To get max psi to the tcc clutch, I pluged a hole in the separator plate,and drilled a hole in the valve body. I also replaced the tcc valve spring ,with a softer one.
Yea, it eliminates the pwm , and is just on or off. You can also do it with tuning,but the valve might not travel all the way. Without pluging that hole there is oil psi pushing the valve closed.
The tcc solenoid inputs varible psi at the front of the valve. At the back of the valve is a spring,and return oil psi trying to push it shut. Its actually a pressure regulator.
It will cause a firmer engagement of the tcc. The first trans I did this to, the tcc was on a toggle switch. This one is a 06 Duramax van,with stock tunning. I do my own tunning, so if there is any issues I can probably correct it.
It goes back to an on off converter lockup like the 700r4 and 1st 4l60e's had. I do not reccomend this with a triple disc converter or any converter with a HD clutch. I would also think this would stress the already weak lockup piston increasing the chance of it cracking(which is a known issue stock).