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The tail of a comet is not suspected to be the cause of unintended acceleration

Toyota has been hit hard with widespread issues with its Prius and other cars that have suffered from glitches with brakes or unintended acceleration. Toyota was forced to recall a large number of its vehicles to install new parts to prevent wear of the throttle pedal that was the cause of some of the issues.

The last headline-making bout of unintended acceleration happened in early March when police in California had to help a motorist who was reportedly unable to stop his Prius from accelerating. reports that the U.S. Transportation Department has announced that it intends to launch a pair of major investigations that will seek to determine if vehicle electronics or electromagnetic interference are to blame for unintended vehicle acceleration incidents that have been rampant recently.

The investigations will be headed by the National Academy of Sciences and the other will be run by NASA. According to U.S. Transportation Secretary Ray LaHood, the investigations will not focus on Toyota alone and will focus on all manufacturers. So far, Toyota is the most affected of the automakers and the recall to fix issues with floor mats and throttle pedals has covered 8.5 million of the automakers vehicles so far.

Since 2000, a total of 3,000 complaints including 51 deaths have been linked to Toyota vehicles that failed to stop accelerating. Toyota maintains that EMI and electronics are not the cause of the issue and that trapped or malfunctioning pedals are the cause.

"Many members of Congress think it's electronics and I heard enough of that -- not only from members but from Toyota drivers ... and so we felt we really needed to get outside experts," LaHood said. "We are tapping the best minds around." 

Toyota added, "We expect they will bring a thorough and scientific approach to their examination of the issues. Separating fact from fiction can only be good for the motoring public and the industry as a whole. We are confident in our vehicles and in our electronics. We will lend our full support and cooperation to DOT and NHTSA as they moved forward."

The investigations will reportedly last 15 months and will seek to find and address any safety issues with any vehicle on the road today in America. All possible causes for unintended vehicle acceleration will reportedly be investigated including electronics, human error, mechanical failure, and interference with accelerator systems.

According to LaHood, the department will spend $3 million on the two studies including the cost of buying cars that have allegedly suffered from unintended acceleration. The NHTSA has brought in engineers and other experts for the investigations on topics such as electromagnetic compatibility among others in an attempt to determine if flaws in vehicles on the road warrant a defect investigation. The review of the Toyota electronic throttle control system is expected to be completed by late summer reports the NHTSA.

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RE: Big Brother Getting to the Bottom of it all!~
By rvd2008 on 3/30/2010 3:11:55 PM , Rating: 2
ok, I will bite one more time. Watch this

It explains why you can not stop a car if throttle is wide open and you lost break power assistance. This is a fact.

RE: Big Brother Getting to the Bottom of it all!~
By porkpie on 3/30/2010 3:24:31 PM , Rating: 3
Response from a test by Car and Driver:
With the Camry’s throttle pinned while going 70 mph, the brakes easily overcame all 268 horsepower straining against them and stopped the car in 190 feet—that’s a foot shorter than the performance of a Ford Taurus without any gas-pedal problems and just 16 feet longer than with the Camry’s throttle closed.

Same test by
The third test simulated a racing engine causing the car to speed out of control and the driver reacting by just hitting the brake pedal as hard as possible. Even though in this case the brakes had to overcome the motive force of the engine, they did. The car came to a halt in 148.8 feet, a distance that perhaps a large, heavy-duty pickup might make under normal maximum braking. With practice (this is, after all, a non-standard test), Josh was able to whittle this distance down to 129 feet. In other words, even if the driver of a runaway car (well, a Camry, anyway) doesn't think to put the transmission into neutral before hitting the brakes, it is still possible to stop the car within a reasonable distance if sufficient pedal force is applied.

Same test by Motor Trend Magazine:
we devised a simple additional test: We accelerated each of the cars to just under 60 mph, floored the gas, and then within two seconds nailed the brakes while keeping the gas pedal floored. We then measured the distance it took to bring each of the cars to a complete halt from 60 mph, and compared that to our tested 60-0 mph braking distances. Same cars, same track surface, same driver.

