In The Scorch Trials Tim made it to the Phase Two along with 19 other Gladers after escaping The Maze. He disappeared during the lightning storm that occurred in The Scorch, alongside six others, including Jack, Stan and Winston. Although not specifically stated that he died, since his body was not found, it is safe to assume that he died in the storm, or supposing he survived that, by Cranks.
In the Scorch Trials film, Tim is shown with the main group in the WCKD facility. He is also seen in the lab in the WCKD facility behind Minho. Later Janson calls the name Tim for testing. He is not shown escaping with the others, and it is not known what happened to him.