Unintended Acceleration

[enigma57]

Randy, there were some cases some few years back where computer engine management systems had caused such things and folks either didn't have the good sense to switch off the ignition or were hesitant to do so because on the newer cars, that locks the steering column and would require more pedal pressure to work power brakes. There were some crashes as a result. Maybe fatalities as well, can't remember now. I believe it was confined to one manufacturer (Toyota?). Faulty info to computer from TPS? Sticky throttle linkage?

Anyway, the manufacturer eventually found and fixed the problem as I recall. This began not long after Toyota went to a 'fly by wire' system. You may recall that there were more than a few military plane crashes following the aircraft industry going to 'fly by wire' as well. My money is on that being the cause. 'Fly by wire' never should have been implemented on production vehicles (or aircraft) until the bugs were worked out.

Aha! Found this on the internet just now. Gives a timeline of events and some interesting info on what happened......

https://www.motortrend.com/news/toyota-recall-crisis/

Best regards,

Harry

[Kevin Johnson]

http://webhost.laas.fr/TSF/IFIPWG/Works ... slides.pdf

Important caveats.

Randy, there were some cases some few years back where computer engine management systems had caused such things and folks either didn't have the good sense to switch off the ignition or were hesitant to do so because on the newer cars, that locks the steering column and would require more pedal pressure to work power brakes. There were some crashes as a result. Maybe fatalities as well, can't remember now. I believe it was confined to one manufacturer (Toyota?). Faulty info to computer from TPS? Sticky throttle linkage?

Anyway, the manufacturer eventually found and fixed the problem as I recall. This began not long after Toyota went to a 'fly by wire' system. You may recall that there were more than a few military plane crashes following the aircraft industry going to 'fly by wire' as well. My money is on that being the cause. 'Fly by wire' never should have been implemented on production vehicles (or aircraft) until the bugs were worked out.

Aha! Found this on the internet just now. Gives a timeline of events and some interesting info on what happened......

https://www.motortrend.com/news/toyota-recall-crisis/

Best regards,

Harry

[enigma57]

http://webhost.laas.fr/TSF/IFIPWG/Works ... slides.pdf

Important caveats.

Thanks, Kevin! Good read. I kinda figured they had computer management issues and were covering it up. Watched a documentary on military plane crashes following implementation of 'fly by wire' technology. And there have been civilian air crashes due to defects in fly by wire as well. Looks like the auto industry did pretty much the same. Implemented this technology before all the bugs were worked out and as in the air crashes, people died in many of these car crashes.

Best regards,

Harry

[pdq67]

Gimmie a hard linked throttle assembly, this crap WON'T happen to it...

As well as I don't want a hydraulic clutch because eventually, it wears out and I have to fix it.

Just ask me how I know!!

pdq67

[enigma57]

[gruntguru]

http://webhost.laas.fr/TSF/IFIPWG/Works ... slides.pdf

Important caveats.

Thanks, Kevin! Good read. I kinda figured they had computer management issues and were covering it up. Watched a documentary on military plane crashes following implementation of 'fly by wire' technology. And there have been civilian air crashes due to defects in fly by wire as well. Looks like the auto industry did pretty much the same. Implemented this technology before all the bugs were worked out and as in the air crashes, people died in many of these car crashes.

Best regards,

Harry

I can't wait for "steer by wire".

[pdq67]

http://webhost.laas.fr/TSF/IFIPWG/Works ... slides.pdf

Important caveats.

Thanks, Kevin! Good read. I kinda figured they had computer management issues and were covering it up. Watched a documentary on military plane crashes following implementation of 'fly by wire' technology. And there have been civilian air crashes due to defects in fly by wire as well. Looks like the auto industry did pretty much the same. Implemented this technology before all the bugs were worked out and as in the air crashes, people died in many of these car crashes.

Best regards,

Harry

I can't wait for "steer by wire".

Oh, my word!!

I forgot about, "steer by wire"...

Bad, Bad, Bad, imho...

pdq67

[MadBill]

Don't know about others, but the 2021 GM pick ups have brake by wire...

