TCC Lock Up Issue
-Dave
I believe the reason yours is doing what it is might be a mechanical issue not electrical one. If I had to guess I would suspect a cross leak some where in the circuit or a short to ground for the TCC solenoid.
With a 4l60e the trans is capable of locking the TCC in first gear. So in your case if there is a cross leak when the oil pressure gets high enough, the oil is getting into the tcc apply valve circuit in the pump and stroking the valve. Another thing that might be causing this is if the TCC solenoid in the pump is restricted or has a plugged filter in the snout of it.
If you have a 60e.......you could check this by removing the solenoid in the pump and then inspecting the filter and the snout. It might be filled with lock up clutch material. If there is room in the pan area to remove the solenoid leave it out and drive it again. You will have to leave the solenoid out of the pump to do this if that makes sense. This way the solenoid will no longer be used as an orifice for the tcc oil circuit.
If this is an electrical issue remember one thing. The solenoid has power the second you turn the key. With that being said from the solenoid itself all the way to the computer you could have a short to ground. This short will allow the solenoid to activate itself regardless of what the computer is telling it to do. Hope this helps. Vince


