Panic Braking Today

[adoihcj]

Driving on a side street today and came to the top of a hill and was suprised by a school bus coming the other direction with their stop lights on. I didn't think it was a panic braking situation, but the 4R obviously thought it was. I felt I could stop without having to apply full brakes. I must have reacted so fast and pushed harder on the pedal than what I normally do and the anti-locks engaged and the tires chirped while coming to a stop.

I've been in panic braking situations in other vehicles before ('03 Ford Explorer for example), but this really suprised me. It almost felt as if the 4R had a mind of it's own and thought it needed to come to an immediate stop when I really didn't need to (the bus was far enough away that I felt I would have been able to stop on my own). It kind of scared me a little, so wanted to know if anyone else had this experience yet (I think I remember reading a thread here about a similar situation, but couldn't find it).

 

[Hawkdog21]

Its called the Brake Assist. In that giant textbook for an owners manual it says that when you brake in a panic situation (faster than normal switch from gas to brake, or quick press on break) it will send more power to the brakes...

i have noticed it too once...

 

[tkr128]

This is the Brake Assist feature. It senses how quickly you let off the accelerator and hit the brake pedal to interpret if you are intending to do a panic stop. It will then apply full braking pressure even if you're not.

Here's the definition from Toyota:
Brake Assist (BA)
In emergencies, some drivers, especially inexperienced ones, often panic and do not apply sufficient pressure on the brake pedal. Brake Assist measures the speed and force with which the brake pedal is pushed to determine whether the driver is attempting an emergency stop. If the system determines that is the case, it applies additional brake pressure to allow the driver to take full advantage of the ABS brake system. When the driver intentionally eases up on the brake pedal, the system reduces the amount of assistance it provides. This feature comes with VSC.

 

[adoihcj]

This is the Brake Assist feature. It senses how quickly you let off the accelerator and hit the brake pedal to interpret if you are intending to do a panic stop. It will then apply full braking pressure even if you're not.

Here's the definition from Toyota:
Brake Assist (BA)
In emergencies, some drivers, especially inexperienced ones, often panic and do not apply sufficient pressure on the brake pedal. Brake Assist measures the speed and force with which the brake pedal is pushed to determine whether the driver is attempting an emergency stop. If the system determines that is the case, it applies additional brake pressure to allow the driver to take full advantage of the ABS brake system. When the driver intentionally eases up on the brake pedal, the system reduces the amount of assistance it provides. This feature comes with VSC.

Not sure I like it now that I experienced it. If someone was following close, there's no way they would have stopped as quick as I did and they would have rear-ended me. I appreciate the fact that the vehicle can come to a stop so quickly, but I'd like to have a little more control than that.

 

[Ryan_S]

Not sure I like it now that I experienced it. If someone was following close, there's no way they would have stopped as quick as I did and they would have rear-ended me. I appreciate the fact that the vehicle can come to a stop so quickly, but I'd like to have a little more control than that.

+1 I wish all these "inexperianced driver" aides had an off button.

 

[SeattleMike]

You panicked, it did what it was supposed to do. Don't blame the truck.

 

[Treestand]

It's the dumbing down of the masses. Most folks on this forum know how to drive and know how to stop.

I've had the brake assist engage a couple times when I didn't want it to, and was concerned about getting hit from behind too. Luckily my dog wasn't in the runner or he would have got hurt. I'm actually finding myself braking less forcefully than I should sometimes just to keep it from engaging.

 

[Ryan_S]

Is it always gas to brake that activates it? Or could it be coasting to hard braking as well?

 

[pokwa]

Driving on a side street today and came to the top of a hill and was suprised by a school bus coming the other direction with their stop lights on. I didn't think it was a panic braking situation, but the 4R obviously thought it was. I felt I could stop without having to apply full brakes. I must have reacted so fast and pushed harder on the pedal than what I normally do and the anti-locks engaged and the tires chirped while coming to a stop.

I've been in panic braking situations in other vehicles before ('03 Ford Explorer for example), but this really suprised me. It almost felt as if the 4R had a mind of it's own and thought it needed to come to an immediate stop when I really didn't need to (the bus was far enough away that I felt I would have been able to stop on my own). It kind of scared me a little, so wanted to know if anyone else had this experience yet (I think I remember reading a thread here about a similar situation, but couldn't find it).

