2017 GMC Sierra 2500 HD 4wd 6.0L 6L80e 6 speed Transmission Code PO741 Issue

RV Johnson · October 2, 2021

Has anyone had a MIL code of P0741 "Torque converter clutch circuit performance or stuck off" code come up? 2017 GMC Sierra 2500 HD 4wd crew cab has 108k miles on it when the the check engine light came on. Drained trans fluid and replaced filter. No metal on pan magnet and fluid looked okay. Reset code and it came back after 35 miles and only at freeway speeds. Has anyone else experienced this?

--Update-- After a 2 week waiting period, 2 days in the shop, and 2k poorer, a new torque converter appears to have solved the issue as those on this great forum believed. The truck runs like new.

RV Johnson

Edited October 16, 2021 by RV Johnson
Update

mjm-1957 · October 2, 2021

Thats the beginning of the end for that unit. I am the transmission guy at a GMC Buick dealer and that code means the TCM is attempting to apply the convertor clutch and the rpm is not dropping enough meaning the clutch is slipping. The lining on the clutch comes off and the piston now has metal to metal contact with the convertor housing sending metal threwout the complete unit destroying the pump and lowering the line pressure burning up the clutches. Absolute horrible design and to make matters worse GM allows the TCC to slip all the time. What the hell were the engineers thinking when they designed the shift program??? I can't keep up with all the transmission failures between the 6 speeds, the horrible 8 Speed and now starting to see 10 speeds towed in for broken pump gears ,.Good job GM.

RV Johnson · October 2, 2021

That doesn't sound good at all. Dealer believes its the torque converter and I have an appointment with a tranny shop in 2 weeks to change it out. Though the truck still runs good with a reset, and only gains 2k rpm when the light comes on, I still wonder if its a solenoid in the valve body or a programming issue.

CamGTP · October 2, 2021

It's not a valve body or solenoid problem. It's the torque converter itself, they are a well known failure point of the 6L80e and 6L90e transmissions.

I honestly wouldn't drive it much at all to lessen the chance at more damage. The code is coming on for a reason and the more you drive it the more it's possibly doing damage.

scole · December 23, 2021

RV Johnston, any other follow ups on this issue? Did you experience any shudder in the drivetrain? My transmission issues started with it not shifting into high gear/overdrive and throwing a P0741 code. After the torque converter was replaced it developed a shudder in the drivetrain. They replaced that torque converter but the shudder continued and the dealer thinks it's another bad torque converter. They've apparently had the same problem with torque converters from the same supplier and trying to get one from a different source.

My issue here... 6L90 torque converter shudder

A big concern I have is whether the shudder has caused debris to be sent through the rest of the transmission and will that cause problems.

Edited December 23, 2021 by scole

RV Johnson · December 31, 2021

As a follow up. It's been a couple of months now since the torque converter was replaced. I did not take it to a dealer for the simple reason the dealership quoted twice as much as a transmission specialist. The PO741 code has not returned and the 2017 Sierra 2500 has not had the shudder issue, which I noticed only a couple of times before replacement. I did ask, and was assured by the transmission shop, that the replacement torque converter was an updated one before the work was started.

One way to check your transmission is by pulling the pan and checking the magnet for metal shavings. It's what the dealership was going to do in order to diagnose if it was the converter or trans, but I had already checked and found no shavings on the magnet.

After the replacement I inquired into what shape the old torque converter was in. The tranny shop responded that looked okay, but the only way to know was to cut into it and look at the internal.

On a side note: I just had the output seal of the 4wd transfer case replaced, which was likely disturbed when the shop pulled the drive line for the converter job, which can easily happen with such seals. All it takes is a tiny nick and it will leak. You may want to check for signs of leakage there.

Hope this helps,

RV Johnson --epic fantasy author

Louthechevyman · January 24, 2022

On 12/30/2021 at 7:43 PM, RV Johnson said:

As a follow up. It's been a couple of months now since the torque converter was replaced. I did not take it to a dealer for the simple reason the dealership quoted twice as much as a transmission specialist. The PO741 code has not returned and the 2017 Sierra 2500 has not had the shudder issue, which I noticed only a couple of times before replacement. I did ask, and was assured by the transmission shop, that the replacement torque converter was an updated one before the work was started.

One way to check your transmission is by pulling the pan and checking the magnet for metal shavings. It's what the dealership was going to do in order to diagnose if it was the converter or trans, but I had already checked and found no shavings on the magnet.

After the replacement I inquired into what shape the old torque converter was in. The tranny shop responded that looked okay, but the only way to know was to cut into it and look at the internal.

On a side note: I just had the output seal of the 4wd transfer case replaced, which was likely disturbed when the shop pulled the drive line for the converter job, which can easily happen with such seals. All it takes is a tiny nick and it will leak. You may want to check for signs of leakage there.

Hope this helps,

RV Johnson --epic fantasy author

Hey guys, new here. Just came across the forum/ thread after going through a very similar situation with the 6L90 trans in my 2010 Silverado 2500hd. However, in my case the transmission shuddered off and on for a week or two before I took it to the shop by which time there were tons of metal shavings in on the magnet. Ended up replacing the trans with a remanufactured unit from these guys, https://reman-transmission.com/transmission-codes/?code=6L90. They told me over the phone that they fix manufacturer defects in the rebuild and that their 6L90s don't have the same issue... I guess only time will tell.

Edited January 24, 2022 by Louthechevyman

WT35002017 · January 25, 2022

2017 Silverado 3500hd. Had PO741 code and shudder that would come up while trailering on the highway, first time at around 35k miles. I noticed it would happen when my trans 6L90 reached temps of 200 or more. It even got up to 225 at one point. It would shift erratically and I felt sure the high temp was causing something to not work well. I installed a bunch of trans coolers since I would mostly be using the truck for towing. The extra cooling made it so the temp would no longer exceed 185 degrees even in the hottest of days in souther Florida. The trans coolers stopped the code from happening again and no other problems were observed. When I did this I installed a valve that would easily allow me to drain tranny fluid later because I wanted to change the fluid at around 45k miles. This I did and dropped the pan to clean everything out. I used Amsoil. The pan was pretty clean and I changed the filter. No metal shavings luckily. To change the fluid I would drain by opening my installed valve and let it drain into a marked bucket 1 quart at a time, replacing old quart with a new quart into the trans dipstick tube. I realize it it not really a flush but a good percentage got changed out. I did a total of 4 gallons this way. My truck hasn’t had any issues so far reaching 65k.

rdonarski · August 15, 2022

My son's 2015 Silverado 2500HD started doing this last weekend. He 1st noticed it and got the check engine on the highway a week ago. We checked the code on Saturday and found the P0741. Cleared the code. Yesterday it started getting real bad to the point of being stuck at a stop light. Limped it in to a shop. Only has 55K miles on it and has never been used hard.