1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Starting Issues

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Matt Gardiner, Sep 8, 2023.

  1. Matt Gardiner

    Matt Gardiner New Member

    Joined:
    Sep 8, 2023
    2
    0
    0
    Location:
    New Jersey
    Vehicle:
    2006 Prius
    Model:
    N/A
    Looking for any ideas that might be out there for what this problem could be.
    I have a 2006 Prius and it has issues with being able to start consistently. For whatever it seems to inconsistently recognize that the key is in the car, or something along those lines.
    When we purchased the car, we were told by the previous owner that their mechanic said that the 12V battery was dying and that was the issue. I can verify that this is certainly not the issue.
    I attempted to replace the start/stop button, but can confirm that this is not the issue either.
    We’ve replaced the battery in the fob, but the fob is not the issue. The car will unlock when we place the fob next to the door handle, but for the sake of starting the vehicle the key is not always recognized.
    Fuses are all in good shape across the board.
    When the brake is depressed I can hear the actuator kick on.
    The only thing that I haven’t explicitly ruled out is low voltage at the front of the vehicle. The battery (which is new) is doing just fine, but I have seen some people reference low voltage at the front causing this issue. Given it’s lack of consistency, I don’t believe this to be the issue either. Sometimes it will start right up, other times it will take 10 minutes or longer to convince the car that the key exists and that it needs to do its job.
    But it is not that the car is searching for the key and unable to sense it, sometimes it doesn’t seem like it even wants to search for it. If the dash indicator (red car with key imprint) is lighting up, we usually have little issue, but that doesn’t always come on and that’s where we have trouble.

    Any crazy guesses out there?
     
  2. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    9,075
    1,574
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    Is yours a silverbacked logoed remote It has SKS obviously because you can put the remote next to the door without touching the buttons or doing anything and the door will unlock you hear it You pull on the handle and open the door You've done nothing to the remote and what if you do not put the remote in the slot You just sit in the car and attempt to start You get the same thing or you get absolutely nothing until you slot the remote actually put it physically in the dash? Being that you're so close and actually inside of the car I wouldn't think it would be a problem with the transponder chip being amplified enough to wake up the car so then maybe the receiving antenna which has to do with that slot you're putting the remote in which that slot you're putting the remote in is actually called an amplifier maybe it is unplugged or something I had to change one one time the slot.
     
  3. dolj

    dolj Senior Member

    Joined:
    May 14, 2012
    7,645
    3,858
    0
    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    So, is that how it really works on the NA model? I ask because I actually have to touch the backside of the door handle before it unlocks.
     
  4. Matt Gardiner

    Matt Gardiner New Member

    Joined:
    Sep 8, 2023
    2
    0
    0
    Location:
    New Jersey
    Vehicle:
    2006 Prius
    Model:
    N/A
    Yes, my fob has the silver logo on the back. Though it lights up when the door is open, the slot really doesn’t do anything to help the situation. Either the car is able to power up and then start, or nothing happens at all.
     
  5. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    9,075
    1,574
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    But when you start the car or try to ready the car to drive you are slotting the remote or not? Or you have to slot the remote or it will not start at all? The slot all I can tell you is it's an amplifier somewhere there's also I imagine an antenna It may be built into that amplifier It seems to me the green board amplifies the transponder business so that you can stand outside the car with the remote in your pocket and the proximity sensor will open or unlock the door no problem and then allows you to start the car because again that signal's being amplified from your pocket fob through the antenna which I'm guessing is probably in the amplifier and then to the SKS box forward of the speedometer under the dash pad and then everything works.
     
  6. dolj

    dolj Senior Member

    Joined:
    May 14, 2012
    7,645
    3,858
    0
    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    That's not at all how it works. There's no amplification of the fob signal involved.
    You can verify the 12 V is not the issue because ...?
     
  7. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    9,075
    1,574
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    Read the label on the back of the slot I can post it maybe It is called an amplifier. When one of my remotes at one point couldn't work I believe I discovered that the transponder the trapezoidal shape thing in the bottom of the remote when my green board in the same remote was dead and not working I would have to slop the remote in order to start the car had nothing to do with any buttons on the car it had to do with the fact that the green board in my remote was dead a battery wouldn't fix it it was broken and the only reason I guess I could start the car is because I can fit the remote in the slot. Which picks up the signal turns off the red key and allows me to start the car and ready the car when I found the other remote and put the green board from that remote in this remote that I was slotting and I got the red light on the green board to work and all was good then the remote never had to come out of my pocket again so I don't know what we're calling what but that's what happened. And the back of the slot there's a big white label and it talks about it being an amplifier. My Italian motorcycle works very similarly It actually has a wire antenna that's wrapped around the key cylinder but behind plastic that senses the transponder key.
     
  8. dolj

    dolj Senior Member

    Joined:
    May 14, 2012
    7,645
    3,858
    0
    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    'Amplifier' is a generic term that simply means the unit is used to read the RFID chip.
     
  9. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    9,075
    1,574
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    Seems to me slotting the remote is the closest thing you're going to get to a direct connection. So basically it should always start with the remote in the slot whatever goes on with it out of the slot there are variables at play the green board the transponder chip and all that. When the remote is in the slot none of that other stuff matters at least it seems to look like it works that way. Other cars of this type that I have purchased other Prius have been just like this the remotes are destroyed they're permanently slotted looks like they haven't been taken out and eons there's no other remote with the vehicle but yet everything works fine until you pull that remote out of the slot and the green board doesn't work there's no light you can't lock the doors except with the metal key.
     
  10. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    108,822
    49,434
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    sounds like rodente