Board Thread:Manga/@comment-5774380-20160109013258/@comment-24930713-20160206213103

Tausendberg wrote: No, Eren never offered to be eaten by Rod as a titan. He tried to control Rod's titan using the coordinate but he only offered himself to Historia.

I believe he made the suggestion when they were trying to catch up to Titan Rod. Historia basically tells him that it wouldn't work for various reasons, and that by giving Eren the Coordinate he was giving humanity a chance to be saved from the First King's ideology.

It's only after they make it to Orvud that he tries to control Titan Rod, to no success.