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PCS question

Discussion in 'Gen 3 Prius Main Forum' started by Yiannifun, May 31, 2011.

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  1. Tideland Prius

    Tideland Prius Moderator of the North
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    ok so just to build on Chris and twitteel..

    Yes, it's passive and is always on regardless of DRCC setting. The PCS OFF button under the dash only disables the PCS braking. (the auto-brake).

    There are 3 parts to the PCS safety net.


    1. PCS Brake Assist - It primes the brakes by bringing the brake pads closer to the rotors in anticipation
    2. PCS Braking - This is the one that brakes for you if you don't respond and collision is imminent
    3. PCS Seatbelts - this one tightens the seatbelts to hold you in place

    #3 can activate even if a collision isn't imminent (i.e. someone just cut you off or you missed a turn off on a country road and you're braking hard). It activates > 60km/h (personal testing) and as long as you give the car a reason that your brake application may be an emergency-type brake application, PCS will tighten the seatbelt. No beeping required.

    e.g. I had a guy coming into my lane but he didn't shoulder check (I could see the driver's seat from my seat) and I didn't see his indicators. When he started sliding into my lane right in front of me, I tapped the brakes and the seatbelts tightened. I lost maybe 10km/h (60-50km/h).

    Note that normal Brake Assist will apply if you lift off the accelerator fast enough.

    I've also had the PCS warning engage as I coast/glide to a light and the person in front of me is slow to start off on the green light. I'll just keep coasting/gliding until he accelerates fast enough to allow me to accelerate as well but because my closing speed is faster than his (It's basically near 0km/h for the other guy and maybe 15-20km/h for me) that PCS will beep. Freaked me out the first time but I've learned to realise what it is if I happen to be coasting/gliding and it beeps.

    My guess is that #1 activates when the PCS is beeping (BRAKE!). #3 is independent as I think as long as you're over 60km/h and brake hard or over 60km/h and you release the accelerator pedal quickly (thus the car will recognise it as a potential panic stop) and then tap the brakes, PCS seatbelt will engage.

    I hope to never use #2.
     
    #21 Tideland Prius, Jun 5, 2011
  2. macman408

    macman408 Electron Guidance Counselor

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    Yeah, I had mine beep at me this week for about the second time; I made a quick lane change to the right to get around a car turning left, and was briefly pointed in the direction of a bicyclist and a parked car. I'm not certain which it saw as the threat (I'm guessing the parked car, even though it was less in front of me, since it's larger and had a greater difference in speed compared to my car). In any case, all it did was beep and flash the warning on the screen; I didn't touch the brakes that I can recall, and it didn't cinch up the seatbelts.

    The other time it beeped at me was when I was using DRCC in heavy traffic and the guy in front of me braked quickly. I'm not sure if the use of DRCC adjusts when it will start beeping, but I had plenty of time and space to slow down myself, and was actually mostly satisfied with the DRCC's rate of deceleration (DRCC has a limit to how hard it will apply the brakes).

    One of these days, I intend to find an empty road and try to fake an "emergency" by moving quickly from the gas to the brakes, just to feel what the car does, and see what the seatbelts do.

    And just to elaborate on Tideland's answer; it's always on, however the PCS system will only activate if you are moving at >9 mph, and closing at a rate of >18 mph, IIRC.
     
    #22 macman408, Jun 5, 2011
  3. ksweet

    ksweet New Member

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    I have a new 2011 Prius V with ATP and seem to be missing the PCS disable switch. The manual shows that it is on the wall of the driver's foot well, but I can't seem to locate it.

    Can anyone point me in the right direction?

    Thanks for your help.
     
    #23 ksweet, Jun 5, 2011
  4. mad-dog-one

    mad-dog-one Prius Enthusiast

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    Mine is directly in line with the brake pedal, straight up and slightly closer to the driver seat than the brake pedal. Put your head under the dash on the driver side and look up. :)
     
    #24 mad-dog-one, Jun 5, 2011
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