“Service transmission Now, unable to shift soon” message on 2021 Tahoe

[BigE_In_TX]

Good Afternoon, I am hoping to get some advice from tech’s or if any other 2021 & up Hoe/Yuke owners have seen this dash message:

“Service transmission Now, unable to shift soon”​

Some Background-
Tahoe has 63,000 miles
The temperature just dropped to the teens
Impeccable maintenance history

I did read a couple of Silverado owners saw this message when their temperature was under 0 and when it warmed up, this message has not popped up since

I also read about a possible wiring issue causing this, which is interesting as I had an airbag warning about 7 months ago and Chevy wiggled the wires under the seat and it hasn’t thrown that message since, the tech said the wiring harness for 2021 was a bit shorter causing this in many Tahoes…

Thank you for any feedback

 

[89Suburban]

@NickTransmissions

 

[Micahsd]

I haven’t seen that meaaage on my 21 yet. I’ve been pretty fortunate not running into too many issues.

The temp here was down to -12 when I drove it around down a bit ago and it seemed fine.

Hopefully someone else chimes in with some good advice.

 

[WalleyeMikeIII]

Good Afternoon, I am hoping to get some advice from tech’s or if any other 2021 & up Hoe/Yuke owners have seen this dash message:

“Service transmission Now, unable to shift soon”​

Some Background-
Tahoe has 63,000 miles
The temperature just dropped to the teens
Impeccable maintenance history

I did read a couple of Silverado owners saw this message when their temperature was under 0 and when it warmed up, this message has not popped up since

I also read about a possible wiring issue causing this, which is interesting as I had an airbag warning about 7 months ago and Chevy wiggled the wires under the seat and it hasn’t thrown that message since, the tech said the wiring harness for 2021 was a bit shorter causing this in many Tahoes…

Thank you for any feedback

I’d get it to the dealer. You are 3000 miles past the warranty…but could be simple like connector bad or something. If you haven’t changed transmission fluid, you are probably due.

 

[BigE_In_TX]

I’d get it to the dealer. You are 3000 miles past the warranty…but could be simple like connector bad or something. If you haven’t changed transmission fluid, you are probably due.

Yeah dealership is a stop that I am dreading. As you mentioned, 3,000 miles past powertrain warranty, plus $150 diagnostic fee, so before I opened up my checkbook and going round and round, I was hoping to get someone who either experienced this or maybe a tech’s input.

This did just have a big maintenance visit several months back, I am quite sure the fluids were changed then? I quite possibly could be wrong though.

 

[BigE_In_TX]

I haven’t seen that meaaage on my 21 yet. I’ve been pretty fortunate not running into too many issues.

The temp here was down to -12 when I drove it around down a bit ago and it seemed fine.

Hopefully someone else chimes in with some good advice.

@Micahsd I saw another transmission post from late 2022 you chimed in on. My issue definitely doesn’t sound like his, but I wanted to share I bought mine June 2020, so I think it was one of the first batches produced. Again, I doubt that is a factor in this, but have read some horror stories about the very early 21’s. Now your not going to believe me, but we like Tahoe’s so much (have owned one since 2012, various years) I also have a ‘22 in my garage that’s been a gem compared to the issues the 2021 has had pop up within the last year.

 

[NickTransmissions]

Yeah dealership is a stop that I am dreading. As you mentioned, 3,000 miles past powertrain warranty, plus $150 diagnostic fee, so before I opened up my checkbook and going round and round, I was hoping to get someone who either experienced this or maybe a tech’s input.

This did just have a big maintenance visit several months back, I am quite sure the fluids were changed then? I quite possibly could be wrong though.

What transmission and what, if any, drivability symptoms are you having?

 

[BigE_In_TX]

What transmission and what, if any, drivability symptoms are you having?

@NickTransmissions Great questions- I have the 10 speed automatic transmission that GM put in starting for the 2021 model to current. As far as issues driving, there was zero noticeable shifting issues, but I did not drive it very far due to this pop up message. I shifted into reverse and pulled out of the garage down the driveway. I shifted into drive and went back up driveway. Shifted into park, then shifted into drive into the garage and into park again all smoothly. Only symptom is that error message pop up.

 

[NickTransmissions]

@NickTransmissions Great questions- I have the 10 speed automatic transmission that GM put in starting for the 2021 model to current. As far as issues driving, there was zero noticeable shifting issues, but I did not drive it very far due to this pop up message. I shifted into reverse and pulled out of the garage down the driveway. I shifted into drive and went back up driveway. Shifted into park, then shifted into drive into the garage and into park again all smoothly. Only symptom is that error message pop up.

Full transparency, I have never worked on or even physically seen one of the 10L transmissions as of yet so dont know a whole lot about them.

I did find a TSB on that error/warning message though it applies to Buicks but may be similar in terms of general pattern causes in the truck/SUV chassis.

Also found this GEARS Magazine article on the front-wheel drive equivalent to the rear/AWD longitudional 10 speeds which may be describing the same kind of problem (solenoids/valve body).

Here's what the article says about that specific DIC message:

Service Transmission Now, Unable to Shift Soon
The “Service Transmission Now, Unable to Shift Soon” message indicates that one or more ETRS system faults have occurred. It is a warning to get the vehicle into the shop for service immediately, or it may shortly leave you unable to engage the selected range

I'd call and make an appt and maybe even have it towed to the dealer, esp if the thing could just drop dead at any time, which seems to the case with that message.

Dealer Svc will likely replace solenoids or do a valve body swap after diagnosis.

If you're DYI you can purchase a diagnostic subscription from GM's on-line texh portal, buy whatever laptop-OBD2 cable you need and see what's up with it. Then follow the procedures for parts repair/replacement and reinstallation.

 

[89Suburban]

Full transparency, I have never worked on or even physically seen one of the 10L transmissions as of yet so dont know a whole lot about them.

I did find a TSB on that error/warning message though it applies to Buicks but may be similar in terms of general pattern causes in the truck/SUV chassis.

Also found this GEARS Magazine article on the front-wheel drive equivalent to the rear/AWD longitudional 10 speeds which may be describing the same kind of problem (solenoids/valve body).

Here's what the article says about that specific DIC message:

Service Transmission Now, Unable to Shift Soon
The “Service Transmission Now, Unable to Shift Soon” message indicates that one or more ETRS system faults have occurred. It is a warning to get the vehicle into the shop for service immediately, or it may shortly leave you unable to engage the selected range

I'd call and make an appt and maybe even have it towed to the dealer, esp if the thing could just drop dead at any time, which seems to the case with that message.

Dealer Svc will likely replace solenoids or do a valve body swap after diagnosis.

If you're DYI you can purchase a diagnostic subscription from GM's on-line texh portal, buy whatever laptop-OBD2 cable you need and see what's up with it. Then follow the procedures for parts repair/replacement and reinstallation.

Thanks Nick.