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Discussion Starter #1
i was telling a friend what happened to me and he said traction control may be to blame for this:

i was in the left lane of the highway and coming off a ramp someone cut in front of me. i did a hard brake until i was safe enough behind then i pressed down hard on the pedal. there was nothing. took half a second or a second for the engine to kick in. he said this is a traction control feature. any truth to this?

ive also had a few times where i put the pedal down and theres nothing for a short time. i hate to drive with TC off to test this theory but i may someday. first have to get something totally reproducable with it on.
 

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This is a large sedan - it's designed to have slow shifts (much to my chagrin). In an effort to keep the car in in the highest gear possible (to decrease RPM and increase MPG), this is more or less what you get.

Glacial shifting is my biggest tingle complaint about this car. It's a (relatively common complaint for reviewers.
 

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Just turn traction control off and try it. As long as it's not raining or snowing (or icy), then you don't need traction control anyway...

It could also be "torque management", which is something that controls the engine so that you don't get too much torque-steer or spin the wheels (for example). My guess would be torque management over traction control...
 

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Traction Control uses a combination of engine control and anti-lock brakes to control wheel spin. I doubt that it caused your problem. Wheel speed sensors must first detect a wheel spin condition before traction control will kick in.
 

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If you put the car in manual mode - and are like 30-50mph in 5th or 6th - and go WOT - nothing really happens.....
30mph is a bit slow to be in 5th or especially 6th gear, I would not expect much power under that condition, plus being in manual mode there will be no downshift, it will hold what ever gear you have it set to. The trans will deny you a shift or down shift to a lower gear if it is going to cause a stall condition such as 5th gear at 20 mph.

One thing that I have seen in the reviews is a complaint of a slight shudder when driving at low speeds. All vehicles these days use a Lock Up Torque Converter meaning that at a pre-selected engine rpm & speed the torque converter will lock up and become a 1:1 ratio with no slippage. This obviously aids in economy and efficiency, bit the reviews state that GM Engineers set the time of lock up a bit on the low side to gain max fuel economy from the engine and it may cause an occasional shudder.
 

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30mph is a bit slow to be in 5th or especially 6th gear, I would not expect much power under that condition, plus being in manual mode there will be no downshift, it will hold what ever gear you have it set to. The trans will deny you a shift or down shift to a lower gear if it is going to cause a stall condition such as 5th gear at 20 mph.

One thing that I have seen in the reviews is a complaint of a slight shudder when driving at low speeds. All vehicles these days use a Lock Up Torque Converter meaning that at a pre-selected engine rpm & speed the torque converter will lock up and become a 1:1 ratio with no slippage. This obviously aids in economy and efficiency, bit the reviews state that GM Engineers set the time of lock up a bit on the low side to gain max fuel economy from the engine and it may cause an occasional shudder.

interdasting....I noticed that when I let off the gas (say coasting to a stop sign) it seems to "release" the transmission and coasts MUCH better (not trans drag at all). This part of that lockup deal?
Also noticed that when I drop the trans into manual, and down shift to get some engine braking, it actually coasts more and takes a while to shift down...and it hardly "brakes" at all. All part of the energy saving stuff?
 

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Discussion Starter #8
This is a large sedan - it's designed to have slow shifts (much to my chagrin). In an effort to keep the car in in the highest gear possible (to decrease RPM and increase MPG), this is more or less what you get.

Glacial shifting is my biggest tingle complaint about this car. It's a (relatively common complaint for reviewers.
my SS had fast shifts and i really got used to it :) heck u could have a rolling start and floor it and still get rubber.. ah the old days

but getting back to slow shifting. is that really what its called when you hammer it and get no response? then ill add myself to the list of complainers. what if you really need the getup and go to escape a disaster.

interdasting....I noticed that when I let off the gas (say coasting to a stop sign) it seems to "release" the transmission and coasts MUCH better (not trans drag at all). This part of that lockup deal?
how do i get your car. when i'm doing a long coast the downshift is noticable/harsh and actually seems like someone bumped the car from behind. very annoying. and i dare say it drags the car and kills mpg (relatively speaking)

but all cars have their quirks. the old SS , when you were in heavy traffic, had a huge clunk around 10 or 11mph so you never wanted to get out of 1st when you were crawling or you'd hear that horrible shift to 2nd

i will have to turn off TC sometime and do some tests on braking and accelerating. the only time i saw the TC lite come on was onetime my driveway was covered in snow up the hill and it came on but made it up
 

