Toyota Recall 7

[keller36]

Hello. I am new to the forum and had a rather extensive question. I am wondering what system is causing the sudden acceleration problems in Toyota vehicles as well as the specific part in that system, if any specific part is respoinsible. I was also wondering, depending on the system involved in the problem, whether the problem is electrical, mechanical, or a problem in the vehicle's software. Thank you for any responses.

 

[MastDesgin]

I would put money that the Camry wasn't the base model with the lowest brakes, also after a few years of driving what happens when your brake fluid has a little water in it (its hydroscopic), you have changed your brakes to the cheap brand, or your not strong enough to depress the pedal enough.

there's a lot of factors that go into it, yes a 2010 brand new v6 Camry with brand new brakes and new fluid and a experienced male driver behind the wheel will probably be fine in the end. Its the few year old models that probably wont.

 

[evelrod]

Brian, the problem, at least with the car that had the throttle surge here in our area a while back, was the driver could NOT select neutral. He was on the surface streets next to the dealer and was able to bring the car into the service department with the engine still surging. Lucky guy, I guess as his problem was at very low speed. None the less, it was not directly related to carpet or APP sensor or TPS as I was told. What does that leave as a causal factor?
I'm not going to jump to the conclusions yet, all this is still 'second hand' and/or media driven. This very well may turn into the "Audi unintended acc" witch hunt...I hope not. I will say, as with the Audi deal, there will be some substantial changes in the way our cars can be shut down in an emergency situation. I'll guess a master kill switch.

Rod

 

[ivymike]

have you checked ebay? if there's not a retrofit master kill switch already there, check again next week for my offering.

 

[70AARCUDA]

+1, another "personal opinion" for 'unintended' software programming results/escapes, probably caused by less-than-100% testing of EVERY possible conditional condition(s).

 

[izzmus]

I wonder how many people have the presence of mind to realize that you can fit TWO feet on the brake pedal of an automatic.

If you can stand up, you can apply a very large amount of force to the brake pedal with both feet, especially if you're pumped full of adrenaline.

 

[MastDesgin]

Izzmus the problem there can be if the engines at WOT you might not have brakes, Brakes use vacuum to boost there effectiveness but if that vacuum goes away (like at WOT) then you only have 1-2 good pushes on the brake pedal before you burn all the vacuum, then even I (6'2 300ish lbs) can put enough force on the brakes to lock them (or even engage ABS). So in a panicked situation where they're trying to stop is the lay person going to know they only have a push or two?

 

[BrianPetersen]

There is no automatic transmission built, that can not be shifted to neutral at any road speed and at any accelerator position.

It is a direct Federal Motor Vehicle Safety Standards violation to be otherwise.

 

[ivymike]

so it would be more accurate to say "there is no... legally built, that..."

that doesn't strike me as a very convincing argument against "it wouldn't shift."

 

[MastDesgin]

I think we can all agree that some of the cases have been driver error, but there have been such a huge volume of them that it cant be the only plausible reason. Too bad they don't make a wrench big enough for the loose nut behind the wheel!

 

[LionelHutz]

Rod - Funny but I recall reading in a version of that story that said he kept shifting between drive and neutral as he drove it to the dealership. He then left it parked outside the service area with the engine racing...

 

[TrackRat]

Folks I can see this is getting to be a hot topic... FWIW, all of the theories were offered a couple months ago when the CA police officer crashed and there were four fatalities.

FWIW, I and others have actually tested numerous vehicles at WOT to see if they could be stopped with reasonable brake effort and all of them could including the Toyota Lexus involved in the CA accident. Most of the car mags have also conducted their own test and seen the same results.

Yes an auto trans does downshift as you are braking and yes the torque multiplication increases and yes even then you can stop the vehicle with the brakes but of course it requires more pedal pressure than normal - which is why some people report the brakes "didn't stop the vehicle". They aren't aware that more pedal pressure is required when the engine is running at open throttle.

Pumping the brakes will eventually use up the brake boost and require even more pedal pressure and that is why people are told to firmly apply the brakes and not pump them. Even at WOT all cars have a reserve of boost assist at first so the brakes most definitely will stop if applied properly. In the case of the CA accident the officer rode the brakes for miles before they finally burned out. The rotors were glowing red with sparks flying off them while he drove which confirms they were functioning. He also failed to shift the trans into neutral or shut off the ignition which proved fatal...

 

[drwebb]

I am also mystified that shifting to neutral, applying absolute braking force, and/or switching the engine off, or even the old 'by cable' counter measure of tapping the accelerator pedal sharply to try and jar it loose are apparently ineneffective countermeasures. They are presumably ineffective because I hardly hear anyone saying 'if this happens to you, here's what you should do'. Could the NHTSA know a lot more about what's going on than they are letting on? At least with the Ford/Firestone problems they issued some PSAs reminding drivers to periodically check their tire pressure.

