2008 Auto transmission shifting problem
03-20-2010, 10:10 AM
#21
Safety Car
Hey guys, long time no talk.
I bought a Brand New 2008 C6 Covertible with Z51, NPP, A6, and 2.73 rear in 2/09.
It has been over a year and it is to the point I want to drive the car through Chevy's window, this Transmission programming SUCKS.
I took it to the dealer, they said it was NORMAL
I don't race anymore since my last C6, no ATCO Raceway, heck I can count on both hands how many times I've went full throttle, but this transmission programming is wrong.
If I go to pass somebody at part throttle, it feels like the car bogs, it doesn't kick down for 1-2 seconds and by that time it is too late to pass.
Even at full throttle it takes 1-2 seconds at certain speeds.
The car has plenty of power, heck I had a C6 Z06 and I still feel the LS3 is plenty fast, but it is hampered by the Transmission programming.
I don't want to void my warranty, but this transmission can be dangerous.
There are times when you need part throttle passing NOW, not 1 Mississippi 2 Mississippi later.
Obviously the Service Departments are clueless ot following Chevy's directive to call it normal to protect the transmission, but this is ridiculous.
My previous Automatic was a Mercedes C63 AMG 7 speed, WOW!!!!
It was GREAT. No lag, immediate shifts, even with the paddles.
It felt like the Tranny was tunes to the Engine, I'd say as good as a manual, maybe better in terms of response.
Now I am back to Chevy's ****, please help.
Yes the Vette is faster than the AMG once the transmission engages, but by the time it does that Mercedes would be 2-3 car lengths ahead and the C6 would NEVER catch up.
HELP ME PLEASE!
I bought a Brand New 2008 C6 Covertible with Z51, NPP, A6, and 2.73 rear in 2/09.
It has been over a year and it is to the point I want to drive the car through Chevy's window, this Transmission programming SUCKS.
I took it to the dealer, they said it was NORMAL
I don't race anymore since my last C6, no ATCO Raceway, heck I can count on both hands how many times I've went full throttle, but this transmission programming is wrong.
If I go to pass somebody at part throttle, it feels like the car bogs, it doesn't kick down for 1-2 seconds and by that time it is too late to pass.
Even at full throttle it takes 1-2 seconds at certain speeds.
The car has plenty of power, heck I had a C6 Z06 and I still feel the LS3 is plenty fast, but it is hampered by the Transmission programming.
I don't want to void my warranty, but this transmission can be dangerous.
There are times when you need part throttle passing NOW, not 1 Mississippi 2 Mississippi later.
Obviously the Service Departments are clueless ot following Chevy's directive to call it normal to protect the transmission, but this is ridiculous.
My previous Automatic was a Mercedes C63 AMG 7 speed, WOW!!!!
It was GREAT. No lag, immediate shifts, even with the paddles.
It felt like the Tranny was tunes to the Engine, I'd say as good as a manual, maybe better in terms of response.
Now I am back to Chevy's ****, please help.
Yes the Vette is faster than the AMG once the transmission engages, but by the time it does that Mercedes would be 2-3 car lengths ahead and the C6 would NEVER catch up.
HELP ME PLEASE!
03-20-2010, 11:08 AM
#22
Could you contact your friend at work and see if he could provide more info?
03-20-2010, 11:43 AM
#23
Heel & Toe
Thread Starter
Member Since: Jul 2009
Location: Miami Florida
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
A6 Auto transmission Woes
I feel much better seeing that lot of people have the same problems I have. That's why I posted this.
I've been doing a lot of research and have an idea that may work. The issue seems to be related to the TPS. In the old days, the transmission knew what to do based on how far you pushed the accelerator pedal. There was a Kick-down control that was linked to the throttle cable.
Now days we have drive by wire, which also in my opinion, is what may be causing acceleration "sag" and similar issues.
I've been reading about the Sprint TPS booster. Essentially what it does is makes the gas pedal more sensitive. This should fix the acceleration "sag" as well as help the transmission kick-down.
Cost of this is $395. I may try it.
I've been doing a lot of research and have an idea that may work. The issue seems to be related to the TPS. In the old days, the transmission knew what to do based on how far you pushed the accelerator pedal. There was a Kick-down control that was linked to the throttle cable.
Now days we have drive by wire, which also in my opinion, is what may be causing acceleration "sag" and similar issues.
I've been reading about the Sprint TPS booster. Essentially what it does is makes the gas pedal more sensitive. This should fix the acceleration "sag" as well as help the transmission kick-down.
Cost of this is $395. I may try it.
03-20-2010, 12:18 PM
#24
Safety Car
I feel much better seeing that lot of people have the same problems I have. That's why I posted this.
I've been doing a lot of research and have an idea that may work. The issue seems to be related to the TPS. In the old days, the transmission knew what to do based on how far you pushed the accelerator pedal. There was a Kick-down control that was linked to the throttle cable.
Now days we have drive by wire, which also in my opinion, is what may be causing acceleration "sag" and similar issues.
I've been reading about the Sprint TPS booster. Essentially what it does is makes the gas pedal more sensitive. This should fix the acceleration "sag" as well as help the transmission kick-down.
Cost of this is $395. I may try it.
