ItzFilyO

Gentlemen,

Since the RC forum is pretty much dry, I'll just ask here. I don't know why other forums aren't as active as the 4GS.. and some of u are lurking around the RC forums too anyway.

So, how does this thing work? My RC is equipped with radar cruise control and I think it has PCS too but I don't have the lane keep assist though. When the cruise control is engaged, it follows the car in front of me and when we're coming to a stop, it will only slow the car down to about 30 mph and it lets go, it doesn't actually stop the car.

Can the PCS actually stop the car if I don't brake? Can it see a person too? I know the newer GS has the PCS too right?

OneFunGS

That is odd that it doesnt feature start/stop technology. If it has pre-collision warning then it will not stop but if it has pre-collision avoidance then it should slam on the brakes last minute to avoid or mitigate a crash. Most systems avoid crashes up to about 20 MPH then it is just mitigation at that point. Except the Mercedes S class which will avoid a crash all the way up to 60 MPH.

dchar

Unfortunately the adaptive cruise control on the RC is different than the one on the 2016+ GS. The RC's adaptive cruise will only work above 30 mph and will not bring the car to a complete stop. PCS is not meant to be used to stop the car on a regular basis, but more for emergencies...like already mentioned, it will bring the car to a complete stop at the last moment from speeds below 20 mph. PCS is meant to detect pedestrians too, but again it will only bring the car to a complete stop at speeds below 20 mph.

ItzFilyO

So if I'm rolling at 20 MPH (or below) and someone jumps in front of my car, it should stop by itself?

I did see a red and loud warning sign on my cluster when I drove too close to the car in front of me at a high speed, right before I moved over to the next lane, kind of like a reckless driving. I'm not a reckless driver but at that time my exit was coming up and the cars around me didn't want to give me room, so I did what I had to do and unleashed the power.

So I'm guessing that was the PCS kicking in? But it didn't actually apply the brakes though, just that loud red warning on my cluster.

OneFunGS

^ That is Lexus first stage like "hey...uhhh...pardon me, but you're super gonna crash" and then the second stage will take over. The same with the 2013/2014 with the driver awareness package. Its basically making you aware that you're in trouble before taking the reigns.

dchar

Yep. First stage: warn driver with audible and visual info...Second stage: apply full braking power at last moment possible to avoid or mitigate impact. Basically the PCS gives you an opportunity to take evasive action before slamming on the brake. I also believe that the wheel needs to be straight in order for PCS to apply full brakes, or it'll think you are trying to avoid the accident.

There are some videos on YouTube of people walking in front of a Lexus with PCS traveling at a low speed and the car coming to a complete stop.

mikha619

iTrader: (1)

Like the above stated, you have the high speed radar cruise which will disengage if the car in front slows down to below 30 mph then you have to re engage your cruise. Currently only a few cars (RX, LS, GS) have that the safety system + will have the ALL speed radar cruise, meaning they will come to a complete stop if the car in front does, and will pick back up without canceling the cuise control. The PCS will slam on the breaks if it detects you are not reacting to closing in on something relatively fast. 2 different systems.

PearlFocal

Why doesnt my 2017 GSF have the all speed radar cruise control... sign...

dchar

Wow...I had to double check the online brochure...the GSF didn't have All-Speed DRCC or Lane Keep Assist like the rest of the GS range with Lexus Safety System + for the 2016 and 2017MY. Looks like Lexus gave the GSF the lower grade Lexus Safety System + as seen on the IS and ES. Lexus didn't do a good job on helping customers understand what features are actually in their cars and confusing them with different features with the same name package. Idk why Lexus would offer a different safety package for a car in the same range.

They added All-Speed DRCC and Lane Keep Assist for the 2018MY GSF.

lobuxracer

iTrader: (2)

I despise the car braking for me. I know where I am going, I've got a working plan, and then without anything more than a quick flash of the warning light on the dash, the brakes are actuated. It did this at 85+ mph when I was closing on a semi but planning to move into the left lane. I was not amused at all. The car was NOT going straight, and the chassis was very unhappy about what the braking system did. I mashed the accelerator to the floor, but the brakes always win. It was a wonder nothing bad happened as unhappy as the car was.

All these "driver aids" are annoyances to me. I wish I could selectively turn them off. I don't mind the stability control, but the "I'll brake because you are being inattentive" when I definite am not will cause an accident one day. And I will sue Lexus when it does because I only have one way to turn it off - disable ALL stability controls. This should be an LPS setting. I choose no braking. Warning me is fine. Just don't apply the brakes. I know how to do that myself just fine.

Dallasguy1

Had a 17� RX loaner the Pre Collision system came into play 3 times in 2 days I say a gr8 feature if u do a lot of city driving.

talltrini1

I guess I'm the one of the few that really doesn't like this feature. If I need the car to brake for me, maybe I shouldn't be driving

MustangSal

For my 15’ Gs450h, If LKA is on by itself - it’ll beep for drifting out of the lane but not apply assistance to the wheel. PCS kicks in for emergency closure-rate too high.

Adaptive cruise by itself will manage distance and go to PCS flash warning mode if closure rate is too high and then brake to prevent collision. It’ll brake to a stop as necessary.

If both LKA and Adaptive Cruise are on together, the system manages selected distance, and the acquired lane, even turning the wheel in mild corners to help manage direction. I’ve actually gone hands-off for 15 seconds or so before the car flipped out and said it was cancelling the LKA unless I put my hands back in the wheel. It’ll brake to a stop even in non emergency and It’ll pick the car back up from ‘very slow’ (<10mph, my only experience) all the way to the previous ordered cruise speed. I don’t know if it would resume from a complete stop without being ordered to do so.

I also have the driver-eyeball detection thing...I have no idea if they actually do anything. No way to test it and it somehow works in conjunction with these systems (apparently). I guess I should ask the dealer about it. Nobody seems to know anything about how they actually work.

All that said, I like having it all there. I do a lot of mixed driving and the automation doesn’t bother me a bit. If I’m being aggressive and I know what it’s going to do than all it’s going to do is beep and flag. Btw, if you apply accelerator while Adaptive Cruise is on it still goes faster than the ordered speed but will flag and beep and whistle and cry if you put the car too close to another bumper on purpose (I suppose it would crash too without opposing your orders). PCS isn’t preventative as you can still drive the car into a wall if you drive it there. If you give the car the option through automation (meaning it’s all on and working on its own) it’ll do what it can to save you & itself.

mikha619

iTrader: (1)

what car do you have? With the safety system plus, you can turn the safety features on and off individually without disabling any stability control

JDR76

I had PCS on my RX350 and have it on our current Highlander. I've never had it actuate, thankfully, but use the radar cruise a ton and love it.

My Highlander has LDA, but I find it to be very annoying. It often misreads the road and beeps at me despite being fully in the lane. I don't see the value in that.