I purchased my 2013 ES300h UL with PCS, LDA last week. It happened 3 times already.

While crossing the metal drawbridge in my area, the small display screen turns Red with rapid beeps. The car immediately decelerated and I even felt it is braking by itself. The seat belt was tightening also.The gear shifted to ‘N’ (It would be me that push the gear shifter by accident when the car suddenly slow down or baking but I am not sure). After about 3 seconds, the seat belt loosens up and I notice a Yellow triangle with an exclamation mark on the small display screen. I shifted back to ‘D’ and everything was back to normal.

The 1st & 2nd time when it happened, the car in front of me was far away (at least 1 car length) and my speed was about 25mph. The 3rd time when it happened, there was no car in front of me and I was driving about 25mph. I cross that metal drawbridge multiple times each day and only happened 3 times and I can’t reproduce it every time. I just called my dealer and they said they never heard of this problem. My dealer is investigating and said they will call me back next Monday.

This is quite scary. On the 3rd time when it happened, the car behind me almost rear-ended me because my car was slowing down suddenly.

Any one heard or experiences this?

 

I have 13' GS350 with PCS, and I almost got into an accident twice because of this system. You can read about one of my experiences here, https://www.clublexus.com/forums/gs-...use-of-it.html

We have another member here with PCS who had similar issues with this system.

Anyways, I turned my PCS off after my dealer told me that I probably drive too aggressive and that's causing the system to engage......Complete BS, there is something wrong with PCS and not the way we drive.

 

Were either of you using cruise control when it happened? Also, if there is a curve in the bridge, the radar might be "seeing" the outer side of the curve and think you are approaching it head on. I have notice that when I am driving with the cruise control on going around a curve, but this also would occur when I was driving my Infiniti G37X with the adaptive cruise control on.

 

Nope, I was not on the highway when this happened.

 

Interestingly enough I was reading the manual last night and it specifically states that the PCS system may activate on an iron bridge. I thought it odd that the manual would get that specific and then I read your post. Who would figure!!

 

As a follow-up, please see page 309 in the 2013 ES manual, for conditions that may trigger the system even if there is no possibility of a collision: one of the conditions include when driving over a narrow iron bridge.

 

I've had mine kick in twice when accelerating to pass a car on the highway, from getting too close to the car before pulling out to pass. Luckily it shut off again as soon as I got out into the passing lane. Working correctly , I just have to change the way I pass a bit. :-) definitely good knowledge to have about metal bridges.

 

I find it very difficult to believe that a manufacturer would even offer a collision avoidance system that has the potential of such a failure to correctly deploy itself without giving the driver some means of instantly overriding the system. What are you supposed to do if you are driving on that narrow iron bridge and the vehicle decides suddenly to brake when you also have a semi following at a close distance? It sounds like the collision avoidance system has the potential to switch, in an instant, to a collision causing system.

 

You can turn it off. There is a switch in the glove box.

 

But my point was that, if it is turned on and it deploys when it shouldn't and doing so puts you and the vehicle in danger, there is no way to instantly override that deployment quickly enough to prevent what could be a dangerous situation.

 

I'm a fan of technology and no Luddite, but a few of the latest options are far too invasive for my taste. Anything that takes command of the braking system (ABS/traction control excepted) or steering wheel will not be in command of my vehicle!

 

I'm not sure what is putting you in danger, here. The throttle is still available to accelerate you. The brakes are still available to slow you. The steering is still available to control your course. Are you concerned that the danger is that someone will rear-end you during an unexpected deceleration? Any slowing that I have experienced are not locked-up and the slowing has been short duration, for the car moves on as the detected radar contact moves off to the side and out of radar view. Those I have experienced have been more of a pause for a second or so.

 

The iron bridge that I cross wasn't narrow. It has 2 lanes in each direction for total of 4 lanes. There is no quick way to turn off/on the PCS while driving. The point is that I am paying for a safety features and now it may cause harm. My friends who drive Volvo and Mercedes (Pre-Safe Collison) and never have this type of problem. I am a proud owner of 3 Lexus in the last 10 years and never have any trouble (No PCS on them). The ES300h is still the best i ever own but this will really put a dent in my trust on Lexus technology.

jrlxr7: Thanks for the reference on the manual.

 

You must be talking about the radar cruise control system, it is different from the PCS. When PCS engage, your dash starts blinking red, you get beeps similar to park assistant beeps. This is only a warning though. When PCS takes over the control of your car, first thing it does is disables your gas pedal. That's right, you can floor it and nothing will happen. Then it starts to slowly apply brakes, if that is not working it will slam on brakes so hard that you will hear your tires screech.

 

Although this is an unsafe way of passing, the PCS kicking in (applying the brakes) unexpectedly could have caused the driver to hit the car in the other lane.

I've only had PCS "activate" twice. One time was when I changed lanes coming too close to the car in front of me. And the other time when a vehicle decided to make a two-lane lane change in front of me (from the outer lane to the inner lane while I was in the middle lane). I never felt the PCS slowing down the vehicle though, just the red dash light and beeping sounds.

Knowing how the PCS engages will sure make you a more defensive driver, which I think is a good thing.