ETNFUEL

so about a year ago when the car was a 4L60e car I lost 1st and 4th gear and I thought it was a solenoid and pulled the pan and replaced it which didn't fix it. When I pulled the pan it was full of clutch debris. so the car sat for a year and I just put a built 4L80e in the car. I did the segment swap and had it tuned. well when we got it off the dyno we were going for a road tune. We figured out that the 4L80e doesn't have 1st or 4th. with a different transmission and different shift solenoids and still have the same problem.... so I checked to see what voltage was going to the shift solenoids at the plug on the side of the transmission and PIN A which is shift solenoid A (1-2) I was getting 0.3 ground voltage in 1st gear and PIN B which is shift solenoid B (2-3) I get 14.1 positive voltage in 2nd gear. so I thought I might of had a break in the wire in the harness so I went to the PCM side and checked which was Red 47 & 48 and I got the same result. I am kinda stuck anyone know what voltage is suppose to be the voltage in the wire to the solenoids and any ideas how to get this thing fixed??

mrvedit

The PCM grounds the solenoid to engage it.
So, the voltage at both the solenoid and the PCM should be close to Zero (0.3V is OK) when the solenoid is supposed to be ON.
In the 4L80E, for 1st gear, Solenoid A should be ON (Zero volts) and Solenoid B should be OFF (12+ volts).
In the 4L60E for 1st gear, both Solenoid A and B should be ON (Zero volts).

While relatively rare, PCMs do fail.