Another recall - stick accelerators
#11
01-23-2010, 07:08 AM
Ridiculously Active Enthusiast
Join Date: Sep 2006
Location: Beautiful Pacific NW
Posts: 1,678
Re: Another recall - stick accelerators
I talked with the local toyota tech here in town. He said they sent him to a toyota school a few weeks ago to certify him to do the upgrade on the various recalled models.
He said they will be installing a new fly-by-wire accelerator assembly. The new one will make the pedal higher from the floor. This may include replacing the throttle body assembly. Looks like this is on the gas models only.
He did mention the TCH has the throttle release feature on the brakes. No matter what the throttle, you press the brakes and it should relax the engine to idle.
I did read on some web news page that if your accelerator is physically slow to return after pressing it down or if it's hard to depress.
This test would be done while sitting still with the engine and key off.
Not so sure about this test. Many throttle systems, direct and DBW, have a mechanism (possibly firmware implementd) through which the throttle buttefly valve is PREVENTED from quickly/instantly returning to idle position. Many use a "dashpot" arrangement for this.
To much danger of an engine stall if the throttle is allowed to quickly close to idle. A dashpot failure could not be detected via ths test.
If your accelerator has those symptoms, they included a toyota 800 phone number to call to get it quickly fixed. Sorry I did not keep the number. I think it was the main Toyota Customer Service number in California.
He said they will be installing a new fly-by-wire accelerator assembly. The new one will make the pedal higher from the floor. This may include replacing the throttle body assembly. Looks like this is on the gas models only.
He did mention the TCH has the throttle release feature on the brakes. No matter what the throttle, you press the brakes and it should relax the engine to idle.
I did read on some web news page that if your accelerator is physically slow to return after pressing it down or if it's hard to depress.
This test would be done while sitting still with the engine and key off.
Not so sure about this test. Many throttle systems, direct and DBW, have a mechanism (possibly firmware implementd) through which the throttle buttefly valve is PREVENTED from quickly/instantly returning to idle position. Many use a "dashpot" arrangement for this.
To much danger of an engine stall if the throttle is allowed to quickly close to idle. A dashpot failure could not be detected via ths test.
If your accelerator has those symptoms, they included a toyota 800 phone number to call to get it quickly fixed. Sorry I did not keep the number. I think it was the main Toyota Customer Service number in California.
#12
01-23-2010, 07:16 AM
Ridiculously Active Enthusiast
Join Date: Sep 2006
Location: Beautiful Pacific NW
Posts: 1,678
Re: Another recall - stick accelerators
While this all makes sense, it also brings about a real dilemma.
I don't think anyone wanted to have their pedal chopped down
"Chopped up". The bottom of the pedal is cut off so that if the carpet does slide forward it will go under and behind the gas pedal rather than over the top of the gas pedal....and behind the brake pedal.
This all reminds me 'way too much of the Jewish rabbi, and his new Cadillac's tail pipe.
just to make enough room for extra thick **** carpeted floor mats with padding, so I doubt many would have availed themselves of recall solution #1.
Now that it appears there's something mechanical or firmware at work here, the need to address the situation has changed significantly. I imagine all drivers would want their pedal assembly throttle valve control to be working properly.
I'm not happy with having anyone touch anything (I'm from the school that says "if it aint broke, don't fix it")...but it appears that it's broken and needs to be fixed, right?
I don't think anyone wanted to have their pedal chopped down
"Chopped up". The bottom of the pedal is cut off so that if the carpet does slide forward it will go under and behind the gas pedal rather than over the top of the gas pedal....and behind the brake pedal.
This all reminds me 'way too much of the Jewish rabbi, and his new Cadillac's tail pipe.
just to make enough room for extra thick **** carpeted floor mats with padding, so I doubt many would have availed themselves of recall solution #1.
Now that it appears there's something mechanical or firmware at work here, the need to address the situation has changed significantly. I imagine all drivers would want their pedal assembly throttle valve control to be working properly.
I'm not happy with having anyone touch anything (I'm from the school that says "if it aint broke, don't fix it")...but it appears that it's broken and needs to be fixed, right?
