Car Moved On Its Own. Any Ideas?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Julie Walsh, Jan 19, 2020.

  1. Julie Walsh

    Julie Walsh New Member

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    This happened to me this winter morning, but I’m 99% certain it wasn’t user error.

    My car was parked on the street in front of my house. I got in, turned the power on, turned the heat on, flipped the windshield and wiper fluid once to clear off the windshield ice. Realized that didn’t clear the ice off enough, and I that I needed to scrape the windshield. Grabbed my scraper from the passenger seat, got out of the car, scraped the drivers side of the windshield for 5-10 seconds, walked in front of my car to the other side, scraped the passenger side of the windshield for a few seconds, then OUT OF NOWHERE my car starts moving forward toward my neighbor’s car parked 12-15 feet ahead. Keep in mind the street is flat and the car seemed to be in Drive, not neutral. It was moving too quickly to be at a roll, IMO. I ran around the back of the car, slipped on the ice and fell to the ground (btw I’m 21 weeks pregnant, extra scary), got up, car is still driving on its own toward my neighbor’s car, I open the driver door and basically jump on the brake, which stopped the car. My car probably ended up traveling a total of 5-10 feet in all.

    As you can read, 30-60 seconds lapsed between me turning on my car and the car moving into drive when I was outside of the vehicle. This is not the latent lurch situation described in this thread, which I’m familiar with.

    Taking it to the shop in a few mins and will update with what I learn.
     
  2. Julie Walsh

    Julie Walsh New Member

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    Edit: i just got home and saw my tire tracks. The car actually traveled about 15 feet. Service dept at my local Toyota dealership is closed Sundays so I don’t have an update from them.
     
  3. alanclarkeau

    alanclarkeau Senior Member

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    Is your car a Gen 4 (20162020) - or a 2007?
     
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  4. Julie Walsh

    Julie Walsh New Member

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  5. Elektroingenieur

    Elektroingenieur Senior Member

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    Was the parking brake set? If not, regardless of any faults that might exist in the electronic shift lever system, a rollaway is the driver’s responsibility.

    As @Mendel Leisk (post #13), @ETC(SS) (post #17), and Toyota—“When you leave your vehicle, put the hybrid transaxle in ’P’ and set the parking brake,” 2007 Prius Owner’s Manual (PDF), page 15—have all kindly recommended, whenever there isn’t a driver at the controls and ready to operate the vehicle, the parking brake should be applied. It’s a separate, completely mechanical system, by the way.

    This thread is about fourth-generation Prius cars (model years 2016 and later). Earlier models don’t record vehicle control history events in the way I described in post #4, but the shift-by-wire system was still designed to avoid inadvertent operation. I can’t say it’s impossible, of course, but a broken wire or loose connector wouldn’t be enough to cause an uncommanded shift from P⃣ to D⃣.
     
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  6. The Professor

    The Professor Senior Member

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    Just tested this in my Gen4 (so kind of moot I guess). Even in D, the car doesn't move at all with the handbrake/right-hand-foot brake/emergency brake/whatever your region calls it/etc applied. It feels like it's trying to move, so I guess if the road was slippery, and for some reason the front wheels had considerably more traction than the rear, it could drag the car along the road like a sledge.

    It may sound harsh, but despite seeing a few posts like this, I feel it always comes back to user error. The car was almost certainly in D and not P, they don't magically shift by themselves (there are fail-safes and it is specifically designed to prevent this), and the manual brake probably wasn't applied.

    Sure - stuff happens, people forget, people make mistakes, I know I do, but I feel with all electric cars people more often forget that just because they can't hear an engine running, doesn't mean it's not in a configuration where it can start moving once you take your foot off the brake. If you get out of a car for any reason, ALWAYS double check that it's in P, and the manual brake is applied, and if you live in an area where it's stupidly referred to as an "emergency brake", don't assume it's only for emergencies, it's for parking, use it as such, because failing to do the above can result in people getting killed.
     
  7. alanclarkeau

    alanclarkeau Senior Member

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    If it's in "D" - open the door and the following happens:
    • BEEPER sounds solidly;
    • Yellow Exclamation Signal flashes;
    • Red Seatbelt sign illuminates;
    • Another RED Door Open sign illuminates;
    • And the entire Middle screen lights up - "SHIFT TO "P" before exiting vehicle" is displayed.
    It's basically impossible to get out while in "D".

