4R100 Tranny Upgrade...Need a Program Change?

[ChrisCNC]

I took time off work this Saturday, hooked my trailer up to the truck and made the ~100 mile roundtrip down to the transmission place that upgraded my transmission. We hooked the system to his scanner to get an idea of what was going on and proceeded to tow the trailer up and down the hills of southwest Eugene toward the coast.

I was able to duplicate the problem readily, between a throttle position of approximately 1.8 - 2.1 volts and a torque of 250 to 300 ft-lbs, if the transmission is in 3rd gear and not in TCL it will not lock up because it is never commanded to. Everytime the TC was commanded to lock up, it did so.

So what happens is this, I'm towing trailer and family over a pass and coming out of a sharp corner or rough patch of road I press down on the throttle and the system shifts out of 3rd w/TCL and into 3rd WO/TCL and it will not go back into TCL because it is never told to. The road is such that I cannot accel up fast enough and if I let off the throttle is slows down too much. Since it is never commanded to lock up the torque converter it does not and the transmission overheats quite quickly on the steep grade.

My tranny guy is more than happy to engage in a phone conversation to help get this system working like should, and better than it is.

Let me know as soon as convenient.