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Questions and Answers

Buick Park Avenue TCC Problems

Q. I am driving along the highway at 60, no problem at all. I slow down or coast to approximately 45, no problem. Now, going from 45 to 60 I sometimes experience a "lugging" or "bucking" as I am accelerating back to 60. I am a backyard mechanic at best, however I DID do a few tests as recommended by other "backyard" trouble shooters.

Buick Park Avenue TCC Problems
  1. Transmission fluid is clean
  2. While lugging is occurring, I hit the brake pedal lightly; the "lugging" or "bucking" immediately stopped then Immediately returned when I released the brake, so I suspected my "Lock up" condition is less than perfect.
  3. Here is the part that keeps me up nights! During this "lugging" at the 45 to 60 mph acceleration, my buddies on board computer reports the TCC signal is in fact active.

If I understand correctly, this means the computer is commanding the Torque Converter to "Lock up" BUT, and I am no expert, when I am on the highway at 45, then slowly accelerate to 60 or so, I would assume a down-shift would occur or if not at least "Lock up" should be released! I do understand "Lock-up" occurs in both 4th AND 3rd in my car).

This auto repair pro guy on the radio says it is probably the TCC solenoid but I should have the transmission checked out. I would like to pin point problem with out paying a lot of $$$ for a "less than accurate diagnosis".

I do not understand how it could be the TCC solenoid if the computer is commanding the Lock-up mode. Is there some sort of feedback? Would something very bad happen if I cut the wire going to the TCC solenoid and just lived with it? I understand this is an electrically controlled transmission.

P.S. There are about 3 other "back yard" troubleshooters awaiting your opinion! Have a lovely day!
  • 1995 Buick Park Avenue
  • 3.8 V-6
  • 4T60E automatic transmission
  • 71,000 miles

Thank you!

A. Since it's a 1995 the ECM may set a code if you cut the TCC wire so beware if you do. Sounds like a chuggle when it's applying. There could be a bad seal in the circuit that feeds transmission fluid to the TCC or the actual clutch material inside the torque converter is bad.

Sounds to me like it needs to come out and be checked unless the disconnect fixes without a Check Engine Light coming on. Good luck!

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© 2005 Vincent T. Ciulla

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