Transmission slip?
Thread Starter
Burning Brakes
Joined: Oct 2001
Posts: 860
Likes: 40
From: Woodforest
Transmission slip?
2012 GS Auto - about 15K on it.
Two days ago, on the way to work, was waiting in traffic at a light, car was warmed up to operating temp. As the line moves forward on green, I noticed I had to give it more pedal than usual to get the car to move forward. Normally, just lift off the brake, and it starts to move. Actually had to give it some gas, and it felt like it was slipping somewhat, saw the tach go up about 1K.
Reached the light, turned and accelerated and no issues, behaved like it should. I've been a bit wary since that happened, and did some full throttle accels to see if something was going to break, but nothing since. Driven it about 100 miles since.
Anyone else experienced this or have an explanation?
Thanks for your replies.
Two days ago, on the way to work, was waiting in traffic at a light, car was warmed up to operating temp. As the line moves forward on green, I noticed I had to give it more pedal than usual to get the car to move forward. Normally, just lift off the brake, and it starts to move. Actually had to give it some gas, and it felt like it was slipping somewhat, saw the tach go up about 1K.
Reached the light, turned and accelerated and no issues, behaved like it should. I've been a bit wary since that happened, and did some full throttle accels to see if something was going to break, but nothing since. Driven it about 100 miles since.
Anyone else experienced this or have an explanation?
Thanks for your replies.
Race Director
Joined: Mar 2005
Posts: 11,549
Likes: 27
From: Southampton NJ
2012 GS Auto - about 15K on it.
Two days ago, on the way to work, was waiting in traffic at a light, car was warmed up to operating temp. As the line moves forward on green, I noticed I had to give it more pedal than usual to get the car to move forward. Normally, just lift off the brake, and it starts to move. Actually had to give it some gas, and it felt like it was slipping somewhat, saw the tach go up about 1K.
Reached the light, turned and accelerated and no issues, behaved like it should. I've been a bit wary since that happened, and did some full throttle accels to see if something was going to break, but nothing since. Driven it about 100 miles since.
Anyone else experienced this or have an explanation?
Thanks for your replies.
Two days ago, on the way to work, was waiting in traffic at a light, car was warmed up to operating temp. As the line moves forward on green, I noticed I had to give it more pedal than usual to get the car to move forward. Normally, just lift off the brake, and it starts to move. Actually had to give it some gas, and it felt like it was slipping somewhat, saw the tach go up about 1K.
Reached the light, turned and accelerated and no issues, behaved like it should. I've been a bit wary since that happened, and did some full throttle accels to see if something was going to break, but nothing since. Driven it about 100 miles since.
Anyone else experienced this or have an explanation?
Thanks for your replies.
Team Owner
Joined: Mar 2008
Posts: 21,502
Likes: 461
From: Southern Utah
I agree...low fluid level is the first thing to check. This issue was common on some Hydra Matic 400 transmissions years ago. If the level was just a bit low, the pump would suck air for a sec and the converter would slip. With the 400, it was more likely when starting out and turning, like turning left in traffic. The 6L80 is a direct descendant of the 400. There really isn't anything in the auto that can slip except the converter, as the gears are in constant mesh.
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Team Owner
Joined: Mar 2008
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From: Southern Utah
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What the OP described actually sounds like it may have briefly gone into limp mode, where it temporarily gets freaked out and ends up requiring a lot more gas just to keep it barely moving forward. I'd recommend that he have it scanned for codes even if the check engine light didn't actually come on when/after it happened.
Team Owner
Joined: Mar 2008
Posts: 21,502
Likes: 461
From: Southern Utah
What the OP described actually sounds like it may have briefly gone into limp mode, where it temporarily gets freaked out and ends up requiring a lot more gas just to keep it barely moving forward. I'd recommend that he have it scanned for codes even if the check engine light didn't actually come on when/after it happened.
I've never seen one of those have an electronic "freak out"...but then they never generated any trouble codes either!
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Thread Starter
Burning Brakes
Joined: Oct 2001
Posts: 860
Likes: 40
From: Woodforest
I checked the fluid after I got to work that day, level was fine. I was on level ground, and had the car In drive all the time to answer a couple of other questions. I had no check engine light, planned to scan it this weekend, but things came up with the wife. Going to try and do that early this week. I have about 150 additional miles, and no reoccurrence of the issue, with several attempts to break the thing.
The limp mode sounds like a potential. Don't know why it would do that though. Hope it doesn't do that when you really need it.
The limp mode sounds like a potential. Don't know why it would do that though. Hope it doesn't do that when you really need it.
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I checked the fluid after I got to work that day, level was fine. I was on level ground, and had the car In drive all the time to answer a couple of other questions. I had no check engine light, planned to scan it this weekend, but things came up with the wife. Going to try and do that early this week. I have about 150 additional miles, and no reoccurrence of the issue, with several attempts to break the thing.
