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  1. MeGuinness

    MeGuinness Member

    Joined:
    Jan 19, 2013
    217
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    0
    Location:
    UK
    Vehicle:
    2010 Prius
    Model:
    III
    2010 Prius 200k on clock and hybrid battery on his way out.
    I keep getting the engine light on with P261B that relates to the water pump ...but only when the outside temperature is 17c or less.....in days when the outside temperature are over 18c it doesn't happen...! I'm clueless. Any ideas? Thanx

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  2. Hypemasta

    Hypemasta Junior Member

    Joined:
    Dec 30, 2017
    14
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    0
    Location:
    Los Angeles
    Vehicle:
    2010 Prius
    Model:
    II
    I'm having same issue with 2010 prius 170K miles. It happened 3 times. Car losses power and check hybrid system, check engine, and yellow triangle lights appear. I pull over and then off engine. On another occassion, the overheating light flashed for 5 second and another day overheating light went on for about 5 mins. Eventually car runs and lights disappear. Autozone says code is P261B. I looked online and it could be several remedies in addition to replacing coolant pump. This is not for the hybrid engine. My hybrid tech says to replace engine coolant water pump for $450 but wanted to get anyone's thoughts on this issue before I go and spend this amount. It's strange because the car runs and lights are off.
     
  3. m.wynn

    m.wynn Senior Member

    Joined:
    Oct 24, 2013
    684
    1,226
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    Location:
    Queensbury, NY
    Vehicle:
    2014 Prius
    Model:
    Three
    Your tech is likely correct in that with P261b you need an engine water pump. Being that you've had the "check hybrid system" message and have variation in symptoms, I would have your tech verify codes with his hybrid aware scan tool. There is a chance the Autozone scanner only picked up the engine ecu code and doesn't recognize hybrid system ecu codes.