My Theory on Toyota's Unintended Acceleration Problem

You are entitled to your theory, of course, but I find it weak, as noted below.

Not true at all. All cars today use computers to control a wide range of vehicle functions. The Prius is similar in this respect to all other cars, and nowhere near as complex as, say, modern aircraft.

Apparently this is due to extreme over-precaution. A pilot (sitting next to me and using his cell phone while we were in the air) told me that there was ONE airline accident ONCE where the investigators postulated a possible cell-phone interference, after they were unable to find any other explanation. They had no positive evidence that the cell phone was the cause. But because of the litigious nature of our society, and the fact that nobody ever gets fired for recommending that something be prohibited, cell phones were prohibited on commercial aircraft.

Mr Sikes "may have" done or had anything you care to speculate. He "may have" had a psychotic pet hen who caused his accident by telepathy because he forgot to feed her that morning. Your speculation about what he may have had or done is useless. I suggest you find out what he DID have or was using before you offer arguments of this nature.

Several million Prius drivers have never experienced unintended acceleration. Your argument (that bluetooth is at fault because you have made calls without it and had no problems) is silly and illogical in the extreme. You can rule out a cause if you can demonstrate that the cause existed and did not cause a problem. You cannot indict a cause based on the fact that you do not have that cause, and have no problem.

 

My theory is oompa loompa's causing the problems. I think they jump out from under the dash when you're not looking and hold the pedal down. If they can transport a chocolate bar across the TV airwaves, there's no telling what they can do!

 

Though the OP has a point, I too find it weak. There are so may electronic devices these days and if the theory holds any weight, then there would be more incidents involving haywire ECUs. What about a modern bus with dozens of passengers with blue tooth enabled smart phones? I don't hear too many stories about runaway buses. I could go on and on, but I think you know where I'm going with this.

 

The OP's theory is not impossible, but nor is it likely. RF interference, if it could get into the CAN bus, would increase the error rate on the bus, not produce false messages. If the error rate gets too high, the ECUs will log a code and/or go into failsafe mode.

Tom

 

LOL. That's the best thing I've read all day.

- D

 

It's got to be the iPhone...

 

I agree with your observations, with one critical exception that ensures political correctness. Mr. Sikes psychotic and telopathic pet could, just as likely, have been a hungry rooster.

 

If your theory is corrrect wouldn't there be much more of these occurances starting from the time this option was introduced?
In addition don't some people have laptops connected for added instrumentations and recording data?

 

one would think if the theory is correct, it could be replicated in some form in the lab. i'm sure toyota has done extensive testing to see if any possible interference could occur. but, i'm am not an engineer, or a scientist, nor do i play one on t.v.

 

Some of us have tried RFI experiments; some owners who are hams
have high-power HF transmitters installed in their cars, and I
don't remember exactly where the reference is but Toyota claims
that they test all the electronics both in the lab and as installed
with DC to daylight at 200 V/meter or some fairly high figure.
Sensitive signal lines and computer units are well-shielded. As
others have pointed out, interference from other parts of the car's
own electronics or numerous common consumer devices is not only
fundamentally unlikely, it wouldn't have all of a sudden happened
so many times THIS WEEK and not before.
.
Next?
.
_H*

 

Do you know of any conclusive evidence that communication devices can interfere with modern electronics (car or plane)?

You should be able to test your hypothesis (not theory) - fill your back seat with notebook computers with their wireless radios on, chat on your cell phone, walkie-talkie, wireless home phone, listen to an old CD player ... you can probably also set up a blue-tooth connection from your cell to computer. I'll bet you can still stop your car, and you probably won't even hear your car radio buzzing.

 

There's an app for that.

 

Well...YES and NO....!

Having deat with complex electronics for the last 40 years, I have run across many instances of RF from Walkie Talkies, AM Radio, FM Radio, and even RADAR getting into places where it did not belong. The fix always involved gounds, shielding, and ferrite beads. That usually would take care of the problem.

That being said, as the OP stated, this is one of the most complex package of electronics on 4 wheels. You can bet your nice person, EMI, RFI, and even possibly EMP? (although I kinda doubt that one myself) were one of the first topics discussed at design meetings. I pretty much have dismantled as much as I could when I installed all of my added electronics, including a 50 watt 144 - 148 Mhz, 30 watt 430 - 450 Mhz and 10 watt 900 - 925Mhz NFM Transmitter in my personal vehicle. I have never had a problem with the car while I am "ON the Air" talking, and I can be pretty long winded sometimes.
One thing that I was looking for during the install was Vehicle grounding and Electronics shielding. I did not want to turn on the radios and all I hear was a constant harmonic computer generated buzz. I was quite impressed with both the level of shielding and grounding used in this car. That along with my using proper RF installation techniques, I really hear nothing. If I dont hear it that pretty much proves to me that the shielding is effective enough so that outside RF is not getting in!
I also noted that key ECU's etc. were mounted inside metal boxes, effectively shielding them, the wiring harnesses were wrapped with dense braided cable, such as you would find in RG-213, 9913 etc type COAX. and well gounded. Of course all it takes is 1 bad ground, or a gound point that has become rusted, loose, or broken to screw up the shielding.

The idea is valid, however, if really true, there should have been a hell of a lot more instances of major electical problems. Also, the problems should have been noted right away if a poor design was at fault.
Feasable, Yes...Probable, Maybe...Have I noted it in my car, NO!!!

 

I asked because as far as I know even on airlines there is no evidence that consumer electronics can interfere with the plane. They just can't say it's impossible. I hadn't thought of the effects of a faulty ground though.

 

Hmnnn... as long as we're tossing about crazy theories - how far from Miramar MCAS was this?

- D

 

NO! NO! NO! Oompa Loompas are GOOD little people, grateful for the opportunity to work in a chocolate factory. They'd NEVER do anything like that!

Miramar??? How far from Roswell was it?