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Posted

Sorry if this seems long winded but I want to provide as much info as possible.

 

Just picked up a 2019 Silverado 1500 custom. Has the 4.3 V6 with the 6 speed transmission (6L80 I believe)

 

The truck had 99 miles on it. Currently around 2500.

 

No issues out of the gate, after about a week of driving I noticed a very delayed shift I think it was from 1-2 or 2-3. The engine revved 1-2k high RPM than normal before shifting.

 

a few days later while on the highway (cruise set at 75mph) out of no where the RPM’s spiked as if it had downshifted. There was no additional load on the engine to cause this, like going up or down a hill. This happened a few times.

 

I called the dealership immediately and brought the truck to them a few hours later. Got a loaner for a few days while they looked over it.

 

They called me to come pick it up, said the tech noticed a little bit of rough shifting and said they “re-set” the shifting points. Since it was an intermittent problem for me I don’t think it arose for them.

 

So I took the truck home, no problems. My wife drove it to work that same night and the same problem happened again. This time the engine light came on.

 

I scanned the codes this morning and the ECM showed P0700 (transmission control system

the TCM showed P2714 pressure control solenoid D performance/stuck off.

 

So back to the dealer it goes, waiting for them to bring me a loaner this time.

 

I was was told by a dealer technician that GM has been having them put a different type of transmission fluid in some of these trucks due to issues with the torque converter. But I guess if a solenoid is stuck it could be due to a fluid issue as well? Just speculating.

 

I’m curious if anyone else has had similar issues. I haven’t had much luck finding anyone else online with the same problem. Which is guess is more of the reason I’m posting this, in case there’s someone else lost like myself. I will keep this updated when I get further down the road with the dealership.

 

I get that there are fluke problems that can arise, but this is a bit irritating considering it’s a brand new vehicle. I will say that the dealership I’m working with has been extremely supportive and not trying down play anything I’m complaining about.

  • Like 1
Posted

UPDATE

 

Got a call this afternoon from the dealer. Sure enough, they had to replace the pressure control solenoid I previously referenced.

Hopefully that's the extent of the issue.

I will update once I pick the truck up and put some miles on it.

Posted

It's the 8 speed transmissions that are getting new fluid to deal with a shutter issue, not the 6 speed. Hopefully yours is fixed.

 

Jay

Posted
1 hour ago, Jay P said:

It's the 8 speed transmissions that are getting new fluid to deal with a shutter issue, not the 6 speed. Hopefully yours is fixed.

 

Jay

Exactly what I was going to say.

 

From what I've read, the 6 speed is supposed to be pretty bullet proof. It's a little clunky, but supposed to be really reliable.

Posted

UPDATE

 

More issues.

 

According to dealer notes...

“found code P2714. followed document 5118349 and determined transmission fluid pressure OK. determined sticking solenoid #4 inside control assembly. replaced control assembly. programmed and set up TCM. Program code 18YN25983767. filled and adjusted fluid level. flushed and flow tested cooler. road tested several times. drove/shifted fine no codes returned.”

 

I picked up the truck. Drove for about 27 miles and it started the same problems as before including check engine light. Got home, about another 11 miles and scanned for codes and got the same one as before.

 

I did the math on the mileage when I got home and it seems as though it was only driven 13 miles while they had it. Not sure if that matters. If you add that to my 38 it’s 51 and isn’t that around the miles the ECM usually needs to re run most of it’s tests?

 

Anyways, waiting on yet another loaner to be dropped off, let’s see where this goes this time...

Posted
3 hours ago, Shawn Dutton said:

UPDATE

 

More issues.

 

According to dealer notes...

“found code P2714. followed document 5118349 and determined transmission fluid pressure OK. determined sticking solenoid #4 inside control assembly. replaced control assembly. programmed and set up TCM. Program code 18YN25983767. filled and adjusted fluid level. flushed and flow tested cooler. road tested several times. drove/shifted fine no codes returned.”

 

I picked up the truck. Drove for about 27 miles and it started the same problems as before including check engine light. Got home, about another 11 miles and scanned for codes and got the same one as before.

 

I did the math on the mileage when I got home and it seems as though it was only driven 13 miles while they had it. Not sure if that matters. If you add that to my 38 it’s 51 and isn’t that around the miles the ECM usually needs to re run most of it’s tests?

 

Anyways, waiting on yet another loaner to be dropped off, let’s see where this goes this time...

That sucks man! I wonder if yours is just a lemon? I always thought that the 6 speeds were supposed to be pretty bullet proof.

