Car door lock project

Hi everyone,
I have a Toyota Prius 2008 and I want to build a custom door lock system. The idea is to use an arduino connected to a phone to open or lock the doors.
I've seen that there is a toggle door lock cable that I can access and that toggle the state of the doors when shorted to ground. Is all of this correct?
And do you think that if I use a relay to short this cable to the ground it will work?
Thanks for your answer

PS : the site where I found the wiring information : 2008-2009 Toyota Prius Vehicle Wiring Chart and Diagram

And do you think that if I use a relay to short this cable to the ground it will work?

Did you read the information on that page ?
Where does the DOOR TRIGGER go ?
Hint: If it goes to the battery/fuse box, what will happen if you short it to ground ?

The door lock solenoid is probably connected to ground on one end and the door trigger is the POS lead.
I don't know if this is the case because DOOR TRIGGER implies it is not actually the solenoid power but
a control signal so I cannot definitively answer your question. If you can measure the resistance from the door trigger ground , it might show the coil resistance. (or not). You need to find some way to determine
if the wires going to the toggle switch are what you think they are. Think about it. If the solenoid must reverse direction, how does that work with the 3-conductor toggle switch ? Is it the HOT or the GND and
if so how is the solenoid reversing polarity ? Normally this is done with and H-bridge but there are many other ways to do it. We better intell to answer your question. An auto mechanic may have the answer.
I don't.

In fact, i had the idea of doing pretty much the same cirquit as shown in this instructable : http://www.instructables.com/id/RFID-Car-LockUnlock-v10/
but instead of connecting two wires for locking and unlocking, I would use one single cable for toggling the doors.
I don't have access to the care, but do you think that this solution would work?
thanks

When you figure out how to control the door lock we can help you.
We ( at least I) don't have enough info. Like I said, a mschanic should know.
Come back when you can say " I have figured out whivh connections
to make to control my door lock. I have tested it by manually
touching the wires. Now I need help to do it with arduiino."