But only after the "shotgun" trouble shooting period has sub-sided.
#13
01-23-2010, 07:28 AM
Ridiculously Active Enthusiast
Join Date: Sep 2006
Location: Beautiful Pacific NW
Posts: 1,678
Re: Another recall - stick accelerators
I talked with the local toyota tech here in town. He said they sent him to a toyota school a few weeks ago to certify him to do the upgrade on the various recalled models.
He said they will be installing a new fly-by-wire accelerator assembly. The new one will make the pedal higher from the floor. This may include replacing the throttle body assembly. Looks like this is on the gas models only.
He did mention the TCH has the throttle release feature on the brakes. No matter what the throttle, you press the brakes and it should relax the engine to idle.
I did read on some web news page that if your accelerator is physically slow to return after pressing it down or if it's hard to depress. This test would be done while sitting still with the engine and key off. If your accelerator has those symptoms, they included a toyota 800 phone number to call to get it quickly fixed. Sorry I did not keep the number. I think it was the main Toyota Customer Service number in California.
He said they will be installing a new fly-by-wire accelerator assembly. The new one will make the pedal higher from the floor. This may include replacing the throttle body assembly. Looks like this is on the gas models only.
He did mention the TCH has the throttle release feature on the brakes. No matter what the throttle, you press the brakes and it should relax the engine to idle.
I did read on some web news page that if your accelerator is physically slow to return after pressing it down or if it's hard to depress. This test would be done while sitting still with the engine and key off. If your accelerator has those symptoms, they included a toyota 800 phone number to call to get it quickly fixed. Sorry I did not keep the number. I think it was the main Toyota Customer Service number in California.
No, it may or may not.
When you depress the brake pedal the HSD firmware, engine and "transaxle(PSD)" control firmware, is programmed to switch into regenerative braking mode. If your hybrid battery is extraodinarily low that might mean sustaining the engine/ICE RPM level to help recharge the hybrid battery. The dual electric motors would then go into a mode of "summing" the two power inputs, regenerative braking AND ICE with the net HSD wheel drive being NEGATIVE.
When you apply the brakes on an HSD system the ICE RPM may not drop significantly but the "summed" PSD output to the drive wheels will go negative, or neutral if no battery charge is required or 100% frictional braking is required.
#14
01-23-2010, 02:40 PM
Ridiculously Active Enthusiast
Join Date: Jun 2007
Location: Southern New Mexico
Posts: 1,312
Re: Another recall - stick accelerators
I was indicating the engine would let up at any speed when you press the brake on the TCH. Possibly shut off if under 40 mph. This would include while using the cruise control.
I don't think they are shortening the accelerator peddle which is rather short anyway. The new drive-by-wire assembly will be a new pedal, arm, potentiometer and included circuitry for the gas powered vehicles listed on the recent recall by Toyota as I see it.
I read that the top strung accelerators tended to stick more than the bottom strung type. I'm not talking toyota here but all automotive brands.
I have not seen the Camry or Prius hybrids listed on this last recall.
I don't think they are shortening the accelerator peddle which is rather short anyway. The new drive-by-wire assembly will be a new pedal, arm, potentiometer and included circuitry for the gas powered vehicles listed on the recent recall by Toyota as I see it.
I read that the top strung accelerators tended to stick more than the bottom strung type. I'm not talking toyota here but all automotive brands.
I have not seen the Camry or Prius hybrids listed on this last recall.
Last edited by rburt07; 01-24-2010 at 04:19 AM.
#15
01-23-2010, 04:24 PM
Re: Another recall - stick accelerators
In order for an "run a way" TCH ICE to accelerate the car inordinantely at least on the electric motors would have to be stalled, locked in place. Besides which this is not only a rather smallish I4 it is also derated via the use of the atkinson cycle.
So the brakes on the TCH, partially powered by the run-a-way ICE itself, would probably "hold".
So the brakes on the TCH, partially powered by the run-a-way ICE itself, would probably "hold".
http://www.caranddriver.com/features...tion-tech_dept
You are absolutely correct. Assuming the brakes are in good working order the brakes hold in all but the most extreme cases.
