Last part... The part 4 is now served....

This is general, since OBD2 is standard to all vehicles...
This information is sufficient enough to understand how modules communicate with each other, what is the purpose of the sensor and how it affects the entire system... and how all of this are being interconnected to one another.
The OBD2 was designed for one purpose, to save our environment...
all of these electronic modules, sensors, computers... They are there in your vehicle to save mother earth from pollution.....
Hope this will help you understand how your vehicle system works, analyze a little and you can have an idea to what part is faulty whenever you feel that something is wrong on your vehicle....