• Please be sure to read the rules and adhere to them. Some banned members have complained that they are not spammers. But they spammed us. Some even tried to redirect our members to other forums. Duh. Be smart. Read the rules and adhere to them and we will all get along just fine. Cheers. :beer: Link to the rules: https://www.forumsforums.com/threads/forum-rules-info.2974/

Lawyers Making Toyota STOP fixing Faulty Pedals!

Lia

Banned
Lia, Drive by wire means that the gas peddle is not hooked (by a cable or mechanical linkage) directly to the engine. It is an electronic switch (like a dimmer switch in your house) that sends its signal only to the computer that runs the engine. The computer then controls the engine speed.

My VW is also a 5-speed, but it still has a drive by wire gas peddle.

Ohh, ok; thanks for that explanation Av8r3400. I really should try to understand more about it. :smile:
 

Av8r3400

Gone Flyin'
The brake peddle is hooked directly to the brakes, but the computer controls the anti-lock mechanism. Meaning if the computer sees fit it can cancel you braking input. (The current issue with Toyota Prius.)

So far, I don't think any manufacturer has taken away the direct link from the steering wheel to the front wheels. I know it has been done on some experimental cars, but I don't think anything in production, yet.

(That's why if there is a software issue in the computer these newer cars can get really uncontrollable.)

The person driving is really only a voting member of a committee operating the car...
 
Last edited:

muleman

Gone But Not Forgotten
GOLD Site Supporter
That is why I am demanding they disable the ABS and the traction control when mine goes in for service next week. They have taken control of the vehicle away from the driver.:hammer:
 

Av8r3400

Gone Flyin'
That is why I am demanding they disable the ABS and the traction control when mine goes in for service next week. They have taken control of the vehicle away from the driver.:hammer:


Better just get a different, older car. These functions are integrated into the control computer and cannot be singly disabled.

Even if they could, it would open them to serious liability that would not be tolerated. They would rather have an irate customer who won't come back than a liability lawsuit.

Sorry, but you're stuck with that silly hype-brid's computerized idiocy.
 

Rusty Shackleford

Automotive M.D.
SUPER Site Supporter
Better just get a different, older car. These functions are integrated into the control computer and cannot be singly disabled.

Even if they could, it would open them to serious liability that would not be tolerated. They would rather have an irate customer who won't come back than a liability lawsuit.

Sorry, but you're stuck with that silly hype-brid's computerized idiocy.

if you dont mind an idiot light or two on, you can pull the fuse. disables abs and tracs
 

muleman

Gone But Not Forgotten
GOLD Site Supporter
Why aren't you out shoveling? If you take out the fuse it probably won't run at all. My suburban at least has a switch to turn off the stability system.
 

Rusty Shackleford

Automotive M.D.
SUPER Site Supporter
if i remove the abs fuse it will turn off abs and tracs, but the car will drive as normal otherwise. ive done it lol.

and im not shoveling because theres no dam use. the wind is too cold and if i shovel, its covered again in 5 seconds. besides, the snowdrifts are 3 feet high :yum: im too damn lazy for that shit
 

muleman

Gone But Not Forgotten
GOLD Site Supporter
Waaaaaaa! Quit your crying. I hear you though. About the time you shovel the plow will come down the alley and close you back in anyhow.
 

grizzer

New member
The brake peddle is hooked directly to the brakes, but the computer controls the anti-lock mechanism. Meaning if the computer sees fit it can cancel you braking input. (The current issue with Toyota Prius.)

So far, I don't think any manufacturer has taken away the direct link from the steering wheel to the front wheels. I know it has been done on some experimental cars, but I don't think anything in production, yet.

(That's why if there is a software issue in the computer these newer cars can get really uncontrollable.)

The person driving is really only a voting member of a committee operating the car...

Lots of cars are electric power steering now - drive by wire. Saturn suv was the first GM in production in 2002.

The electric steering is more fuel efficient (size weight & power consumption) than old hydraulic systems. In addition EPS allows better software that slows steering response at high speed & increases response.when slow as in parking.

