Procedure to get codes? 2004

Hi all,
I just bought an '04 silverado and was wondering, since I haven't owned a chev newer than 1978, if there is a procedure to get codes out of this thing?
Ie. with the wife's Dodge key on/off/on/off/on and you get codes.
Also, I think there may be a light out in my dash, or another problem with the truck, is there a cluster test with the 04 chev that tests the cluster? ( I know the 02 Dodge does a cluster test by turning on the key while holding trip meter button in).
I tried searching for error code procedures but found nothing, is there a procedure for this truck?
Thanks for the help!
Gord

You need a code reader or scanner, no other way.

Thanks, I was hoping that there was a way like with my 02 Dodge. Oh well, guess the engineers don't want us to know what might be wrong with our trux without spending $$$$

You can get a cheap code reader for 50.00 plus or minus.

YOu can take it into AutoZone or Advanced Auto parts and they will read the codes for you for free