ThinkDiag2 question

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Lioninstreet, Jul 23, 2026 at 8:45 PM.

  1. Lioninstreet

    Lioninstreet Junior Member

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    Thanks in advance for your answers & advice. Everyone here has been great.

    So, while driving my G2 base, the gas motor shut off right after rounding a corner and the dreaded red triangle came on (along with most if not all the other dash lights). The traction motor stayed on long enough for me to make a U-turn back towards home. But shortly afterwards when I stopped at a red light, no more love, the car bumped itself to neutral, AC shut down, and an hour later AAA brought me and the G2 back home.

    • My battery was just under 3 years old and didn't pass a load test. Lucky for me the replacement warranty wasn't pro-rated. Thank you Walmart.
    • The AM2 fuse is OK fine
    • Inverter pump coolant flow looks very weak (ie: peering in the reservoir, the coolant is barely moving). The pump was replaced about 8 years ago so I'm having a new Toyota 04000-32528 and some SLLC2 shipped to me.
    • Using my ThinkDiag2, the primary Fault code is a P0A94. There's also a few SRS codes (B1826, B1650, B1653, B1655, B1821, & B1826), an Occupant Detection code (B1771 which may be the root of the SRS issues), and two AC codes (B1421 & B1442).
    So here are a few questions. Since the biggest concern is the P0A94, I can't for the life of me figure out how to get my ThinkDiag2 to display the P0A94 subcode. Is that beyond the capacities of this scanner? If you happen to know that it's not, could you share the steps to get them to display?
     
    #1 Lioninstreet, Jul 23, 2026 at 8:45 PM
  2. Tombukt2

    Tombukt2 Senior Member

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    So when the think diag maybe going to the freeze frame data and see if offers Alt code .
     
    #2 Tombukt2, Jul 23, 2026 at 9:28 PM
  3. Tombukt2

    Tombukt2 Senior Member

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    You're only supposed to see the coolant barely moving in inverter resvoir. Normal
     
    #3 Tombukt2, Jul 23, 2026 at 9:29 PM
  4. Tombukt2

    Tombukt2 Senior Member

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    So the big question now is what's voltage on 12V sitting they're off ? And the minute you ready the car it should read 14 Volt you should see the change on voltmeter instantly 13.4 and less no good
     
    #4 Tombukt2, Jul 23, 2026 at 9:32 PM
  5. Lioninstreet

    Lioninstreet Junior Member

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    It sits just below 13v after a trickle charge on a brand new battery
     
    #5 Lioninstreet, Jul 23, 2026 at 11:53 PM
  6. Tombukt2

    Tombukt2 Senior Member

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    While it's ready I'm talking. So you walk up to the car in the morning you test standing should be above 12.4 AGM. Then you ready the car and it should jump to 14V . ????? ?. If that's not the case you may be looking at the DC to DC converter
     
    #6 Tombukt2, Jul 24, 2026 at 7:18 AM
  7. mr_guy_mann

    mr_guy_mann Senior Member

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    P0A94 shows as "DC - DC converter performance". Since there are over two dozen sub codes, you really need the additional information to figure out where the problem is.

    As mentioned, go into freezeframe data for the code, and scroll through it. Somewhere should be several lines labeled "INF" or "detail". Most will have 000, but one should have other numbers - the sub code.

    Posted via the PriusChat mobile app.
     
    #7 mr_guy_mann, Jul 24, 2026 at 8:23 AM
  8. Lioninstreet

    Lioninstreet Junior Member

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    @Tombukt2 Could I ask you to rephrase. Im not sure I understand your thought.

    @mr_guy_mann I'll give it a shot. I remember seeing freezeframe data as an option, but I don't remember where it was in the (quite robust) Thinkdiag menu. BTW it was your OBD eval thread that pointed me at this tester to begin with. Much appreciated
     
    #8 Lioninstreet, Jul 24, 2026 at 9:09 AM
  9. Tombukt2

    Tombukt2 Senior Member

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    Walk up to your battery with the car sitting there and measure the 12 volt voltage anywhere you can connect . And then do the same thing after the car is ready . Looking for 14V. Pretty basic stuff here
     
    #9 Tombukt2, Jul 24, 2026 at 9:22 AM
  10. ChapmanF

    ChapmanF Senior Member

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    It's important to remember that while the P0A94 fortune cookie is talking about a "DC - DC converter", it isn't talking about that DC - DC converter.

    It's not about the one that downconverts from the traction battery voltage to 14 volts for the car's electronics and aux battery charging.

    It's talking about the one that upconverts from the traction battery voltage to 500 volts for the drivetrain motors.
     
    #10 ChapmanF, Jul 24, 2026 at 11:34 AM
  11. Tombukt2

    Tombukt2 Senior Member

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    Yep probably the sensors in the transmission under those covers . I believe trans change . Is the way . Hey ya a lower mileage hybrid drive if you lucky . This is the two stupid things called the same thing .
     
    #11 Tombukt2, Jul 24, 2026 at 12:46 PM
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