“Service transmission Now, unable to shift soon” Message

[66ss3964spd]

Did the check engine light come ever come on? If it did the code is probably stored.

[Frankielozano214]

10 minutes ago, Dan H 2023 HC said:

Did the check engine light come ever come on? If it did the code is probably stored.

No check engine light, no hard shifting or jerking. I did notice my alarm said truck had low battery but that was it, it send me a notification to my phone. 

[AnG005]

12 hours ago, Frankielozano214 said:

Wondering what the outcome of this msg was, I’m in same situation first time it’s been 27 degrees over here since I’ve gotten the truck. Truck only has 12,****** miles on it so might take to dealer. 

What city do u live in , same thing popped on on gmc Denali today dfw area .  Is it still showing ? 

[Frankielozano214]

40 minutes ago, AnG005 said:

What city do u live in , same thing popped on on gmc Denali today dfw area .  Is it still showing ? 

No just this morning around 8am, I’m also in Dfw, that’s crazy it’s been driving fine (I do daily my truck on 42s )!

[NurseH]

I have a 2021 Yukon Denali and just got the same message. We are in TN with temps in the low 30s. Hoping it’s just the cold temps but will go ahead and schedule my next maintenance now, lol. 

[Frankielozano214]

1 minute ago, NurseH said:

I have a 2021 Yukon Denali and just got the same message. We are in TN with temps in the low 30s. Hoping it’s just the cold temps but will go ahead and schedule my next maintenance now, lol. 

Mine haven’t popped back up, thinking it had a malfunction due to the battery being low but I’m no expert so ima wait to see if it pops up again then take to dealer if it happens again 

[ChrisinRoc]

I am having this issue with a 2020 Terrain as well.  I took to dealer and paid for the scan, $200.

 

there result was no transmission problem but a fault in the electronic shifter assembly.  They wanted $1,000 to replace it.  F' that.

 

i bought the part myself (online from gmparts direct) and changed it out.  (30 minutes)

 

seems to work now.

 

(after reading this thread, I realize it started when temps dipped to 15°)

[Frankielozano214]

31 minutes ago, ChrisinRoc said:

I am having this issue with a 2020 Terrain as well.  I took to dealer and paid for the scan, $200.

 

there result was no transmission problem but a fault in the electronic shifter assembly.  They wanted $1,000 to replace it.  F' that.

 

i bought the part myself (online from gmparts direct) and changed it out.  (30 minutes)

 

seems to work now.

 

(after reading this thread, I realize it started when temps dipped to 15°)

I haven’t had the msg pop up on my dash since that day it was below freezing, truck seems fine. How much was that  shifter assembly?

[HeatherCooley]

South Louisiana here. Got the "Service Transmission. Unable to shift soon." message on my 2021 Tahoe a several weeks ago. Currently at 51,000 miles. Temperatures were low outside, but I don't recall how low (low 30's I believe). Message cleared itself. Message returned about two weeks later. I've contacted all of the dealerships in my area and none of them can see me before the end of February. No loaner vehicles available either. I have not noticed hard shifting, grinding, or any other signs of trouble with the transmission. One dealership service department said they are getting a ton of calls for transmissions with this message. This morning I also got two other messages, "Service Lane Assist" and "Forward Collision Assist Not Available". To say I'm worried is an understatement, but I was told by two dealerships that if I brought my vehicle to a transmission shop it will void my warranty. 

[Brian Bruns]

My 22.5 with 10 speed been giving me this message every 60ish days in warm and cold. Comes on for 1 key cycle and goes away so I never paid it much attention. End of last week it came on 4 key cycles in a row. Stopped at the dealer with the message active, all the techs were at lunch so it never got scanned. Took it in today, no codes in the truck, and tech can't find anything out of the ordinary. They said next time the message comes on bring it in with the message active so they can scan it again and see what's going on.

[onewheat]

I got the same message last week at 95°+ out. I’m told it’s a problem with the Gear Shift Control Module. I’m at 58k on a ‘23 Sierra Denali with the console shifter. The part is on ‘backorder with no release date’ and it’s an $1100 repair.  

[Frankielozano214]

On 7/15/2025 at 1:33 PM, onewheat said:

I got the same message last week at 95°+ out. I’m told it’s a problem with the Gear Shift Control Module. I’m at 58k on a ‘23 Sierra Denali with the console shifter. The part is on ‘backorder with no release date’ and it’s an $1100 repair.  

Damn yeah mine hasn’t came back on, been fine was also told it the shifter or the shifter harness

Edited July 19, 2025 by Frankielozano214

[Tom73]

If you want a history of this problem, check out this thread

 

23 pages of discussion.  Good read.