2018 Prius

Discussion in 'Gen 4 Prius Care, Maintenance and Troubleshooting' started by Bill Watson, Jul 2, 2026 at 8:30 PM.

  1. Bill Watson

    Bill Watson New Member

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    Location:
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    Vehicle:
    2018 Prius
    Model:
    Four
    The panic alarm in my 2018 Prius goes off when the car is locked and in the hot sun. Only goes off for 30 seconds but does this every hour or so. Anybody else have this issue?
     
    #1 Bill Watson, Jul 2, 2026 at 8:30 PM
  2. jehbie

    jehbie Active Member

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    Location:
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    Vehicle:
    2018 Prius
    Model:
    Four
    I have a 2018 Prius 4 in the Philly area and this has never happened.
     
    #2 jehbie, Jul 5, 2026 at 12:02 PM
  3. BiomedO1

    BiomedO1 Senior Member

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    LE
    It's probably not a "panic alarm" trigger, since that should continue for around 5 minutes. I believe the panic alarm is on the same circuit as the OEM car alarm; same cut-off and timing. Try to manually trigger it, and time it.

    I get a similar warning when I exit the car w/o fully shutting it OFF. Check your OPS manual to see if this is a malfunction or some sort of warning. Also get your 12V battery checked. If it hasn't been replace yet - I would suspect that, as your defect. Low voltage will cause your ECU's to do weird things, due to low voltage starvation and errorours sensor triggers.

    Good Luck.....
     
    #3 BiomedO1, Jul 5, 2026 at 12:17 PM
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