AWD STS4 transmission software fix

[tedasaurus]

Today I confirmed what I feared was happening after a long drive. My transmission has regressed back into torque converter confusion hell. It is not as pronounced as before, but it is obviously there; the long pedal travel, the throttle indecision, the harsh up shifts, all sadly returned. The car feels like junk again. I disconnected the battery overnight just to see by chance if this might reset the trans computer as at this point it seems to me it relearned over about 8k miles the bad behavior from before. I wonder if anyone else has had this problem reappear?

[tedasaurus]

Took car to dealer, got usual cannot duplicate.

[sknovr]

I just came from my dealer this morning after getting this exact issue fixed. I knew this has been an ongoing controversy so I asked the service manager for a copy of the service bulletin. If anyone would like a copy I can either fax it or email it to them. Anyway, here is what it says in part:

Document ID# 2009091
2007 Cadillac STS

Subject:
5L40-E/5L50-E Transmission Torque Converter Clutch (TCC) Surge, Shutter, Exhaust Moan, Chuggle at Low Speed and Light Load (Reprogram TCM) #06-07-30-030A- (09/05/2007)

Models:
2004-2007 Cadillac CTS
2005-2007 SRX, STS with V6 Engine (VIN Codes 7, N, T – RPOs LY7, LA3, LP1)
2004-2006 SRX
2005-2006 Cadillac STS with V8 Engine (VIN Code A – RPO LH2)

Condition:
Some customers man comment on a shudder, surge or chuggle on light throttle under light load just after torque converter clutch (TCC) engagement. Others may comment on an engine exhaust moan in the 1200 RPM range between 65-73 km/h (40-45 mph). This occurs with the transmission at normal operating temperature and commanding the TCC off with the scan tool will eliminate the concern.

Correction:
New transmission calibrations have been released to correct this condition in both V6 and V8 applications. Reprogram the TCM using SPS. This new service calibration is available on TIS2WEB.

After reprogramming the TCM, if the condition persists and mileage is greater than 40,234 km (25,000 mi), replace the torque converter, flush the transmission oil cooler, and replace the transmission fluid.

If the condition persists, contact the Technical Assistance Center (TAC)

Warranty Information:
For vehicles repaired under warranty, use:

Labor Operation – K5364
Description – Transmission Control Module Reprogramming with SPS
Labor Time – Use Published Labor Operation Time

Hope this helps clear this matter up.
Robert

[tedasaurus]

I will talk to them about a new torque converter. Thanks.

[Benjamin Simon]

After getting the software update, I am still having trouble with what the tranny is doing. When I go down a hill, the RPMS go down (1100 RPMS) and back up (1900 RPM) 2 and sometimes 3 times. My foot is NOT on the gas, I am just coasting. It just feels and sounds weird and I know it is not suppose to do that. I have 28K on the clock? Should I suggest my torque converter be changed and a tranny flush?

I like the word tranny.

[dkozloski]

Originally Posted by Benjamin Simon

After getting the software update, I am still having trouble with what the tranny is doing. When I go down a hill, the RPMS go down (1100 RPMS) and back up (1900 RPM) 2 and sometimes 3 times. My foot is NOT on the gas, I am just coasting. It just feels and sounds weird and I know it is not suppose to do that. I have 28K on the clock? Should I suggest my torque converter be changed and a tranny flush?

I like the word tranny.

Disengage the cruise control.

[Benjamin Simon]

Originally Posted by dkozloski

Disengage the cruise control.

The cruise control is not engaged or active. I turn it off totally. I have the ACC and the warning sound is annoy from the ghost.

[dkozloski]

Mine will buckle and do some strange things on a long mild downgrade withthe cruise control on but if it's off it works fine.

[themightymezzo]

I have a 2005 RWD STS V8 and believe I have the same problem.

Guess it's not just related to the all wheel drive STS-4.

Anyone else w/ RWD have the same problem? After I looked into it seems some CTS's have the same sypmtoms as well.

Getting ready to call dealership this afternoon as they have already replaced my torque converter, etc. I want to see if they used the updated TCM program or not.

[ahuyghe]

Hello all:
I have experienced the shudder or Chuggle in the shifting of my 07 STS4. I have ~ 28000 miles and the dealership is changing the torque converter. I have a big concern with their process. The Dealership tells me that they repair it on the bench, no special requirements. I remember distinctly reading prior to puchasing the Cadillac that this sophisticated transmission is hand assembled in a clean room environment. I have a very good knowledge of cleanrooms and why items are produced in them. What i cannot for the life of me understand is why the dealership would be allowed to open up the transmission in an uncontrolled environment, exposing the vales etc to brake dust and what ever else is in the air of the dealership shop. The service manager tells me that she has never heard of a clean room for this and doubts that there is such a facility in North America! Has anybody else had their transmission repaird exposed in the shop? A friend of mine just had his transmission repaired on his 02 Rendezvouz and his dealership sent it out to a shop with a cleanroom facility to do the work.
Should i be concerned? Any advice? I don't know if i want them to bust it open and then i have problems down the road when it's off warranty.
Any help would be greatly appreciated.

Al

2007 Cadillac STS 4

[BaTu]

I'm not sure they're going to actually "open" the transmission just to change the torque converter though.... - are they? The converter is a self-contained unit that's separate from the transmission internals and serves as the coupler between the engine/trans.

[ahuyghe]

BaTu:
I hope your right. I've never worked on a transmission and don't plan to. so my knowledge is very limited as to the components amd placement of them. But i feel i have no choice, so i am getting it done anyway and am trusting the dealership completely on this one.

Al

2007 Cadillac STS 4

[kjanks]

Just got mine done too w/ a torque converter replacement along w/ it.

[themightymezzo]

I wish you all better luck than I've had. Seems to me like they can't really get this problem fixed. They have a newer TCM code which may help temporarily but seems over time to fall back into the torque converter just "vibrating" away causing resonance etc. through the drivetrain/exhaust.

Just hope after they fix everything you dont' end up with more problems then you had at the get go. Seems to be what has happened to me.

Best of luck.

[ahuyghe]

Just as a follow up to this issue, The dealership did do the work and they replaced clutch plates 4-5-6 and the torque converter. The Car has a very noticeable change in the shifting. It shifts a lot more positive now, no more surging. Feels so much better.

Al