DTC C1249/ 49: Stop Light Switch Circuit: DTC Detecting Condition
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.
Detection of the following condition may set DTC 49: When the ignition switch is ON, terminal STP in brake ECU is 3-12 volts and continues for 1 second or longer.