue11]

Thanks for the upload Eric. No worries on the delay. We know these videos aren’t easy to produce when you’re busy.

[@jkline999]

11 years of college, and I didn't even keep up with you. Damned inspiring.

[@HouseCallAutoRepair]

Lesson here: If you have voltage where you should have ground, and all of your connections appear to be good... Call Eric! (Ok... DON'T call...) GO see him and bring donuts, coffee, ice cream and a rust free car to work on... Everyone will be well wired!

[@BrianB14471]

I don't think that low side is supposed to be a ground.

[@markh.6687]

"Bring donuts, cars, and money! As quickly as you can! Bring donuts, cars, and money! The sensor's hit the fan!"

[@anhnambinhtrungtay7330]

Good analysis! Always disconnect your battery negative before you do any welding!

[@oliverdavidpatrick]

Dude, I kinda got interested in your channel about a month ago when I was looking for instructions on a Honda Civic EP2 (01-05) rear wheel bearing replacement. Back then I thought you were mostly into the heavy and rusty stuff with your puller and Big Nasty... But now I am very surprised about your diagnostic abilities. Thumbs up and best wishes from Germany! Keep it up, dude!

[@thomasshaffer8547]

Eric O has been teaching automotive system troubleshooting for years. The heavy rusty stuff is his side job.

[@jackc7084]

A SMA upload and Line of Duty season finale, this Sunday is awesome!! Greetings from a British guy in Germany!

[@jamesu]

Thanks for the video Eric. We all appreciate what you do!

[@db3467]

I love your videos since I'm semi retired from a car accident. Your an excellent instructor.

[@freetolook3727]

"What we have here, is a failure to not communicate."

[@Garth2011]

I think Martin used the word "got"

[@freetolook3727]

It was meant as a goof on "What we have here is a failure to communicate." Cool Hand Luke movie. Meaning that there shouldn't have been any current communicating along the circuit. I think the joke just lost something in the translation.

[@NoName-zn1sb]

What we have here, is failure to not communicate."

[@pontiacsrule8761]

Don't worry. We are just lucky viewers that you run a repair shop & still take the time to make videos whenever you can, THANKS

[@cycledood]

Thanks for the heads up! I always disconnect the bat but, will unplug the PCM and bat from this point forward when welding.

[@throttlebottle5906]

unplug all the sensors and connectors nearby, as there are large induction fields around the welding area, which induce currents where things shouldn't be. even with the fabricobbled exhaust work, I'm still not positive the welding is what got that ECM though! maybe old O2 wires melted together and someone played the keep fuse swapping game. I forget if the heater on those is +12V ignition source and ground side PWM switching or not.

[@lrebelo100]

I love this channel. This guy is always very detailed in his explanations and what he shows during the repair. That's good for those of us studying automotive technology

[@canifixit3504]

Yep been saying that it makes no difference if welding with or with out the battery been hooked up or not keep the ground next to where ones welding

[@grunthostheflatulent9649]

The classic long travel welding earth. Rusty exhausts make bad grounds for welding, wiring looms make really good ones.

[@waysshenanigans6982]

OMG dude I finally found your channel again!! I first started watching when you only had like 1500. Last time I saw you only had like 60K congrats on half a million!! So happy to of found you again man you're seriously one HELL of a mechanic man. Taught me soo much, how to test sensors, scope things, the harder stuff nobody really teaches. Keep up the good work man!!

[@2405jacko]

I thought Eric forgot about us, we missed you man.

[@josephbelmaresiii7682]

Thanks for the thought process on tracking this kind of problem down

[@robtheslob3940]

Bought a shirt, hopefully you get a few bucks out of that. I love your content; working on a car is tedious enough but with a camera and teaching people while you go truly is a feat unto itself.

[@thickwristmcfist3399]

I love all of your videos!! I love your customer service style, and i love your honest fixes! Good job on this one! I wish you were local, because i'd turn you loose on my 06 Sonata.... Yay!

