I know that vehicles use a CAN bus (Controller Area Network) to communicate between subsystems, but I do not know how (and if) extensively my Jeep Cherokee Sport 1998 Sport 4.0 Liter uses it. I mean when I trigger a door lock, is it a voltage wire that triggers the door lock or is there a CAN device in the door lock assembly that receives the CAN message and acts on it, and sends back a message on success or failure? Are there any technical books on this? Are there 'regional' CAN hubs that control interior and exterior lights, etc.? For example, I realize my lights are incandescent, but if I wanted to replace them with LED's, and fading them requires pulse width modulation, is there a CAN BUS hub I can replace with my own device to upgrade to that?

I mean alarm systems trigger door locks, lights, but not sure how that is done. It can't just be wires from mosfets (or relays) to end systems directly from the brain, can it?

WHY do I want to know? Because I am an embedded systems designer and would LOVE to install a subsystem that controls my door locks, lights, even start the Jeep based on my device. I know ODBI and ODBII uses CAN BUS, but I want to know if there are subsystems to the actual brain that handles all this. Like my headlights waiting a few minutes to turn off if they are on when I turn the key off, then turn the lights off. It cannot be as archaic as a simple timer circuit... I hope. I am talking a Jeep that is 20 years old, not today's rolling media servers. lol

This is also big for me if I can find a dash (or mod) that allows me to upgrade my electronics.

I know this is deep. There HAS to be someone out there that has gone down this deep and dark rabbit hole. Anything that individual can offer would be so appreciated!

I know, just go buy a new Jeep right? NO! I love my 98 Cherokee and she runs beautifully. I would rather keep her and fit her with some upgrades inside and out.

Thank you for your time!