2005 SKS component location & wiring diagrams

I might try to tackle my 2005's SKS problems before I sell her..
non of the door handle black buttons work,
the fob must be inserted into the dash for the car to turn on,
doors do not unlock when I approach the car with the fob in my hand,
no response to the fob buttons being pressed but the red LED does come on, fresh battery in fob,
all fuses are good, all other options are working.
no error codes
same reaction when the switch under the steering wheel is pressed (NOTHING).

Id like to know what components could cause this and where they are located before ripping the car apart.
Maybe a wiring diagram so I can follow the correct harness..
Thanks