 

Maybe I was wrong

  • 2 months later...
Posted

Just had the same thing happen to me this evening. Took off from a light, shifted fine to third and then revved as it tried for 4th. Put it in L and it again shifts fine but won’t engage 4th or higher. I’m driving a 2019 custom trail boss, 4.3 with the 6 speed. Taking it in tomorrow morning but it’s quite annoying considering it only has 7400 miles. 

  • Like 1
  • 2 weeks later...
Posted

I just purchased a 2019 Z71 5.3 with the 6 speed. The transmission can't decide which gear it wants to run in. With this in mind it's in a constant state of vibrating and slight shudder.

However, per the tech at the dealership everything is perfect, it's peachy.

Posted

I have a 19 custom TB 5.3 6 speed now has 10,000 miles tranny smooth as can be I did plug in a range technology at 700 miles want all 8 all the time,but I doubt it would run any worse if I took it out. To be honest my 6 speed is flawless

Keith

 

 

 

 

 

  • 1 month later...
Posted

My 2019 trail boss with a 6 speed has extremely hard shifts and cant decided what gear it wants. And some times under wot it will let it hit the rev limiter before it try's to shift

Posted (edited)

I have a 19 TB 5.3 with the 6 speed. I’ve had the shutter happen on occasion usually when gassing it out of a corner and the tranny is in between shifts, it’s like the tranny is searching for the gear. Every now and then I get a hard shift from 2-1. Its pretty random and hard to duplicate for the dealer.

Now I drive in L5 all the time and I don’t have any issues. Tranny shifts smooth as butter. Idk.

 

my truck is at 4,700 miles 

Edited by Ryguy
Posted

My 2019 GMC Cannon has a V6 with 6-speed which did the same thing that the 8-speed transmissions were doing. It worked fine until around 5,000 miles, when it began to shutter when driving normal speeds. The dealer changed the transmission fluid and it fixed the shutter but now doesn’t shift as smooth as it originally did. It also started slipping sometimes when taking off from a stand still and also when making low speed left or right hand turns, as if you pushed in a clutch letting the engine rev before gears engage. The dealer reset the trans and now the slippage is worse but only happens every once and awhile, not all the time. It now also started acting like I was applying the brake sometimes when letting off the gas when the truck was rolling while in second, third, and sometimes in fourth gear, similar to my diesel truck that has a transmission brake that can be applied without applying brakes. I just picked it up again from the dealer which said they couldn’t Get it to duplicate the problem. Will keep driving and see what happens. 

  • 5 weeks later...
Posted (edited)

Brand new 2019 Custom Silverado. V6 with the 6 speed transmission (less than 75 miles had hard shifting, violent downshifting and slipping reverse) 23 days later they replaced a transmission pump. Fast forward a few months and it spent another 10 days at the dealer getting a complete new transmission after experiencing similar transmission issues (Less than 3500 miles at new transmission install.) 35 days in the shop in the first 101 days of ownership. Lemon claim has been placed. Good luck everyone. Mine had 14 miles on it and downshifted hard and stalled in my driveway when I got home from purchasing it. Love the truck or wouldn't have purchased it. Don't like lemons much. 

Edited by Jay Miller
  • 4 weeks later...
Posted

I've gone thru all of this. It's been to 4 different dealers 11 different times. Its starting to cost me money because I have to miss time at work to take the truck. If they dont get it right I'll have no choice but to get a lawyer. My concern is what happens when the warranty runs out after they been patching this now for about 7k miles my truck now has 26k on it so I'm worried. Mine is a 2019 trail boss 5.3 6 speed. I would reccomend to anybody not getting this issue fixed to get a lawyer. If enough people got together and hired the best lawyer you can get because with 10 -20 people you could get a good one we are whoever could start a lawsuit over this. I dont know what else to do. I take it to dealer and they give right back just to have check engine light come right back on. One  more kicker mowat 26k miles over have to disable the break pad sensor because it says breaks pads wore out that's a whole other issue. Anybody that is feeling this way please comment.

Posted

I had an awful experience with my previous vehicle. 2018 GMC SLT 5.3 6 Speed.

I purchased it CPO and had all of the transmission issues which everyone here experienced. Many times having to pull over on the side of the Interstate and restart the  truck so it would go past 2nd gear. After all most being rear ended by another vehicle with my wife in the car I traded it in for a loss of 4k. 2020 RST 3.0, so far this truck has a superior transmission (10 speed) and engine combination. I love GM so I hope to avoid further issues and went new so if it does happen I can file lemon law. Due to buying the GMC CPO I could not file for lemon law. BE WARNED. 

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