Coolant temperature and delayed acceleration

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Cs964111, Sep 19, 2023.

  1. Cs964111

    Cs964111 Junior Member

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    Location:
    Acworth
    Vehicle:
    2012 Prius c
    Model:
    Three
    Yesterday I turned on my 2012 Prius and put it in reverse. When I put my foot on the gas the car wouldn’t move but I could hear the engine revving and the back up beep. I turned it off and on again and it backed up fine. When I switched to drive it wouldn’t accelerate immediately when I pressed the gas. I would have to press all the way before it began to jult and go but once it started moving it drove fine. There was a delay in acceleration after stopping at a stop sign again. I could hear the battery fan blowing extremely loudly through the vent in the backseat. It eventually got quiet as I drove and I didn’t have anymore problems until this evening. I was merging onto the highway and as I got up to speed, the red thermometer light appeared on the dash. It stayed on for a few seconds and then shut off.


    Any advice? There are no codes. I took it to my local auto shop and they recommended a pressure test to look for leaks and a coolant flush. I wanted to check here first to see if there are any other recommendations.
     
    #1 Cs964111, Sep 19, 2023
  2. bisco

    bisco cookie crumbler

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    what's the ambient temp?
    how many miles on her?

    is the coolant low? if not, why look for leaks?

    maybe a bad thermostat? but it shouldn't hesitate in reverse, that's pure electric.

    maybe check the battery cooling fan for clogging, have toyota check for trouble codes. idk if a temporary trouble light would set a code or not.
     
    #2 bisco, Sep 19, 2023
  3. JC91006

    JC91006 Senior Member

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    if you check for codes, you might find a code for a battery failure
     
    #3 JC91006, Sep 19, 2023
  4. Brian1954

    Brian1954 Senior Member

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    Model:
    III
    What scanner was used to check for trouble codes? Most scanners can not communicate with all the ECU's in a Prius and can not retrieve the trouble codes. You may need to use a better scanner. Toyota dealerships use TechStream software installed on a windows PC to check for trouble codes.

    The high temperature light is triggered by one of two coolant temperature sensors when the coolant reaches 120C (248F). So you are having an overheating condition. Your engine water pump maybe is going bad.

    You could also have trouble codes for the hybrid vehicle battery base on your desciption.

    So, it is very important to retrieve all the trouble codes.

    Posted via the PriusChat mobile app.
     
    #4 Brian1954, Sep 19, 2023
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