So I posted this as a reply in another thread but wanted to make its own post to be more visible in case anyone else is having this problem, I haven't seen another thread that addresses this specific issue.

While cruising on flat terrain on the highway or freeway, the rpms on my 2000 TL would constantly flick up and down about 250 rpms, which I suspected to be the torque converter locking and unlocking from extremely mild throttle changes. The Transmission is supposed to do this sometimes when the throttle is opened a lot, in order to help you get up steep hills, but not constantly on flat ground.

Well I seem to have fixed it. I did more reading on how the torque converter clutch lockup works and replaced the "A/T Clutch Pressure Control Solenoid Valve C" I got the $80 SINS one off Amazon. From my understanding this solenoid is what controls the extent of the lockup, whereas the Torque Converter Clutch Solenoid is simply an on/off valve that controls IF fluid gets to the internal lockup solenoid. So after the new part I no longer have the constant locking and unlocking (rpms flicking up and down) while cruising on the highway from tiny changes in throttle position, hills, etc in 4th and 5th gear. This appears to be a completely separate and peripheral issue from the serious issues that usually plague this transmission.

So is you have this problem and this problem alone, your transmission might not be toast, you might just need an $80 external solenoid and 20 minutes of your time.

 

Nice job!
Please keep this thread updated on the longevity / performance / reliability of the aftermarket SINS A/T Clutch Pressure Control Solenoid Valve C you purchased compared to the high $$$ OEM at $424.22.

 

Will do. So far so good. There was no way I was gonna spend that much when a used av6 is not even double that and will probably need to be replaced eventually. But $80 I can swallow

 

As a FYI, if you do an AV6 swap, if the donor AV6 trans is used if it is more than 100k miles, you SHOULD replace ALL the solenoids.

The ONLY good ones besides OEM are the Rostra brand solenoids.

I am glad you got a properly calibrated SINS single linear solenoid, but the VAST majority of people that buy the cheap aftermarket solenoids like SINS find they are not properly calibrated and end up causing codes. Trust me, went that route originally and sent all fo them back, then tried the "refurbished solenoids" that are OEM and supposedly "tested" and those failed as well, so they went back and went with Rostra solenoids. Cost about $450 or so for ALL The solenoids and that was by catching a deal from a supplier closing them out. OEM all new solenoids run like $850 or so and even Rostra would run about $550-600.

 

Well thought I would report back, months later the solenoid is still working perfectly and has not shown the Locking and unlocking Behavior even once since I installed it. The Acura has been my daily driver all winter because of issues with my other car and the transmission has been working fine for now. How long this tranny will last overall who knows, but the solenoid seemed to be the entire cause of the problem I described in this thread and the cheap sins unit I bought has been working well.