The limp mode sounds like a potential. Don't know why it would do that though. Hope it doesn't do that when you really need it.
The limp mode sounds like a potential. Don't know why it would do that though. Hope it doesn't do that when you really need it.
Team Owner
Joined: Sep 2000
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From: Far NW 'burbs of Chicago
St. Jude Donor '13
I checked the fluid after I got to work that day, level was fine. I was on level ground, and had the car In drive all the time to answer a couple of other questions. I had no check engine light, planned to scan it this weekend, but things came up with the wife. Going to try and do that early this week. I have about 150 additional miles, and no reoccurrence of the issue, with several attempts to break the thing.
The limp mode sounds like a potential. Don't know why it would do that though. Hope it doesn't do that when you really need it.
The limp mode sounds like a potential. Don't know why it would do that though. Hope it doesn't do that when you really need it.
Anything else can produce an inaccurate level, but I don't know how much error you might get.
Thread Starter
Burning Brakes
Joined: Oct 2001
Posts: 860
Likes: 40
From: Woodforest
Still hasnt had it happen again, so maybe just an electronic glitch. Heres hoping.
Team Owner
Joined: Sep 2000
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From: Far NW 'burbs of Chicago
St. Jude Donor '13
Sorry, misunderstanding. I had the fluid checked because that was the first thing I thought of, the second sentence was in response to where the car was and status of transmission when the issue occurred.
Still hasnt had it happen again, so maybe just an electronic glitch. Heres hoping.
Still hasnt had it happen again, so maybe just an electronic glitch. Heres hoping.
Thread Starter
Burning Brakes
Joined: Oct 2001
Posts: 860
Likes: 40
From: Woodforest
It really felt like I had lost my transmission for about 30 seconds or so, starting in second wouldn't use the R's I saw with very little forward movement. Oh well, as they say, It's a Mystery!
Thanks for all the replies guys, this forum is, and always has been since my Crossfire C3 days, a great source of information and help.
Melting Slicks
Joined: Jul 2010
Posts: 2,999
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From: Surprise, Az
Woodstoc, the A-6 when in 'D' will downshift to 1st when coming to a stop. When in 'S' and using paddle shifters it will downshift to 2nd when coming to a stop. When in 'S' and not using the paddle shifters, it will downshift to 1st when stopping.
I have about 12k on my GS, haven't had any issues with the transmission as you have described.
I have about 12k on my GS, haven't had any issues with the transmission as you have described.
Team Owner
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From: Far NW 'burbs of Chicago
St. Jude Donor '13
In other words, the A6 will only start out in second if you are using the paddles and tell it to start in second; or you were using the paddles and forgot to downshift as you came to a stop. In both those situations, it will start in second and stay there until you either use the paddles, or put the selector back into D.
If you are not using the paddles, the 1 to 2 shift comes so soon and so smoothly that many people think the car never used 1 at all. But it did.
If you are not using the paddles, the 1 to 2 shift comes so soon and so smoothly that many people think the car never used 1 at all. But it did.
Thread Starter
Burning Brakes
Joined: Oct 2001
Posts: 860
Likes: 40
From: Woodforest
Excellent, thank you both for clarifying that. I read somewhere else that it started in 2nd in D, unless you caused a downshift by acceleration quickly. I always wondered about that, but it runs through the gears so smoothly and fast, it's hard to keep up with since it doesn't show unless your using the paddles or S.
I put it in S yesterday when coming to a stop light, and made sure it stayed in 2nd. Took off, and it felt just fine, nothing like what I experienced, so that wasn't it.
Still no repeat issues, I'm chalking it up to an electronic glitch right now. Again, thanks for the help, I know engines, but transmissions are the eternal source of mystery for me.
I put it in S yesterday when coming to a stop light, and made sure it stayed in 2nd. Took off, and it felt just fine, nothing like what I experienced, so that wasn't it.
Still no repeat issues, I'm chalking it up to an electronic glitch right now. Again, thanks for the help, I know engines, but transmissions are the eternal source of mystery for me.
Melting Slicks
Joined: Jul 2010
Posts: 2,999
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From: Surprise, Az
If the dealer can't find any codes, I wouldn't be all that worried about it though it is a bit unsettling. When we bought our brand new Yukon Denali a few years ago we had a couple of anomolies similar to what you experienced. I turned the vehicle off and back on a couple of times and headed to the dealership. Aparently a code was set so they replaced the computer under warranty. No problems since then and that was several years ago. There are so many electronic controls in these vehicles it is amazing they are as trouble free as they are.
Team Owner
Joined: Sep 2000
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From: Far NW 'burbs of Chicago
St. Jude Donor '13
