My son drives a 2006 prius. Today he forgot something needed for work and pulled back into the driveway. He presses the park button and gets out of car with engine running. Runs inside and returns to car. Before he gets to car, it starts to go backwards. Crosses road and down a bank to the neighbors. He tries to stop the car physically but neighbor tells at him to let it go. He is fine and damage is limited to the door. What could have made the car move? He should have pushed the power button off, but thought just the park button would do it. What do you think happened? When the car stopped, the neighbor claims he saw park button green. Just want to advise him of proper procedure. New to the Prius. Thanks for any advice.
Given your story, I don't know if your son actually depressed the Park button, or just thought he did. I also don't know if the switch is working properly or not. May I suggest the following procedure: 1. Press Park button. 2. Set the parking brake. 3. Turn off car (which will also set the parking pawl as the car powers down). 1 and 3 are redundant because either should set the parking pawl. 2 provides an additional safety measure. Your son's process had no redundancy or safety associated with it, hence the car rolled away and damaged the door.
This is very strange indeed, if he left it in gear, he would have been in DRIVE and not REVERSE. And the car won't wait that long before it starts moving, especially when left in gear.
I ran over my own foot with my MGB once. This hot chick had broken down and I was in such a hurry to help I forgot to put the car in gear and set the parking brake. When the car started rolling I put my foot in front of the tire to stop it. Just rolled over and kept going. Limped alongside and pulled the parking brake. Got the car fixed, distributor cap was loose. Didn’t get a date though.
If you're not going anywhere, or even just getting out of the driver's seat: push the power button (turns the car completely off and sets it in Park), and set the parking brake. And survey the dash for confirmation that it's off. Always.
The only magical thing about park is the pawl. Basically in a Prius it is the same as neutral which never disconnects anything from the wheels, it just doesn't apply power. Gravity can pull it wherever it wants to. But the parking pawl is just like jamming a stick into your bike spokes. It prevents it from starting to move. This is a mechanical linkage activated electronically. The electronic input could have failed: Parking button. The electronic actuator could have failed: The 12v 3p motor that shoves the pawl into the HSD. The pawl itself could have failed: One too many engagements at speed, eventually it breaks. Or it could just be human error which is the most likely scenario but the hardest to admit especially since the human mind likes to falsify experiences. Trick of the human brain... The park button being green is an oddly specific thing to say. If you remember the first time you ever got in a Prius, how long did it take you to find the park button? A random observer not familiar with the vehicle being able to identify that specific button and its illumination pattern after a traumatic incident is not likely. Possible, but not likely. This is the thing in question (other than the humans):
OMG, was it your left foot or your right foot? I never would of thought to stick my own foot under a tire to stop a runaway car... But then again you probably don't car about your foot as much as I care about mine, I mean at least my right foot that is...
Had that happen to me once... I forgot something and pulled back into the driveway, car was in reverse and didn't hit the parking button all the way, but always use emergency brake. So once I saw my car backing out without me the brake kept it going slower than normal and jumped in and headed out. Cars are dangerous when left improperly unattended...
18 + Horny (what 18 year old isn’t?) + Hot Girl = Stupid. Every where on the Earth I would guess. To make even worse it was on gravel, not pavement. Those rocks hurt.
Oh, this was a pre-frontal cortex development thing... You never make those mistakes twice though... But being in teenager years you have to make those dumb moves at least once to learn why. Like the time I was trying to look cool in front of the ladies leaning hard into a sharp corner going fast on my moped as the wheels came out from under me and rather than minimizing the impact to my body I tried to stand up while crashing and slid 10 feet on both knees... No skin left on 'em, put a bag of ice on 'em and then went to work at the auto shop... Soon as the boss saw what my knees looked like he sent me home. Lol. I'm like what? I'm not just suppose to keep working?
That probably hurt much more than me running over my foot. My car was an MGB. They didn’t weigh that much.