Olds Aurora was the first model attempt at hydraulic graduated smart steering. You don't want to know the cost. The system was basically the conventional hydraulic parts and adding a computerized electromagnetic coil which stepped up steering wheel effort at speed.
 

muleman

Gone But Not Forgotten
GOLD Site Supporter
They are just announcing that it is now believed to be an electronic problem, not mechanical sticking of the pedal.
 

waybomb

Well-known member
GOLD Site Supporter
Figured that all along. A car does not accelerate with a sticking pedal. It will stick at the furthest deflection, not go to WOT.

As for Prius, I believe the problem to be in the regenerative mode. The brakes don't fail. The computer is supposed to "tell" the electric motor to turn into a generator on deceleration, to recharge the batteries. This is done on electric lift trucks as well.

Seems that in the Prius, the computer for some reason is telling the motor to go forward, fast, when it should be transitioning into regeneration mode.
 

muleman

Gone But Not Forgotten
GOLD Site Supporter
The dealer is telling me it is the dwell time between regen braking and enabling hydraulic braking. They swear it will stop if you stand on the brakes. I have tried to get it to do it a few more times and it did not. when it does happen it catches you by surprise when you are driving the same road every day and it might happen once in 250 times. It did feel almost like it accelerated to me . I blew through a Y intersection in a hurry at about 30mph.
 

waybomb

Well-known member
GOLD Site Supporter
Just to be clear -

You want to stop the car, so you press the pedal, but the electric motor is still in power?

So there is a lag?

So when it actually switches to full braking / regen, it must stop real fast?

Or, you are running on dino, step on the pedal, and instead of going into regen, the motor actually becomes powered for split second? Or longer?

Interesting. And must be spooky when it happens.
 

muleman

Gone But Not Forgotten
GOLD Site Supporter
Yeah it is almost like when the abs on early versions locked out your rear brakes. You apply the same amount of pedal but if you are on a bumpy washboard type of road it feels like you are pressing on a brick. Two times it was very brief but the last one was NOT brief when you blow through the yield sign. I can make it repeat the brief lockout but not the long one. I do think the ABS has something to do with it as well. It acts like it gets 2 inputs and can't process fast enough to give proper response.
 

waybomb

Well-known member
GOLD Site Supporter
It's the Oriental way of keeping you awake while driving.......

I wouldn't drive that car until they fix it. What if you were attempting to stop for a pedestrian? Damn.
 

Av8r3400

Gone Flyin'
I watched the lady testify today in front of congress.

To the comments made earlier in this thread: She testified that she not only was on the brakes with both feet, applied the emergency brake, but attempted to shut off the ignition to no effect, shifted to all gear selections - including reverse - with no effect on the car.

This is truly scary. The recording of the policeman driving his Lexus to a fire filled crash has a whole new meaning.
 

muleman

Gone But Not Forgotten
GOLD Site Supporter
I don't know about any other models but I can shift the Prius to neutral or hold the power button 3 seconds and it will shut off and stop. I did experience the brake issue again on ice this past Sunday while going to visit my dad. I am certain it is ABS related and maybe has to do with the stability control as every time it happens going downhill. One time in 460 miles on Sunday.
 

grizzer

New member
If the university + lab testing simply shorted the gas pedal wow. Most safety critical circuits should have failure mode redundancy built in. For example if an action resistance goes up there has to be a corresponding lower resistance on a parallel circuit. If both circuits do not act as expected, output goes into limp home mode and a trouble code is set.

With the testimony today Toyota not knowing the answer it's unreal...

My electric vehicle ESC knowledge is pretty limited but in a nutshell it takes various inputs, adds directional accelerometers & pulses individual wheel brakes and/or power.

The Prius sounds like the software hierarchy has a problem with certain function combinations.
 

fogtender

Now a Published Author
Site Supporter
I figured all along that this is a computer program issue, not a floormat or gas pedal problem. I have a Toyota Rav4, but it was built in Japan and shipped to the Alaska Dealers, so far there is no recall for that version.

But I am going to install a manual power kill switch that will shut the engine off deader than a doornail when it is flipped on (or off) and will totally bypass the computer. Not going to deal with this stuff, otherwise it runs fine.
 

grizzer

New member
A power on/off is not as simple as a light switch. Under operation you could get back feed power that maintains PCM module power. Unintended switching is going to trip DTC's putting you in limp home mode (2nd gear, rpm limited, etc...)

Another problem when messing with vehicle switching is voltage spikes & power surges. They have enough potential to kill the module you are trying to save, or another one in the vehicle.

