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Possible bad TCC unit?

I drive a 2007 Buick Lucerne cxs with a 4.6 liter north star V8 with the 4T80 automatic transmission.
Recently noticed when the car is at about 45-55 mph and I’m going down hill it will kick or maybe slip but I don’t notice any change in the RPMs. Occasionally this will happen while going up hill and sometimes on the highway but it’s never nearly as noticeable and very subtle also my feels like the car is hesitates and then picks back up. The car will also kick or shudder while sitting in drive with he breaks applied at a stop sign for example for extended periods of time. I’ve read that the tcc units in the transmissions have a tendency to go out with age in my car and didn’t know if this sounds like it could be my issue.
My trans fluid is a Healthy color smells like it should. And the car seems to shift fine and normally with an occasional shift that’s a bit harder but nothing terrible.

Unplug the TCC solenoid, item 334, and see if the shudder stops.


Is it possible to unplug this sensor without testing apart the transmission??

Changed fluid at 30K?? Worth a shot. The thing with the torque converters is they are relatively cheap (part anyway) but if they go, they will spew junk throughout the transmission requiring an overhaul. So a little preventative measure can be cost effective. I believe there is a solenoid also that could pose a problem but change the fluid and get it checked.

The diagrams I’m seeing show’s there’s a tn/blk wire from the computer to the transmission that controls the tcc selenoid, using connectors c101 and c3. the problem looks to be if you remove either of those connectors it disables other stuff, like the 1-2 and 2-3 shift solenoids. A person might be able to judiciously nip that wire though (for test purposes) to only disable the tcc selenoid. . It might also be possible to remove the connector pin, but that would often require a special tool.

Also, a shop with a Buick scan tool might can easily disable that function at the press of a few buttons. Now wouldn’t that be nice.

Cross your fingers the tcc solenoid doesn’t need to be replaced as it is a 10 hour job on the 4T80E.