Car not powering down completely after electric-only start

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Dave Falasco, Oct 8, 2015.

  1. Dave Falasco

    Dave Falasco New Member

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    all. I have a 2007 Prius with about 135k miles on it. I am having a strange problem with the car not powering down completely when I haven't engaged the gas engine (what I am calling an electric-only start). Whenever I turn the car on but do not engage the gas engine (for example, to roll up the windows or to move the car around in the driveway), when I power it off it looks as if it is powered down (no dash lights), but the next morning my 12v battery is drained. The only indicator that the car is not powered all the way down is if I leave the driver side door open for ~5 secs or so, then (sometimes but not always) I hear a fast-pitched beeping.

    The only solution that I have discovered is to pull the car out of the driveway, drive it around the block so that the gas engine engages, and then pull back in the driveway and turn it off.

    Any thoughts? I have already drained the 12v battery at least four times by not realizing that the car was not powered down all the way. I am going to replace the 12v battery but just curious if anyone has seen this issue before. Thanks!
     
    #1 Dave Falasco, Oct 8, 2015
  2. bisco

    bisco cookie crumbler

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    how do you do an ev only start, aftermarket switch?
     
    #2 bisco, Oct 8, 2015
  3. Dave Falasco

    Dave Falasco New Member

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    Sorry, I'm not explaining it well. You know how you can push the start button and the car turns on but gas engine doesn't engage until you press the gas pedal? That's all I'm talking about. If I start the engine normally simply by pressing the start button but do not press the gas pedal to engage the gas engine, then push the power button again to shut the car off (for example, to roll up the windows), it doesn't shut off all the way.
     
    #3 Dave Falasco, Oct 8, 2015
  4. Eclipse1701d

    Eclipse1701d Prius Enthusiast

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    That will happen if you are NOT pressing the brake pedal when starting...
     
    #4 Eclipse1701d, Oct 9, 2015
  5. dolj

    dolj Senior Member

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    As far as I'm aware, after you press the power button with your foot on the brake pedal, the ICE will come on after about 7 seconds, regardless of whether you press the gas pedal. Pressing the gas pedal within this time forces the ICE to start immediately. So, I think we're having problems understanding the state you are calling an electric-only start. Unless you have installed an EV button, then it makes sense.

    I have done as you describe and have never had any issue with the car not going IG-OFF when pressing the power button.
     
    #5 dolj, Oct 9, 2015
  6. bisco

    bisco cookie crumbler

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    exactly, i'm still not understanding. have to drive it around the block to get the engine to start?
     
    #6 bisco, Oct 9, 2015
  7. Dave Falasco

    Dave Falasco New Member

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    Okay, I am failing here, sorry guys. I'm a technical writer, too, jeez. How embarrassing. Anyway, here's the sequence, maybe this will help:

    Scenario: car windows need to be rolled up
    1) Press brake pedal and then press power button.
    2) Dash lights and touch display come on but ICE does not engage
    3) Roll windows up, then press brake pedal and press power button again to turn car off
    4) Dash lights and touch display turn off
    5) Open door and leave it open for a few seconds: a fast beeping indicates that the car is not completely turned off (this is what drains my 12v battery if I don't notice it)

    The solution:
    1) Press brake pedal again and push power button to turn car back on
    2) Put car in gear and drive it enough that the ICE engages (note: simply rolling the car backwards and forwards in the driveway does not engage the ICE, that is why I have to drive it around the block)
    3) Press brake pedal and push power button to turn car back off.
    4) Open door and leave it open for a few seconds: no beeping indicates that the car is well and truly off

    Does that help explain the situation?
     
    #7 Dave Falasco, Oct 9, 2015
  8. bisco

    bisco cookie crumbler

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    what do the windows have to do with anything? the fact that your ice is not engaging may be a clue. is it possible that your 12 volt battery has been compromised by the repeated draining? that can make the car do funny things.
     
    #8 bisco, Oct 9, 2015
  9. RRxing

    RRxing Senior Member

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    Scenario: car windows need to be rolled up
    1) Press brake pedal and then press power button.
    2) Dash lights and touch display come on but ICE does not engage

    As mentioned, at this point, IF YOU DO NOTHING ELSE, the ICE will automatically start after about 7-12 seconds. No need to drive around the block...
     
    #9 RRxing, Oct 9, 2015
  10. bisco

    bisco cookie crumbler

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    that's why i think it's a clue...
     
    #10 bisco, Oct 9, 2015
  11. Dave Falasco

    Dave Falasco New Member

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    Okay, thanks guys. The windows is just an example of when the issue happens...basically any time I need to quickly start the car, do something, and shut it off. Like, for example, to move it out of the driveway or to roll up the windows. It's a for instance, that's all.

