Shifter shows reverse, car does not reverse. P3120?

Discussion in 'Generation 1 Prius Discussion' started by AlsoJakob, Nov 29, 2025 at 3:20 AM.

  1. AlsoJakob

    AlsoJakob New Member

    Joined:
    Nov 14, 2025
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    Location:
    Portland, OR
    Vehicle:
    2001 Prius
    Model:
    N/A
    Hi all, I’ve got my hands on a 2001 Prius that a coworker had sitting for 2+ years after the cat was stolen.

    I just repaired the HV battery, but now having trouble getting into reverse. The shifter will go into reverse but the car won’t reverse. Park, drive, neutral and “B” work fine however.

    As for codes, I pulled a P3120 and C1259. Also have the triangle of death. Currently looking for my J2534 cable from my Volvo-owning days to set up with techstream to get subcodes, but wanted to see if anyone had any ideas as to what the issue could be.

    Thanks!
     
    #1 AlsoJakob, Nov 29, 2025 at 3:20 AM
  2. ChapmanF

    ChapmanF Senior Member

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    Mar 30, 2008
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    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    When you say "shifter will go into reverse", does the R highlight on the dash PRNDB display? Or are you saying the mechanical shift lever can click to the R position but the R on the dash doesn't highlight?

    The codes you're not (yet) seeing from the hybrid system are probably going to be most helpful.
     
    #2 ChapmanF, Nov 29, 2025 at 11:54 AM
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