if you hear clicking, humming noise below dashboard and you have problems with ventilation (windshield fogging, low foot air circulation...) you have bad vent servo motor or possible air mix servo motor. I replaced upper (ventilation direction) servo, air mix servo was ok. those are on driver side (EU model) seen from bottom. bad servo motor (scratched contacts on contactor inside) see attached file It is not so easy to replace this, you have to remove: driver seat (for easy access) left air vent upper and lower plastics around steering wheel white plastics for leg ventilation remove 12 batery terminal in trunk! remove ecu (3screws)-this is most difficult. Two 10mm screws are easy to do it from bottom but one is well hidden and I unscrew it with a lot of rachet extenders (80cm together) then you can remove upper or lower servo or both with philips screwdriver adapter on rachet and unplug the servo cable this fix is difficult but i did it in 5 hours and i didn't have to remove the whole dashboard as the mechanics on toyota do (1500eur costs) Now prius heats and cools as new. Oh I have 298.000km on it
That's great!! Any other pictures that you can share? Not sure if the 'bad servo motor (scratched contacts on contactor inside)' image made it online.
It would also be nice to see a picture of the ECU (as well as its location) that the OP had to remove. I am also wondering where the OP obtained a replacement servo motor - is that a Toyota service part, or did the OP cannibalize the motor from a used unit.
Here's a related post with my experience accessing the upper actuator Blower won't go to defrost | PriusChat