By Chillin1248 on 3/30/2010 6:43:17 PM , Rating: 4
And to finish up his point, here are Toyota's findings regarding the runaway prius:

• The accelerator pedal was tested and found to be working normally with no mechanical binding or friction. It should be noted that the Prius is not subject to a recall for sticking accelerator pedals and the Prius component is made by a different supplier than the one recalled.

The front brakes showed severe wear and damage from overheating. The rear brakes and parking brake were in good condition and functional.

• A Toyota carpeted floor mat of the correct type for the vehicle was installed but not secured to the retention hooks. It was not found to be interfering or even touching the accelerator pedal.

The pushbutton power switch worked normally and shut the vehicle off when depressed for 3 seconds as the 911 operator advised Mr. Sikes to do.

The shift lever also worked normally and neutral could be selected. The neutral position is clearly marked and can be easily engaged by moving the lever left to the “N” marking.

• There were no diagnostic trouble codes found in the power management computer, nor was the dashboard malfunction indicator light activated. The hybrid self-diagnostic system did show evidence of numerous, rapidly repeated on-and- off applications of both the accelerator and the brake pedals.

• After examination of individual components, the front brakes were replaced and the vehicle was test driven, during which the vehicle was observed to be functioning normally.

During testing, the brakes were purposely abused by continuous light application in order to overheat them. The vehicle could be safely stopped by means of the brake pedal, even when overheated.

And finally:
The Prius braking system uses both conventional hydraulic friction brakes and a regenerative braking system which switches the electric drive motors into brakes to generate electricity.

The system features a sophisticated self- protection function which cuts engine power if moderate brake pedal pressure is applied and the accelerator pedal is depressed more than approximately 50 percent, in effect providing a form of “brake override.”

This function, which is intended to protect the system from overload and possible damage, was found to be functioning normally during the preliminary field examination.

Toyota engineers believe that it would be extremely difficult for the Prius to be driven at a continuous high speed with more than light brake-pedal pressure, and that the assertion that the vehicle could not be stopped with the brakes is fundamentally inconsistent with basic vehicle design and the investigation observations.


By lyeoh on 3/31/2010 12:50:35 PM , Rating: 2
If it's that Sikes guy you are talking about , unless there's lots of bad reporting, apparently he claimed to have reached down with his hand to pull up the accelerator...

He was repeatedly told to shift to neutral but refused because he claimed he thought it was unsafe, and yet he still dared reach down and try to pull up the accelerator while his car is speeding along?

Toyota cars _might_ have "unintended acceleration" problems, but that guy is unbelievable.

On the other hand the case of Juanita Grossman prevents me from confidently blaming the drivers and saying it's not Toyota's fault. Perhaps Grossman did screw up at first, but who knows, the evidence has gone cold or has been destroyed.

RE: Big Brother Getting to the Bottom of it all!~
By gsellis on 3/31/2010 8:43:13 AM , Rating: 2
It was not a Camry. It was a Prius. The Prius has regenerative braking, ABS, and master ECU all tied together. When it finally fleshes out, I will bet that the fault is in error handling from the ABS module.

As far as Camrys go, this proofs that if there is no lockout by any of the systems, the brakes will stop the car.

By porkpie on 3/31/2010 12:18:57 PM , Rating: 2
Hello, regenerative brakes use the electric motor to retard movement. This is supplanted by a regular hydraulic system which uses normal brake pads.

Since the brake pads in this Prius were hot and smoking (by the driver's own admission and a state trooper on the scene), the hydraulic system had to be working normally.

Even if this were NOT the case, this case would have required the failure of three independent systems simultaneously (abs, hydraulic brakes, and engine throttle) AND for all 3 systems to magically fix themselves a few minutes later, leaving not a trace for anyone to see.

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