The move comes one day after the Tigers gave up 55 points to Alabama in the Iron Bowl in a 55-44 loss. It was the most points Auburn gave up in a game all season.
The 2014 season was Johnson's second as the DC at Auburn. He previously was the head coach at Southern Miss, but was fired after one season when the team went 0-12 in 2012.
Defensively, Auburn ranked 60th in the FBS for total yards given up, 85th for passing yards per game and 47th for rushing yards per game in the regular season. Teams averaged 26.1 points per game against Auburn, which ranked No. 61 in the FBS.
Last season, which saw Auburn go 12-2 and reach the national championship game, the Tigers gave up 24.7 points per game. That was No. 48 in the FBS.
Auburn, which lost three of its final four games, finished the regular season 8-4, with losses to Mississippi State, Texas A&M, Georgia and Alabama.
On Friday, Texas A&M fired its defensive coordinator, Mark Snyder.
- Molly Geary