LS3 A6 Weird transmission issues
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Joined: Aug 2018
Posts: 9
Likes: 0
LS3 A6 Weird transmission issues
Hey guys, So i have a 2010 C6 automatic and im having some extremly weird transmission issues its also as if the transmission is slipping, It has 79k Miles on it.. When slowly accelerating maybe 10% throttle through the gears Especially 1-2 2-3 it will up shift likes its supposed to but when it does it will Upshift rev past where it should maybe 500 RPM hold it for a second or so then drop back down to where it should be, This also happens occasionals but more rarely on the downshifts when going very slow. The strange thing is at maybe 25-30% throttle and up this doesnt seem to happen NEARLY as frequently.
What all could this be? Should i change the transmission fluid? im at a loss.
Thank you!
What all could this be? Should i change the transmission fluid? im at a loss.
Thank you!
Advanced
Joined: Jun 2016
Posts: 76
Likes: 16
From: Chicago IL
What your experiencing is a shift flare. Unfortunately it’s pretty common with the 6L80e trans. Supposedly the TCM ( trans control module) adapts or “learns” to the driving habits and will adjust line pressures to complete a shift. It apparently does a **** poor job at learning, because just about anything that has a 6L80e in it there are people complaining of a shift flare.
Happened to me, I did a TON of searching on what was going on and how to fix it. You will come across a bunch of possible solutions and their may be more than 1 solution but again after days/weeks of research I found that the fix was to either take the car to the dealer. Or my friend who owns an updated tech 2 😬
and have him reflash the TCM with the newest, most recent software EVEN IF your trans is already up to date have the reprogram done. They will also reset the learned data in the TCM. On the way home the trans may feel funny, maybe soft shifts maybe hard shifts. But just give it a few days, the trans will learn how to shift properly again. I have not had the shift flare issue sinc.
Now my car is super charged so I learned, that after the shift flare issue was fixed. At WOT my car would smack the rev limiter before it could complete a shift and go into limp mode so I had to go back to my tuner and have him reload his tune to lower the shift speeds None the less, I have not had the shift flare issue since.
Theres no actual definite answer to what causes the shift flare but supposedly what causes it, is when you are just cruising around the trans will go to grab the next gear right at the same time as you are lifting your foot off the gas to slow down. That happens enough times, the trans will start to “learn” that is only needs a few psi of pressure to complete the shift.
THEN when you are at a nice slow accel and the trans goes to shift under partial power there isn’t enough pressure to complete the shift, RPMs will hang there a moment till the trans goes ah crap, and forces the shift.
Hopfully this helps you and saves you a lot of research.
Happened to me, I did a TON of searching on what was going on and how to fix it. You will come across a bunch of possible solutions and their may be more than 1 solution but again after days/weeks of research I found that the fix was to either take the car to the dealer. Or my friend who owns an updated tech 2 😬
and have him reflash the TCM with the newest, most recent software EVEN IF your trans is already up to date have the reprogram done. They will also reset the learned data in the TCM. On the way home the trans may feel funny, maybe soft shifts maybe hard shifts. But just give it a few days, the trans will learn how to shift properly again. I have not had the shift flare issue sinc.
Now my car is super charged so I learned, that after the shift flare issue was fixed. At WOT my car would smack the rev limiter before it could complete a shift and go into limp mode so I had to go back to my tuner and have him reload his tune to lower the shift speeds None the less, I have not had the shift flare issue since.
Theres no actual definite answer to what causes the shift flare but supposedly what causes it, is when you are just cruising around the trans will go to grab the next gear right at the same time as you are lifting your foot off the gas to slow down. That happens enough times, the trans will start to “learn” that is only needs a few psi of pressure to complete the shift.
THEN when you are at a nice slow accel and the trans goes to shift under partial power there isn’t enough pressure to complete the shift, RPMs will hang there a moment till the trans goes ah crap, and forces the shift.
Hopfully this helps you and saves you a lot of research.
Last edited by Judge387; Sep 3, 2018 at 08:59 AM.
