2019 Acura RDX. Acura Infotainment system is fading in and out...and then the message 'Drive mode change unavailable'.

2019 if under warranty bring to dealer -ice build up could have damaged gear

I found the spring for the latch at https://productworldusa.com/search?q=rdx

Charging system computer controlled , do yourself a favor an take it to a qualified repair shop.

Acuras don't use orifice tubes. Orifice tubes meter liquid inlet. Expansion valves meter vapor outlet. All Acura systems use expansion valves. Expansion valves are on the evaporator outlet

This is an excellent way to get into the nitty-gritty of low-level API programming. I was very impressed with RSX/RDX, which I hadn't seen yet, and it had one of the best tutorials on Direct3D Immediate Mode I've seen. There examples are well written, and they don't water-down the APIs with un-needed wrapper classes. They also go into detail on how to profile your application to improve performance in critical areas. All-in-all, this is the best book on DirectX I've seen, and an excellent introduction to other multimedia . DirectX RDX RSX and MMX Technology Jumpstart Guide to High Performance...

Your car's computer is probably "relearning" and will return to the way it was after a short time.

You will have to call a Acura dealer for that information

you have to have it reset after every oil change.

You can check this website, you find there fuse box diagram and description for Acura RDX (2006 - 2008)

Acura RDX 2006 2008 fuse box diagram Auto Genius

Courtesy of oilreset.com:
Turn the ignition to (II) - do not start the engine. Press the SEL/RESET button on the steering wheel repeatedly until engine oil life is displayed. Press and hold the SEL/RESET button for more than 10 seconds. The remaining engine oil life reset mode will be shown on the multi information display. Select RESET by pressing the INFO (??²/??¼) button, then press the SEL/RESET button to reset the engine oil life display. The maintenance item code(s) will disappear, and the engine oil life will reset to 100. Turn the ignition off and then start the engine to verify the indicator has been reset. *Models equipped with the keyless access system have an engine start/stop button instead of an ignition switch. Pushing start/stop button once without starting engine is equivalent of ignition (II).
Best of luck! Greg