[@mikeoden4179]

Learned from a old school mechanic, he always brazed exhaust on the newer cars. A major pain, but never had electric or computer fails

[@drewdude444]

You don’t have to comment and say your busy. It’s written all over the place with your demeanor. I know this feeling all to well. Glad to see your human like the rest of us LOL 😆

[@davidrobins4025]

Convoluted path to find the problem. Congratulations on your determination to find the problem.

[@michaelmerta8956]

Great day on a day of Saturday with an German beer to watch Eric work, love your show watching it from Mississauga Ontario Canada. I'm only 71 years and an old farmer in Alberta told me once he you young wipersnaper don't throw anything away doing my break fluid flash. He said break fluid he is using to remove rusty spark plugs and bolts as well. I said I know better and try it broke off the spark plug. Happy to say it was a lesson to me.

[@charlesadams41]

A different brand of brake clean doesn't make the sound...lol, who knew?!

[@wirenutt57]

Nah, he's mistaken. I got a guy who tells me it's the same stuff, just a different label. Don't let him fool you!

[@davidd8435]

Thanks for the content Mr. O, how's Mrs. O like her Kia Sedona van so far? Stay safe and keep on fixing things you are a good teacher.

[@jamesterrill1938]

Great video, experience is the answer, hard work does not hurt either, Thanks

[@jeffryblackmon4846]

Your logic in trouble shooting is excellent! Thank you for the information! It's a fine video, folks!

[@rdgabriel7398]

I never realized that the brake clean sound was brand specific. Good to know!

[@John375PD]

What I would do for the heck of it to take the PCM apart look on the inside and see if any noticeable component is blown which is sending a 5 volt charge to ground. Excellent diagnostic skills that's why I love watching South Main Auto!

[@markjohnson5081]

Excellent, as always! Love watching these bug shooting videos. Always learn something. Tnx!

[@jareddiamond6607]

Love the intrigue on this one. Thanks Eric

[@OneMechanic]

Always love how you tackle the issue... Thanks

[@dennisbailey4296]

And here I thought you were perfect and didn't make any mistakes. Haha all the best from Canada

[@nop3noperson]

Life is good. Eric is great. Mechanics are crazy. (Break clean sound effects)

[@chadwickroyal2133]

Wish you were in Vegas. But grew up with a dad who is a mechanic and he worked the same way. Great info to have when and if I have issues with my 2020 F-150 XLT 4 x 4. That way I can ask good questions. All my Fords have been 10-15 years with no major issue so I hope I’m good with mine now. Thanks Mr. O

[@norcal715]

In the diagram the PCM showed switched ground(s), I wonder if the code set criteria disables the O2 sensor depending on conditions after a failure. You should clear all of the codes and see if the ground returns when the PCM commands it. Great video as always Eric!

[@61rampy65]

I think the switched ground shown is for the heater ckt. The other two ckts measure the voltage of the O2 sensor itself, tho I could be totally wrong on that.

[@CoolAirVw]

Send Ivan in to take apart that ECU, he'll solder in a paperclip for a "no-parts" fix!

[@throttlebottle5906]

it's likely potted under shmoo with nothing visible or clear gooey shmoo that's hard to remove. last ECM I tried around that year was.

[@richardmackenzie9551]

Nice one. I always hate having to call an ECM unless I can totally prove its bad.

[@dewaynek8591]

I’ve got it easy, I’m a collision tech so when I call an ECM it’s kind of obvious because it’s usually been smashed.

[@pkav8tor]

When welding on any computer control vehicle I would always ground clamp the welder within inches of the weld. If the item being welded was not capable of being clamped by the ground clamp, I would clamp a small piece of flat stock in the ground clamp and spot weld it to the part first, very near to the weld area, then proceed to weld up the part. Keep the weld electron path small and you will not cause the wild pixies to wander thru the computer ...... Mr. O, your synopsis on the cause of the blown computer is spot on !

[@Tommerd]

My SMA tee shirt should be here this week! I shall wear it proudly. Probably the only one in Western Canada?

