97PA - TCC Lockup Converter

My transmission started shifting very hard and the "service engine soon" light came on. After turning the car off the problem ceased. The stored code was "TCC lockup converter stuck...cleared." Problem appeared again (not as bad and did not trigger a code). Again, turning engine off and restarting "fixed" the rough shifting. Wondering if anyone else has experience with this problem? (A mechanic said it was an electronic part.)

My transmission started shifting very hard and the "service engine soon" light came on. After turning the car off the problem ceased. The stored code was "TCC lockup converter stuck...cleared." Problem appeared again (not as bad and did not trigger a code). Again, turning engine off and restarting "fixed" the rough shifting. Wondering if anyone else has experience with this problem? (A mechanic said it was an electronic part.)

I've not had a problem as yours, but have experienced what I've called
"Herky Jerky." Do a search in this form and in alt.autos.gm for my ordeal, not yet over. GM calls it "chuggle," and it's related to the Torque Converter Clutch," TCC. The function of the TCC is to lock up the input and output shafts of the torque converter when the normal "fluid link" is not necessary,
e.g., fairly constant loads and speeds. It is under control of the power-train control module, and works through several solenoids under the front cover of the transmission. That's about all I can tell you, as I've not had your symptom or code. In fact, I'd give anything for a code to give me a clue about where to go on this thing.

If I were you I'd go to a transmission shop. Be absolutely sure they have a scanner capable of sending signals to the TCC controls, not just reading the data. They should be able to tell you what's wrong and how much.

Good luck

Ed

My transmission started shifting very hard and the "service engine soon" light came on. After turning the car off the problem ceased. The stored code was "TCC lockup converter stuck...cleared." Problem appeared again (not as bad and did not trigger a code). Again, turning engine off and restarting "fixed" the rough shifting. Wondering if anyone else has experience with this problem? (A mechanic said it was an electronic part.)
Try and get the code, there are issues with valve body problems and pwm solenoids.

Thanks for the replies. Will get to work and will try to post an update (hopefully a fix).

http://www.my3cents.com/showReview.cgi?id=8968


Check eBay for a transmission parts (http://www.buickforums.com/forums/showthread.php?t=1963&page=2) store called "tranzparts1" selling refurbished 4T60E valve bodies for 59 bucks, with a money back guarantee and 100% feedback rating. You might also consider an upgraded TCC Regulator and Isolator Valve from Sonnax. This is the valve body valve responsible for the converter shutter. A new solenoid is under 15 bucks, so for around 100 bucks and some labor, you should have a fix.

...
refurbished 4T60E valve bodies for 59 bucks, with a money back guarantee and 100% feedback rating. You might also consider an upgraded TCC Regulator and Isolator Valve from Sonnax. This is the valve body valve responsible for the converter shutter. A new solenoid is under 15 bucks, so for around 100 bucks and some labor, you should have a fix.

Interesting thread over there on the Buick Forum. Thanks.

Wish I could tell for sure if it was a tranny problem or an engine problem.
I'm now studying a bunch of squiggle lines from a NemiSys scanner trying to spot something significant at the time of an episode. Only suspicious thing so far is the throttle position dropping down to 0 even though it's in cruse control at 65 mph and speed has dropped down to 55. Seems the throttle should be open to regain speed.

Ed

Just an update...I haven't taken the car in yet as the problem has not happened again. Hoping that it was a fluke. Will probably have the transmission flushed. Besides, a larger storm erupted with an upper intake manifold that needed to be replaced.