Hey guys, been scouring the internet and all the forums trying to find answers for some odd problems I've come across but haven't found any answers yet. To make a long story short, I recently bought a '97 F-250 with the 7.3, with automatic trans. I got it knowing it had some issues but the price was right...

Issue #1: I got the truck knowing the trans was close to shot and just finished installing a remanufactured one with a new torque converter this afternoon. Before the swap I wasn't getting any tranny related codes, now I'm throwing OBD codes P0713 (trans fluid temp sensor circut high input) and a related P1748 (EPC malfunction, which is tripped because of P0713), plus the OD light is flashing. The install went clean and everything is plugged back in nicely. The truck will shift into forward and reverse just fine, but won't shift gears except for at really high RPMs and then it slams through them.

Issue #2: I'm throwing a RABS code 11 as soon as I hit 15 mph, which is odd because this isn't supposed to trip unless there's a brake light failure and ONLY after hitting 35 mph. I have a flatbed with LED tail lights, but I installed resistors to send the system the right ohms, etc.

I've swapped out trannys in many other vehicles and my mechanical knowledge is fairly adept, but this one has me stumped.
If anyone has any input it would be greatly appreciated, I'm sitting here pulling my hair out and somewhat pissed the install didn't go to plan. I need to get the truck up and running ASAP since it's my only mode of transportation.

 

Why do you think the P0713 caused the P1748? I can't make that connection in my head.

Both codes indicate electrical problems. You have a wiring issue which probably happened during the trans swap. I recommend electrically checking both the TFT and the EPC circuits to find the problem. It's possible that the two have shorted together. That would explain both codes.