I have a few questions about installing remote starter kits and other aftermarket alarm systems on cars that are push to start(Smart key fob no keys).
If the car doesn't start unless you have the key fob inside the car, How does the remote starter work? Does it for example access the can bus of the car and convinces the ECU that the key is inside? Or do they use bypass modules and put the key fob in them? Or is there another way to override the car's immobilizer?
The same also goes for aftermarket alarm systems, how do such modules take control of the door locks and the trunk...etc.?? Do they wire them directly to the door locks or is it a can bus reverse engineering thing?in other words, is there a way to disable the manufacturer's alarm system and replace it with an aftermarket one?