With this in mind it is confusing to me as to what might have happened in the case of Mark Saylor (the police office who was killed along with his family in a runaway Lexus).
http://www.nbcsandiego.com/news/loca...-58663982.html
It is as if the brakes and the accelerator both went crazy!
#16
01-23-2010, 05:43 PM
Ridiculously Active Enthusiast
Join Date: Sep 2006
Location: Beautiful Pacific NW
Posts: 1,678
Re: Another recall - stick accelerators
According to this:
http://www.caranddriver.com/features...tion-tech_dept
You are absolutely correct. Assuming the brakes are in good working order the brakes hold in all but the most extreme cases.
With this in mind it is confusing to me as to what might have happened in the case of Mark Saylor (the police office who was killed along with his family in a runaway Lexus).
http://www.nbcsandiego.com/news/loca...-58663982.html
It is as if the brakes and the accelerator both went crazy!
http://www.caranddriver.com/features...tion-tech_dept
You are absolutely correct. Assuming the brakes are in good working order the brakes hold in all but the most extreme cases.
With this in mind it is confusing to me as to what might have happened in the case of Mark Saylor (the police office who was killed along with his family in a runaway Lexus).
http://www.nbcsandiego.com/news/loca...-58663982.html
It is as if the brakes and the accelerator both went crazy!
While I do not have much personal experience with FWD the two instances I encountered the floor mat issue were both FWD. I was NOT able to "restrain" the vehicle, Mazda minivan, from moving forward from a full stop. The other case was a Mazda Miata and those occurred at hwy speed and I had the definite impression that the engine was over-coming the brakes.
#17
01-24-2010, 04:26 AM
Ridiculously Active Enthusiast
Join Date: Jun 2007
Location: Southern New Mexico
Posts: 1,312
Re: Another recall - stick accelerators
I looked at the Wikipedia site and they have some interesting details on the drive-by wire design and feedback circuit to the ecu.
http://en.wikipedia.org/wiki/Electro...rottle_control
http://en.wikipedia.org/wiki/Electro...rottle_control
#18
01-26-2010, 12:37 AM
Re: Another recall - stick accelerators
Here is a recap of my personal experience with sudden unintended acceleration in my TCH,
including some hard facts on a few items about which we have had some speculation in this forum.
I have TWICE experienced sudden unintended acceleration in my 2009 TCH.
In both cases I was traveling about 30 mph on city streets.
Both events were DEFINITELY caused by the floor mat.
The errant floor mat was a genuine Toyota overlay mat (thin clear plastic) specifically designed for the Camry. It is exactly the size and form of the standard carpet mat and is intended to be installed OVER the standard mat and secured to the standard mat with a binding clip supplied, depending upon the standard prong for the bottom mat to hold the whole combination in place.
The clip seems plenty strong enough enough to do it's job, but it's not. When it looses it's grip, the overlay mat can slide forward, in spite of the fact that it's bottom side is dotted with hundreds of little spikes to grip the carpet mat.
The notch in the mat near the accelerator pedal allows the mat to "hump up" over the accelerator pedal if the mat slides forward while the main part of the mat slides UNDER the brake pedal; so when you step on the brake pedal, the mat under the brake pedal and over the accelerator pedal actually inhibits your braking effort while pressing down harder on the accelerator pedal.
In this situation I could hear, as well as feel, the engine speed up more and more the harder I tried to brake - a little frightening at first.
The TCH definitely did NOT cut the gas or cut the power to the wheels as a result of the brake pedal being depressed.
On the first occasion, I was able to use the brakes to overpower the engine/motors and bring the car to a safe stop, although with very hard pressure on the brake pedal and in a somewhat longer distance than I would have been able to "panic stop" from such speeds if I were not fighting the engine.
The brakes can DEFINITELY overpower the engine in this situation, at least from moderate speeds.
