PedroJ

So I tested the E circuit wire at the transmission plug and it's only got 9.62 volts. Plus I inspected the wiring harness all the way from the tranny to the tcm no splits, breaks or exposed wired any where.

Sorry it took me so long to reply I've been working on some other vehicles. Since I posted last I tried unplugging the pcm for an hour, and after I plugged it in in It went into a lower gear just for a while and I could manually shift from that to 3rd. Im not sure if it was 2nd or 1st. Also after I clear the codes and restart the engine, the codes are back before I even put it in gear. I pulled up the data display on the transmission and all three circuits say there open/short to ground. I also replaced the ignition switch and no luck. Another thing the cluster is working fine before and after the new ignition switch. I'm about to go over the harness from tranny to pcm. I also recently acquired a volt meter so I will be checking voltage on each wire. I think someone posted which ones to check and what to check for, but if not could someone point me in the right direction. Thanks to everyone for all the support. You are all great and amazing people.

Please Help. We're working on a 2001 Chevy Silverado 2500HD.It was stuck in limp mode. We first got the P0783-85 codes, so we replaced both shift solenoids, as well as the wiring harness. Still shot the same codes and was stuck in limp mode. So we replaced the transmission. Still didn't work. Now it's pulling up P1860 and both shift solenoid again. Also I realized it was shooting these codes before I even put it in gear. And that's what makes me think it's the ignition switch. Any help at all will be greatly appreciated and save my sanity.