I confess that until I saw the Nightline segment on this earlier this week, I was unaware of this story. My parents had a Toyota but we don’t have one so I was ignorant.
People should be aware that, though there has been a rash of instances with Toyotas, the phenomenon can happen with any car. It happened to my 80-something mother several years ago, in a Mercedes she had driven since 1986. The car went over an embankment and flipped over on its roof on the pavement about 15 feet below. Miraculously, my mother suffered nothing worse than some bad bruises and blood loss (we still tease her about quitting stunt driving!). Statistically, it’s unlikely to happen to most of us, but the important thing is to know what to do if it should: shift into neutral. I think the ABC website has a good video clip about this.
As to Toyotas, I am suspicious of the claim that it’s a floor mat or accelerator problem. I agree with Stabill that Toyota ought to be more forthcoming about software information.
Until I heard the 911 recording last week I haven’t paid this issue much attention. I’d like to explain a few things. The system in question is called “drive-by-wire.â€
In the traditional normal aspirated fuel injected vehicle, when a driver presses on the throttle pedal a cable directly connected to the pedal pulls on leaver which opens the throttle plate within the throttle body allowing more air into the engine. Essentially the throttle is nothing more than a butterfly valve. Imagine a circular plate fitted into a pipe that is allowed to pivot along a center axis across the plate. When it pivots, the valve allows more matter to flow thru. All throttle bodies contain a Throttle Body Senor (TBS) which measures the degree to which the valve is open from 0-100. This information is given to the vehicles Electronic Control Module (ECM) known to mechanics as a “brain.†The ECM then calculates along with the information provided by the two oxygen sensors, how much fuel to inject into the engine.
In a “drive-by-wire†vehicle, when the driver presses down on the throttle pedal they are actually pressing down on a potentiometer or “pot†for short. This is an electronic component that works as a variable resistor to control how many milliamps are sent back to the ECM. The ECM then sends a signal to a servo actuator that is attached to the throttle. The actuator is nothing more than an electric motor. The more the driver presses on the throttle the more the ECM calculates how much the actuator should open the throttle allowing for the correct fixture of air to fuel. Oh yeah, the ECM is also calculating if it should cut back on the engine speed if the Electronic Stability Control is triggered.
When I started reviewing Toyota’s issues I wondered if at first the cars were using Drive by Wire. It didn’t take long to note that they were. Then this morning I watched a CNN reported interview a mechanic installing a modified throttle pedal. The mechanic, holding the throttle pedal, explained how he dropped a wear plate in behind the something or other and… Bam! Complete! Oh yeah, except for a computer program update. The interviewer then asked what the computer update installation was for. The mechanic, who of coarse doesn’t know what is actually in the updates, explains that it is for controlling the engine when the engine is turning at high revolutions and the driver applies the break. The camera man’s last image is of the mechanic installing the updates, but if you look at the computer monitor there are two other updates as well. What are they for?
I don’t know if the ECM programming is to blame but I am terribly upset that Toyota went forthright blaming car owners and Toyota’s two throttle pedal manufactures. They even blamed it on their rugs. I am highly disappointed with Toyota for their negligence and lack of accountability. People are catching on, that’s the only reason they are taking the massive recall – don’t sell approach of Tylenol. It’s a business approach that worked for Tylenol, but I doubt it will work for Toyota; Tylenol did not blame other people or their victims first.
Future points to consider: Does the throttle pedal potentiometer have a UL approval? Is it possible for a driver to turn off their vehicle with the push button ignition switches that you see in the dual electric-gas propulsion engines, “hybridsâ€, while the engine is engaged and the vehicle is moving?
What to do if ECM runs away from you:
1. Place vehicle in neutral if possible. Very high RPMs may make this difficult.
2. Apply brakes generously. Be weary of applying breaks while the engine is pushing forward as this will wear down the brake pads. In the case of the Toyota incident, I bet Toyota uses a break-by-wire system. Oh no!
3. At an appropriate time shut engine off. Why not do this earlier, because vacuum pressure will be lost making it more difficult to brake and because shutting the engine off will result in a loss of power assisted steering. The engine may be racing, but the engine over-speed limiters should keep the motor from immediately over heating and catching fire.
If the steering column catches fire, its over. Firefighters can’t put out burning magnesium.
This does sound like a software problem. Maybe Toyota should be asked to make its source code — all of it — available for public inspection.
