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Pre-Collision system

Discussion in 'Gen 4 Prius Technical Discussion' started by RCS51, May 11, 2021.

  1. RCS51

    RCS51 New Member

    Joined:
    May 8, 2021
    1
    1
    0
    Location:
    Houston
    Vehicle:
    2017 Prius
    Model:
    Two
    I have a 2017 Prius 2, last week the 12v battery went dead so I went to the Toyota dealer and they installed a new one. Shortly after that I noticed that the Pre-Collision system was not working. More specifically whenever I get too close to the garage wall the red BRAKE warning does not shows and the car will not break. I get no malfunction warning signals. If I disable the PCS I do get a warning that the PCS is off. However when I reactivate it there is no notice to show its on. All other features, lane deviation, too close warning lines, etc. work. Even when in cruise control the system automatically decreases the car speed if too close to the car in front.

    Please advice, the dealer wants $90.00 to diagnose it.
     
    Valiant V likes this.
  2. GRF819

    GRF819 Junior Member

    Joined:
    Sep 23, 2017
    7
    0
    0
    Location:
    Los Angeles
    Vehicle:
    2007 Prius
    Model:
    Two
    I disconnected my battery for storing car 2.5 months. Pre-collision system did not come back after reconnecting battery - did you find what the problem was? Thanks
     
  3. AzWxGuy

    AzWxGuy Weather Guy

    Joined:
    May 22, 2011
    959
    485
    0
    Location:
    Tucson, AZ
    Vehicle:
    2021 Prius
    Model:
    Limited
    I'm guessing either you have a Generation 4 Prius but you haven't updated your vehicle type in your profile, or you might actually have a Generation 2 (2007). I'm not sure if a Gen 2 with an Advanced Technology Package (ATP) has a PCS system, and I don't think a Model Two would have the ATP. Think it was Model Five or so. If the systems were similar, Gen 2 to Gen 4, then there is a certain amount of driving at a certain speed you have to do after a 12V battery disconnect to re-initialize the system. In my Gen 4 user manual that information is on page 301.