C7 auto transmission weird issue

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Jun 19, 2017 | 10:42 AM

brookman

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From: chandler az

C7 auto transmission weird issue

I am going to try to explain this the best I can, From a full stop the car behaves as expected. But from 45mph plus, on a regular basis , when I go to full throttle the rpms bounce up to near red-line and just hang out there like it is stuck in gear and doesn't seem to be accelerating.

I don't know how to troubleshoot this. Any ideas?

Jun 19, 2017 | 11:09 AM

BlueDevilZ51

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From: Long Island New York

Sounds like its going into performance shift mode after you went wot. Does it upshift on its own or just over rev and bounce off the rev limiter? Are you in drive or manual mode?

Last edited by BlueDevilZ51; Jun 19, 2017 at 11:12 AM.

Jun 19, 2017 | 01:57 PM

brookman

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From: chandler az

Quote:

Originally Posted by BlueDevilZ51

Sounds like its going into performance shift mode after you went wot. Does it upshift on its own or just over rev and bounce off the rev limiter? Are you in drive or manual mode?

In Drive, when it seems to hang there, I let up. I haven't seen it bounce off the rev limiter. I have it set to sport mode if that matters.

Jun 19, 2017 | 02:05 PM

BlueDevilZ51

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From: Long Island New York

Well if its up shifting without bounching off the limiter i dont see a problem. It will definitely hold the gears longer and stay in a more aggresive rpm range if you were just full throttle due to the computer putting the the car in performance shift mode.
it will again return to normal shifting behavior after around 10 seconds.

Last edited by BlueDevilZ51; Jun 19, 2017 at 02:06 PM.

Jun 19, 2017 | 04:22 PM

laserdude2215

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From: San Dimas CA

You probably see a message in the DIC indicating "Performance Shift Active". No troubleshooting necessary!

Jun 21, 2017 | 09:19 AM

Kraz8s

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From: Fuquay-Varina

Completely normal yet unsettling the first time it happens.

Jun 27, 2017 | 10:30 PM

dollarbill

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From: Ridgeland MS

St. Jude Donor '06-'07-'08-'09-'10-'11

If you drive it in Economy mode or in Touring mode it won't go into performance shift mode. Performance shift mode lets you accelerate and make a corner then power out without up shifting mid corner as it would in touring mode. It is even more 'aggressive' in track mode. All normal for performance driving. Stay out of WOT and it stays out of performance shift mode.

Jun 27, 2017 | 10:39 PM

NSC5

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The OP isn't clear about whether he is continuing at WOT and it isn't accelerating. If he is backing off the throttle I can understand it maintaining a high steady RPM due to PAS/PAL programming but if he literally meant what he wrote: "when I go to full throttle the rpms bounce up to near red-line and just hang out there like it is stuck in gear and doesn't seem to be accelerating" then that is a problem if it doesn't accelerate as it should. Either a transmission or engine issue could cause this but normally that would result in one or more DTCs being set.