[@bradklingensmith]

My 2nd should be here Tuesday. Don't know how many in SW Pennsylvania

[@markh.6687]

No, I'm sure there's more than 1 tee shirt in Western Canada, it just isn't a SMA one. :)

[@billclinton6040]

Very insightful diagnosis at the end that the ground got shorted out inside the PCM when they were welding on the O2 sensor. Dr. O to the rescue!

[@anthonymakley1530]

Thank you for another great video Eric

[@ua7pyro591]

The ol traverse. The Chevy cavalier of today's Suv's

[@cesare8020]

The terrain and equinox are the cavaliers of suvs.

[@d.a.2742]

Don't forget the Corsica !😅

[@robc8468]

@@ColdStartAuto Only with near perfect maintenance, BTW any decent car should make to at least 150K without major failures.

[@AndrewKidd14145]

Fuck man I’m working on one right now, replaced faulty t body, then drove for 1 hour all went well 2 days later traction control goes off but no misfires. Damn thing never had a check engine on and still doesn’t and it’s fucking up -.-

[@robc8468]

@@AndrewKidd14145 GM electronics/wiring is on par with Chinese Christmas lights.

[@kidscarsindagarage11]

Thanks for the videos bro you help more than you'll ever kno 💯

[@pdinardo9472]

Good video Eric!! 👍👍👍

[@sharedknowledge6640]

Nice one and I agree it’s likely they welded it with the O2 connector attached and trashed the ECM.

[@mikebiron7339]

One more "test" would be to probe the other downstream O2 ground to see if it has any voltage on it for comparison sake. But, with the fan issue and such I agree it needs a new box.

[@niallseddon8657]

Had the same thought, maybe for circuit integrity test had something similar on a MAF signal ground the other day, reading 12.5v but not enough grunt to light a test lamp.

[@donnierobertson3088]

Great job and video like always

[@terencehawkes3933]

First-rate diagnosis Mr. O!

[@elchuco00]

Great video! I usually fix this type of problem with an average to large size hammer.....

[@wirenutt57]

Nuke it from orbit!

[@rickybrown4448]

Good job. You have to program the new pcm to the vehicle. Some people may not know that.

[@brianbridges1844]

I agree the welding could have easily fried a transistor or two in the ECM. In computers even a small static charge when working on them is enough to fry a component or two. Another reviewer posted that two grounds when welding in close proximity to the weld is great strategy for controlling the current to a defined area. Kudos for posting that bit of info.

[@scowell]

Those negative references are created by the circuit... like a regulator, but a regulator for ground, a 'virtual ground'. Chances are it was also the ground for the cooling fan sensor, or its ground was nearby when the insult happened. Shade tree pecker-tracks all over this one.

[@kevinfenwick5068]

You are an electrical genius! Well but your really good at finding cause without the old test parts that a lot of people will try before they give up, like the owner of this car.

[@tarasb.ukrainian1947]

Lesson from this video: don't weld your exhaust with O2 sensors plugged in....

[@stevenoman8094]

Or your PCM to be safe safe...

[@jimpantherdrivervickers5439]

Been a while!!! Missed all the mechanical info...need some WUW

[@vwwrenchie314]

Yeah SMA today is a little different..no WUW..and no SMA decals..don't ask!☹

[@AntonioClaudioMichael]

🤔 Wonder if when the welding was done the battery was left hooked up and it partially fried the pcm Eric O @SouthMainAutoRepairLLC

[@richb.4374]

When I worked for a shop building ambulances, it was a strict rule in the place that if you had to weld on the vehicle, make sure to unhook the batteries. The electrical department guys would scream when someone forgot and they had to repair all the damaged circuits that would cause. As Eric said in the video, even with the battery unhooked, the welding current can find it's path to ground via sensitive electronics and fry things.

[@AntonioClaudioMichael]

@@richb.4374 which is why I made that comment

[@casparberends2719]

Battery can also absorb the stray currents, could even have limited the damage. Proper method is very important when welding on a car.

[@AntonioClaudioMichael]

@@casparberends2719 yes that is true but if the battery couldn't absorb all of the current it would have gone to other components

[@kain0m]

I had a similar one at work once. ECM case had been shorted to battery positive. Lots of strange things going on with the car, like 7V on a 5V Referece - in the end, the internal ground pin had desoldered itself from the PCB, a little blob of solder was on the lower lid. Resoldered it and the box was OK again...

