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2010 Prius HVAC Issues

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by DailyPrius10, Dec 12, 2021.

  1. DailyPrius10

    DailyPrius10 New Member

    Joined:
    Dec 12, 2021
    2
    0
    0
    Location:
    Upstate NY
    Vehicle:
    2010 Prius
    Model:
    IV
    My 2010 prius had a mouse nest inside cabin under dash and inside the HVAC box. After many hours I have the HVAC system cleaned out and operating as it should except for one of the servo motors. The air mix servo motor seems to be rotating the wrong direction? This motor is accessible from the passenger side, I can test the movement thru an OBD connection and see its commanded position and actual position. However based on what I see it seems the motor is moving the internal HVAC gate the wrong direction. The motor spins counter clock wise when going from low to high, moving the gate all the way forward blocking the heater core therefore getting no hot air? Does anyone have a gen3 to verify the rotation of that servo motor?

    Thanks,
    bryan
     
  2. Pdaddy

    Pdaddy Member

    Joined:
    Dec 10, 2013
    153
    49
    0
    Vehicle:
    2010 Prius
    Model:
    II
    I hope you can figure this out. We had to replace the entire system when the blend door failed sans mice.

    SM-G960U ?
     
  3. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    23,327
    15,111
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    This is a case where I would want to have Techstream open so I could watch the commanded and current position numbers for the mix door.
     
  4. DailyPrius10

    DailyPrius10 New Member

    Joined:
    Dec 12, 2021
    2
    0
    0
    Location:
    Upstate NY
    Vehicle:
    2010 Prius
    Model:
    IV
    I can see the command and current position with my obd adapter, not techstream. The servo motor seems to going to where it is supposed to based on readouts. I am confused because when the heater is on high the interval hvac gate is blocking the heater core, the gate is all the way forward in HVAC box. When servo motor is on the warmest air comes out when I set the temp to 65F.

    The other thing I cannot figure out is my temperature setting does not match my OBD readout, at high the OBD reads 112.5 F and at low reads 92.5F. Is there a way to reset or caliprate that setting? Is my control unit shot?

    it was 8 F outside this morning, I have the air mix gate manually set (servo motor off) to where I think it forces all the air through the heater core. The warmest I could get the car on my 30 minute commute was 62F, the coolant temp runs around 185-190F. I previously verified flow thru heater core with temps matching collate temp. I have flushed core and exhaust flow with coolant and thermostat change.

    Any advice would be appreciated.