I've been doing a lot of research and have an idea that may work. The issue seems to be related to the TPS. In the old days, the transmission knew what to do based on how far you pushed the accelerator pedal. There was a Kick-down control that was linked to the throttle cable.
Now days we have drive by wire, which also in my opinion, is what may be causing acceleration "sag" and similar issues.
I've been reading about the Sprint TPS booster. Essentially what it does is makes the gas pedal more sensitive. This should fix the acceleration "sag" as well as help the transmission kick-down.
Cost of this is $395. I may try it.
I'll risk the warranty, this delay could potentially be unsafe.
I would trust ECS or Chuck COW if they say they can fix it.
I'll keep you posted after I get a response and if I have it done.
03-20-2010, 12:27 PM
#25
FYI, I just went through all the TSB's for the 2008 A/T and can't find a single one that refers to a change/update in the programming for the transmission. That doesn't mean there isn't one out there, but if there is, I can't find it.
03-20-2010, 12:41 PM
#26
Safety Car
I truly believe this is Chevy's way of preventing tranny damage.
Again, I never race the car, but heck, even my 2004 Lexus GX470 SUV has better throttle to tranny response.
I kind of miss my Yellow 2005 Corvette Convertible with the A4/3.15.
As great as the C6 is, this truly ruins my enjoyment of the car.
Sure, it might be capable of a 11 second 1/4 mile from a dead stop, but I don't race, I'd much rather have great part throttle response on the street from any speed.
Right now it's like hit the gas, then
, pass the other car.
03-20-2010, 12:42 PM
#27
Advanced
Member Since: Mar 2010
Location: Harvey Louisiana
Posts: 73
Likes: 0
Received 0 Likes
on
0 Posts
I have had the same issues with the exception of the engine revving and not accelerating. I have been thinking about a cow tune also, but have concerns about loss of warranty. Let me know if the tune resolves your issues.
03-20-2010, 01:18 PM
#29
Safety Car
I am worried about a warranty, but the way this car is driving is not what I paid $53K for.
I love the car, I just want it to drive as good as it looks.
03-20-2010, 02:16 PM
#30
I have a suspicion that the ECM not only looks the the position info from the TPS, but also looks at the rate of change (speed) of the TPS sensor change. Which means to say how quickly you are pushing down on the accelerator pedal.
Try this, next time you want to accelerate to pass, push on the pedal in a faster "stabbing" type of motion instead of slowing increasing pressure on it, and see if it responds better and shifts quicker. My guess is that you may be able to solve your issue simply by modifying how you push on the pedal. You don't have to push it to the floor, but just trying pushing on it in a quicker motion. Let us know if this provides some improvement for you.
Try this, next time you want to accelerate to pass, push on the pedal in a faster "stabbing" type of motion instead of slowing increasing pressure on it, and see if it responds better and shifts quicker. My guess is that you may be able to solve your issue simply by modifying how you push on the pedal. You don't have to push it to the floor, but just trying pushing on it in a quicker motion. Let us know if this provides some improvement for you.
Last edited by CSixDude; 03-20-2010 at 02:24 PM.
03-20-2010, 02:40 PM
#31
Safety Car
I have a suspicion that the ECM not only looks the the position info from the TPS, but also looks at the rate of change (speed) of the TPS sensor change. Which means to say how quickly you are pushing down on the accelerator pedal.
Try this, next time you want to accelerate to pass, push on the pedal in a faster "stabbing" type of motion instead of slowing increasing pressure on it, and see if it responds better and shifts quicker. My guess is that you may be able to solve your issue simply by modifying how you push on the pedal. You don't have to push it to the floor, but just trying pushing on it in a quicker motion. Let us know if this provides some improvement for you.
Try this, next time you want to accelerate to pass, push on the pedal in a faster "stabbing" type of motion instead of slowing increasing pressure on it, and see if it responds better and shifts quicker. My guess is that you may be able to solve your issue simply by modifying how you push on the pedal. You don't have to push it to the floor, but just trying pushing on it in a quicker motion. Let us know if this provides some improvement for you.
03-20-2010, 02:45 PM
#32
03-20-2010, 02:49 PM
#33
Safety Car
Car is mechanically sound, but I can tell it is tuned for prevention rather than aggression.
08-27-2018, 06:16 PM
#34
1st Gear
Member Since: Aug 2018
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
I have a 2008 with the 6 speed automatic transmission. I have been concerned with the transmission ever since it was new. At low speeds - like if I have my foot off the gas and am coasting - when I step on the gas again, the transmission seems like it is not in gear. Then it will slam into gear and operate normally. It's sort of like it is in neutral and then goes into gear.
I've asked the dealer about it twice and he keeps telling me it is something called "torque control". To me this is BS.
I also notice something I've heard referred to as "sag". At low speeds the car feels like it is going to bog down when you step on it.
Anybody have any TSBs or thought of how I might explain the transmission and "sag" issues to the dealer?
Thanks!
08-30-2018, 12:05 PM
#35
Instructor
I also just posted an new thread in GD before finding this one.
https://www.corvetteforum.com/forums...r-replace.html
This thread is old, but curious how things have worked out and if solution could be as easy as new programming.
https://www.corvetteforum.com/forums...r-replace.html
This thread is old, but curious how things have worked out and if solution could be as easy as new programming.
