Hi All. My 2005 Prius has developed a random grunt when powered on. It doesn't sound to be related to the coolant pump or ABS actuator but it could possibly be the ABS. No codes displayed. Here is a link to the sound. You can hear the normal startup sounds and the the grunt a few times before the brake actuator comes on and even after. does it in parks before and after the engine starts and at a light if in park. Any guesses? idk if hmtl links are allowed here so copy and paste into a browser minus the REMOVE THIS PART REMOVE THIS PARThttps://drive.google.com/file/d/177QcxUcOkU3sveV7LW_Q3Ngcw9N9e4Ux/view?usp=sharing
try putting your ventilation mode on something different and see if the sound goes away. IE..if you're on defrost with the air going to the front windshield, change it so it's coming out the floor or dash vents.
Yeah that sure sounds like a damper that is stuck, like in the ventilation system. I guess it could be many things.