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

2012 Prius Intermittent Hybrid Battery Warning

Discussion in 'Gen 3 Prius Technical Discussion' started by Ms.B, Jul 1, 2024 at 7:20 PM.

Tags:
  1. Ms.B

    Ms.B New Member

    Joined:
    Monday
    5
    1
    0
    Location:
    OR
    Vehicle:
    2012 Prius
    Model:
    ----USA----
    Hello everyone,

    I have a 2012 Prius that has had the hybrid battery warning light come across the dash many times in the last 2 years of ownership. I took it to Toyota and they said they couldn’t find ANYTHING wrong with the car. Causing me to unhook the battery EVERY time this light comes on to reset due to no known issue causing this.

    I have had codes read and not noticed anything in particular related to the battery. When the engine turns off from being in hybrid mode it rattles pretty bad. Even after having them engine replaced over a year ago.

    Any suggestions? I’m not sure if it’s the MAP sensor etc, but this car is my daily driver and I really want to fix this problem as it is not safe, when driving on the freeway and the light comes on randomly causing the gas to become slow to respond.
     
    #1 Ms.B, Jul 1, 2024 at 7:20 PM
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    108,670
    49,372
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    welcome!
    how many miles on your car?
    is the battery original?
    what codes did the dealership pull?
    who installed the engine?
    was it new or used?
     
    #2 bisco, Jul 1, 2024 at 9:37 PM
  3. Ms.B

    Ms.B New Member

    Joined:
    Monday
    5
    1
    0
    Location:
    OR
    Vehicle:
    2012 Prius
    Model:
    ----USA----

    Thank you for your reply!
    The car has a whopping 312,000 miles, I have had it since 250 K and it has had regular maintenance. The engine was installed by a somewhat known Prius mechanic in my area, it was a used JDM with very low miles. I believe the battery is original but as I was cleaning out the hybrid filter today i noticed there was clips left out near the fan which makes me think someone has at least looked at the battery. Toyota told me NOTHING was wrong a year ago, so from pulling the codes multiple times myself the only one showing is pending P0180. The car doesn’t have the hybrid light on currently due to disconnecting the 12v and it turning off for a while and only turning on at random times.☹️
     
    #3 Ms.B, Jul 2, 2024 at 1:39 AM
    bisco likes this.
  4. ASRDogman

    ASRDogman Senior Member

    Joined:
    May 29, 2018
    6,059
    3,253
    0
    Location:
    Florida
    Vehicle:
    2010 Prius
    Model:
    Two
    Just because it says the hybrid battery is bad, it doesn't mean it is.
    It's the whole hybrid system. Which includes many things.
    You need a good code reader that will read ALL the codes for the hybrid system
    and it's likely you'll get codes so you know where to look.

     
    #4 ASRDogman, Jul 2, 2024 at 9:16 AM
    Danno5060 likes this.
  5. Ms.B

    Ms.B New Member

    Joined:
    Monday
    5
    1
    0
    Location:
    OR
    Vehicle:
    2012 Prius
    Model:
    ----USA----
    Thank you! I will try to get an accurate reading.
     
    #5 Ms.B, Jul 2, 2024 at 10:10 AM
  6. Eddie25

    Eddie25 Active Member

    Joined:
    Dec 31, 2018
    354
    129
    0
    Location:
    IL
    Vehicle:
    2011 Prius
    Model:
    III
    Yep, as mentioned the light is just telling you something is wrong, which no one can just guess on. Get the code and it'll send you in the right direction.

    I would suggest a cheap OBD2 bluetooth dongle from amazon that works with your phone OS. There are a few free apps that will read codes, (Torque for android and Car Scanner for ios) then you can just leave the dongle plugged in so the next time it happens you just run a code scan and get the codes right there.
     
    #6 Eddie25, Jul 2, 2024 at 10:50 AM
  7. Ms.B

    Ms.B New Member

    Joined:
    Monday
    5
    1
    0
    Location:
    OR
    Vehicle:
    2012 Prius
    Model:
    ----USA----
    I really appreciate it. I will order it tonight! Thank you:)
     
    #7 Ms.B, Jul 3, 2024 at 1:29 AM
  8. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    108,670
    49,372
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    #8 bisco, Jul 3, 2024 at 1:31 PM
    Brian1954 likes this.
  9. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    108,670
    49,372
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    i would take it to thehybrid shop that replaced the engine. might be something simple like a loose hose or connector.
    ask them if the engine came with the egr valve, or if they cleaned up the old one. see here:

    professional-egr-cleaning-resources.236215

    merv is great!
    watch
     
    #9 bisco, Jul 3, 2024 at 1:39 PM
(You must log in or sign up to post here.)