AUTO TRANS WILL NOT UPSHIFT

[GearHeadPeter]

While I had mine in Sport mode and from a dead stop when I turned the tranny would not shift up like it would normally do. No I did not have the paddle shifter in 1 as it is in S.

I did find some tranny spots in the driveway and under the trans cooler lines when it was in the garage. Took it to the dealer and found I had a cracked tranny cooler line and it had leaked about 1 qt. of tranny fluid over time, but nothing that I saw until it became worse. Dealer fixed it, and topped of the tranny fluid and it works great again.

[myold88]

Originally Posted by JeffP

I am also experiencing this problem. Did your dealer resolve this issue?

I've been off the interstates Due to winter. If this happens again I'll be returning to the dealer. On local roads there's no problem.

[myold88]

I took a short trip towards Boston on I-90 yesterday. Set my cruise @ about 70. No problem going but
on the return trip my Camaro would not go back into 6th gear twice.
At 65 MPH my tach was reading way above 2300 RPM and it obviously stayed in 5th gear- One time
when I stopped to get my toll ticket and again while stopped at an accident for a few minutes.
Unless I put it in "S" and upshifted it would stay in 5th gear.

[myold88]

Update:
I stopped back at my dealer and explained that the problem cotinues per above ^^.
They contacted GM again who states the problem could be cruise control related as I
always have it on, and the car will also shift into 6th gear if I just turn the cruise off.
I'm not a tech, but it sounds more like a computer problen than a transmission problem.
The dealer promises to get back to me soon.

[JeffP]

Mine was at the dealer today and I had the same result - tech could not replicate the problem. I was advised if the problem continues, bring the vehicle back. I will do some experimenting to see if the problem continues with the cruise control activitated/deactivated. 5,900 miles here.

[Chevrolet Customer Svc]

Let us know what you find Jeff. Did you take a tech from your dealer for a ride to try and reproduce this issue with them there? That would be another good idea to try and get this resolved. I hope you're able to get this all taken care of. If all else fails send me a message and I'll do what I can to help you.

Jeff Morris, Chevrolet Customer Service

[myold88]

Originally Posted by Chevrolet Customer Svc

Let us know what you find Jeff. Did you take a tech from your dealer for a ride to try and reproduce this issue with them there? That would be another good idea to try and get this resolved. I hope you're able to get this all taken care of. If all else fails send me a message and I'll do what I can to help you.

Jeff Morris, Chevrolet Customer Service

Mr Morris,
My dealer at first stated they would road test the car to try to duplicate the transmission problem. The only difficulty is you must be on an interstate and it can take many hours &/or miles. Like I previously said, I went over 100 miles without a problem and then it happened twice on my return trip from Boston.
I'll be glad to do this but will GM authorize it ? If so please let me or my dealer, O'neill Chevrolet in Avon, Ct know.

[acatlover13]

I have this issue now. Just did an LS3 conversion and cam install, and it has started doing this. Mine acts like it can't "decide" what gear it wants to be in. Going to the dealer on Wednesday to get checked out.....may need new clutch pack. :(

[myold88]

Here's an update to this old problem but I rarely take my SS on trips:

I went to the Annapolis Md area last week. Over 1,000 miles total, about 800 on the interstates round trip.
On the way home on the Jersey Tpke with the cruise control set at about 70-72 all was fine until
I had to slow down for traffic to about 45-50.
When I hit the cruise "resume" button the car speeded up but again the RPM's stayed way above 2200
and the trans would not upshift out of 5th gear.
I then put the car in M/S mode and shifted into 6th gear and the RPM's returned to about
the normal 2,000 range which is normal for about 70-72 MPH.
I don't know what to do as I can't expect my dealers tech to go on a long trip to try to duplicate this problem.

[myold88]

Brandon @ Chevrolet Customer Service contacted me re the above problem.
Per his request I sent him all my vehicle info including the case number set up
during my first dealer visit.
I hope GM can resolve this problem for me.

[TooCool5]

Originally Posted by myold88

Brandon @ Chevrolet Customer Service contacted me re the above problem.
Per his request I sent him all my vehicle info including the case number set up
during my first dealer visit.
I hope GM can resolve this problem for me.

Sounds computer / sensor related to me. The dealer needs to find out what parameters it needs to see before up shifting into 6th and then check those senors for variations.
Will it up shift if you accelerate without cruise control?

[myold88]

Originally Posted by TooCool5

Sounds computer / sensor related to me. The dealer needs to find out what parameters it needs to see before up shifting into 6th and then check those senors for variations.
Will it up shift if you accelerate without cruise control?

I'm reviving this thread after checking my records due to the continueing problem with my L99 transmission.
A case number (71-105462-0191) was set up by Chev Cust Service on 3/14/12.
I had the car road tested at a second dealer on 8/14/12 but after 15 minutes the problem could not be duplicated.
It seems to only get worse after an hour or two on the interstate.
I'm at a loss as to how to proceed at this point but I hope the new current thread/posts
will get some action from GM.

[TooCool5]

Originally Posted by myold88

I'm reviving this thread after checking my records due to the continueing problem with my L99 transmission.
A case number (71-105462-0191) was set up by Chev Cust Service on 3/14/12.
I had the car road tested at a second dealer on 8/14/12 but after 15 minutes the problem could not be duplicated.
It seems to only get worse after an hour or two on the interstate.
I'm at a loss as to how to proceed at this point but I hope the new current thread/posts
will get some action from GM.

Keith, Hope it works out for you. Has anyone checked the fluid level or offered the flush the transmission.
Does the SS have an external cooler? If not have one installed. My LS has a cat 2 " from the trans cooler lines
so I made up a heat shield so it will not bake them.
Later models have a shield around the hot exhaust pipe near the trans lines.

[white ZL1]

Originally Posted by TooCool5

Will it up shift if you accelerate without cruise control?

This. Do you only have this problem when hitting the resume feature on the cruise?