Engine shuts off when the wheels slip on water, snow or ice.
Almost got me killed, but only twice.
If you are looking to buy a Prius, my guess is it's because of the gas mileage. If so, the money you save in gas, use to buy an insurance policy, especially if you live anywhere you might get snow, ice or rain on the road.
Once the wheels start slipping, the engine shuts off and the car losses momentum and will stop, DEAD. Dead in, not able to move, possibly on a hill, possibly with traffic coming at highway speeds and you can't even get to the shoulder of the road. But this only happened to me whenever it snowed.
When this happened to me, I almost got rear-ended by a tractor trailer making speed to get up the hill. If this wasn't a loaner car, while my truck was being repaired, I'd have left that car in a ditch and hitched to work everyday.
This is a dangerous situation with this car and you need to be aware of it BEFORE you buy one. What may be deemed a safety feature by some at Toyota equates to a life threatening situation to others.
First off, I am an educator for Toyota in the Chicago Region. I present safety and accident procedures seminars for first responders and fire departments as well as hybrid and auto tech seminars each month for the general public.
The Vehicle Stability Control (VSC) available on the '09 Prius does not shut down the gas engine completely and stop the car. It is not designed to do this.
The VSC is designed to reduce throttle input and apply the brakes through the ABS system to only slow the tires enough to give them an opportunity to regain their grip, at which point the VSC system releases the brakes and boosts throttle input to the previous level.
The VSC will only slow the vehicle to essentially a stop when the vehicle is moving at a very low speed, such as when you are starting to move from a complete stop and the tires cannot get grip.
An example of when this might happen is when a person is attempting to enter traffic and the road conditions are slippery. If the driver accelerates too hard and the tires slip, the VSC will come into effect, slowing the vehicle. This is not a problem with the VSC or the vehicle, it is because the system, through a series of sensors, realizes the conditions are possibly unsafe at that attempted wheel speed/throttle input.
In any event, the electric portion of the Hybrid Synergy Drive would still be providing power, although at a lower input than the gas engine, and it would keep the vehicle moving. Only by applying the brakes could the vehicle be brought to a complete stop.
I have driven every hybrid produced by Toyota in the last five years and have never experienced this situation. I even have VSC on my personal Sienna van and it does not behave this way (speaking for both a hybrid and a standard vehicle).
VSC that is "available" for the 2009 Prius... In other words, the car doesn't really come with it. The original comment doesn't seem to indicate anything about VSC. Might be a defective car.
Note: A Comments RSS Feed is available. New comments appear in the Members Area before the main site