It was happened to me yesterday.When I was driving with around 55 mph,I didn't realize that red light was a head and I was looking to the other direction.I suddenly pressed the break and anti locks system engaged. I almost hit the car in front of me but the car did stopped. Another thing I realized was,the vehicle was dragged to the right side,I didn't know why.

 

[westwind77]

(I think I remember reading a thread here about a similar situation, but couldn't find it).

You are right, it was mine....

http://www.toyota-4runner.org/5th-gen-t4rs-its-finally-here/62268-braking-hold-tight.html

It does work well and stops you quick, only had it engage just that once so far, but less the 3k on it so far, time will tell more.

 

[adoihcj]

You panicked, it did what it was supposed to do. Don't blame the truck.

Not blaming the truck at all. If you were in my situation (again, it wasn't necessary for me to come to a full stop as abruptly as it did), you would understand what I'm trying to explain.

 

[SeattleMike]

Not blaming the truck at all. If you were in my situation (again, it wasn't necessary for me to come to a full stop as abruptly as it did), you would understand what I'm trying to explain.

I do understand, it's happened to me twice. What I am trying to say is that the problem is that you are not used to *this* truck's braking. Once you become used to it, you won't brake the same way and you won't have the problem again.

But the truck is working as it should, while you implied it was bad design. Had you not overreacted when surprised by the school bus, you wouldn't have triggered the assist. You seem to expect the truck to read your mind, rather than you learning what to expect from the truck.

 

[chimyz]

The truck penalizes you for having lighting fast racer reaction times...kinda sucks. I vote for a mod to disengage this, perhaps the dealer can shut it off?

 

[TTown]

Just to clarify' Brake assist will not bring the vehicle to a complete stop. Once you let off the brake, brake assist will disengage.

If the vehicle came to a complete stop then one of two things happened:

1. You kept your foot on the brake

2. Something went wrong with the sysyem and you should get it checked out.

Brake assist is not a new feature and has been used by Toyota/Lexus since 1999. My initial guess would be that your foot was on the brake until the vehicle came to a complete stop, but only you would know.

 

[adoihcj]

The truck penalizes you for having lighting fast racer reaction times...kinda sucks. I vote for a mod to disengage this, perhaps the dealer can shut it off?

This is exactly what I'm talking about (regarding my lightening fast reaction time). I doubt I would want to mod it though because I want to have the system in a situation where I MUST come to a full stop immediately. I just have to get used to it and hope I'm not "trigger shy" the next time I have to come to a panic stop.

 

[adoihcj]

Just to clarify' Brake assist will not bring the vehicle to a complete stop. Once you let off the brake, brake assist will disengage.

If the vehicle came to a complete stop then one of two things happened:

1. You kept your foot on the brake

2. Something went wrong with the sysyem and you should get it checked out.

Brake assist is not a new feature and has been used by Toyota/Lexus since 1999. My initial guess would be that your foot was on the brake until the vehicle came to a complete stop, but only you would know.

That's an interesting comment. I did release my foot a little from the brake but it still came to an abrupt stop. In fact, I stopped so abruptly that my wife of 20 years said "what did you do that for?" She knows how I drive and this even suprised her. Maybe I should have it checked out just in case.

 

[Scoobs]

The truck penalizes you for having lighting fast racer reaction times...kinda sucks. I vote for a mod to disengage this, perhaps the dealer can shut it off?

I doubt the dealer will be able to turn this off. It's a safety feature and it worked exactly the way it was supposed to. It would not have been such a surprise if the OP had been aware of it.

 

[westwind77]

1. You kept your foot on the brake

The 1st time this happens I think people are a little shocked, might lighten up on the brake a little, but not fully release it. Plus when you get slammed that hard forward suddenly it is not that easy to pull your foot from the brake. I think as time goes on, and people get used to how the system works, if it is triggered the person should be able to compensate for it without the surprise factor.

 

[ciaz]

The brake assist in my Infiniti G35 was much more intelligent than our 5th gen 4runners... I've had several false interruptions already, however, i did almost hit a pedestrian with my new 4 runner, so it's a trade off.

 

[M1911]

Yup, brake assist. I believe Mercedes was the first to develop it. Their research had found that in accident situations most people did not push the brake pedal hard enough to get maximum braking, but that most people did push the pedal down very quickly. So the system looks for the speed of brake application -- if you push the pedal down very quickly, but not all the way, it assumes you are in an emergency and boosts the braking power.