1st Gear
Joined: Feb 2022
Posts: 1
Likes: 0
What your experiencing is a shift flare. Unfortunately it’s pretty common with the 6L80e trans. Supposedly the TCM ( trans control module) adapts or “learns” to the driving habits and will adjust line pressures to complete a shift. It apparently does a **** poor job at learning, because just about anything that has a 6L80e in it there are people complaining of a shift flare.
Happened to me, I did a TON of searching on what was going on and how to fix it. You will come across a bunch of possible solutions and their may be more than 1 solution but again after days/weeks of research I found that the fix was to either take the car to the dealer. Or my friend who owns an updated tech 2 😬
and have him reflash the TCM with the newest, most recent software EVEN IF your trans is already up to date have the reprogram done. They will also reset the learned data in the TCM. On the way home the trans may feel funny, maybe soft shifts maybe hard shifts. But just give it a few days, the trans will learn how to shift properly again. I have not had the shift flare issue sinc.
Now my car is super charged so I learned, that after the shift flare issue was fixed. At WOT my car would smack the rev limiter before it could complete a shift and go into limp mode so I had to go back to my tuner and have him reload his tune to lower the shift speeds None the less, I have not had the shift flare issue since.
Theres no actual definite answer to what causes the shift flare but supposedly what causes it, is when you are just cruising around the trans will go to grab the next gear right at the same time as you are lifting your foot off the gas to slow down. That happens enough times, the trans will start to “learn” that is only needs a few psi of pressure to complete the shift.
THEN when you are at a nice slow accel and the trans goes to shift under partial power there isn’t enough pressure to complete the shift, RPMs will hang there a moment till the trans goes ah crap, and forces the shift.
Hopfully this helps you and saves you a lot of research.
Happened to me, I did a TON of searching on what was going on and how to fix it. You will come across a bunch of possible solutions and their may be more than 1 solution but again after days/weeks of research I found that the fix was to either take the car to the dealer. Or my friend who owns an updated tech 2 😬
and have him reflash the TCM with the newest, most recent software EVEN IF your trans is already up to date have the reprogram done. They will also reset the learned data in the TCM. On the way home the trans may feel funny, maybe soft shifts maybe hard shifts. But just give it a few days, the trans will learn how to shift properly again. I have not had the shift flare issue sinc.
Now my car is super charged so I learned, that after the shift flare issue was fixed. At WOT my car would smack the rev limiter before it could complete a shift and go into limp mode so I had to go back to my tuner and have him reload his tune to lower the shift speeds None the less, I have not had the shift flare issue since.
Theres no actual definite answer to what causes the shift flare but supposedly what causes it, is when you are just cruising around the trans will go to grab the next gear right at the same time as you are lifting your foot off the gas to slow down. That happens enough times, the trans will start to “learn” that is only needs a few psi of pressure to complete the shift.
THEN when you are at a nice slow accel and the trans goes to shift under partial power there isn’t enough pressure to complete the shift, RPMs will hang there a moment till the trans goes ah crap, and forces the shift.
Hopfully this helps you and saves you a lot of research.
Burning Brakes
Joined: Apr 2016
Posts: 833
Likes: 119
From: Raeford NC
Hey guys, So i have a 2010 C6 automatic and im having some extremly weird transmission issues its also as if the transmission is slipping, It has 79k Miles on it.. When slowly accelerating maybe 10% throttle through the gears Especially 1-2 2-3 it will up shift likes its supposed to but when it does it will Upshift rev past where it should maybe 500 RPM hold it for a second or so then drop back down to where it should be, This also happens occasionals but more rarely on the downshifts when going very slow. The strange thing is at maybe 25-30% throttle and up this doesnt seem to happen NEARLY as frequently.
What all could this be? Should i change the transmission fluid? im at a loss.
Thank you!
What all could this be? Should i change the transmission fluid? im at a loss.
Thank you!
low fluid will definitely cause flairs, the fluid sloshes and sucks up air. Could be a filter issue.
Is anything done at all? If so could be a tuning issue or all of the above.
Instructor
Joined: Jan 2021
Posts: 114
Likes: 111
From: Redwood City, CA
What your experiencing is a shift flare. Unfortunately it’s pretty common with the 6L80e trans. Supposedly the TCM ( trans control module) adapts or “learns” to the driving habits and will adjust line pressures to complete a shift. It apparently does a **** poor job at learning, because just about anything that has a 6L80e in it there are people complaining of a shift flare.