    Maybe I am not allowing the car to turn on all the way by turning it on and turning it off before that 7-12 second gap before the ICE kicks in. So by turning it on and off quickly it may be stuck in some limbo state between on and off, which drains the battery. I'll try waiting that 7-12 seconds for the ICE to turn on before turning it off to see what happens. I'm also going to replace the 12v because it has been drained a half dozen times by now and that can't be healthy for it. Appreciate the help and sorry again for my ambiguity in explaining the issue.
     
    #11 Dave Falasco, Oct 9, 2015
  12. goldfinger

    goldfinger Active Member

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    Do you have sks keyless system? If so try putting the key in the dashboard instead. The car shouldn't let you remove if it thinks its running.
     
    #12 goldfinger, Oct 9, 2015
  13. Eclipse1701d

    Eclipse1701d Prius Enthusiast

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    Okay. First, you do not have to depress the brake pedal to turn it off, if it is already in park. Second, I have done exactly what you have described countless times with my Gen II and Gen III. There should be NO delay. If you turn it off, it should turn off. You should NOT have to wait for the ICE to kick in... First, to rule out any issues, go ahead and change the battery. If it still does it with the new 12 Volt, you have some kind of delay going on with one of the ecu's. Whether it is a communication bus error, or one of the ecu's is not booting up quickly enough. At that point, it would be a good idea to invest in mini-vci and monitor what is going on.

    Also, you should be able to press and HOLD the power button, if need be, and after about 10 or 15 seconds, it SHOULD turn off. For example, you are driving down the highway and you mat is not secured, it catches the gas pedal and the car starts accelerating. Press and HOLD the power button, and it will turn off.

    Maybe someone on the forum is more familiar with this, but before we get crazy, could it be as simple as a bad power switch or relay connected to the switch? I have never heard of it before, but it IS possible...
     
    #13 Eclipse1701d, Oct 9, 2015
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  14. The Electric Me

    The Electric Me Go Speed Go!

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    I think the OP's problem is centered around how he thinks the vehicles is SHUTTING DOWN.

    Not a debate about how it is starting up.

    I think I know what he means by "Electric Only" start.
    Usually, at least with my Prius, when I first hit start, it powers up BUT the gas engine doesn't immediately kick in. There is usually a gap of time.

    I think all the OP is saying is that IF he powers down before the gas engine kicks in, he believes it isn't shutting down entirely and his 12 volt battery is being drained for some mysterious reason.
    This evidently ISN'T happening if he shuts down after the gas engine has kicked in.

    Why this specific would happen? I have no idea.

    But if your 12 volt is routinely being drained? If it's the original, it's easily probably time for a replacement anyway.

    My only suggestion is that perhaps you are imagining the connection? Are you sure the battery is ONLY being drained if you shut down before the gas engine kicks in?

    I can easily imagine a scenario where an aging 12 volt, becomes drained while sitting all night. I can't imagine a scenario where it would make a difference whether you SHUT DOWN..while the engine was running or whether the engine was off.
     
    #14 The Electric Me, Oct 9, 2015
  15. Dave Falasco

    Dave Falasco New Member

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    Good questions, EM. I am quite sure that the battery is being drained only after I shut it down before the gas engine kicks in, and it's because of that fast beeping when I leave the door open. When I wait until the ICE kicks on and then power off, I can leave the door open and it never beeps at me, and I have no issues with the battery. When I don't wait until the ICE kicks on and then power off, when I open my door and leave it open for a few seconds it beeps at me. If I ignore that beep (or, more commonly, if I close my door before it beeps and therefore I never hear it), my battery gets drained.

    You guys have given me some things to research and think about, and I appreciate it. If you are saying that you can get into your car when it is powered down, press the power button to turn it on, then press it again after a few seconds (before the ICE kicks in) and you do not have issues with the car (i.e. it doesn't beep when you leave the door open and the battery doesn't drain), then that confirms that there is something wonky with my car. I will see if it persists after changing the 12v and if it does, I will continue to poke around to see what is going on.
     
    #15 Dave Falasco, Oct 9, 2015
  16. bisco

    bisco cookie crumbler

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    there is no limbo state, you can power up and down immediately without concern. before putting in a battery, make sure you solve the problem so you don't damage the new one. all the best!(y)

    how long time/miles have you owned the car?
     
    #16 bisco, Oct 9, 2015
  17. 04priusnow

    04priusnow Active Member

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    Fyi.. If you press the start button twice without stepping on the brake pedal it powers accessories only, Ready indicator does not illuminate, so you can roll up your windows.. Then just press the start button once more to turn car off... All this is done without depressing the brake pedal.

    Nexus 6 ?
     
    #17 04priusnow, Oct 9, 2015
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