1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Serious problem

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by 04prius318, Jul 1, 2022.

  1. 04prius318

    04prius318 New Member

    Joined:
    Jul 1, 2022
    4
    1
    0
    Location:
    Louisiana
    Vehicle:
    2004 Prius
    Model:
    N/A
    Hey guys first post. I have a 2004 Prius and it has given me some serious problems lately.

    First the ABS went out. Then it seemed like the battery was going dead however it appears that sometimes it is just not charging at all. I am not familiar with hybrids but if I had to correlate my problem with a standard gasoline motor, I would say that the alternator is going out because sometimes the battery charges and sometimes it doesn't and when it doesn't it begins running extremely bad it loses almost all horsepower, the transmission seems like it's slipping, and the brakes will not work well, power brakes will go out completely, ABS will go out completely, and in rare situations the entire braking system will go out.

    Does anyone know what the cause of this problem might be? Someone I know mentioned a regulator of some sort but as to that I have no clue. Thanks in advance!
     
  2. SFO

    SFO Senior Member

    Joined:
    Feb 7, 2017
    5,286
    4,225
    0
    Location:
    Northern California
    Vehicle:
    2007 Prius
    Model:
    N/A
    Welcome to PriusChat!!
    Which battery is that, the 12v battery or the HV traction battery?
    Given the description, you should have obd2 codes (DTCs) that are stored in the computers (ECU). Many auto part chains will offer a basic scan for free. Every location is different, and some may have an OBD2 scanner that is more compatible with a toyota hybrid, so visit all of the stores, even within the same chain. Record all of the obd2 codes from each scan (don't erase them), then post them here for additional guidance.

    FYI : you're moderated until you've posted 5 times.
     
    04prius318 likes this.
  3. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    how many miles on your car?

    unfortunately, this is not something you can guess at.

    make sure the 12v is healthy and the inverter pump is working. is the cooling fan in back louder than usual?
     
    04prius318 likes this.
  4. 04prius318

    04prius318 New Member

    Joined:
    Jul 1, 2022
    4
    1
    0
    Location:
    Louisiana
    Vehicle:
    2004 Prius
    Model:
    N/A
    The hv traction battery.
    The codes say yye battery is bad, but there are times where the battery charges and runs just fine. Then all of a sudden, it's like the entire electrical system shuts off for a half a second, then the battery no longer charges, loses all power and the transmission seems like it's slipping.

    I say yye battery stops charging because when on the screen that displays the engine battery an electric motor schematic where the arrows tell you if the power is going to battery, wheels etc.... The arrow pointing to and from the big battery goes off and the battery drains quickly.
     
  5. 04prius318

    04prius318 New Member

    Joined:
    Jul 1, 2022
    4
    1
    0
    Location:
    Louisiana
    Vehicle:
    2004 Prius
    Model:
    N/A
    Car has 179k miles yes the cooling fan in the back is louder than normal, yes. I'm not sure how to tell if the inverter pump is working, but my guess is no. Whatever mechanism determines if voltage should go to/ from the battery appears to malfunction after the car is driven 15-20 min, as evidenced by the arrows to and from the battery, on the real time power distribution display in the maintenance tab, stopping all of a sudden.
     
    bisco likes this.
  6. SFO

    SFO Senior Member

    Joined:
    Feb 7, 2017
    5,286
    4,225
    0
    Location:
    Northern California
    Vehicle:
    2007 Prius
    Model:
    N/A
    What were those battery codes again? (please list them all)
    Generally speaking if you can hear the HV battery fan in the back seat there is a HV issue, and it could be a simple fix or more involved.

    Do you carry pets or long hairs in the vehicle?

    When was the last time you cleaned the HV battery fan?
     
    #6 SFO, Jul 3, 2022
    Last edited: Jul 3, 2022
  7. ammdb

    ammdb Active Member

    Joined:
    Aug 8, 2019
    263
    106
    1
    Location:
    Indianapolis
    Vehicle:
    Other Electric Vehicle
    Model:
    N/A
    Sounds like you're describing limp mode, when the car gives up on the HV battery, causing the gas engine to run at high RPM to both drive the wheels and generate electricity for the drive motor that would otherwise come from the battery. An imbalance between battery modules will created excessive heat, and when the fan can no longer keep the battery cool enough the car goes into limp mode.
     
  8. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    open the inverter coolant reservoir with the car ready and engine off. there should be movement in the fluid
     
    04prius318 likes this.
  9. 04prius318

    04prius318 New Member

    Joined:
    Jul 1, 2022
    4
    1
    0
    Location:
    Louisiana
    Vehicle:
    2004 Prius
    Model:
    N/A
    There is no movement with the car ready or the engine on
     
  10. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    there's your problem. start with the fuse, then the connections, then the pump