[Truckedup]

Don't know about others, but the 2021 GM pick ups have brake by wire...

Is that just a different name for a more sophisticated anti lock brake system? I would think, maybe wrong, there's still a hydraulic fluid path from the master cylinder to the brake caliper...
Edit....is this GM's automatic emergency braking that uses cameras and radar to stop the vehicle in case the driver is too busy to actually drive?

[Walter R. Malik]

Randy, there were some cases some few years back where computer engine management systems had caused such things and folks either didn't have the good sense to switch off the ignition or were hesitant to do so because on the newer cars, that locks the steering column and would require more pedal pressure to work power brakes. There were some crashes as a result. Maybe fatalities as well, can't remember now. I believe it was confined to one manufacturer (Toyota?). Faulty info to computer from TPS? Sticky throttle linkage?

Anyway, the manufacturer eventually found and fixed the problem as I recall. This began not long after Toyota went to a 'fly by wire' system. You may recall that there were more than a few military plane crashes following the aircraft industry going to 'fly by wire' as well. My money is on that being the cause. 'Fly by wire' never should have been implemented on production vehicles (or aircraft) until the bugs were worked out.

Aha! Found this on the internet just now. Gives a timeline of events and some interesting info on what happened......

https://www.motortrend.com/news/toyota-recall-crisis/

Best regards,

Harry

I remember a famous Formula 1 driver getting killed because a "steer by wire'" system malfunctioned.

[MadBill]

Don't know about others, but the 2021 GM pick ups have brake by wire...

Is that just a different name for a more sophisticated anti lock brake system? I would think, maybe wrong, there's still a hydraulic fluid path from the master cylinder to the brake caliper...
Edit....is this GM's automatic emergency braking that uses cameras and radar to stop the vehicle in case the driver is too busy to actually drive?

I don't know much detail, but I believe it uses pedal travel as an indicator of desired braking force and a high pressure hydraulic/electric pump to pressurize the calipers.
I don't know about additional features, but those would be relatively easy to add.

[FC-Pilot]

Don't know about others, but the 2021 GM pick ups have brake by wire...

Is that just a different name for a more sophisticated anti lock brake system? I would think, maybe wrong, there's still a hydraulic fluid path from the master cylinder to the brake caliper...
Edit....is this GM's automatic emergency braking that uses cameras and radar to stop the vehicle in case the driver is too busy to actually drive?

I don't know much detail, but I believe it uses pedal travel as an indicator of desired braking force and a high pressure hydraulic/electric pump to pressurize the calipers.
I don't know about additional features, but those would be relatively easy to add.

I can’t speak about the gm system, but have worked with the systems of other manufacturers. Some at least have an internal link (as a failsafe), but the unit acts as the “booster” and is able to provide the higher pressure. The nice thing is there is no vacuum to deplete so you don’t have to rely on a high vacuum condition in the intake to build vacuum. The other thing is instead of designing complete systems to provide a good “brake feel” which some manufacturers sucked at you slap this thing in and you can just program it to provide the feel you want for the driver. Ford has done a good job on that end in my opinion. Some units design is still poor and provides a lackluster feel along with outdated programmability. Mercedes went to it years ago, but came back to standard hydraulic systems, but has now gone electric again (at least on the models I have tested)as the level of equipment is now capable of providing the feel and performance they demand.

As far as UA goes, I never saw data to support that it was real, but also saw data where it is possible. We had law firms employ one of my former employers (Link Engineering) to outfit vehicles with all sensors and data recorders for their testing. We were not suppose to know what they were doing, but when we downloaded the data and looked it over to verify that all instrumentation was working we could tell what they were doing.

I worked for Toyota for a while. With what I know I won’t be buying a Toyota EVER! That is my personal opinion. Many of my former coworkers happily drove them.

While testing we once had an electrical short in a wiring harness that caused the car to make an immediate left turn. It did have a connected steering shaft to the rack so luckily the monster in the driver seat was able to keep it out of the guardrail. The other person that had that happen was not so lucky, and his happened in local traffic. Any of these systems can fail.

Paul