Three NCAA defenses (at any level) have yet to allow a passing TD
Only three NCAA teams in the entire country (FBS, FCS, D-II, and D-III) have not allowed a passing touchdown this season.
In D-III, Trinity (CT) has not allowed a passing touchdown through their first two games, ranking #4 in the country in pass defense. Teams have attempted 46 passes against Trinity, completing just 21 of those (46%).
Amongst D-II teams, only Harding (who is through 4-0 through their first part of the season) has not allowed a passing touchdown. They the lead all of Division II in pass efficiency defense (69.53), total defense (172 ypg), and pass defense (77 ypg), while also ranking in the top 14 in sacks (3.5 per game). Teams have tried to throw against Harding 89 times, and completed just 42 of those passes (47%).
FCS Princeton ranks 64th in the country in pass defense, allowing 213 yards per game, and they also have not allowed a touchdown through the air this season. We saw a note this morning that their opponent, Lafayette, has a quarterback who has thrown for 5 touchdowns in a single game on three occasions this season.
Amongst FBS teams, Oklahoma and Boise State are two of the best at keeping teams out of the end zone when passing, allowing just a single touchdown each.