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

Aaagghhh!! P0A78 & P0A94

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Don402, Nov 22, 2020.

  1. Don402

    Don402 Member

    Joined:
    May 15, 2017
    50
    29
    11
    Location:
    Omaha, NE
    Vehicle:
    2005 Prius
    Model:
    ----USA----
    I was driving and all of a sudden CEL lights lit up all over the dash. Power diminished for a little bit too. Got off the interstate and drove back home on smaller streets.

    Got these codes: P0A78 & P0A94

    Just starting my research now, but would be thankful for suggestions and trouble shooting tips.

    I also have been having the noise in the video.(Not sure if the noise can be heard. Might need loud speakers.)
     
    #1 Don402, Nov 22, 2020
  2. PriusHead05

    PriusHead05 Member

    Joined:
    Oct 23, 2020
    312
    89
    0
    Location:
    Florida
    Vehicle:
    2006 Prius
    Model:
    ----USA----
    Those two codes sounds like it lead to a bad inverter or bad wiring to the inverter.

    Posted via the PriusChat mobile app.
     
    #2 PriusHead05, Nov 22, 2020
    Don402 likes this.
  3. Don402

    Don402 Member

    Joined:
    May 15, 2017
    50
    29
    11
    Location:
    Omaha, NE
    Vehicle:
    2005 Prius
    Model:
    ----USA----
    Would a bad wire be obvious? Signs of scorching? Is there a way to test the inverter?

    I forgot to mention, when I went to get the codes all the CEL light were gone. Car was running like nothing ever happened.

    Posted via the PriusChat mobile app.
     
    #3 Don402, Nov 22, 2020
  4. PriusHead05

    PriusHead05 Member

    Joined:
    Oct 23, 2020
    312
    89
    0
    Location:
    Florida
    Vehicle:
    2006 Prius
    Model:
    ----USA----
    Wires: maybe or maybe not. Most of them have a shield on them so you might not be able to tell.

    If it went away, then it may have gone back to normal temporarily. It was probably the sign of a future problem. The codes are stored in the computer as history codes.

    Posted via the PriusChat mobile app.
     
    #4 PriusHead05, Nov 23, 2020
  5. dolj

    dolj Senior Member

    Joined:
    May 14, 2012
    7,855
    3,968
    0
    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    Both of those codes have many sub-codes that will help narrow down the trouble area. The next time they flag, get the sub-codes. You will need to have a good scanner that can read freeze frame data to get the sub-codes.
     
    #5 dolj, Nov 24, 2020
    SFO likes this.
  6. Don402

    Don402 Member

    Joined:
    May 15, 2017
    50
    29
    11
    Location:
    Omaha, NE
    Vehicle:
    2005 Prius
    Model:
    ----USA----
    Do MFD codes mean anything? Will I need to go to a dealership to get the sub-codes?

    Here's what my MFD listed:
    01-DA 1F1-97-1
    01-DA 440-97-1
    01-D8 190-29-1
    01-D5 190-74-F
    01-DA 178-19-1
    01-DB 178-EB-F
     
    #6 Don402, Nov 27, 2020
  7. dolj

    dolj Senior Member

    Joined:
    May 14, 2012
    7,855
    3,968
    0
    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    Yes, they do but only relating to AV, Nav, and Gateway areas of the system.

    The above all look like communications errors.

    See the attached PDF for more details. Look at page AV-39 ff for diagnosing, paying attention to where they advise clearing the codes and then rescanning.

    For complete information you should look at the repair manual; more info.)
     
    #7 dolj, Nov 28, 2020
  8. Don402

    Don402 Member

    Joined:
    May 15, 2017
    50
    29
    11
    Location:
    Omaha, NE
    Vehicle:
    2005 Prius
    Model:
    ----USA----
    I went and bought a used inverter. Question I have now is how do I know if it's the pump?

    Posted via the PriusChat mobile app.
     
    #8 Don402, Dec 4, 2020
  9. Don402

    Don402 Member

    Joined:
    May 15, 2017
    50
    29
    11
    Location:
    Omaha, NE
    Vehicle:
    2005 Prius
    Model:
    ----USA----
    Okay, did some more research and look at my Prius again. I hear the pump running.

    Guess I'll go ahead with the inverter swap. Only paid $100 and have a 90 day gaurentee.

    Posted via the PriusChat mobile app.
     
    #9 Don402, Dec 4, 2020
  10. Priusdriver06

    Priusdriver06 New Member

    Joined:
    Apr 11, 2024
    7
    0
    0
    Location:
    USA
    Vehicle:
    2006 Prius
    Model:
    N/A
    Did that fix your problem swapping out the inverter?
     
    #10 Priusdriver06, Apr 11, 2024
(You must log in or sign up to post here.)