Think of the car as a 9600 baud network where stuff is communicating in order. Disrupt the order and the machine begins to save itself.
 

fogtender

Now a Published Author
Site Supporter
A power on/off is not as simple as a light switch. Under operation you could get back feed power that maintains PCM module power. Unintended switching is going to trip DTC's putting you in limp home mode (2nd gear, rpm limited, etc...)

Another problem when messing with vehicle switching is voltage spikes & power surges. They have enough potential to kill the module you are trying to save, or another one in the vehicle.

Think of the car as a 9600 baud network where stuff is communicating in order. Disrupt the order and the machine begins to save itself.

NO, you put the relay in-line with the auto's power supply with a diode so there can't be back-feed to the relay's remote power supply. When the power is off, the relay goes dead, as well as the engine..

I haven't had a chance to look at the engine yet, but when I installed the factory made remote starter system, there is a few points that I may tap into the system. Either the fuel or spark lines. When the power is cut, the engine will die, there is no bypassing of those power supply systems. Not going to interfere with the computer itself, as you stated, it can get power from a couple of sources in a bad system.
 

Lia

Banned
I am awed by everyone's expertise and comprehension of the jungle of metal, pipes and rubber tubes under the bonnet of a car. Just blows me away to hear y'all talk about it...

Well, I guess I'm off the hook then; no need to worry about my 107. It sounds like it's a computer problem after all; which is just as well, because mine still hasn't been recalled. It's 4 years old now, manual, never had a problem with it, and recently I put another 5/600 miles onto an already 57,000 on the clock, on an out of town trip, with not one hiccup.

You're absolutely right Av8r3400, it truly is scary!
 

rlk

Bronze Member
GOLD Site Supporter
I watched the lady testify today in front of congress.

To the comments made earlier in this thread: She testified that she not only was on the brakes with both feet, applied the emergency brake, but attempted to shut off the ignition to no effect, shifted to all gear selections - including reverse - with no effect on the car.

This is truly scary. The recording of the policeman driving his Lexus to a fire filled crash has a whole new meaning.

Can anyone explain to me why shifting to neutral will not work? Or is shifting gears controlled by the computer as well? I have a Rav4 and the gear shift lever sits right over the transmission, so I assumed there was a mechanical link between the two, but I may be wrong.

Thanks, Bob
 

Av8r3400

Gone Flyin'
Many of these cars will not allow you to do the "wrong" thing with the shifter. The transmission is computer controlled and the shifter is only a switch in the system. Often times they are not mechanically hooked to anything. This is to prevent the "dumb driver" from doing something like bumping the shifter into reverse while traveling forward, or shifting into gear without a signal from the brake interlock switch. They are not just a mechanical gate, hooked to gears like in years past.

To me the only real safety mechanism is a manual transmission with a clutch peddle!

(or an older car)
 

fogtender

Now a Published Author
Site Supporter
To me the only real safety mechanism is a manual transmission with a clutch peddle!

(or an older car)

That does seem to be the only really solid answer for newer cars, push the mechanical clutch in, the power to the wheels is 100% gone... Engine may be racing, but no place to go.

Most people have no idea of how to shift a standard though, almost a museum piece in many cases.
 

grizzer

New member
Sorry for old tech 1999 but story is about Mpls police van that killed 2 injured 10. To summarize van was modified with police eq. by trained mechanic. Mechanic pulled relay power from the brake circuit as always. Vehicle computer sensed foot on brake allowing PRNDL shift lock interface to release allowing trans lever out of park position. Only during the ON flashing light sequence. Cop climbs in vehicle steps on wrong pedal & shifts in gear... dead baby.

http://www.cs.york.ac.uk/hise/safety-critical-archive/2000/0567.html

The trans will go into neutral in all cases. Depending on speed, RPM's, etc it will not downshift into too low a gear to avoid damage. Reverse at speed logic says no again avoiding damage.

Yesterdays testimony I took at face value, people panic & think they do things which may or may not make sense later.

Years ago I was driving a relatives 396 Impala back from the lake with a hottie early one morning & somehow popped the trans in reverse at 60 mph. Did not know why the car was shaking & slowing down, so hit the gas harder, the car started backing down the hwy in a cloud of burnt rubber. Then spotted the shift lever. That car left 2 truly impressive black stripes on the asphalt!

Never have told my aunt. he he he
 
Top