: Rough shifting between 30-40 mph 2006 sts

08-31-08, 10:28 PM
I have a 2006 sts4 v8. It seems when driving between 30-40 mph , the idle is too low for the speed and in oder to speed up it takes a good amount of rpm boost (roughly 3000) to get the car moving again

Anyone have thoughts or ideas??

08-31-08, 11:07 PM
There is a technical service bulletin out for this. Do a search on here, if you can't find info, I'll update you. My shifting improved dramatically after the fixby the dealer under warranty. Unfortunately if you tell the dealer about a technical service bulletin, they usually take offense as if you are challenging them on their job. Just tell them the symptoms and let them make the diagnosis... they like to feel like doctors. :)

09-01-08, 07:39 PM
were you having the same issues and how did you best describe it to the dealer? I never have a pleasant time at the service the department, I have found that it seems they all take it waaayyy to personal. I need to bring it in this week and also have to have them find out why the battery keeps dying

09-01-08, 09:00 PM
I had a "transmission shudder", which is actually the terminology used in the technical service bulletin (TSB). When I had the problem some time ago, someone described the TSB to me and I did a google search and it was readily available. It is no longer available by searching... GM trying to hide things, I guess. I scanned the TSB for you that I printed out some time ago before it became "top secret". If you can't see it well, let me know, I can email it to you. I had to both resize and compress in order for this forum to let me post it.

09-03-08, 02:01 PM
Thanks for the info,
Its going to the dealer tomorrow, i'll let you know

09-09-08, 10:20 PM
I had the same problem when ascending a hill near work. It happened to me every day. My local dealership was only 3 miles from the hill. I went on a test drive with my service adviser who then experienced it first hand. The problem is now gone after the dealer applied a software upgrade to the system. Now when you let your foot off the gas at about 41 MPH and it drops below 40, I feel a down shift where before it use to just free wheel. The first problem was more annoying so I guess I made out better (trading one problem for another).

09-09-08, 10:59 PM
It is just a simple computer software modification changing the cars shift points so that the engine does not "bog down" and has more power... particularly in the 30mph range. Since it does not cost the dealer anything to do this as they already have the programmer to make the changes, they shouldn't complain about fixing problem.

Actually noticed my car doing it again (about 30K miles later after fix) so I may mention it to them again, although does not do it consistently like it did in past.

I have noticed it takes my local dealer 2-3 tries to fix most things to my satisfaction, but the dealer I take it too is less than 1 mile away, so easier to bring it in several times rather than drive to next nearest dealer (20 miles away). Besides, I get a new loaner on each visit no charge.

09-10-08, 01:06 PM
Ok well this dealer did notice the issue as the first dealer said "nothing is wrong, it just how a person drives" and then they wonder why they have a bad reputation..

Anyway the second dealer installed the software and it does run better , the only abnormal thing i notice now, is the issue when the automatic tranny downshifts, its rather noticeable and not smooth.

Its due in again next week because I needed to have the steering wheel replaced because it doesn't heat up.

i'll keep everyone updated

09-24-08, 06:35 AM
How did you make out with rough downshift? Was the dealer able to fix it? If so, what did they do?

09-24-08, 08:09 AM
My 05 STS4 started to hesitate/buck ( for lack of a better word) at about 30-40 mph and when turning corners, the traction control light would also flash on for about 3 seconds so I made an appointment with the dealer. I just asked them to check their database and see if my car had the transmission software upgrade.He said no and I asked to have it reprogrammed and they did it , no questions ask. Now my car runs much,much better and no more TC light. I would advise that anyone who has not had this service done please do it before your warranty runs out.