My 2002 Saturn SL's cylinder lock has worn out and I bought a replacement but it did not come with a key. Does anyone know how to recode a new cylinder lock or would it be better to being the cylinder lock to a GM dealer to do it for me.

 

I choose "b" --- GM dealer.......... Final answer

 

I've done it, but I had the instructions in front of me supplied by a service manual that I had purchased. And I have not done it in years. I'd vote with derf or some one who specializes in locks and keys. I had to have it done one night when I screwed up the lock on a "Ford Focus" and a lock smith can by the house late and stayed until the wee hours of the morning. That one cost me 3 or 4 hundred dollars.
Expect to pay for having it done.

 

Maybe I'm like totally niave, but I woulda thought that when I purchased a new lock cylinder, I would get a new key to go along with it ...

 

No, a new ignition key cylinder is generally re-keyed to your existing key by the installer. A dealer or a specialty shop. Even more so now with the new smart keys that some how work with the electronics with your car. These can cost upwards of so much money you have no clue as to how far down the toilet you are with that expense. Lemme see what I can find.
This is one piece of information:
http://home.howstuffworks.com/home-improvement/household-safety/security/lock-picking4.htm
This one is kinda vague but it has information:
http://www.ehow.com/how_7868238_rekey-ignition-lock.html
This one is related to a Volkswagon but is very detailed and gives some idea what is involved
http://forums.pelicanparts.com/porsche-924-944-968-technical-forum/697121-how-remove-ignition-lock-cylinder-repair-rekey.html
The point I guess is that the information is out there in some form or another some where and searching for it may come up with some information on getting the ignition cylinder out of it's steering wheel location and re-keying it.
I have one car that something was changed on it as there are three keys to get into various locations.
Who knows?
This search gives Saturn unique information:
https://www.google.com/search?hl=en&q=rekeying+ignition+lock+cylinder%2C+ Saturn&oq=rekeying+ignition+lock+cylinder%2C+Satur n&gs_l=serp.3...478871.481261.0.481844.8.8.0.0.0.0 .166.1085.1j7.8.0.les%3B..0.0...1c.1.NVQY02Zzejw
Good luck

 

When it's done by the dealer they use the VIN to get the key code so they place the tumblers in the correct sequence. When you buy it from Pete on the street you get half the job at 25% off.