 

[evelrod]

Lionel, I think your version sounds as good as mine. Like I said, this is all media driven.

Brian, I'm sorry, but in the instances where there is NO mechanical connection with the transmission, where all control is through the ECM, failure to engage is a DEFINITE possibility.

I dislike absolutes. I'm not too crazy about extremism's either. I try to NOT throw a blanket over an entire industry's problems, hard as that may be. Having built and raced cars since 1958 and been around them longer than that, I have seen "the impossible"...at least a couple times.

Rod

 

[bob9250]

ur mom kyle.......ur mom

 

[buddha555]

anyone know any good jokes

 

[BrianPetersen]

Evel, I'm totally with you on the inadvisability of relying completely on the electronics.

But the guy who drove his "sudden-accelerating" Toyota (or Lexus? forgot) to the dealer by shifting between drive and neutral to demonstrate the problem, and countless videos on Youtube of people demonstrating what happens when you shift to neutral at full throttle on a variety of Toyota vehicles, suggests that at least by design intent, there is nothing stopping the vehicle from being shifted to neutral.

I don't dispute that there could be some sort of glitch that might be causing the engines to accelerate. But to simultaneously occur with a glitch that prevents the transmission from being shifted to neutral and prevents the ignition from being switched off and prevents the brakes from being used, AND YET the vehicle operates with all of these systems normally after inspection, sounds like a combination of things so remote in possibility that they would never happen together unless there is something deliberately causing this to happen.

A lot of parties including Toyota are defending the electronics as being more fault-resistant than mechanical systems, and I can't really dispute that. But what I can say is that programmable electronic systems are much more difficult to validate for proper operation than, say, a mechanical system, or an electrical switch that has mechanically opened contacts, or a direct mechanically operated hydraulic spool valve inside a valve body. I don't like the complete reliance on electronics for safety related systems. But it's hard to dispute that the most likely underlying cause, is driver error. (Or people abusing the system, trying to create a situation where they can file a lawsuit.)

 

[evelrod]

I agree that there is a lot of wiggle room in the 'honesty' dept. Still, the volume of complaints that Greg linked us to is astounding. Especially since they were made before the big bruhaha about the Lexus crash in San Diego. I've always believed the "smoke/fire" cliche. One thing for certain, we have not heard the end of this Toyota thing. Too bad for the auto industry. I agree with what Greg said, that it's a shame when an engineer is faulted for only being 99.9% right.

Rod

 

[YvesLLewelyn]

I don't know if anybody has mentioned it - but can the electric motor/battery part of the Prius suddenly come to life unexpectedly - with or without the petrol motor? Turning off the ignition is not going to stop the electric motor. Can the electric motor be put into "neutral" or otherwise mechanically disconnected from the drive train?

 

[BrianPetersen]

No, it can't. On a Prius drivetrain, the motor/generators are inherently permanently connected. Even in "neutral", all it's doing is telling (via software) the motor-generators to not deliver output torque in the direction of acceleration. It doesn't stop braking. Or at least, that's the design intent. That particular vehicle is *totally* reliant on software.

We are FAR from hearing the end of this. The problem is that as software becomes more and more complex, the probability of that software being absolutely error-free becomes lower and lower.

Should also note that Ford's hybrid system is every bit as software-dependent as Toyota's, since it uses essentially the same mechanical layout.

 

[dicer]

I personally have lots of experience in my little car with the accelerator sticking. It does it constantly because of the after market cruise control I installed some years back, the cause is the ball chain is too short and gets caught in the cable sheave, and there no quick cure for it.
The first time it happened it was a surprize, my reaction was to tap the pedal, and then push clutch in and key off, all with in micro seconds of each other, so yes the driver and skill plays huge in a situation like that.
As far as brakes stopping a car with WOT and at speed, maybe with the right driver and conditions, I would think someone would have a very difficult time after getting into fade due to the heat factor, I have been into that many times in years past, its like hauling a trailer twice the vehicle weight and without trailer brakes.

If these problems are not an electric and or computer fault, then it is something commandeering the system.
I have questions, did all these cars have ABS? What other systems are run through the PCM or BCM ? I remember hearing many years ago about ABS applying the brakes when ever without driver input, or cases where the driver hit the brake pedal and there where zero brakes.
Can the computers in these cars isolate the ignition switch?

Also I remember seeing a system that was created for police agencys, that gave them the ablity to shut off the engine fuel and ignition systems in a chase, so commandeering is not out of the question. Just curious.