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TSB software update

Discussion in 'Gen 2 Prius Technical Discussion' started by PRPrius, Nov 21, 2009.

  1. PRPrius

    PRPrius Active Member

    Joined:
    Jul 5, 2004
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    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Advanced
    Last Sunday just one minute from my house, multiple warning lights came on. The big triangle with exclamation mark, VSC, yellow brake light with exclamation mark, check engine and a car with exclamation mark on the MFD. I sort of knew what the problem was; in fact I was proven right when I took the car to the dealer the next day. I have to say that the car's performance was not affected at all! It turned out to be the Coolant Heat Storage Water Pump; I already knew it was not working properly by the noise it made every morning. I was waiting for December to take the car to the dealer (the issue becomes very noticible the colder the ambient temperature, being Texas I figured December was a good time to let the dealer hear the noise). The car had other plans! The dealer immediately put me in a loaner car (2009 Toyota Highlander) and next day the car is fixed.

    My question is, does the new pump include a new operating software? The new pump operates in a completely different manner! It always pumps the coolant back to the thermos under shutdown procedures. However, under start-up procedures it only pumps coolant back to the engine when the car has being sitting for a long time. My old pump would work everytime I started the car. I think the new pump will wait for the engine temperature to drop below a new threshold and them pump warm coolant to speed up warm-up time.
     
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
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    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    Failure of the coolant heat recovery system pump would not cause the warning lights that you noticed. It would cause only the check engine light to come on.

    Regarding your question about when the CHRS pump operates: it is controlled by the engine ECU. It would not be customary to reflash the engine ECU firmware when the pump is replaced.

    It's more likely that your inverter coolant pump had failed. When the inverter overheats, the voltage on the 12V bus will sag which will cause the skid control ECU to turn on the brake and VSC lights. The master warning light and the hybrid system icon in the MFD will also appear.

    Please take a look at your repair invoice and post the part number and description of the pump. Thanks.
     
  3. Bob64

    Bob64 Sapphire of the Blue Sky

    Joined:
    Apr 9, 2007
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    Location:
    Virginia
    Vehicle:
    2007 Prius
    Model:
    N/A
    Do you have an engine block heater?