Testing Procedures
WARNING: This page is about a different car, the 2003 Toyota Prius, 2002 Toyota Prius, and 2001 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.
For wiring diagram, see Fig 1. For testing procedures, start by checking for open or short circuits in wiring harness and connector between terminals HVI+, HVI-, HVO+ and HVO- of brake ECU and HV ECU. If wiring harness and/or connectors prove faulty, repair or replace. If they are fine, check and replace HV ECU or brake ECU.