I've looked at a bunch of posts, googled my symptoms, and even tried the local Ram dealer to no avail. Truck is a 2018 Ram 1500 Crew cab 6'4 bed, 5.7, 3.21 gears, 8 spd trans, 65K miles. Truck shifts fine when taking off from a dead stop. During a rolling stop, anything above 1mph the trans stays in 2nd gear and will not downshift until the RPMs are around 2500. Then, it downshifts and throws you back in your seat. When the truck is upshifting, it shifts from 1 to 2 around 10-14mph (depending on driving conditions) and feels completely normal. Ive completed the gas pedal reset numerous times and doesn't have any effect on this. Ive disconnected the battery for 30 minutes, no dice. The dealer says the TCM is up to date and stated I need to drive it "more spirited". "Spirited driving" for a month resulted in, my MPG's going down and my tires might be a little more bald. I call BS. I've driven other 4th gen Rams and they downshift how you would expect them to.

Question is, short of swapping transmissions, has anyone had any luck with programmers, or the gas pedal commander to resolve this issue. Or, does this sound like a kickdown actuator giving up, torque converter, valve body, electronics, etc....

I love the truck, but need to get this resolved.

 

A scan tool could provide a DTC code, which is likely to indicate your PU's problem. With these electronic
cars, it behooves you to have a good scan tool, like having a spare tire.
Considering how today's cars are packed with electronics,
a scan tool is a must.
Today's vehicles should be equipped via the IPC, with a readout of the codes and vitals.

Your Ram might be suffering from a faulty solenoid, or sensor.