Rolling back when you turn off the car

FWIW, my brand new 2012 3 does the same thing...caught me a little off guard as I am just getting acquainted with the car and glad to hear someone else is experiencing the same thing; therefor, it must be normal, right?

 

I can answer this - the transmission has a "park gear" in it - as all cars do in some form or another...
essentially - it's a flat toothed gear or to explain it easier - a round disc with notches in it - ok - so when you shift into park - a solenoid fires and shoves a pin out- this pin fits into one of the notches on the park gear. if you happen to end up on a 'tooth' the pin is not out fully - and the car will roll slightly - until the next open notch is available- then the pin pops in-place and whala - you're in park. i'm assuming you're parking on a slope when this happens...??

I get a slight forward motion in my garage (about an inch) ... and at work sometimes nothing - and sometimes it rolls back about a half-inch.

if you have your window down - pull up to your spot - hit off instead of park - you may actually hear a "clunk" or click noise as the car stops moving - that would be the pin locking into place.

if you're concerned - talk to your dealer - but based on what you describe - it seems perfectly normal. I had a gas car that did this on occasion- it however had some wear on it -but ... that's a different car with a completely different setup.

it rolls a bit more than say a normal car - only because the prius has no direct connection of the engine to the wheel. where a gas engine has more of a direct conect - though the torque converter is technically a fluid connection - i think you get what i am sayin -

hope that helps -

 

Another thing that will probably catch you by surprise is the first time that the Internal Combustion Engine (ICE) starts while you are in Park with your foot off of the brake. If you are not already up against the parking pawl, the car will move forward just a little until the parking pawl is pushing against the next gear tooth.

This also is perfectly normal.

 

I found the picture of electric parking brake in my PC album: http://priuschat.com/photos/img_3636_56072-jpg.3165/standalone
Really several seconds? So big difference for V? My 2010 is locked almost immediately after the "P" hit or switch off the car.

 

I find this happens more when I neglect to press the Park button before shutting the car off.

That reminds me. Day two of owning the V I got out of the car before putting it in park. Scared the tar out of me as it started rolling forward toward a wall. I had left it running because it was 115 outside and I wanted the AC to run. I'll never make that mistake again.

 

Situations like that are why I am choosing to press the park button and make it a habit and ingrain it into my muscle memory while I am getting settled in my new car vs. skipping the step and going straight for the power button.

My "insurance policy" for the occasional brain fart