Car wouldn't up shift in sport.

[Taintedveins]

Alright I know this might be considered in the wrong section but I think the v6 community will know best.

Recently over the past two weeks or so my car has been refusing to upshift from second to third or from thrid to fourth. This only happens in sport mode and when I put it into drive it finds the gearing immediately. But as soon as I put it back in sport, it down shifted and put my revs back up. Today when it happened I Ended up getting back in drive stopped at a light and put it back in sport. Didn't happen again this morning. Any ideas what it could be? I am running a stock tune and oil seems fine after that I am clueless.

[Ice Demon]

If I were you I would uninstall the tune and go for a drive and if it continues to happen take it to a good chevy dealer.

[KMPrenger]

very weird.

If it happens anymore...I'd be heading to the dealer for sure.

[scrming]

Anything on the DIC, like "Shift Denied"?

[MMC]

Read the owners manual it might just be this. See the whole section about the V6 Auto trans.

M(Manual Mode):

This position
allows the driver to select the range
of gears appropriate for current
driving conditions.
In M(Manual Mode) the
transmission will shift as an
automatic until the Tap Shift
controls are used. Tap Shift
activates driver manual gear
selection.
While driving in M(Manual Mode),
if Tap Shift has not been activated,
the transmission determines when
the vehicle is being driven in a
competitive manner. It selects and
holds the transmission in lower
gears and has more noticeable
upshifts for sportier vehicle
performance.
See Manual Mode on page 9‑32 for

more information.

[formare]

If you are in "s" mode and on curvy roads the transmission will go into "track mode" and will downshift into the turns and hold the gears upon exit much longer than any other mode.

Originally Posted by Taintedveins

Alright I know this might be considered in the
[B[/B]wrong section but I think the v6 community will know best.

Recently over the past two weeks or so my car has been refusing to upshift from second to third or from thrid to fourth. This only happens in sport mode and when I put it into drive it finds the gearing immediately. But as soon as I put it back in sport, it down shifted and put my revs back up. Today when it happened I Ended up getting back in drive stopped at a light and put it back in sport. Didn't happen again this morning. Any ideas what it could be? I am running a stock tune and oil seems fine after that I am clueless.

[KMPrenger]

I didn't even think about S mode holding on to gears longer, but yes S mode will hold on to gears and keep the car at a high rev if it happens to think you want to drive the car really sport like.

Also...make sure you are not accidentally going into manual mode...because then it will definitely not shift up for you.

[stlrammer]

I just shift mine any way I want. Its manual.

[rtcat600man]

Originally Posted by stlrammer

I just shift mine any way I want. Its manual.

ME TOO.........but I have an automatic and use the tap shifts.......