Happened to me, I did a TON of searching on what was going on and how to fix it. You will come across a bunch of possible solutions and their may be more than 1 solution but again after days/weeks of research I found that the fix was to either take the car to the dealer. Or my friend who owns an updated tech 2 😬
and have him reflash the TCM with the newest, most recent software EVEN IF your trans is already up to date have the reprogram done. They will also reset the learned data in the TCM. On the way home the trans may feel funny, maybe soft shifts maybe hard shifts. But just give it a few days, the trans will learn how to shift properly again. I have not had the shift flare issue sinc.
Now my car is super charged so I learned, that after the shift flare issue was fixed. At WOT my car would smack the rev limiter before it could complete a shift and go into limp mode so I had to go back to my tuner and have him reload his tune to lower the shift speeds None the less, I have not had the shift flare issue since.
Theres no actual definite answer to what causes the shift flare but supposedly what causes it, is when you are just cruising around the trans will go to grab the next gear right at the same time as you are lifting your foot off the gas to slow down. That happens enough times, the trans will start to “learn” that is only needs a few psi of pressure to complete the shift.
THEN when you are at a nice slow accel and the trans goes to shift under partial power there isn’t enough pressure to complete the shift, RPMs will hang there a moment till the trans goes ah crap, and forces the shift.
Hopfully this helps you and saves you a lot of research.
Happened to me, I did a TON of searching on what was going on and how to fix it. You will come across a bunch of possible solutions and their may be more than 1 solution but again after days/weeks of research I found that the fix was to either take the car to the dealer. Or my friend who owns an updated tech 2 😬
and have him reflash the TCM with the newest, most recent software EVEN IF your trans is already up to date have the reprogram done. They will also reset the learned data in the TCM. On the way home the trans may feel funny, maybe soft shifts maybe hard shifts. But just give it a few days, the trans will learn how to shift properly again. I have not had the shift flare issue sinc.
Now my car is super charged so I learned, that after the shift flare issue was fixed. At WOT my car would smack the rev limiter before it could complete a shift and go into limp mode so I had to go back to my tuner and have him reload his tune to lower the shift speeds None the less, I have not had the shift flare issue since.
Theres no actual definite answer to what causes the shift flare but supposedly what causes it, is when you are just cruising around the trans will go to grab the next gear right at the same time as you are lifting your foot off the gas to slow down. That happens enough times, the trans will start to “learn” that is only needs a few psi of pressure to complete the shift.
THEN when you are at a nice slow accel and the trans goes to shift under partial power there isn’t enough pressure to complete the shift, RPMs will hang there a moment till the trans goes ah crap, and forces the shift.
Hopfully this helps you and saves you a lot of research.
perfectly describes my A6. I found that if I give it a little extra throttle, it shifts perfectly.
Burning Brakes
Joined: Jun 2015
Posts: 826
Likes: 140
From: AZ
the throttle sux ***** on the C6. Slam it down and the delay is ridiculous. it was the first thing I noticed. Maybe a Throttle controller would fix the "shifting" issue. Either way if the fluid has 40k or more ....now would be a good time for fresh fluid.
Melting Slicks
Joined: Jul 2010
Posts: 3,001
Likes: 243
From: Surprise, Az
Judge387, in your research, did you run across any information regarding a battery disconnect which may cause the transmission control module to re-learn?
In 2012, GM reprogrammed the TCM for faster shifts, it is supposed to prefill the next gear select solenoids when under WOT and from my own experience they did a good job. I had an '08 I tracked on a road course and had to shift early if I wanted to hit the next gear (5k shift points). In the '12 I can run the shift points to 6k without issue.
In 2012, GM reprogrammed the TCM for faster shifts, it is supposed to prefill the next gear select solenoids when under WOT and from my own experience they did a good job. I had an '08 I tracked on a road course and had to shift early if I wanted to hit the next gear (5k shift points). In the '12 I can run the shift points to 6k without issue.
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