WARNING: This page is about a different car, the 2004 Toyota Camry Solara. However, it is still accessible from the selected car via links, so may be relevant.
A short to GND is suspected in the CAN bus line when there is continuity between terminals 4 (CG) and 14 (CANL) of the DLC3.
Fig 1: CAN Bus Line (CAN-L) For Short To GND Circuit Description