After I had brought the car to a stop, but before I could park and investigate the cause of the problem, I shifted to neutral. Not thinking about the way the system works, I expected to hear the engine race, but upon shift to neutral, the engine went immediately to idle speed. Realizing, then that the engine would be returned to idle in neutral, I then maneuvered safely to a parking spot by riding the brake and shifting into and out of neutral.
After the first incident, I put two clips on the driver's side mat, borrowing one from the passenger's side, and I took great care to secure both clips very tightly.
On the second incident I knew what was happening, and I was able to cope with the situation much more easily by shifting immediately into neutral.
Shifting the TCH into neutral, even at high throttle, will very definitely both disengage the drive from the wheels and idle the engine. An unintended sudden acceleration can be managed more easily by shifting into neutral than by use of the brakes only.
After the second incident, I bolted the mats to the floor clip. Those mats are not ever going to move again except when I remove them for cleaning. (I topped off the bolts with flat hand ***** to make removal for cleaning quick and easy.) With this solution I will not need to worry either about the overlay mats sliding or even about the standard mats coming loose from their "prongs."
including some hard facts on a few items about which we have had some speculation in this forum.
I have TWICE experienced sudden unintended acceleration in my 2009 TCH.
In both cases I was traveling about 30 mph on city streets.
Both events were DEFINITELY caused by the floor mat.
The errant floor mat was a genuine Toyota overlay mat (thin clear plastic) specifically designed for the Camry. It is exactly the size and form of the standard carpet mat and is intended to be installed OVER the standard mat and secured to the standard mat with a binding clip supplied, depending upon the standard prong for the bottom mat to hold the whole combination in place.
The clip seems plenty strong enough enough to do it's job, but it's not. When it looses it's grip, the overlay mat can slide forward, in spite of the fact that it's bottom side is dotted with hundreds of little spikes to grip the carpet mat.
The notch in the mat near the accelerator pedal allows the mat to "hump up" over the accelerator pedal if the mat slides forward while the main part of the mat slides UNDER the brake pedal; so when you step on the brake pedal, the mat under the brake pedal and over the accelerator pedal actually inhibits your braking effort while pressing down harder on the accelerator pedal.
In this situation I could hear, as well as feel, the engine speed up more and more the harder I tried to brake - a little frightening at first.
The TCH definitely did NOT cut the gas or cut the power to the wheels as a result of the brake pedal being depressed.
On the first occasion, I was able to use the brakes to overpower the engine/motors and bring the car to a safe stop, although with very hard pressure on the brake pedal and in a somewhat longer distance than I would have been able to "panic stop" from such speeds if I were not fighting the engine.
The brakes can DEFINITELY overpower the engine in this situation, at least from moderate speeds.
After I had brought the car to a stop, but before I could park and investigate the cause of the problem, I shifted to neutral. Not thinking about the way the system works, I expected to hear the engine race, but upon shift to neutral, the engine went immediately to idle speed. Realizing, then that the engine would be returned to idle in neutral, I then maneuvered safely to a parking spot by riding the brake and shifting into and out of neutral.
After the first incident, I put two clips on the driver's side mat, borrowing one from the passenger's side, and I took great care to secure both clips very tightly.
On the second incident I knew what was happening, and I was able to cope with the situation much more easily by shifting immediately into neutral.
Shifting the TCH into neutral, even at high throttle, will very definitely both disengage the drive from the wheels and idle the engine. An unintended sudden acceleration can be managed more easily by shifting into neutral than by use of the brakes only.
After the second incident, I bolted the mats to the floor clip. Those mats are not ever going to move again except when I remove them for cleaning. (I topped off the bolts with flat hand ***** to make removal for cleaning quick and easy.) With this solution I will not need to worry either about the overlay mats sliding or even about the standard mats coming loose from their "prongs."
Last edited by Smilin' Jack; 01-26-2010 at 12:41 AM. Reason: typo
#20
01-26-2010, 02:19 PM
Re: Another recall - stick accelerators
Will do, gladly, but it might be the weekend before I get the right light to take photos.
And I'll also need to learn how to post pix.
Jack
And I'll also need to learn how to post pix.
Jack
