2005 Toyota Sienna, parked on a steep hill. No key in the ignition and no ebrake on. Our toddler jumps into front seat and plays around with the shifter. It pops out of park and into reverse. Chaos ensues. Wife (who is in back seat with baby) throws it into park, but van keeps on a truckin. Before she can get into frontseat and hit the brakes, they go diagonal across the street and crash into another car. Everyone is FINE. Thank you lady luck.
First off, is this a common occurrence? At the cop at the scene said it happens a lot on this particular hill.
Second - as an engineer, I really want to understand the possible point(s) of failure. My understanding is that two things must happen to engage the transmission:
power to ignition switch
break pedal depressed, triggering a sensor to release the shifter
I tried to reproduce the problem again tonight (on another hill), but nothing.
Is it possible for this system to fail? Will there be signs that a mechanic can identify?
Very puzzling. My understanding is the same, at the very minimum, that the brake pedal must be pressed before it will shift out of Park. I learned this the hard way. I was driving a rental car in the Calif desert, parked for a minute, then found I couldn’t shift out of park. In themiddle of nowhere! Finally I see a little sign on the dashboard saying you have to press on the brake first. My own car is a manual, so I never hear of this until then.
Anyway, back to your case. It’s possible it wasn’t fully engaged in Park is about the only thing I can think of. Or it wasn’t in Park at all, maybe it was in D or R or neutral all along but the wheels were turned against the curb so it didn’t move; i.e. the kid didn’t shift from Park to Neutral, just turned the steering wheel.
The other question is why did it keep going after your wife put in back into Park? My guess is that putting it in Park while the car was moving quickly may not be allowed, and the mechanical contraptions just ignored it, or it tried to go into P, but it have damaged the parking prawl. That’s the part in the xmission that stops the car from moving when it is in Park. But it isn’t designed to hold a car back that is already moving, only when it is stopped.
I do hope you plan to emphasize to your wife that she was quite careless here. The parking brake absolutely should have been on. The front wheels could have been turned toward the curb for extra safety as well.
Yeah, not being fully engage in Park is the only thing I can think of. Does anyone know if it’s true that “modern” cars can not be put into Park once moving? I know that was not the case with my older cars but probably true nowadays.
This is a picture of a shift lever in a sedan, note the pocket screwdriver used to press a recessed button to defeat the brake shift interlock.
The brake shift interlock won’t release when the battery is dead. A tow truck driver will remove (and lose) the cap and press the button to shift from park so the vehicle can be moved.
Wow that’s a ride. Glad all are ok. I don’t know so I’m just asking but is there an adjustment on the parking paul? Maybe if it is not fully engaged even though the shift lever is in the park position, but then you wouldn’t think you could move the lever without turning the key and stepping on the brake unless you have two points of failure at the same time. I think I’d have the dealer take a look see.
Yes the parking angle could have contributed.
See if you can shift gears without your foot on the brake.
plus,
She seems to have a pre-developed habit of parking on any incline with no parking brake. THAT constantly stesses the parking pawl and hence has worn it some…
to the point that…
Since the van has a shift cable there is a constant physical connection to the shift lever on the trans.
The toddler wiggled it , even without the shift interlock allowing it to move normally, and those little teeth just let go, and once rolling, the parking teeth had no chance to find each other.
( this is why we advocate using the park brake at all times. not because you need it in the wallyworld parking lot, but because you need the habit in practice. )
As many have said, this was actually a “cascade of failures” that allowed the incident to occur.
The driver failed to set the e-brake; the driver failed to curb the wheel; allowing the failure of the parking safety to cause the incident.
As an engineer, you surely understand the value of redundancy in mission-critical or safety-critical functions. By neglecting the e-brake and curbing the wheels, you’ve voluntarily created a “single-point failure” setup in a vital safety system.
(Also, why was the toddler allowed to jimmy with the shift lever, safety interlock or not? This is akin to letting a toddler play with a loaded handgun, trusting the gun’s “safety” to avert disaster!)
I appreciate all the advice, but some of you folks need to walk a mile in someone else’s shoes. geez. This was the first time parking on this hill (she usually avoids it like the plague). And yeah, no shit, our toddler should not have been in the front seat but as anyone else with > 1 kid will tell you, being out numbered, things can happen in a blink of an eye.
Here’s an odd note. I don’t even know if Consumer Reports (the dictator of what WE should do) even tests for that problem. It’s also kind of sad that just one child can prove that our safety devices can’t be trusted.
We have some steep hills where I live and I don’t dare to park there without setting the brake and turning the wheel. If you park near water, turn the wheel and set the brake or your car will be on television.
If you drive an SUV in snow, be very careful in those 40 MPH zones or you may be going off road. We seem to be crashing Jeep Libertys all over Maine now. They may be the king of the 25 MPH zones but they aren’t made for speeding down back roads.