12v or traction battery causing errors

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Jeff Young, Aug 4, 2021.

  1. Jeff Young

    Jeff Young New Member

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    2005 Prius
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    I’ve read so many posts about Prius batteries and such, but I still want to clarify about the two batteries. It’s a 2005 With 140k miles and the traction battery was reconditioned by somebody who has an unadvertised shop.

    I started getting the red ! Warning, And then one day the VSC light came on, and later it suddenly stops electrical power/ battery charging and the car seems like it’s in second gear. I stop and power down the vehicle once every trip to work. I often hear the battery exhaust fan running loudly.

    Investigating batteries, I learned about the hidden service menu on the screen and check the 12v battery voltage, and it was down to 12.0 or 12.4, and turn on the headlights and It would be below 12. So I figured that battery was also bad. I bought one and got ready to install it. Before I installed it, I started charging it with a trickle charger and found I had fewer problems driving if it was fully charged. When I took it out, 24 hours after charging it and driving that day, the voltage was 12.66. The current battery is only one year old. Don’t want to pay $240 for a new battery of it’s not a problem. ( also I noted that the on screen voltage Is always a lower rating than at the battery.

    I am wondering if a faulty traction battery brings about problems with the 12 volt battery.

    Also, is it possible there’s some other problem bringing up the VFC errors and canceling out the power to cruise control?

    I’m considering buying a battery from newpriusbatteries and installing it myself, but having no other knowledge, I wouldn’t know if another problem exists.

    Thanks for your time.

    Newbie Jeff and Prius

    PS. AnyoneWho has purchased from newpriusbatteries could post a praise on the Better Business Bureau website, as there are currently only two complaints listed on there, not related to the quality of the battery.
     
  2. rjparker

    rjparker Senior Member

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    12.66 v out of the car or when the car is not in Ready is fine. That voltage while in Ready should over 13v indicated it is being charged by the hybrid system.

    The battery fan running in high means the battery is hot. Could be very hot outside or the fans blower wheel could be dirty. Or the fans intake or exhaust is blocked. Or the modules are bad in some way.

    Codes are the real answer.
     
  3. SFO

    SFO Senior Member

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    Welcome to PriusChat!!
    When was the last time the inverter coolant pump was replaced?

    You can check the dealer service history by entering the VIN at : Track Your Service Records with Your Toyota Owners Account

    FYI : your posts are being moderated until you've posted 5 times.
     
  4. ChapmanF

    ChapmanF Senior Member

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    ^ This.

    The red triangle warning generally indicates trouble codes logged by the hybrid powertrain controllers. But you don't know which codes or what they are for without reading them.

    Lights from the skid controller in this circumstance generally only mean that the skid controller knows there are codes in the hybrid powertrain controller. It gets notified of those and sets a couple codes of its own.

    Almost everybody posting about a problem is in a hurry to find out what it is without getting the trouble codes.

    Generally delays the finding-out part until the trouble codes have been got.
     
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