So you've been out adventuring in the wastes, when you suddenly realize your beloved [Insert companion name here] is gone! So you fast travel to an area, expecting them to be there, but are shocked to find they are not. You wait/sleep for several days at your home, hoping they'll come back, but they don't. Well have no fear, Lucius is here.

1) First thing you'll need to fix this problem is to get a hold of your companions "reference ID" number. This can be found several ways. Easiest is to look it up on the wiki page. At the time this was written, there still isn't a whole lot of information on FNV Wiki yet, so you might have to use a different method. Load back another save, find your companion, and and open up the console. This can be done by pressing the ` or ~ key on your keyboard. Next, click on the companion. At the top it should say:
"[Character name]" (xxxxxxxx)
Copy that number down.

2) Open the console in your current save file. Type in:

prid xxxxxxxx (The reference number of your companion)

At the top of the screen it should come up with the name of your companion, and then their ID number.

Then, type in:

moveto player

Some text should appear, saying "[companion] picked package guard ()"

3) Exit the console, and your loving friend should be standing/floating/haunching/drooling nearby!

An example, say Rex went missing. I would get his ID number, which is 0010d8df, open up my console, type in
prid 0010d8df
moveto player


As always, you should make a backup save whenever using the console.

sadly that did not work for me, i did all the steps but i never got the msg saying "[companion] picked package guard ()" so my companion is still MIA

On the 360, my companion(BOS lady) disappeared after I left Lucky 38. I didn't care too much because I always worry about forgetting to give them stimpacks. Then I was in the middle of Vault 3 and she just appeared and started talking about technology and i was like "wut?"

well the one im missing is ED-E i only found out it was gone after i got into some fights and did not hear the music it plays, and im sure its not dead because i still got the passive perk it gives me and that i never got a msg that it died

I've only tried this with Rex, and Cass, so far. Will try with Boone soon, haven't got Ed-E. I don't see a reason why it would be companion specific though. Also, this only works on the PC, since as far as I'm aware, there isn't even a console on the 360. Not sure about PS3