P0B3D [0x0B3D] Check Hybrid System

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Notamechanic44, Aug 3, 2026 at 9:22 PM.

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  1. Notamechanic44

    Notamechanic44 New Member

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    I got 3 codes on my 2012 Prius:
    • P0B3D [0x0B3D] Hybrid battery voltage sensor A - circuit low
    • C1259 [0x5259]
    • C1310 [0x5310]
    The car can drive but it does not engage the electric motor at all. It does not charge the hybrid battery at all either. The car says "Check Hybrid System Stop The Vehicle In A Safe Place". I checked all the battery packs with the obd scanner and they are all reading within the correct range. Checked the auxillary battery and the battery tester said it was good. People are saying that it could be a possible corrosion on the battery control board but not sure how to test for that.
     

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    #1 Notamechanic44, Aug 3, 2026 at 9:22 PM
  2. Tombukt2

    Tombukt2 Senior Member

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    Well you got brake issues in unit 2 nice it tells ya. That 1310 will get ya everytime
     
    #2 Tombukt2, Aug 4, 2026 at 11:00 AM
  3. Notamechanic44

    Notamechanic44 New Member

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    So do you think I just have to replace the braking sensors?
     
    #3 Notamechanic44, Aug 4, 2026 at 11:18 AM
  4. ChapmanF

    ChapmanF Senior Member

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    C1259 and C1310 from the brake system are both codes that simply mean "yes, the brake system is aware of the hybrid code(s) you have". Doesn't mean anything wrong with the brakes (only they won't do regen, because that requires the hybrid system to be trouble-free).

    A Prius that can't "engage the electric motor at all" is also a Prius that can't start the gasoline engine or move. So in your case, the car definitely can "engage the electric motor", you're just noticing a change in the rules of engagement, because of the known battery problem.

    Those voltage sensor wiring issues can be not too hard to fix. Toyota doesn't sell that sensor wire harness as a separate part for gen 3, but there is a vendor (acenbay?) that has posted around here and sells a version.

    In some cases, the battery smart unit will also need repair or replacement.
     
    #4 ChapmanF, Aug 4, 2026 at 11:31 AM
    Brian1954 likes this.
  5. Notamechanic44

    Notamechanic44 New Member

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    This seems more involved than what I can do myself. Should I take it to a Toyota dealership just to diagnose it and see if someone else will be a little cheaper?
     
    #5 Notamechanic44, Aug 4, 2026 at 1:17 PM
  6. Brian1954

    Brian1954 Senior Member

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    If you take it to a Toyota dealership, they will check for trouble codes and charge you a diagnostic fee ($150 to $200). If they read the same codes you listed in post #1, they will tell you that the hybrid battery needs to be replaced ($2600 to $3400) and the hybrid battery smart unit may also need to be replaced ($$$).

    The best thing to do is find a hybrid specialist near you and have them look at the car. One very good specialist in Florida is Tampa Hybrids, which is located quite far from you. There are other hybrid specialists near you. Just do a search.
     
    #6 Brian1954, Aug 5, 2026 at 8:34 PM
    Last edited: Aug 5, 2026 at 10:08 PM
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