Halo 2 Auto-Updates
From Halopedia, the Halo wiki
This page lists all Xbox Live Auto-Updates for the Xbox version of Halo 2. The updates were released by Bungie as free downloadable content, though the release of the Halo 2 Multiplayer Map Pack did come with Auto-Updates 1 and 2 as disc installations for players who are not connected to Xbox LIVE.
The number of Auto-Updates released for Halo 2 is unclear, as many sources list five updates as having been released for the game. These lists typically posit a second auto-update released between the November 2004 and April 2005 patches, though no information on this update's content and release date can be found in any official Bungie.net source; as such, it is likely that this confusion arose from Bungie's labelling of the final two patches as Autoupdates 4 and 5, despite being the third and fourth patches to have been released.
Prior to the shutdown of Xbox LIVE for the original Xbox in April 2010, the Halo 2 Did You Know? quotes were updated to poke fun at the game and the Halo franchise as a whole.
Auto-Update 1 (1.0)
Auto-Update 2 (1.1a)
Split Screen Enhancement
Auto-Update 4 (1.1b)
Auto-Update 3 was initially intended to be released in the second week of July 2005 following the release of the Maptacular Pack and Halo 2 Multiplayer Map Pack, though was delayed and eventually released on July 20, 2005. In the official Bungie.net announcement, this autoupdate was referred to as "Autoupdate 4", though is the third known auto-update to have been released.
Auto-Update 5 (1.5)