Kracka

Because the tolerances are likely further away from where they began life brand new from the factory. A quick learn procedure is typically the 1st step (assuming no external case leaks are detected), and often times only one needed, when diagnosing an ill-shifting modern transmission with age/miles on it. One of our Jeeps, that hasn't lived an easy life, is 5 years old w/60k miles on it and the improvement in shift quality was night & day.

flyforC4

yep, sad but true. This dealership is particularly badly run on the front side. Hopefully the techs are good.

EvanD

Well, the last straw at the close by dealer was I bottomed out my C6 a couple years ago pulling into a parking lot, the sidewlk was raised... When I did it immediately threw a code. IIt was a flapper valve code and I reset it a couple time before going in. The cute tattooed hip chick writer had no clue what I was talking about, didn't even really care or listen to me. They say they replaced the valve but it was a bad computer (I really doubt it but how can you argue it? I didn't get the bad valve and the computer was turned over as core). When they said it was ready I went down (less than 5 minutes away), paid the bill, got my fob and went to the car. Got in and the whole dash was dead like nothing was plugged in. Battery was connected as I got lights and chimes. It was 5 and there was no one from service still there. The SALES manager took my fob, made a note and said call in the morning. I asked if he would put it in the enclose service acceptance area for the night and he said he would. Went by the next morning and it was still sitting where it was the evening before. They called late morning to pick it up. Again went down and it was in the same spot (mechanic probably worked on it in the parking lot) and this time everything was working but the carpet and panel on the passenger side was up and open still. I asked if another mechanic could fix that and verify everything was correct. Their answer was the mechanic that screwed up is responsible to fix their mistakes, no. And they couldn't look at it right then, to come back again. Third times a charm and I got it the next trip over.

I wrote a letter to the dealership and wrote a honest review. The letter was never acknowledged, and the review somehow never showed up...

So now I have a C8 and I can tell another story of woe about another dealers service service and what they did... Another day.

Vetteman Jack

Hopefully it is just a learning process for the new software.

JToddH

My ‘24 (built Feb 19th) felt a little clunky at first, especially 2nd to 3rd gear. After 2,200 miles, all seems pretty smooth.

Is that normal during break-in?

robob

lol

Kracka

Yes. The clutch discs are wearing in.

flyforC4

Kracka! You just cost me 169$ for the bidirectional OBD scanner.

Thanks, always appreciate your inputs.

flyforC4

“Kid” tech reflashed the trans. Back to normal. Love happy ending.

EvanD

That’s awesome and thanks for letting us know.

MarkMeHopeful

Another example of the dealer "finally" getting it right - scary!

JayRo

I'm dealing with this right now and now have to pay for a drain and flush. I was like damn dude I just brought this car in it was fine You do the reflash and now my car is f*****. GM says the only way to fix it is to do a drain and flush which is not covered by the warranties f*** my life.

Andybump

I do not understand if fully, but there are some items in the Service Manual that suggests that the transmission may have some 'adpative learning". The is a DTC that can be set for Transmission Adaptive Values Not Learned. One of the remedies is "Perform the scan tool learn/reset function: Transmission Service Fast Learn." Here is what is said about that procedure. Note that one reason for performing it is if there was a "software update" which there was in in your case. Looks like it could be performed even if a DTC is not set. Ask them to perform this. Ask also to see the bulletin calling for the update you received. There should be a procedure associated with what they did,. That procedure may or may not call for the Transmission Service Fast Learn.

"Description
The learn procedure performs a series of individual clutch applications which allows the control module K71to learn initial clutch apply pressures.
The control module uses the learn values for clutch control and timing of shifts.
When to Perform the Procedure
Note :
Failure to perform this procedure may result in poor system performance, DTCs being set, or customer dissatisfaction.
This procedure is required when the following component has been repaired, replaced, removed, or serviced:
K71 Transmission Control Module
T12 Automatic Transmission Assembly
Any condition/repair related to the following: Shift Quality
Calibration Update or Software Update
Clutch Assembly or Torque Converter Assembly

EvanD

First it's not GM saying this it's the dealer and they should reflash the transmission again to be sure it was done right. Others have reported the same and a reflash fixed it.