Circuit Description
WARNING: This page is about a different car, the 2003 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.
Constant battery voltage is supplied to +BM terminal of ECM as the power source for the Electronic Throttle Control System (ETCS). If DTC P1127 exists, ECM will turn off the power to throttle control motor and throttle valve is closed by the return spring.