I realize this is an old subject, but I"m new to it. I bought a 2022 Limited, that had Cruise but not adaptive. By reading the forum, I learned that I already had the correct hardware in the truck (all generation 5 Ram 1500's do) In order to add ACC, it needed to change the HCU from the origional to the new model, HCU: 68415320AA ACC w/Stop and Go , and ABS Module: 68436462AJ Adaptive Cruise Control w/Stop and Go], Then I had the cruise control button on the steering wheel changed to ACC Button - 68309592AD SWITCH. Speed Control. So I bought those, as well as purchasing OBD link MX+, plus a security module bypass link..(kaodtech), and finally a software app for my PC - alphaOBD.There is very descriptive information on this forum.
So I bought it all, had the switch installed, and then decided to trade my truck for a new 2024.
The result, I have all the parts.. due to inflating, I think I spend around $1,200.
If anyone on this forum wants to add ACC, let me know, I'd be happy to sell all for half price, since I no longer have a need for it.
Chuck Yeager