Field Test of the Toyota Pre-collision System /PCS

I hope NOBODY here is relying on this for primary collision prevention. It was never intended as such. It is merely a driver assist, a secondary system, meant to reduce (but not anywhere good enough to eliminate) collisions or [update: OM doesn't advertise avoidance at all] collision severity against other cars.

And in a 2012 car, it is at least 8 years behind the current technology, in an era where the technology is advancing very rapidly but no one is yet offering a consumer system reliable enough to be a primary. Judging such an old system against today's standards is absurd.

From my 2012 Owners Manual (non-Plug-in)

 

Personally, I like an empiricist, especially one willing to risk his car and an irate policeman to get actual data.

 

The boxes should have been round shape so the radar can reflect back

Also the radar signature might not match an actual car

 

Mine's come on one time. Car cut me off and braked in front of me. I came off the gas, and before I hit the brake, the brake sign came on and the brake engaged. I've had other times the "brake" sign came on, but that was the only time it intervened. Now I wonder if you have to be off the gas for it to work.

 

I have a plug in and the children in the back once reported the seat belt getting tighter as the brake warning came on.
As opposed to only the front being active

 

There are some people who would come here time to time to post that theirs failed to stop or even warned to stop, and rear ended another car.

 

Are the PCS seatbelt pretentioners pyrotechnic single-use devices, or are they electric for repeated use?

 

The pre-collision system (pre-crash safety system, outside the U.S.) can activate electric seat belt motors, if equipped. There are also pyrotechnic seat belt pretensioners in the supplemental restraint system, which are fired only in an actual collision.

 

They're electric... had mine go off about 5 times since I've had the car (7yrs). They'll really pull you into the seat!

First time it happened my wife and I were going about 70mph in rather heavy traffic, someone cut RIGHT in front of us... not a mild cut off, a pretty severe one. The seatbelts pulled us into the seats and the car started making all types of warnings. I dont remember if it put the brakes on because I did that myself anyway.

Another time I was driving in a neighborhood and someone ran a stop sign without looking both ways. The car auto braked, reeled me in, and beeped a lot.

There is a physical switch near the OBDII port where you can disable auto-braking if you want full control of the car, but I leave it on until I have reason to disable it.

My only guess as to why it didnt work in this test is the radar cross-section is too small. It needs to be a car size object, or at least a foot wider.

One other time a car in front of me slammed on its brakes on the highway. The prius responded with putting on its brakes and beeping (did not reel me in that time because a collision wasnt imminent, just likely.