Ok....I'm stuck.

I have a 2014 Ram 3500 6.7 single cab dually. I have the MM3 tunner/delete from Ray ( I only use the tow mode). I installed complete exhaust from turbo back, S&B cold air intake, intake manifold, fass fuel system. I keep getting codes P06D3 Sensor reference voltage 5 circuit low, & P2121 Throttle/pedal pos sens/switch D circ range/perf. These codes only come up when I am towing. This started in August after I did the tune/delete. The truck ran fine until I did the delete.

What I did in August was checked wires for any chaffing, pinched or bare wires. I secured them away of any thing sharp or potential for heat. I installed a new Throttle with throttle position sensor. I test drove with the 5th wheel hooked up and pulled a couple of hills and it appeared to be ok.

Fast forward to today (Oct).
I rechecked the wiring (3rd time) under the hood, down the exhaust, trailer plug, and under the dash. Checked connections on the module, and monitor.
I did record the trip on the monitor when the truck acted up. I don't know how to access the recording.

Symptoms:
Same symptoms. The truck runs fine empty. I had a load of 2300 pounds in the bed and did about 80 miles pulling a few hills and it ran fine. I hooked up a equipment trailer with a side x side (UTV) on it and drove about 100 miles pulling a few hills and it ran fine. I came back from that trip and was pulling a hill and the TPS gauge was jumping all over and the truck was cutting out and loss of power. The check engine light came on along with the red lightening bolt. I made it to the top of the hill and the truck started smoothing out and ran fine. I pulled over and cleared the codes (P06D3 Sensor reference voltage 5 circuit low, P2121 Throttle/pedal pos sensor/switch D circ range/perf). The red lightening bolt went out but the check engine light stayed on. The truck ran fine the rest of the trip. The check engine light went out the next day. So far it only acts up going up hill pulling a trailer.

Well before the tuner was installed the integrated trailer brake went out. I installed a aftermarket trailer brake (Tekonsha) and purchased the plug and play harness. The instructions said to go to the dealer to have the computer updated. I just plugged it in and it worked with no problems, so I didn't have the computer updated. I put on over 4000 miles trouble free. I don't know it the aftermarket electric trailer brake had anything to do with these symptoms so I replaced it with the original electric trailer brake module. I drove this morning with a loaded trailer and it acted up (TPS gauge was jumping all over and truck was loosing power and the codes came back on P06D3, P2121, P2122, P2127 along with the check engine light and red lightening bolt. I checked the voltage at the throttle sensor this morning with the key on and it read 5.0 volts.

I am at a loss on what to do.

I replaced the throttle position sensor/pedal in August.

Is it possible for the tuning module to be bad?

Any help would be greatly appreciated.