Multiple 4l80e pressure control solenoids failures

[SLDPULR]

Really need some help here guys.

I put a 4l80E in my truck and have it wired for full manual shift. I have had 2 pressure control solenoids fail back to back. Can anyone help me out with what might be causing this? Each solenoid fails after the first drive. This morning I drove the truck 15 miles to work and the previous time it failed after about a 5 mile drive. Each time the transmission is shifting fine until i shut it off and let it sit for a few minutes. Go to fire it back up and drive off and no forward gears. I can unplug the harness and it will default to second gear.

Wiring setup: Pins N-R-A together and tape into the harness.
Pins P-B together and tape into the harness.
Supply switched power to pin E to power up the transmission solenoids.
Supply ground to pin S to control lock up.

[YoungPup1977]

This should help:

[twinturboc10]

The wiring should work as far as running the shift solenoids. Is it the shift solenoid or pressure control solenoid (which isn5hooked up?) that is failing? When it has no drive is it free rev or bound up? And unplugging the harness allows it to work in second gear? With no PCS the trans runs at max line pressure all the time. What is the condition of trans?

[wildwilly4x4]

I'm not sure on the shift solenoids, but if you are running full power to the pressure regulator, that may be experiencing a burn out due to most of the later ones being PWM. I'm not sure when all of that changed, but it may be something to check into, if that is possibly part of your problems.

[Bigdav160]

AFAIK, unplugging the PCS (no power) is max pressure. The solenoid is PWM down to minimum pressure.

The OP doesn't mention in his post if it is hooked up.

OP, have you put a pressure gauge on the trans to verify that it is a pressure issue? No mention of what happens if reverse selected. And unplugging the harness it goes into limp mode (?) makes me think something else is amiss.