Topic: Auto Tech: Unintended acceleration

[Autos_Editor]

Sticky throttles and unintended acceleration can be a frightening experience, but there are simple ways to manage this problem in those relatively rare occasions when it happens, says Technical Editor Jim Kerr.  The first rule is, “Don’t panic!”

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[Mark H.]

I have a 2005 Toyota Sequoia. The family loves this car and it's always the first thing we go for on long trips etc.. The Toy has 105K on it and other than lots of brakes, we  haven't had  a single mechanical failure to date!

 My assumption is every new Sequoia is sold with the factory mats. Our mats have one hook located on the lower left and ride side. Even with the mat attached, I remember the driver side mat interfering with the accelerator. This happened the first couple years of ownership. My fix was to simply pull the matt out and reposition it on the floor. No big deal.. Thinking about it now, I haven't seen the problem in a couple of years. My guess is the mats are so worn down they stay "glued" to the floor.

[Shnak]

Most drivers automatically try to stop the vehicle with the brakes. The brakes will work, but there is less engine vacuum available with the throttle open so any vehicle with vacuum-boosted brakes (which is most of them) will have less brake assist. It may feel like there are no brakes, but that�s not the case; shifting to Neutral helps here.

You could turn the ignition key off, but there are dangers here. First, with the engine off most vehicles lose their power steering. There is still manual steering, but it will take more effort and you need to be prepared. Secondly, if you turn the key too far, it could lock the steering on some vehicles. Most vehicles have an interlock that prevents the steering from locking unless the transmission is in park, but not all do. Simply turn the key to the off position � not to lock � and be prepared to use manual steering and brakes while coasting safely to a stop.


Great info there, especially the part about locking the steering wheel if turning the key too far. You can easily imagine someone doing this while panicking with disastrous results.

In these situations, panic is the enemy.

[jitsu303]

Jim, you failed to mention that the Audi unintended acceleration was one of Dateline's many automotive hoax's (remember the GM sidesaddle gas tank scare?)

[Alex]

My thanks to Jim for being on the neutral side of the big3 - paid hoopla, and providing some historical insight too. Thanks for vindicating Toyota!

[blur911]

Jim, you failed to mention that the Audi unintended acceleration was one of Dateline's many automotive hoax's (remember the GM sidesaddle gas tank scare?)

Yeah, the article represented the Audi debacle as if it actually happened. 

BTW, it was 60 Minutes, not Dateline in the Audi hoax.

[Whofan]

Run away Toyota story is the most stupid thing I have ever heard.

Been there done that.

Just put the vehicle in Neutral (auto or standard), coast to the side, turn off vehicle, so the engine revs high, so what.

my 2� anyway

(...ops, I had a typo)

[new age group]

The whole Toyota pedal thing makes me laugh sometimes.

If people don't know what to do when a vehicle's gas pedal is stuck, they should not be driving at all ..... period. Take away their driver license if they panic ......  ... they should not be driving. ....

I think if anyone involve in a car accident that is caused by gas pedal stuck, the driver should be charged ......



Put it to NEUTRAL!!!!!!


The good thing about the recent Toyota problem is that I can prepare to shop for a once in a life time good deal on a new or slightly used Toyota.

I am hopping people who have a 2009 Rav4 / Venza etc... they are panic and traded in their Toyota and drive down the resale value a lot and I will be shopping for bargains!!!!!

 

[edcar]

I am wondering if anyone has the answers to some of my questions below.

I have been watching the runaway Prius story out of California...a police car pulled in front to assist the Prius to a stop. Some stories noted that the driver tried to put it in neutral but it wouldn't go. I know the Prius has a unique shift knob, but is there any possibility that it cannot be put into neutral while driving? It also has the push button start feature...how would that keyless start system available on many vehicles work here? Do you just press the button and the engine shuts down? And what would happen regarding steering lockup in that scenario? Cheers!

[blur911]

My first encounter with unintended acceleration was when I was a teenager driving my dad's truck, a 1981 F150 with a 302 automatic. It was on snowy roads and very, very cold and I was on my way home very, very late one night.
 
The linkage had frozen up when I was about halfway home.  I could push it further, which I of course did by kicking at it when it first froze at about 1/4 throttle, it was quickly to the floor and lifting it back up didn't do anything so I shut the engine off and coasted to the side of the road. 
I got out and under the hood, pulled back the frozen linkage to idle position.  Started the truck again, very loudly blew up the muffler, checked my shorts and then proceeded home at about 50kph (after a few judicious taps of the throttle which stuck again) while waking everyone for the last few km because of the aforementioned exploded muffler. Then I had to time shutting off the truck in time to still coast up the driveway without running through the garage.  Made it fine, coasted far enough I didn't even wake my parents.  Dad was impressed when he started the truck in the morning.

The other encounter was with a VW Jetta 5-speed I was driving down the 401.  Again it was stupid cold out and the throttle linkage had frozen where it could go more open, but wouldn't close on it's own.

 I drove about 30 km to my exit at about 130kph, a bit faster down hills, (back when that was the normal speed on the 401 and we weren't so frightened)   It was like having adaptable one-way cruise control.
 
