Welcome to PriusChat!! It should be right there (behind the MFD) : Why do you need to replace the ECU? Which metroplex are you near, and how many miles on vehicle?
What part are you looking for? The TPMS ecu mounts in the dashboard in front of the MFD. The TPMS receiver mounts in the right side of the cargo area, "behind" the little triangle window, underneath the upper plastic interior trim? Posted via the PriusChat mobile app.
As mr_guy_mann pointed out, the OP asked about a TPMS "module". If the OP meant the TPMS ECU, that's in the dash as shown; if the OP meant the TPMS receiver, that's back in the hatch area. The photo in the original post is of a TPMS receiver, so, that would go back by the hatch.
