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Toyotas Suddenly Accelerate; Owners Up In Arms
cyclocommuter writes "Some Toyota owners are up in arms as they suspect that accidents have been caused by some kind of glitch in the electronic computer system used in Toyotas that controls the throttle. Refusing to accept the explanation of Toyota and the federal government (it involves the driver's-side floor mat), hundreds of Toyota owners are in rebellion after a series of accidents caused by what they call 'runaway cars.' Four people have died." The article notes: "The National Highway Traffic Safety Administration has done six separate investigations of such acceleration surges in Toyotas since 2003 and found no defect in Toyota's electronics."
Throttle by wire has been proven to be extremely responsive. More importantly, it is part of a closed-loop operation, whereby the ECU can properly evaluate requested levels versus actual in pretty much everything. If the fuel line is pinched, for example, flooring it would cause devastating detonation, EXCEPT in "by wire". Once the fuel present was mismatched to the air, the ECU would force the throttle to close somewhat, regardless of pedal position. The exception is in many cases of a wide open throttle request, when some output levels like fuel overrich are ignored, and the ECU uses an internal map of what "should be going in and out, given the max power request.
It is exceedingly easy to test the Throttle Positioning Sensor in modern vehicles. In fact, your ECU probably tests idle throttle position every time you turn the key on for a while without staring the engine. The ECU will also log 'implausible signal' for TPS that get an out of range reading, or inconsistent reading throughout the range.
Note: This information was gathered while researching diagnosing my personal car, a B5 Audi S4. It is a summary, not the automotive gospel.
This sounds like people getting paid for being stupid. I do not approve, but who am I, eh?
How do you think the speedometer that the odometer is connected to works?
Besides, wheel radius on a car is variable and is constantly changing. This is one of the primary reasons that speedometers read fast - the car maker provides a conservative buffer to ensure that no matter what your tire wear, air pressure and wheel size are, there is a much better chance of you traveling equal to or slower than the displayed speed, as opposed to faster than the displayed speed.
The government & Toyota are probably right about the floor mat. But that's what recalls are for.
This is exactly what happened to me and I was heading to a cliff - 3rd gear - floored and I had the presence of mind to turn off the ignition. Seriously - I was terrified.
Picture this, you turn a corner, accelerate, change gears, and suddenly you are going around 80 Km/h with about 1 block to the edge of cliff and a 90 degree turn on a residential street with a cliff in front of you.
I had the time to turn off the ignition and jerk to a stop... BTW taking it out of gear under full acceleration is not simple either. I can hear the vacuum cleaner sound of the engine too - it was crazy. However, when the engine red-lines - it kill the accelerator for a second and then lets it restart... grabbing the ****ing anything with that is un-fun.
AFTER it stopped I could diagnose the problem being that the driver's side floor mat came off the hook that is supposed to hold it in place and inched up over the gas-pedal... thus couldn't un-press it until the carpet was pulled back.
Since there was a slot in the peg that holds the carpet in place, I took a handy dandy twist tie and wrapped the peg with the carpet in place preventing the carpet from EVER popping off that peg. Since then - no scary shit.
Toyota and Nissan should fix this problem - at their cost - and it should be a recall. - After all - it's a 10 cent fix - a peg that has a simple spring latch on top would fix it with no problems. Picture hanger anchors have used that technique for decades now.
The Audi 5000S was never defective...
It might be true that some people hit the wrong pedal, but I actually owned an Audi 5000 Turbo and experienced sudden-acceleration.
I was driving down an Interstate highway in Texas, when the car suddenly began accelerating. I was on cruse control, and my feet were not touching any pedals. Since I'm comfortable at high speeds (past racer) and the weather and road were good, I was pretty calm. I put my foot behind the accelerator pedal and pulled back. It moved freely. I realized the cruse control had opened the throttle wide open.
I tapped the brakes to shut down the system. The pedal wouldn't move. I pressed hard with both feet, and could feel the arm flex, but it would not move. Realizing I had no brakes, and a wide open throttle, I hit the dash switch to shut off the cruse control. As the car slowed, the brakes slowly became operational. I noticed the turbo boost gage was now reading negative pressure. When the turbo boost was on, you could not apply the brakes.
It turns out that there was a check valve between the intake manifold and the brake booster. If it leaks/leaks, then high pressure air prevents the application of the brakes.
My belief is there was a bug in the cruse control, or it was susceptible to outside interference (trucker with hopped-up CB radio?) Combine that with the check valve issue and you have a car that could very well exhibit the behavior that 60 Minutes indicated. Those people said the car suddenly accelerated and the brakes didn't work. And that matches my experience exactly.
I contacted Audi USA, but they blew me off. The dealer didn't care either.
I'll let others argue whether this is a 'defect', but I've been cured of ever buying another Audi.
Place nail here >+