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interdasting....I noticed that when I let off the gas (say coasting to a stop sign) it seems to "release" the transmission and coasts MUCH better (not trans drag at all). This part of that lockup deal?
Also noticed that when I drop the trans into manual, and down shift to get some engine braking, it actually coasts more and takes a while to shift down...and it hardly "brakes" at all. All part of the energy saving stuff?
Unless something is wrong, it should not be noticeable. The torque converter works on the basis of slippage (Good explanation here)

But all converters have a stall speed, the speed at which the converter must disengage before the vehicle stalls out (like when you do not push the clutch in on a manual trans and the vehicle stalls when you stop) The lock up clutch must disengage as well or the engine will stall out. What the GM engineers did was lower the stall speed of the locking clutch so it is very close to when the engine will stall out. This causes a slight shudder at low speeds especially when coming to a stop. This was done to keep the converter at a 1:1 ratio with no slippage as long as possible for the best fuel economy. If they raised the stall speed a bit it probably would not be an issue at all. Its all in the programming, lock up torque converters have been in use for 20+ years.
 

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I have not experienced this low speed shudder in my 2012, so I would assume that it's just an ECM/TCM tuning issue and they'll probably release an update tune to address the issue. There are typical issues for a newly-redesigned car - they will be addressed within a year or two, I'm sure. Issues like this are all part of the "risk" you take with a newly-redesigned car. The 2012/2013 has already had a few tuning updates to address similar types of issues (since it was the first model year that the 3.6/6-speed transmission came in the 8th gen).
 

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As far as I know, this tuning was done for the 2014 model, not sure about earlier versions with the 3.6L. I saw this mentioned in a couple of reviews for the 2014.
 

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Well, I'm sure it was tuned, but once a vehicle make it to the public, further refinements are usually needed, based on the feedback of the public... Like I said, there have been multiple new tuning "calibrations" released for the 2012/2013 since it was released (and I'm sure it was tuned before initial release as well)...
 

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Hi luckydriver,

I am sorry to hear this occurred! We would be happy to get you in contact with your local dealership for further technical advice. Please feel free to send us a private message at any time so we may assist. You may include your full contact information, VIN, mileage, and name of preferred dealership. Thank you!

Jessica
Chevrolet Customer Care

i was telling a friend what happened to me and he said traction control may be to blame for this:

i was in the left lane of the highway and coming off a ramp someone cut in front of me. i did a hard brake until i was safe enough behind then i pressed down hard on the pedal. there was nothing. took half a second or a second for the engine to kick in. he said this is a traction control feature. any truth to this?

ive also had a few times where i put the pedal down and theres nothing for a short time. i hate to drive with TC off to test this theory but i may someday. first have to get something totally reproducable with it on.
 

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One other thing - (to the OP).

What your friend is thinking of is reduced engine power as a result of wheel spin. The TCS uses the ABS wheel speed sensors to determine if something is slipping. If it senses voltage (it's a hall effect sensor) when it's not supposed to, it will retard the timing on the engine (typically) or pull spark to reduce what it thinks is wheel slipping. You can test this out on the ice.

What you experienced had nothing to do with TCS.
 

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Discussion Starter #16
well i usually doubt most of what my one friend says. he had one bad experience on the internet so wont order anything ever again. pretty crazy!

he also wont do the tests at work to save 1/2 of his health insurance cost and instead pays full price. more craziness
 

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Discussion Starter #17
dealers official answer is this is exactly the way this car is. they said the lack of power is normal operation and has to do with torque management. the car has to apparently think what gear to go to when you floor it.

remember the good old days when there was a cable that told your engine MOVE NOW! i long for those days. if they are gonna have to get all cars to 50 mpg in a few years i wonder what kind of crappy 'managment' they will have on our engines now. truly if you limit every car to 60 you would save so much money. why not do that to everyone?
 
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