Between 1989 and 1992, Jiang was believed to be simply a transitional figure to protect the party from a power vacuum (or even an Eastern Bloc style collapse) until a more stable successor government to Deng could be put in place.
Thus, the "third generation" lasted from 1992 to 2003, with Jiang Zemin as core, and other leaders including Li Peng, Zhu Rongji, Qiao Shi, Li Ruihuan.