[Sparky9319]

I have a 2016 v6 GMC Canyon SLE. I bought the truck at 50k miles in March and have 72k miles at the moment.

About 2 months ago i noticed there was a slight "bucking" that would happen every once and a while when i would accelerate after decelerating. It only happens if i decelerate for a stop light but don't come to a complete stop before accelerating again. At first it was very seldom that it happened, but it has become more and more frequent.

To start with, I'm not a very mechanically inclined person but i have enough common sense to get me by. That being said, I'm not sure if "bucking" is the correct term to use but that's the best way i can explain it. It's not super violent jerking but there's absolutely no way you can miss/ignore it.

The issue only happens when i decelerate from 40s+ and barely press the gas pedal to speed back up. It never happens above 1500 rpms and ALMOST always clears after 46-48 mph. it has only done it a handful of times in the 50s and above. over the past month it has become more and more frequent..

I did add fuel system cleaner to a tank of 93 octane and it damn near made it go away. for good measure i did it with a second tank of 93 octane and cleaner with the same results. as soon as i put more gas (after the cleaner) it went right back to doing it, getting more frequent throughout the week. sometimes I can make the truck do it, other times i can't, which is the main reason i havent put it in the shop yet.

I have a lot of financial obstacles at the moment and need this issue resolved in an efficient manner, which is why im leaning on this forum.

I am almost convinced that it is a fuel issue, however, why the hell has it NEVER thrown a single code. I did change 4 out of 6 spark plugs when i got the truck (which they were in good shape) just to tinker with it, but didnt want to take the engine apart to get to the 2 hard to reach ones.

Would really appreciate a little guidance so that im not throwing a bunch of money at this for no reason.

 

[JasonZR2]

I have a 2016 v6 GMC Canyon SLE. I bought the truck at 50k miles in March and have 72k miles at the moment.

About 2 months ago i noticed there was a slight "bucking" that would happen every once and a while when i would accelerate after decelerating. It only happens if i decelerate for a stop light but don't come to a complete stop before accelerating again. At first it was very seldom that it happened, but it has become more and more frequent.

To start with, I'm not a very mechanically inclined person but i have enough common sense to get me by. That being said, I'm not sure if "bucking" is the correct term to use but that's the best way i can explain it. It's not super violent jerking but there's absolutely no way you can miss/ignore it.

The issue only happens when i decelerate from 40s+ and barely press the gas pedal to speed back up. It never happens above 1500 rpms and ALMOST always clears after 46-48 mph. it has only done it a handful of times in the 50s and above. over the past month it has become more and more frequent..

I did add fuel system cleaner to a tank of 93 octane and it damn near made it go away. for good measure i did it with a second tank of 93 octane and cleaner with the same results. as soon as i put more gas (after the cleaner) it went right back to doing it, getting more frequent throughout the week. sometimes I can make the truck do it, other times i can't, which is the main reason i havent put it in the shop yet.

I have a lot of financial obstacles at the moment and need this issue resolved in an efficient manner, which is why im leaning on this forum.

I am almost convinced that it is a fuel issue, however, why the hell has it NEVER thrown a single code. I did change 4 out of 6 spark plugs when i got the truck (which they were in good shape) just to tinker with it, but didnt want to take the engine apart to get to the 2 hard to reach ones.

Would really appreciate a little guidance so that im not throwing a bunch of money at this for no reason.

When you barely press the pedal to speed back up, does it downshift or does it lug along at low rpm? If it lugs, try giving it more gas pedal input to force a downshift when speeding back up.

 

[JasonZR2]

When you barely press the pedal to speed back up, does it downshift or does it lug along at low rpm? If it lugs, try giving it more gas pedal input to force a downshift when speeding back up.

I have noticed that the shift programming in these tries to keep you in the highest gear possible. Most likely to increase mpg.

 

[Sparky9319]

its not just one nudge though. it will "skip" or "buck" up to 10 times or so in a 15 second period if i let it. it isnt just a one skip. if i dont give it more gas it will keep on doing it until it eventually catches up. i really dont see it being a shifting thing because it 100% went away with the cleaner running through the fuel system. it wouldnt do it at all, no matter what i did.

 

[JasonZR2]

its not just one nudge though. it will "skip" or "buck" up to 10 times or so in a 15 second period if i let it. it isnt just a one skip. if i dont give it more gas it will keep on doing it until it eventually catches up. i really dont see it being a shifting thing because it 100% went away with the cleaner running through the fuel system. it wouldnt do it at all, no matter what i did.

Ok, I see what you are saying now. Try getting gas at different station maybe?

 

[Sparky9319]

im a commercial electrician so i get gas from gas stations all over my city. i dont buy that gas is the issue.

 

[JasonZR2]

Gotcha, only other thing that comes to mind that I remember reading on here was something about a software update for the 15 and 16 trucks with the 6spped auto that address some engine smoothness issues. Maybe someone will have a link to that tsb handy here shortly.

