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Prius V Coolant Temperature Indicator Light

Discussion in 'Prius v Care, Maintenance and Troubleshooting' started by rolan787, Apr 26, 2020.

  1. rolan787

    rolan787 Junior Member

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    Hello, I have a 2012 Prius V with 123k miles. A few weeks ago while driving on ICE the coolant temperature light came on solid for a couple of seconds and then started to flash for maybe 3-4 more seconds. I came to a red stoplight where car switched to EV and coolant temp light went out. I arrived at destination a couple minutes after and the light didn't come back on. After a couple of hours I drove back home same distance and the light didn't come back on. I checked and coolant levels are ok and no visible leaks. Yesterday on the freeway the coolant temp light came on again but didn't blink, I quickly took an off ramp and light went out. I drove back home and light didn't come back on again. Coolant levels ok. Both the AC and engine radiator fans are working. I know coolant replacement is due at 120k but haven't been able to take it in to service because of quarantine shutdown.
    I've never had any issue like this before. Any thoughts as to why this could be happening or what else I can check?
     
    #1 rolan787, Apr 26, 2020
  2. Air_Boss

    Air_Boss Senior Member

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    Water pump is electric. Any codes?
     
    #2 Air_Boss, Apr 26, 2020
  3. rolan787

    rolan787 Junior Member

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    I don't have a scanner but the check engine light isn't on.
     
    #3 rolan787, Apr 26, 2020
  4. Air_Boss

    Air_Boss Senior Member

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    Codes could be stored without the CEL displayed. A local parts store might lend you a scanner for use in their parking lot.
     
    #4 Air_Boss, Apr 26, 2020
  5. sam spade 2

    sam spade 2 Senior Member

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    In the continental US most auto dealerships are still open.
    Could be water pump or a loose connection on the temp sensor.
     
    #5 sam spade 2, Apr 26, 2020
  6. Mendel Leisk

    Mendel Leisk Senior Member

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    Probably not your problem, but just for the record: engine coolant is supposed to be replaced at 100K miles (or 10 years), per the Toyota USA Warranty and Maintenance Booklet.

    Maybe you're confusing with spark plug replacement interval?
     
    #6 Mendel Leisk, Apr 26, 2020
  7. rolan787

    rolan787 Junior Member

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    Ok, yes, just noticed it was at 100k, thanks.
     
    #7 rolan787, Apr 26, 2020
    Mendel Leisk likes this.
  8. rjparker

    rjparker Tu Humilde Sirviente

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    I would check the the three 30 amp and one 10 amp cooling related fuses in the engine fuse box and the three cooling fan relays in the same box. To check the relays may require a meter and appropriate knowledge or you could try to shotgun the relays with new ones. Why three relays? Because a relay is involved with low and high speed of the fans. Its possible they might not go into high under particular failure modes. One of the 30 amp fuses is the electric water pump.

    Certainly a thermostat or water pump issue could be involved. Continue to monitor the coolant level. You should never have to add coolant. Some of these cars have head gasket problems and they sometimes fail slowly and are still driving ok. There are test kits for use in the coolant to help diagnose head gaskets.

    Here is a recent link with some of the same ideas, however in this case the OP "thinks" his fan relays failed.
    radiator fan relays 1 and 3 keep blowing | PriusChat

    water pump relay.jpeg
     
    #8 rjparker, Apr 26, 2020
  9. Mendel Leisk

    Mendel Leisk Senior Member

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    The wording's a little tricky, but the inverter coolant is not due till 150K miles (or 15 years). Then subsequently for both 50K or 5 years.
     
    #9 Mendel Leisk, Apr 26, 2020
  10. rolan787

    rolan787 Junior Member

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    Thanks for the suggestions! Taking it in for service tomorrow, hopefully nothing expensive, I'll post how it goes...
     
    #10 rolan787, Apr 28, 2020
  11. rolan787

    rolan787 Junior Member

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    P148F engine coolant pump over revolution - had to replace the water pump.
     
    #11 rolan787, Apr 29, 2020
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  12. rjparker

    rjparker Tu Humilde Sirviente

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    Glad to here what happened. Too many would rather guess than read codes. If you don't mind saying, how much was an electric water pump installed? Do you know if that car received a water pump early on as part of the recall they had on the pumps?
     
    #12 rjparker, Apr 29, 2020
  13. Air_Boss

    Air_Boss Senior Member

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    When was there a recall on the water pump? Just raised that question in another thread, and it was suggested water pump failures were 'infrequent', then go pound sand...
     
    #13 Air_Boss, Apr 29, 2020
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