When I got to my exit I braked, it was not a problem even without putting it in neutral (not the most powerful of engines in that Jetta). I shut the engine off on the off-ramp, slowing and coasted to the end of the ramp where I put it in 2nd, turned the ignition back on and let out the clutch starting the engine, bounced it off the rev limiter a little while slowing to a crawl at the stop sign,  then proceeded on home. 

I shifted by shutting off the engine and then restarted it by letting the clutch back out again, much easier on the drivetrain than dropping the clutch at redline every shift.  Plus because it was injected, not carbed as my dad's F150, no explosions in the exhaust.


I once saw a 500hp RX-7 do about 3 donuts in a parking lot at full throttle before the owner shut it off.  That was interesting. 

[safristi]

..one good point.............Fantino's RACING LAW IS TOAST...............

[Ben1004]

Back in the 80's I once owned a new toyota Celica and drove it for 8 years .   First, I must state that that particular car was the best car I had ever owned....period!  I remember though, the factory mat was impeding the accelerator once in a while.  It was a stickshift so I tended to press the accel pedal pretty deep after I changed gears and it was sticking to the edge of the mat on the way back up.   It got better once the mat got older and worn out.    Even though factory mats look good, I now use aftermarket mats made of heavy rubber(I live in a snowy area now) in my Chevy and never had such problems.  Of course I do not floor the accel like I used to in my old cars.  I can say that this problem was present way back then and I am surprised this is still an ongoing problem to this day. 

[Prius Owner]

I am wondering if anyone has the answers to some of my questions below.

I have been watching the runaway Prius story out of California...a police car pulled in front to assist the Prius to a stop. Some stories noted that the driver tried to put it in neutral but it wouldn't go. I know the Prius has a unique shift knob, but is there any possibility that it cannot be put into neutral while driving? It also has the push button start feature...how would that keyless start system available on many vehicles work here? Do you just press the button and the engine shuts down? And what would happen regarding steering lockup in that scenario? Cheers!

It appears, Mr. Spikes, the driver of the Prius, pulled a hoax.  He is now being investigated by the Police.

[Leviathan]

It appears, Mr. Spikes, the driver of the Prius, pulled a hoax.  He is now being investigated by the Police.

Link?

[sailor723]

Nothing in Google news about this being a hoax..

but I did find this....http://www.wptv.com/news/state/story/prius-toyota-brake-accelerator-wptv-california-tun/8mrwUTAFhUC8oZduNXD06g.cspx

[sailor723]

It appears, Mr. Spikes, the driver of the Prius, pulled a hoax.  He is now being investigated by the Police.

Link?

You know,even if this one is not a hoax there are bound to be copycats out there. It could be anything ranging from wanting their 15 minutes of fame to wanting a nice fat settlement from a suit against Toyota. It's too bad because it's only going to cause confusion and make getting to the bottom of this issue even more difficult

[BarryM]

..one good point.............Fantino's RACING LAW IS TOAST...............

SHUT UPPPPPPPPPPPPPPPPP

[Rupert]

I had a sticking accelertor peddle years ago. We used to have to drive in temperatures down to 40 f below zero and stuff used to happen...you just got on with it. No mats were in the way; it was just the horrendous cold on the mechanisms that caused it.
I have never had a floor mat that interfered with the accelerator or had the ordinary potential to. Never owned or driven a Toyota though.

[Guy]

In the 70's I had a Yamaha RD-350 whose throttle would stick when it rained. To prevent the engine from racing while shifting I used the kill switch...I'm still alive...

[X-Traction]

...assuming the California Prius story is not a hoax..., there's a lot that can be learned from it.

Much of the speculation about unintended acceleration has promoted the idea that the driver caused it by pressing on the gas pedal instead of, or at the same time as, the brake pedal.  That may be easy to conclude for brief incidents, but in this case the event went on for something like 20 minutes.  Surely the driver would figure out a pedal application problem during that much time.

There have also been tests showing clearly that brakes in good condition have more stopping power than any car's engine power.  But in this case, the brakes obviously overheated. The "why" may be explained in another article recently posted on this site.  Under high throttle, vacuum boost is reduced. The driver may be pressing on the brake pedal harder than they ever have, but may not be braking very hard.  Most of us know how you have to stand on the brake pedal if the engine isn't running.

I believe a quick application of the brakes can stop a car with the throttle on fully.  But we also know how brakes can get overheated by relying on them to get down a long steep hill.  So if they were only partly applied, they would soon overheat under full throttle.  This is different from tests that show (cool) brakes are more powerful than throttles.

People also suggest victims of runaway cars shift into neutral.  I understand the driver in this case said he has a stick shift, and was afraid to remove one hand from the steering wheel.  I once drove a '64 Chev Suburban with a V8.  It had a problem that was around back then.  The engine mounts would break, and if you floored it with a broken mount, the engine would shift and jam the trottle on full blast.  Your arms were too fully occupied with steering the careering vehicle to do something like shift or turn off the ignition.  This is even if you don't panic.

The officer suggested the driver use the parking brake.  If a car has rear drums, they will already be overheated.  If it has rear discs, it will have small drums for the ebrake.  They simply don't have the capacity to be much help.

The other misconception about the Prius incident comes from the picture of the cruiser parked with the Prius against its' rear bumper. It looks like the cruiser acted as a blockade to bring the Prius to a stop.  Probably they parked that way "just in case" after the Prius driver did manage to get the thing under control and stopped.