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Mark, congrats on your RX. We have a thread talking about PCS here. I've had PCS engage when I stepped on the brakes quickly to avoid a collision (other driver's fault). Reaction was immediate. The brakes felt like they were on steroids and did quite a job slowing me down without any further intervention on my part. But it's not designed to stop the RX completely. All I can say is take your RX to an empty area or parking lot, accelerate to around 30 MPH, and then jump on the brakes. That way you have a sense of how it works. Just watch out for the seat belts tightening up.
I had my first PCS experience in our new 2015 RX450h this past weekend. Driving on freeway when driver ahead of me suddenly slammed on brakes. I was probably following a bit closer than I should have been, but as soon as I hit my brakes it suddenly felt the seat belt tighten and the braking was enhanced ("steriods" is a great term). We stopped just short of hitting the car in front of us, so it certainly seems like PCS did its job. Hard to know what would have happened without PCS.
take your RX to an empty area or parking lot, accelerate to around 30 MPH, and then jump on the brakes.
I don't think this would be an adequate test of the system, since it relies on radar readings to detect the probability of impact (unless you decided to take a run at a lamp post or parked car). The seat belt tightening (pre-tensioning) and brake assist features have been around for years and standard function on most cars, long before the pre-collision systems started to be introduced (which augment those 2 features with detection capabilities).
Originally Posted by neodin
Hi there,
However I still don't trust it 100% to stop the car.
Nor should you! While Google uses RXs for their self drive cars, these ain't them. Driver input still required!
I don't think this would be an adequate test of the system, since it relies on radar readings to detect the probability of impact (unless you decided to take a run at a lamp post or parked car). The seat belt tightening (pre-tensioning) and brake assist features have been around for years and standard function on most cars, long before the pre-collision systems started to be introduced (which augment those 2 features with detection capabilities).
I made the suggestion because I don't think anyone wants to give PCS a real world test At least it gives an idea. There's a list in the manual of other possible triggers, like bridges. Members in other forums have turned PCS off because of false alarms. Knock on wood, I haven't had it happen to me. And I hope it never does.
I made the suggestion because I don't think anyone wants to give PCS a real world test At least it gives an idea. There's a list in the manual of other possible triggers, like bridges. Members in other forums have turned PCS off because of false alarms. Knock on wood, I haven't had it happen to me. And I hope it never does.
Yea, that sounds really annoying if you're manoeuvring through a small space and the brakes jam on. Sometimes around here with bridge construction they use a lot of barriers and give you a pretty narrow single lane to share with oncoming traffic that you have to turn into, I could see that being an issue. Still, not having it, I think it's a good idea, if the false alerts can be managed.
I suppose if someone really wants to have a somewhat real world test, find a construction site after hours and try to run down one of their plastic barrels. I think they're soft enough, and if not, well, makes a great story at your next social event!
And watch the video under the section on the left, second one down titled "Pre-Collision System with Pre-Collision Braking and Dynamic Radar Cruise Control". The guy says that it WILL apply the brakes automatically "under some circumstances".
Also, I found this article on pre-collision braking tests which took me to the IIHS page for the RX and it says the RX has autobrake:
Low-speed autobrake
In the 12 mph IIHS test, impact speed was reduced by 5 mph. 1 point
High-speed autobrake
In the 25 mph IIHS test, impact speed was reduced by 9 mph. 1 point
A good recap of how they test is here, basically they drive at a wall and see what happens. So the RX *does* automatically brake, but not enough to actually stop you from hitting anything, just enough to lessen the impact.
EDIT: My personal experience on my 2015 is I have seen the warning to !!BRAKE!! and the chime occasionally, usually when someone is in my lane and turning so I do not slow down a lot since I know they will be out of the way, or every once in a while on the highway when a car is changing lanes. I don't ever remember the autobrake kicking in, but sounds like it is pretty conservative.
I just had my first experience with PCS (after 2.5 years of ownership). I was entering the highway. There were a couple of cars in front of me also entering. I look back and there's a semi on the highway, but I know I can get in front of him as I see him slowing down a little.
All of a sudden, I hear many quick beeps. I turn my head forward and see BRAKE on the HUD. There was a slow car about 4 cars up causing everyone to slow down quite a bit.
It looked something similar to the following image. I don't remember if it had exclamation points after it, nor do I remember if it was flashing. I vaguely remember my seatbelt tightening. It wasn't much of a scary situation as I seemed to be far enough behind the car in front of me. I guess that's a good thing as it alerted me in plenty of time to take action.
Pre-collision system experiences?
At least it gives an idea. There's a list in the manual of other possible triggers, like bridges. Members in other forums have turned PCS off because of false alarms. Knock on wood, I haven't had it happen to me. And I hope it never does.