I confess that until I saw the Nightline segment on this earlier this week, I was unaware of this story. My parents had a Toyota but we don’t have one so I was ignorant.
People should be aware that, though there has been a rash of instances with Toyotas, the phenomenon can happen with any car. It happened to my 80-something mother several years ago, in a Mercedes she had driven since 1986. The car went over an embankment and flipped over on its roof on the pavement about 15 feet below. Miraculously, my mother suffered nothing worse than some bad bruises and blood loss (we still tease her about quitting stunt driving!). Statistically, it’s unlikely to happen to most of us, but the important thing is to know what to do if it should: shift into neutral. I think the ABC website has a good video clip about this.
As to Toyotas, I am suspicious of the claim that it’s a floor mat or accelerator problem. I agree with Stabill that Toyota ought to be more forthcoming about software information.
Until I heard the 911 recording last week I haven’t paid this issue much attention. I’d like to explain a few things. The system in question is called “drive-by-wire.â€
In the traditional normal aspirated fuel injected vehicle, when a driver presses on the throttle pedal a cable directly connected to the pedal pulls on leaver which opens the throttle plate within the throttle body allowing more air into the engine. Essentially the throttle is nothing more than a butterfly valve. Imagine a circular plate fitted into a pipe that is allowed to pivot along a center axis across the plate. When it pivots, the valve allows more matter to flow thru. All throttle bodies contain a Throttle Body Senor (TBS) which measures the degree to which the valve is open from 0-100. This information is given to the vehicles Electronic Control Module (ECM) known to mechanics as a “brain.†The ECM then calculates along with the information provided by the two oxygen sensors, how much fuel to inject into the engine.
In a “drive-by-wire†vehicle, when the driver presses down on the throttle pedal they are actually pressing down on a potentiometer or “pot†for short. This is an electronic component that works as a variable resistor to control how many milliamps are sent back to the ECM. The ECM then sends a signal to a servo actuator that is attached to the throttle. The actuator is nothing more than an electric motor. The more the driver presses on the throttle the more the ECM calculates how much the actuator should open the throttle allowing for the correct fixture of air to fuel. Oh yeah, the ECM is also calculating if it should cut back on the engine speed if the Electronic Stability Control is triggered.
When I started reviewing Toyota’s issues I wondered if at first the cars were using Drive by Wire. It didn’t take long to note that they were. Then this morning I watched a CNN reported interview a mechanic installing a modified throttle pedal. The mechanic, holding the throttle pedal, explained how he dropped a wear plate in behind the something or other and… Bam! Complete! Oh yeah, except for a computer program update. The interviewer then asked what the computer update installation was for. The mechanic, who of coarse doesn’t know what is actually in the updates, explains that it is for controlling the engine when the engine is turning at high revolutions and the driver applies the break. The camera man’s last image is of the mechanic installing the updates, but if you look at the computer monitor there are two other updates as well. What are they for?
I don’t know if the ECM programming is to blame but I am terribly upset that Toyota went forthright blaming car owners and Toyota’s two throttle pedal manufactures. They even blamed it on their rugs. I am highly disappointed with Toyota for their negligence and lack of accountability. People are catching on, that’s the only reason they are taking the massive recall – don’t sell approach of Tylenol. It’s a business approach that worked for Tylenol, but I doubt it will work for Toyota; Tylenol did not blame other people or their victims first.
Future points to consider: Does the throttle pedal potentiometer have a UL approval? Is it possible for a driver to turn off their vehicle with the push button ignition switches that you see in the dual electric-gas propulsion engines, “hybridsâ€, while the engine is engaged and the vehicle is moving?
What to do if ECM runs away from you:
1. Place vehicle in neutral if possible. Very high RPMs may make this difficult.
2. Apply brakes generously. Be weary of applying breaks while the engine is pushing forward as this will wear down the brake pads. In the case of the Toyota incident, I bet Toyota uses a break-by-wire system. Oh no!
3. At an appropriate time shut engine off. Why not do this earlier, because vacuum pressure will be lost making it more difficult to brake and because shutting the engine off will result in a loss of power assisted steering. The engine may be racing, but the engine over-speed limiters should keep the motor from immediately over heating and catching fire.
If the steering column catches fire, its over. Firefighters can’t put out burning magnesium.
Let’s end with the 911 recording:
http://www.youtube.com/watch?v=03m7fmnhO0I
/s/
Ryan W. Kilgo