Located under the driver-side dashboard for plug-and-play Blitz Power Throttle units.
Always pull the negative terminal before touching ECU wiring to prevent shorts. Toyota Yaris WIRING DIAGRAM - Blitz
Never trust a diagram blindly; test for 12V and Ground before crimping. Toyota Yaris WIRING DIAGRAM - Blitz
If you’d like me to look up a specific or the ECU pinout for a certain year, just let me know: What is the exact year of your Yaris? Toyota Yaris WIRING DIAGRAM - Blitz
Which are you installing (e.g., Throttle Controller, R-VIT, Turbo Timer)?