Any 4l80e gurus? Limp mode issue

[Brettny]

I have a 4l80e that all of a sudden wont go into 3rd gear. It will shift 1-2 then go into limp mode when it trys for 3rd. If i leave it manualy in 2nd it wont go ito limp mode, because it never trys to shift itnto 3rd.

Things i have tested/replaced
Voltage to 1/2 and 2/3 solinoids. Replaced the 2/3 solinoid.

Cheked voltage at the TPS.
replaced or ohmed out both speed sensors.
Checked for grounds at the PCM.

What voltage should i have at the speed sensors?

My next test may be to run it on jack stands and ground the 2/3 solinoid.

The pan as been dropped and nothing looked out of the ordinary.

 

[Brettny]

Got the codes out of it tonight. Code 85 and 87. PROM errors. I did get it to shift into 3rd and OD tonight. I would have to hardly be on the throttle and it would do a slow/soft shift.
Any thoughts?

Im going to check the PCM ground and possibly even attach a jumper wire directly to the pcm ground wire.