Need help! Prius turned off while driving.

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Reelingline13, Aug 28, 2020.

  1. Reelingline13

    Reelingline13 Junior Member

    Jul 3, 2018
    Los Angeles
    2009 Prius
    Four Touring
    First want to say thanks for creating such a helpful community. I have a 09 Prius with 136k miles. Today I went driving up a mountain took and took 2 hours before heading back down It was 100 degrees and I had the AC going. Then all of a sudden the car turns off. I coast to a stop when I try to start again no lights or anything came on. It smelled like Burnt wires After an hour I could turn my hazard light on and headlights plus the car was able to see the key and would flash the open door light but nothing else on the dash.

    I did some reading on here and the consensus I found was first make sure your 12v is in good working order. It's an old battery so I will replace tomorrow.

    Then it said it could me the inverter pump needs to be replaced and to check the fuse.

    Are these the right steps to troubleshooting this? Am I missing something?

    Thanks in advance for the advice!
  2. SFO

    SFO Senior Member

    Feb 7, 2017
    Northern California
    2007 Prius
    Always best to first read the OBD2 codes (DTCs) with a toyota hybrid compatible reader, and it may save you time and money. Many prefer a "mini-vci" cable and a copy of techstream (dealer tech software), others use a OBD2 bluetooth adapter and an app like Dr Prius or Torque.

    Before purchasing a simple adapter, read up on the quality options that are available : Hybrid battery diagnostic and repair tool for Toyota and Lexus

    When the inverter overheats, one of the first things to stop working would be the AC.

    It sounds like you have a failed inverter pump, did you check for coolant movement in the inverter coolant reservoir?

    Is the fuse labelled AM2 still intact?

    You can research DTC P0A93, which may be the DTC you are currently experiencing.
  3. sam spade 2

    sam spade 2 Senior Member

    Mar 31, 2018
    2017 Prius c
    And it might not too.
    One needs to be absolutely sure that the 12 V battery and it's main connections are good BEFORE chasing other potential problems.
    Pulling the codes is good.......IF you can do that conveniently.......but considering them valid diagnostic information is NOT good if the 12 V system is weak or dead.
  4. dolj

    dolj Senior Member

    May 14, 2012
    Wellington, New Zealand
    2006 Prius
    Good general information here. Pulling codes is always a good idea and as long as the 12 V supply is assured to be above the critical voltage, they should be considered reliable.

    "Pulling the codes is good.......IF you can do that conveniently.......but considering them valid diagnostic information is NOT good if the 12 V system is weak or dead."

    AND.......the million dollar question that some seem not to want to answer, what is dead? 0 V. What is bad? The Toyota repair manual suggests that if the 12 V battery is not 10.5 V or higher, the 12 V needs to be looked at. Other specific codes suggest voltage as low as 8.5 V as ok to work with, in terms of reliable diagnostic information.

    Seeing as we seem to be giving general information here, with a wide sweeping brush, here is some more general information

    There should also be consideration given to isolating the 12 V battery and its condition from the general ability to diagnose.

    Given that the power bus of the ECUs run on +/- 5 V, that means that as long as the computers receive a steady voltage of 5 V or more, the information stored in them can be considered reliable. Of course, it behooves the diagnostician to ensure this is the case.

    Where a higher voltage is important (for other reasons) you can expect the inspection procedure for a specific code to make mention of it.