2021 Tahoe Shifter Module and Transmission problem

[Gocajuns74]

I have a 2021 Tahoe LT that we purchased July of last year. I don't the know build date but we basically bought it while In-Transit if that means anything time wise. Currently my Tahoe has been at the dealership since mid week before Thanksgiving. The problem I was having was the truck would start but not shift into gear. I had to have it towed. When they 1st started to diagnose the problem the advisor said there was something like 20 warnings or items that popped up. Last week they had a diagnosis of we need to change the shifting module, but not sure that will fix everything. Module will take a few days to deliver. Yesterday, week 3 now, the report was, shifting module was changed but we're still diagnosing the problem. Not sure he was supposed to mention to me but there are other new Tahoes and Suburbans with the same issues getting worked on as well. My truck has 30K miles and up to this point, I've had minimal issues. About a month or so ago I did have to change out some wire that was connected to the fuel gauge that was giving me inaccurate readings on how much gas I had in the tank. Other than that no crazy problems.

Has anyone else experienced this and/or what did they do next?

Thanks in advance.

 

[Micahsd]

I think that’s a new issue I haven’t seen much of on here. I tend to keep an eye on new posts as I’ve got a 21 with 15k miles on it now that was purchased in April 21.

I also haven’t experienced that issue but hopefully they figure it out. That doesn’t sound like a good deal at all.

 

[Gocajuns74]

I think that’s a new issue I haven’t seen much of on here. I tend to keep an eye on new posts as I’ve got a 21 with 15k miles on it now that was purchased in April 21.

I also haven’t experienced that issue but hopefully they figure it out. That doesn’t sound like a good deal at all.

I haven't been bitten by the lifter bug yet. I'm sure that's in my future as well. I'm not sure but I think lemon law comes into play at 45 days here. I really don't want this car anymore.

 

[Micahsd]

I haven't been bitten by the lifter bug yet. I'm sure that's in my future as well. I'm not sure but I think lemon law comes into play at 45 days here. I really don't want this car anymore.

I was hit with the lifter issue at 9,100 miles back in April. Downside is they only replaced the affected bank even though while it was in the shop the TSB was updated to relplace all lifters under $16k miles.

You should be fine as yours was built later and you’re up to 30k miles now. My engine build date fell within the affected range (was a month prior to the build date of March ‘21).

For me I’m kept wondering when the other side will give out.

 

[DuraYuk]

Its sad that these dealers don't have competent techs.

You guys don't have lemons. You have crappy technicians and dealer service centers. They can't diagnose it because they don't know how.

A quick call to TAC and a case number is all it really takes to straighten out any issues a GM branded product may have if the tech is having a hard time.

Sorry about your misfortune. This isn't just a GM problem. Good qualified techs are extremely in limited supply regardless of brand.

 

[Gocajuns74]

Update, this Thursday will be 30 days at dealership. I got a call back today, last call was last Tuesday. Says they're still diagnosing and think they will have to change out the ECM, a shift cable and repair some wires. Shift module was changed out last week and didn't fix all of the codes. We shall see.

 

[DuraYuk]

Update, this Thursday will be 30 days at dealership. I got a call back today, last call was last Tuesday. Says they're still diagnosing and think they will have to change out the ECM, a shift cable and repair some wires. Shift module was changed out last week and didn't fix all of the codes. We shall see.

Tell them to call TAC. They seem like they are guessing. TAC will help them actually diagnose and repair it.

 

[WalleyeMikeIII]

No shudder in mine after 10.5k miles; it’s smooth as butter. One of the smoothest automatics I’ve ever owned; across any brand.

 

[Chad G 1979]

In my 1500 miles the 10 speed has been smooth as butter regardless of if i am gentle driving or needing a big burst of acceleration for onramps etc...

 

[Chris01234567]

What is a TAC?

 

[StephenPT]

Technical Assistance Center

 

[Gocajuns74]

A TAC, from what i understand, is a Support Hotline for the Service Dept at dealership.

A update to my situation isn't all that great at this point. We're 57 days out of service as of today. Apparently there's some water intrusion that has caused significant damage to Power diverter and more. They can't tell me where the water came from. They've changed out the Power Diverter and car still won't start. When the truck left my house, it would crank up just not shift. Now it won't even start. Last I heard they were going to change out the ECM. I've been on the phone with GM customer care and last week submitted for a buy back. I was supposed to have an update today. All I got is their still looking at it. I don't want this car back.

 

[DuraYuk]

A TAC, from what i understand, is a Support Hotline for the Service Dept at dealership.

A update to my situation isn't all that great at this point. We're 57 days out of service as of today. Apparently there's some water intrusion that has caused significant damage to Power diverter and more. They can't tell me where the water came from. They've changed out the Power Diverter and car still won't start. When the truck left my house, it would crank up just not shift. Now it won't even start. Last I heard they were going to change out the ECM. I've been on the phone with GM customer care and last week submitted for a buy back. I was supposed to have an update today. All I got is their still looking at it. I don't want this car back.

Classic case of another bad service department. Sorry about your luck. They are just guessing at this point.

 

[B-train]

I do agree that good technicians are in limited supply. I also believe that GM (as well as others) have pushed stuff out the door without really doing good life cycle testing as much.......fix it in the field as it comes in. I see it in the power generation field as well with the lower quality manufacturer(s).

Then there is the variable of assembly. Changes are made quite often as needed for efficiency, or to accommodate running changes. It sounds like you got a Friday or Monday truck - maybe someone wasn't quite up to speed for their task.....

I hope they figure it out, but I stand with you on having it bought back. It could be 100% good for many miles, or a constant pain in your a$$ for as long as you own it.

50/50 odds don't usually work out in my favor.........not sure what your track record is. LOL

 

[DuraYuk]

I do agree that good technicians are in limited supply. I also believe that GM (as well as others) have pushed stuff out the door without really doing good life cycle testing as much.......fix it in the field as it comes in. I see it in the power generation field as well with the lower quality manufacturer(s).

Then there is the variable of assembly. Changes are made quite often as needed for efficiency, or to accommodate running changes. It sounds like you got a Friday or Monday truck - maybe someone wasn't quite up to speed for their task.....

I hope they figure it out, but I stand with you on having it bought back. It could be 100% good for many miles, or a constant pain in your a$$ for as long as you own it.

50/50 odds don't usually work out in my favor.........not sure what your track record is. LOL

Dude your thinking too much. These big legacy makers run like a sewing machine when it comes to production.

Please don't short change those guys by saying it's a Monday or Friday truck. The standards don't change and didn't for covid.

Dealer level is a different ball game as it's staff specific.

Now start ups are a whole different can of beans.

 

[Ceddibear]

So my wife drives a 2021 Tahoe LT and one day while she was driving she got an alert saying to “service transmission may not shift soon” but it had cleared the next time she turned on the vehicle. We took it to a reliable transmission repair shop and they found nothing wrong. A month later she was driving and a bunch of other codes were thrown. We took it to the dealership and it was a bad battery, but there was also the transmission shifter module was sending a fault code. This was because her D button (pretty crappy after I researched) on her gear shifter had popped off and all we saw was the red light in its place. We never had any trouble shifting but we had to get a whole new part which was about $1100. Since then, no more shift codes. Of course I wanted to glue the old one back on but my wife had threw it away already. And after they replaced it the mechanic did say they had to perform some software update to the ecm.

 

[jerry455]

When I test drove my 21 Suburban, last summer. The first time I used the shifter, the drive button popped off. The reverse also did that. After I bought the truck, I glued the buttons down, so they don't pop off anymore. I never had a problem when they came off, it was more of a nuisance. It has been fine ever since.