 

[Hunter62]

TSB 18-NA-145

here is 32 pages on this issue

2016 "Chuggle Or Shudder" - GM Has Let Us Down

After four (so far) trips to the dealer, reflash # PIP5342B done (resolved nothing) and numerous conversations with ChevrolerCustomerCare, I have pretty much been told to "live with it". In fact, at the bottom of PIP4342B, they have added a note saying "No additional repair attempts should be...

www.coloradofans.com

below is the pdf

 

[Hunter62]

Chugging, Shuddering or Lack of Power While Driving At Low Speeds with Possible Spark Knock/Ping (Detonation) NoiseThis Bulletin replaces PIP5342B and PIP5420. Please discard PIP5342B and PIP5420.Chevrolet Colorado2015 2016 LFXGMC CanyonInvolved Region or CountryNorth AmericaConditionSome customers may comment on one or more of the following conditions at low speed maneuvers:Chugging, Shuddering and/or Lack of power when accelerating at speeds of 12 to 15 MPH (19-24 km/h) in second gear. Chugging, Shuddering, Lack of power or a no downshift when accelerating at speeds of 30 to 40 MPH (48-64 km/h) in 6th gear.Spark knock/ping noise under light acceleration or when climbing an incline under load.Some technicians may find DTC P0326 (Knock Sensor Performance Bank1) set in the Engine Control Module (ECM) as history.NoteThese conditions are most likely to occur when driving on a smooth road, up a slight or moderate grade when accelerating.CauseThis condition may be caused by an anomaly in the Engine Control Module (ECM) and the Transmission Control Module (TCM).CorrectionImportantIt is important that both the Engine Control Module (ECM) and Transmission Control Module (TCM) are updated to the latest software. Not updating both modules will result in ECM and TCM incompatibility and additional undesired vehicle performance.Validate the ECM and TCM have the latest software calibration.If the ECM and TCM are not at the latest calibration, using TIS2Web, select Engine and Transmission Control Module.Both modules must be reprogrammed sequentially to the latest software calibration available to avoid other malfunctions or drive

Service ProcedureImportantStable battery voltage is critical during programming. Any fluctuation, spiking, over voltage or loss of voltage will interrupt programming. Install the EL-49642 SPS Programming Support Tool (GM Dealer Equipment Item #PSC-550) to maintain system voltage of 12.6-15.5 volts. If not available, connect a fully charged 12V jumper or booster pack disconnected from the AC voltage supply. DO NOT connect a battery charger.Refer to K20 Engine Control Module: Programming and Setup and Control Solenoid Valve and Transmission Control Module Assembly Programming and Setup in SI.Parts InformationNo parts are required for this repair.Warranty InformationFor vehicles repaired under the Emission coverage, use the following labor operation. Reference the Applicable Warranties section of Investigate Vehicle History (IVH) for coverage information.quality degradation.A slight decrease in fuel economy may be noticeable depending on driving habits.If the ECM and TCM have the latest calibrations, refer to SI for further diagnostics.2881938* Engine and Transmission Control Module with SPS 0.6 hr*This is a unique Labor Operation for Bulletin use only.Version1ModifiedReleased May 21, 2018

 

[trikermutha]

I would also replace all the spark plugs. Changing 4 out of 6 may also be some or all of your issue?

 

[Sparky9319]

so, I have heard about the programming issue before and it is definitely a possibility. I was under the impression the programming issue fell under a factory recall, and if that's the case, it should have been done before i bought my truck, correct?

changing the spark plugs was definitely something i was going to do regardless with my next oil change. but, if a sparkplug was misfiring, wouldn't it throw a code? that is the most baffling part of all of this! I know there is an issue but it never throws a code.

 

[Xcanuk]

so, I have heard about the programming issue before and it is definitely a possibility. I was under the impression the programming issue fell under a factory recall, and if that's the case, it should have been done before i bought my truck, correct?

The update was under the radar and some dealers don't know about it, so you can't assume it was done, plus it was done only if the owner matched the complaint.
I brought the recall to my dealer, asked them to do it, they said I would be responsible (bla bla), they didn't charge me even though my warranty was up. Made a big difference.
I reported back to them at my next service and they thanked me and said they added the bulletin for future complaints on '15-'16's

 

[modake]

Whenever mine has issues like this it is usually related to the transmission and fluid levels. When the truck has low ATF there are a lot more issues with hard shifts and bucking. When was the last time the ATF was changed/checked?

 

[Sparky9319]

The update was under the radar and some dealers don't know about it, so you can't assume it was done, plus it was done only if the owner matched the complaint.
I brought the recall to my dealer, asked them to do it, they said I would be responsible (bla bla), they didn't charge me even though my warranty was up. Made a big difference.
I reported back to them at my next service and they thanked me and said they added the bulletin for future complaints on '15-'16's

and information like this is why i decided to go to the forums. definitely something im going to look into.

Whenever mine has issues like this it is usually related to the transmission and fluid levels. When the truck has low ATF there are a lot more issues with hard shifts and bucking. When was the last time the ATF was changed/checked?

I haven't done much of any maintenance on it so far, besides the oil change. I have a feeling that the truck was a work truck before i bought it because of a few scratches it had on it (nothing major), so I'd guess things like that haven't been done. I'll add that to my list of things to do.

 

[Sparky9319]

and information like this is why i decided to go to the forums. definitely something im going to look into.




I haven't done much of any maintenance on it so far, besides the oil change. I have a feeling that the truck was a work truck before i bought it because of a few scratches it had on it (nothing major), so I'd guess things like that haven't been done. I'll add that to my list of things to do.

So I called gm customer service today and they said there was no recall for the transmission update. I'm beginning to think it might be this issue and am not sure how to go about it. I do have to get it diagnosed by the dealership before they can do anything but am looking for some direction here.

I'm really trying not to do multiple trips to the shop and it'll be about a month before I can get it into the dealership to do so.

After messing with it today, trying to make it do it, it does feel like it's in too high of a gear until it gets up to about 46 mph or so. What's the likelihood of gm covering the cost on the work?