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Unintended Acceleration - Find the Cause

2237 messages,  Last post on Feb 26, 2013 at 1:36 AM

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What is this discussion about? Toyota, Hyundai, Lexus, Ford, Audi, Automotive News, Legislation

Messages Page 220 of 224

#2191 of 2237 Re: Forget the Red Button [wwest] by Stever@Edmunds HOST

Dec 12, 2011 (3:42 pm)

Replying to: wwest (Dec 12, 2011 3:07 pm)
Better spring for the ejection seat option.

#2192 of 2237 Re: Forget the Red Button [steve_] by plekto

Dec 17, 2011 (11:55 am)

Replying to: Stever@Edmunds (Dec 12, 2011 3:42 pm)
Considering that a typical PC power supply uses a similar "push for three seconds to power off" circuit in it, and often it will simply NOT respond and require you to manually hit the power switch on the back of the computer, the only proper solution would be to install a switch under the dashboard that kills the power to the entire computer. Of course, it should be a big 10+lb hard to move switch like you see on old vacuum cleaners and the like.
 
The other option, of course, is to just drive a manual. Clutch in, move to neutral - problem solved, even if the engine is still going crazy.

#2193 of 2237 Re: Forget the Red Button [plekto] by houdini1

Dec 17, 2011 (4:02 pm)

Replying to: plekto (Dec 17, 2011 11:55 am)
Don't manuals have computers in there somewhere too?
 
Many here have said that in Toyota's case, the computer would not let you shift into neutral...so I guess the computer could also stop you from shifting into neutral with a manual.
 
The darn thing would also probably prevent you from pushing the kill switch.
This whole thing was a tempest in a teapot. Driver error explains everything.

#2194 of 2237 Re: Forget the Red Button [houdini1] by plekto

Dec 21, 2011 (8:40 pm)

Replying to: houdini1 (Dec 17, 2011 4:02 pm)
A manual transmission has a clutch, though, which acts as a purely mechanical means of physically pulling the gears apart. And most manuals have a similar setup for neutral as well where it physically moves the gears out of contact with each other.
 
You'll note that not a single case of UA involved a manual transmission vehicle, though there were a few reports of engines racing out of control.

#2195 of 2237 Re: Forget the Red Button [plekto] by kernick

Dec 22, 2011 (2:48 pm)

Replying to: plekto (Dec 21, 2011 8:40 pm)
Agree that a manual, mechanical device is the best way to assure the driver has the ultimate control. Electronics can freeze-up for no apparent reason. The best example of electronic controls not working at all times, is waiting for you to type on it. How many devices and times have you found the best way to fix an electronic problem is to reboot or power-down?
 
My suggestion was a lever or handle under the dashboard, attached to a rod to a ball-valve in the fuel-line. Normally it is fully open. You need to kill the engine in an emergency you turn the handle 90-degrees. With no new fuel, the engine dies in a few seconds, no ifs ands, or buts.
 
Sensors and other electronics are convenient, nice, and usually work. When they don't, the average person is going to have a hard time making the right choices.

#2196 of 2237 Re: Forget the Red Button [kernick] by carguyfrank

Dec 22, 2011 (2:55 pm)

Replying to: kernick (Dec 22, 2011 2:48 pm)
Why not just shift into neutral then apply the brakes....

#2197 of 2237 Re: Forget the Red Button [carguyfrank] by houdini1

Dec 22, 2011 (6:36 pm)

Replying to: carguyfrank (Dec 22, 2011 2:55 pm)
Their claim is that the computer sometimes can prevent you from shifting into neutral with an automatic transmission.
 
Does anyone know of a documented situation where someone was prevented from shifting into neutral due to computer malfunction?

#2198 of 2237 Re: Forget the Red Button [houdini1] by wwest

Dec 22, 2011 (7:17 pm)

Replying to: houdini1 (Dec 22, 2011 6:36 pm)
A documented sitution is not really required...
 
The "shifter" does not directly shift gears, it only changes the open/closure of a switch set/group that directs the ECU, computer, as to which gear (or not) you wish to be in.
 
Beyond that all you need to know is that computers often "crash" or get locked in executing a "deadly embrace.
 
No computer "monitoring", "polling" those switches, no shift into neutral.

#2199 of 2237 Re: Forget the Red Button [kernick] by wwest

Dec 22, 2011 (7:24 pm)

Replying to: kernick (Dec 22, 2011 2:48 pm)
"..My suggestion..."
 
No, the simple, simplest, solution is to have an independent computer, separate control channel, watching the EFI injectors' PWM and the brake light switch. If the EFI's PWM doesn't drop to idle level with the brake light switch "on" then the "separate channel/path" control computer will open (relay) the EFI circuit.

#2200 of 2237 Re: Forget the Red Button [wwest] by houdini1

Dec 23, 2011 (7:05 am)

Replying to: wwest (Dec 22, 2011 7:17 pm)
In your personal experience, have you ever known of this to actually happen?
 
I can give you several instances which happened to me back in the '60's where various MANUAL transmissions got hung up and would not shift at all. Our family had a fairly new International pick-up where gears would hang up. We also had a Nash Rambler that this would happen to. My brother-in-law had one of those small Metropolitans, and the gears would frequently hang up.
 
All manuals.

Messages Page 220 of 224

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