[@martinboucaud679]

great diagnostic

[@baxrok2.]

Nice little challenge. I've heard that you should unplug the PCM when welding on a car, but who knows. Thanks Dr. O!

[@jwarmstrong]

Also remove the PCM when driving thru high water if you are not James Bond -

[@kjbunnyboiler]

Afternoon Eric

[@rubinbinder6292]

Completely agree on your theory. Sounds like the welder found a path through the O2 sensor ground. I had a similar thing happen to my own car after I had a shop weld up my exhaust. Fortunately just blew the O2 sensor in this case, not the PCM.

[@MySparkle888]

Eric is like survivor man with cars.

[@nyrangers3150]

Thanks Mr O. I am having the same problem on my Silverado. 200k miles. Rep;laced cats, o2's, mass air, pcv, coils, plugs wires, fuel injectors and still o2 bank 2 errors. Even swapped upstreams. I have just replaced the BCM due to many errors and now I think the ECM on my Chevy Thunder is bad.

[@scraiga66]

I've had a couple of Chevys lately with that style of PCM that had voltage crossover in the connector.

[@jakedewald]

Got a similar issue on a Ford van, guess that's one more thing to check before I start opening up the loom...

[@ImranMughal-ju1wk]

DUDE, you are awesome! I've learned too much from you.

[@scutterlibby]

I love the smell of brake cleaner in the morning

[@billscott7370]

Well explained about how the welding ruined the ecm

[@AntonioClaudioMichael]

Interesting looks like a bad low reference 🤔 seems like a bad pcm if you can drive it low and high then that seems like the pcm would also be working hmmm very intriguing Eric O @SouthMainAutoRepairLLC

[@roycewoods9219]

A new SMA video and morning coffee. I was rewatching the video where Marie whacked the raccoon when this popped up.

[@mikekehoe2927]

For once I was way ahead of you. If I can do it you can too. Even a nut can find a blind squirrel.

[@markh.6687]

No more Brake Kleen for you. "If a squirrel can do it, I can find a blind nut with a hamster." WHAT?? :)

[@coaterman]

I used to be a mechanic on a banger (stock car) team, engines needed battery and coil and away they went. Now you need a licence to fly that computer stuff. I'm glad I'm out of it now. great content keep it up

[@spencerduncan]

Another great mystery solved. Great video .

[@normangallant9879]

Nice learning curve

[@DAZ_SR]

Great tip about welding shorting out circuits. Just had a similar PCM situation on a Dodge (P0571 brake pedal performance, C**** brake pedal 1/2 stuck) that was shorted to voltage from the PCM on a circuit that should have been zero. Replaced the PCM from an online seller that pre-flashes it to your VIN. Contact me direct for a referral, don't want to advertise someone who's not a sponsor on E's channel!

[@oceanpout5232]

Thanks for sharing!

[@dans49dodge]

Without even watching the video first,,,,,,, Im going to go out on a limb and guess O2 sensor. Now. Off to the video. I own a 1970 Trans Am and have had it and MANY hot rods for years. No one else touches my vehicals even tho I am a retired union electrician and fiber optic engineer. My point is i love watching your videos Mr. O but ever since I seen Mrs. O honk the horn while you were messing with the coils the other day ..... That's when I figured out who the real star of the show is ;)

[@mikechiodetti4482]

Never saw a heater circuit do that! Ok, on to the next one! Hopefully another PCM will fix the problem.

[@Arachnoid_of_the_underverse]

Damn I thought you had gained Jedi accreditation when the fan kicked in after saying " Ill give it a little throttle"

[@SteelheadTed]

Me too, thought he had Gumby arms or something

[@jamesterrill1938]

Worth waiting for your videos..

[@camarokid1980]

Great job a very thorough job too

[@HotRod-wv4vm]

Well at least your video is exceptionally clear 👌

[@hpelisr]

Well done Eric

[@sting1111]

I love the chevrolet intro. No emphasis intended.