But what happens if the driver incorrectly shifts into 4Low when the vehicle is moving too fast? It's kinda shifting by mistake into 2nd gear instead of 4th on a MT, engine can be severely damaged, can shut down.


How do you know that? Toyota was the target of a lot of unfair publicity over crap like 'self-acceleration', which was nothing else but operator error.

If the pedal went all the way to the floor, returned to the top and stepped on immediately again it's going to dump a lot of air from the booster straight to the intake. This could make the engine go extremely lean and die.

So they paid 1.2 billion and did all those recalls because of operator error?

I don't think so. There are also still many cases claiming acceleration while braking still in process.

Although cars are incredibly reliable and safe these days, there are still many oddball flaws that are major safety concerns when they happen. Odds are they will never happen to you...

Toyota learned a lesson from Audi (which had very similar problems)--pointing out that some drivers are idiots (that is, they press the gas instead of the brake pedal when panicked) is a PR disaster. Better business to just pay up and make the issue go away.

Yes, senior citizens panics, steps on gas instead of brake, car doesnt slow down, panics even more, steps harder on the gas... crashes through store front or church crowd.

The 4Runner will not let that happen, just as it will not let you shift into reverse when at speed, the 4R is smarter than its operator.

Ditto on this post.

Last weak (sp) I had to hit the breaks(sp) quickly and scared the shit out of me. It felt like my front bumper was going to hit the ground so I quickly let off the brakes and reapplied similar to what your wife did.

After that experience I went to a quiet road and tried to replicate what just happened and no go. So I understand completely what your wife experienced.

I'm going with operator error until proven otherwise. It can't be brake assist as the brakes have to work in the first place for the assist part to work. It could be electrical but the brakes themselves are hydro-mechanical in their base operation. Electrical only when VSC or ATRAC or ABS is engaged. It sounds like she missed the brake first time, panicked and hit it a second time really fast which activated the brake assist. BTW these brakes won't lock up unless you are only going a few mph. Hey, everyone else has an opinion, so here's mine.

No one in this thread, including OP, was in the vehicle so everything is pure speculation.

We did learn a great deal about 'sudden acceleration' from the previously mentioned Toyota incident. Yes floor mats and other things in the foot well can interfere with the pedals! More importantly Toyota vehicles selected older individuals (experienced) when in 'stop and go' scenarios such as parking.
A Deep Dive Into Toyota Sudden Acceleration Accident Stats - Business Insider Evil Toyota cars!

Wow, what a politically incorrect article! The data clearly shows the people involved in these incidents were elderly or FOB. The media-induced hysteria forced Toyota to pay up.

Of course that could never happen with a manual transmission. Also, panic braking with a MT always involves pressing two pedals (clutch+brake) so it's hard to see how can even an elderly individual can accidentally accelerate in such situations, even if he pressed gas + brake for example.

gas (stuck due to floor mat) + brake (I don't think this was suicide)
CHP Officer, Family Killed in Crash | NBC 7 San Diego

arent the brakes designed to overpower the engine?

Generally yes. It is likely that the driver didn't fully and continuously depress the brake pedal when the brakes seemed to only slightly slow the vehicle (engine continues to rev and power car). Then do you look to put the transmission in N or set the ignition to acc/off? Horrible tragedy!

yes. And it's not even remotely close. The brakes are good for at least 7-800hp. A Camry at full throttle stops FASTER than a Ford Taurus normally. A 4runner brakes are bigger. Even at full throttle you probably wouldn't even notice the difference.

What happened with the throttle body before?

Honestly the description of events that you've written sound odd to me. The problem is that "pushed to the floor" while concise and accurate is also very vague and uninformative in this particular case. What further complicates things is that most people are not over analyzing how they are applying the brakes and due to the very consistent feedback with these hydraulically assisted systems, it is easy to misjudge your actual brake engagement on feel alone.

That being said, IF the pedal went to the floor the first time and then the second time it engaged; it could indicate an issue with the master cylinder portion of the hydraulically assisted braking system (I had a similar issue in my 4th gen: Inconsistent Brake Pedal Travel) Though a sudden onset seems a bit odd, but not out of the line of plausibility. The issue that bothers me is that the supposed issue went away after the initial incident, if the master cylinder portion did fail you'd be able to consistently replicate the issue to varying degrees.

Additionally, the "Assisted Braking" feature is VERY touchy. If the Skid Control ECU saw the operator do a double-tap on the brakes with a sharp increase in brake pressure in a short timeframe it will kick into overdrive and engage full power to the system. When that happens, these vehicles STOP; it's pretty damn impressive! Additionally, the sharp contrast between "normal/light braking" and the "brake assist" mode is so severe I wouldn't fault an operator for feeling that the system was malfunctioning.

Something else to note (and this is more my personal theory) is that the 4th gen & 5th gen Hydraulically Assisted Braking Systems are notorious for a "spongy/soft" feeling pedal because they have extremely consistent brake pedal feel when applying the brakes. This seems to stem from the fact that unlike our hybrid vehicles which use a valve to block off the pedal passage and provide a false feedback to the customer; the 4th & 5th gen units lack this "feedback generator" circuit in the hydraulic system and hydraulic assistance is directly applied to the hydraulic circuit so pedal effort is very light and consistent.

I almost wish Toyota had installed some sort of variable "feedback" circuit (they couldn't effectively block off operator input completely like the hybrid systems because then the vehicle wouldn't stop; this only works with hybrid vehicles because the first 1/4~1/3 travel of brake pedal depression is completely ignored hydraulically by the vehicle in favor of regenerative braking.)

Almost every modern vehicle (even GMs and Ford trucks with their typically soft/sluggish brakes) can overpower the engine easily. I've tested this on a few Toyota vehicles including my 4.7L equipped 4th Gen at Full Throttle at freeway speeds. Unfortunately many people are quick to ignore the human error part of the equation, particularly so when figures of authority and emotions are thrown around. While the above link does state that the operator was a LEO, that does not mean that human error was not a factor. The assumption people make is that because he/she is an LEO that somehow they are masters of vehicle driving technique (which isn't completely erroneous since they do get additional training in driving techniques,) but that doesn't mean the operator couldn't have been caught by surprise and/or not as competent as most assume. Without going into this in great detail (there's been plenty of threads that I and others have gone in great detail on regarding the above situation and others relating to UAI in Toyotas, so I do recommend if you are interested, to search and read through those) the simple fact is that the brakes in every Toyota vehicle will overpower the engine/hybrid system without issue and trying to use links such as the above really comes down to shock & awe tactics without proper context and understanding.

Great post @BlackWorksInc