    But yes, while I don't always use the Park Brake when parked, I always use it if the car is still "ON".
     
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  8. The Professor

    The Professor Senior Member

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    While I agree all of that happens, I'm not so sure it's impossible. In fact, I'm going to argue people ignore all that kind of stuff quite a lot....

    Humans get so used to such warnings they often ignore them, especially if they see/hear them a lot, which any Prius owner will experience. If I get out of my car to clear frost off the windows, while it's in P and Ready mode (so it can heat up) I'm going to be expecting the car to be flash warnings and beep at me. I also know I can ignore those warnings. So I get out of the car, I ignore the warning, but I don't realise that the very similar sounding warning and flashing lights/messages are actually telling me it's in D.
     
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  9. alanclarkeau

    alanclarkeau Senior Member

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    Yep - I'm not experienced with that - frost, ice, snow - not something which happens here. There are places not far away where they would get frost in winter.
     
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  10. alanclarkeau

    alanclarkeau Senior Member

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    This all could be wrong as the car is 3 Generations older so might behave differently - I've asked the Moderators to move this to a new Thread for Gen 2.
     
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  11. MelonPrius

    MelonPrius Active Member

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    When I first got my Prius (and even occasionally now) I would hear silence and assume the engine was off and in P. My brain has been programmed to think that the silence meant I could safely exit the car. True, there would be warning sounds, but I would ignore them. It was when I could feel the car creeping forward that I would go in a panic and quickly press the brake. Several times, I was outside of my car before I noticed.
     
  12. The Professor

    The Professor Senior Member

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    Yep - been there myself, more than once.

    Really it's a design issue. Important safety warnings, like, you know, the driver exiting the vehicle while the car is in D, should be very different and much more persuasive than warnings that can safely be ignored in the short term.
     
  13. valde3

    valde3 Senior Member

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    Maybe. But I think the problem is actually the constant warning and reminder noise given out by many different things in situations that that they can and will be ignored. That just gets people used to ignoring warning noise.

    So making the noise louder isn't really a good fix. And there are situations where driving with your door open is a useful option so the noise shouldn't be that loud.
     
  14. bisco

    bisco cookie crumbler

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    julie, julie, julie

    the dealer is going to make you pay...
     
  15. edthefox5

    edthefox5 Senior Member

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    What’s the history of the car bought new or used? It’s refreshing you understand the lurching the car does.

    It may have a damaged park pawl which is a lever that engages the trans and locks it into place when in park. I have seen a few here with issues.

    If used check it’s history. Go to Toyota.com/owners forum and join have your insurance card handy as it requires the cars vin.

    Once joined you will see every event the car has seen an authorized Toyota dealer for service. See what has been going on with the car.

    If you do go to the dealer have them check that pawl. Try parking on an incline see if it engages properly.
     
  16. Robert Holt

    Robert Holt Senior Member

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    Um, I am totally intrigued by which situations you find it useful to drive with the door open? Please elucidate?

    E.g., I have HEARD of folks in a very dense fog driving very slowly with the door open and a flashlight shining directly down to track the white line on the side of the road so that they didn’t simply run off the road, but I have not found anyone who would admit to actually doing that.

    ( I had a 1959 SAAB 93B with “suicide doors” that were hinged at the rear and opened to the front (some 1930s cars had those also). Since the airstream force would tend to fling the door wide open and rip it off the hinges, on that car we were particularly careful to make sure the doors were fully closed and locked before starting off.)

    But I’m open to suggestions!
     
  17. valde3

    valde3 Senior Member

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    Mostly just ment driving up to a lift or pit in a shop. Maybe also some other exact parking. But the main point of my post was the unnecessary warning and reminder noise that people just get used to ignoring.
     
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  18. bisco

    bisco cookie crumbler

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    i sometimes crack it open to see the parking line as i back in to a spot
     
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  19. fotomoto

    fotomoto Senior Member

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    Have someone (who's NOT PREGNANT!) repeat the same dance but purposely put the car in N after startup and see what happens. I'm thinking that a door closing or you leaning/bumping the car while cleaning the windshield dislodged it from its icy lock.

    IIRC in a long ago thread, a woman with a big winter jacket had issues with the vehicle operating controls caused by the large sleeves catching on things.
     
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  20. Priuslover09

    Priuslover09 Member

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    The car is haunted quick call ghostbusters.
     
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