Re: mass effect trilogy did not include DLC code

Which platform? The available DLC differs per platform.

In any event, the available DLC should be on disc, except for Cerberus Network and Online Pass (the latter doesn't exist on PC). However, those have been discontinued and should be available for free on the online service of your platform (Xbox Live, PlayStation Network, Origin & BioWare Social Network).

Note that the Trilogy edition does not come with all DLC. Most content still has to be bought seperately. More info here: http://masseffect.wikia.com/wiki/Mass_Effect_Trilogy