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Electronic Throttle Control

By Bull6791, March 26, 2015



Is TOYOTA the only auto company that uses ELECTRONIC THROTTLE CONTROL.

IF other auto companies are using ETC in their cars why are they not having electronic/sudden acceleration issues like TOYOTA had.

Just curious with ETC how do you keep it from failing or how do you stop sudden acceleration.

Nope. There are a number of other manufacturer's using ETC / DBW controls. Some running those significantly earlier than Toyota/Lexus models. So common now, that I'd say it is actually harder to find a new car now that "doesn't" have some sort of electronic throttle control.

As for SUA with Toyota - the electronics were found to be not at fault, after a lengthy investigation by NSHTA and NASA for the DOT. Some owners still feel that they have a problem with sudden acceleration, but no clear, repeatable failure mode was discovered. Most of the fixes in the wake of the media frenzy were more cosmetic / common sense fixes. I still didn't get any of the recalls done on my car - as the quick fixes, IMO, will make the car less drivable.

Also note that Toyota / Lexus were not alone on this SUA issue - quite a few other makes also had complaints against their systems. Some were not even related to electronic control - remember Audi back in the mid- 1980's - also found to be not at fault, but effectively killed off the Audi 5000 at the time. Still ongoing litigation on that, as far as I know.

Probably the biggest outcome from this is Toyota implementing a similar logic that some other manufacturers have on their systems. So called Safe Stop, from Toyota - basically a ECM reflash that overrides manual operation when it detects both the accelerator and brake pedal being engaged simultaneously, and forces the throttle to snap closed - killing power.

Could there be electrical gremlins that are causing atleast some of the cases of SUA to be realized? Anything is possible. Lots of plausible explanations out there - some are more plausible to me than others, based off of what I've seen in my hardware development days. But that is best left for another discussion - as this is still feverishly debated now. Though much less intensely than before, since the media frenzy died down.

In any cases of SUA, regardless of which car make and type of throttle system - how do you stop SUA. #1 - Keep a cool head and bring the car to a stop by:

- Fully and smoothly depressing the brake pedal, don't pump the brakes - even with the throttle pinned full WOT - the brakes on modern cars are more than powerful to bring the car to a stop. Even something extremely powerful like the new Dodge SRT Hellcat with its supercharged 707HP engine will eventually be pulled down to a stop if you stand on the brakes.

- Shift the car into neutral - works with any transaxle. Even if you accidentally shifted into reverse or park at a high-speed - most transaxles will default to neutral until the vehicle speed drops down low enough. Engine could be banging up against the rev limiter, but with no power to the drive wheels - car will fall off of speed relatively quickly. Brakes will still work as normal.

- Shut car down - probably last resort, as in some cars, the steering wheel could lock, power steering and brakes will lose power assist capability. Making vehicle control difficult if not impossible for some. But with engine off - car will quickly come to a stop.

Back in the day with cabled throttle system on big domestic cars - I couldn't remember a day where the throttle "didn't" stick on me at some point. Sometimes the throttle return spring would break or come loose - cable got corroded or cable sheath got damaged. No one freaked out - just blipped the throttle to bring the revs down, if that didn't work - shift into neutral and kill the ignition, coast to a stop.

If the electronics were found not to be at fault in SUA with TOYOTA than what would be the cause.

Sometimes it is simple as driver error - driver steps on the wrong pedal. Thinking they hit the brake while they actually are full on the accelerator pedal. Wearing the wrong shoe can exacerbate the issue. Driver reflex, state of mind, concentration level, experience, etc. - all factor in. Media frenzy that fed into this SUA also didn't help matters - as some people were trying to find all sorts of ways to cause SUA. Others were chalking up anything wrong with the car's behavior as SUA - even Toyota models that were made before ETCS-I and DBW - which was the focus of the investigation.

Also keep in mind, that even though the electronics were found to be not a fault by the DOT - doesn't rule out the possibility that electrical malady could eventually happen. Under the right conditions at the right time - an intermittent electrical issue can pop up and cause all sorts of problems. Lots of research went into tin whiskers, faulty shielding, FET latch-up, improper code/race condition in the ETCS-i control program, manufacturing errors, etc. All are plausible under the right conditions - the problem is determining which conditions were needed to reproduce these fault conditions repeatedly.



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