You will not find this info in your manual , The two feet test is to test the default settings , not for driving. When using ETC, there has to be fail safe's , the main is when you hit the brake all protocols are overridden if WOT is detected , the ecu will return ETC to idle position, if ETC is stuck wide open due to some mechanical reason then your only other recourse is to turn ign off. Sometimes a throttle sweep is implemented on ign on to chk stops before starting, if an error is detected , then Limp mode..
Safety protocols used will vary from model , Magnetti marelli, nippon denso, Bosch, et al , will have different protocols, due to Stability controls , ABS , TC, ES, Accident avoidance system , blah, blah , blah ...
Once lead is removed all forms from all products when will the clean up of all that decayed isotopes residue begin . Stopping the use of Tetra Ethyl lead in millions of gallons in to the air is one thing the amount of lead exposure in electronic is an other. Interesting side note is the toxic level of the chemicals used to replace lead and their staying power.
And you thought diode effect in wire was farfetched.
Last edited:
NASA seems to disagree with that.
Given a carpet problem, which everybody can understand and look out for, and a deep underlying safety design flaw affecting every car produced in their factory for years, what should we expect as the claimed problem?
jn
Culture of fail , very un Toyota,
I'm not in disagreement, with NASA's findings, i need to study it more, unfortunately whenever our GOV is involved i like to follow the money trail as much as the science and what about GM, Toyota's malfeasance pale by comparison, interesting to see how that one pans out, seeing how many were privy to the failures...
Less not forget the BS done to Audi in the 80's over the same crap, no fault was shown and all projected and fabricated by media and politicians..
I'm not in disagreement, with NASA's findings, i need to study it more, unfortunately whenever our GOV is involved i like to follow the money trail as much as the science and what about GM, Toyota's malfeasance pale by comparison, interesting to see how that one pans out, seeing how many were privy to the failures...
Less not forget the BS done to Audi in the 80's over the same crap, no fault was shown and all projected and fabricated by media and politicians..
Last edited:
I worked for NASA (JPL) there is real concern about lead free solders. To us this basically means eutectics. gold mixing becomes and issue such that all pad have to have a prescribed thickness. The melt cycle is critical to prevent further gold mixing into another alloy phase which then produces whiskers, embrittlement etc. With lasers, again all surface, even gold have to be scrubbed, there is then a bake or preheat dwell. This is followed by a rapid rise into the melt temp, 3 -5 sec, and then a rapid cool. This is usually done with LN2 gas. With on of the lasers die bonds, particularly junction down, we deposit the eutectic on the submout to control it's mixing. For structural eutectics, the above applies with some solders requiring an annealing process after. Solder like SnBi, etc.
Work at NASA has shown even with all the precautions above, the solder can still change phase by further ionic diffusion, accelerated by heat and a potential as most bond layers act as part of an anode or cathode.
Work at NASA has shown even with all the precautions above, the solder can still change phase by further ionic diffusion, accelerated by heat and a potential as most bond layers act as part of an anode or cathode.
There was also a large element of rubbish software which Toyota had managed to conceal for quite some time. They didn't follow best practice in avoiding a single point of failure in the software 'architecture'. I use the scare quotes because it didn't look at all achitected to the expert witness, more cobbled together....
It's long term repetitive.
150 deg 'long term' under continuous bias.
(These figures of course are higher than for ICs )
And you were expecting more ...? Obviously haven't dealt very much with typical examples of software "engineering",
.Good software, really, really robust software, is very, very hard to do - if it is done properly, rigorously, then it will cost a small fortune to do - hence in the real world most of it is pretty rubbishy. There are some specialised areas where one can almost "guarantee" the end quality, but the procedures that are followed would seem almost ludicrously pinpricking to the man on the street - but they are what is necessary when you are dealing with humans doing the job ...
No, gave up the expectations years ago
Means other teachers pass off their 'problem' students on to me,,,,I was surprised though that a company so widely lauded as following best practice in hardware (manufacturing) was so spectacularly sloppy in software engineering..
Preaching to the choir - I'm a dyed-in-the-wool hardware (with some minimal firmware - no interrupts for example) guy....
Going to Google and typing in 'edn toyota' brought up the next suggestion 'killer firmware' so I knew I had it right
Toyota's killer firmware: Bad design and its consequences | EDN
Toyota's killer firmware: Bad design and its consequences | EDN
Thanks for the link Brax , thats some chit ....
Toyota’s electronic throttle control system (ETCS) source code is of unreasonable quality.
Toyota’s source code is defective and contains bugs, including bugs that can cause unintended acceleration (UA).
Code-quality metrics predict presence of additional bugs.
Toyota’s fail safes are defective and inadequate (referring to them as a “house of cards” safety architecture).
Misbehaviors of Toyota’s ETCS are a cause of UA.
This makes more sense to me now and answers why none of the safety protocols kicked in, unbelievable Toyota would do this , when even small firms are doing the necessary work to make ETC safe ....
Wow ....
Toyota’s electronic throttle control system (ETCS) source code is of unreasonable quality.
Toyota’s source code is defective and contains bugs, including bugs that can cause unintended acceleration (UA).
Code-quality metrics predict presence of additional bugs.
Toyota’s fail safes are defective and inadequate (referring to them as a “house of cards” safety architecture).
Misbehaviors of Toyota’s ETCS are a cause of UA.
This makes more sense to me now and answers why none of the safety protocols kicked in, unbelievable Toyota would do this , when even small firms are doing the necessary work to make ETC safe ....
Wow ....
This is frightening ..........
"Unintentional RTOS task shutdown was heavily investigated as a potential source of the UA. As single bits in memory control each task, corruption due to HW or SW faults will suspend needed tasks or start unwanted ones. Vehicle tests confirmed that one particular dead task would result in loss of throttle control, and that the driver might have to fully remove their foot from the brake during an unintended acceleration event before being able to end the unwanted acceleration."
"Unintentional RTOS task shutdown was heavily investigated as a potential source of the UA. As single bits in memory control each task, corruption due to HW or SW faults will suspend needed tasks or start unwanted ones. Vehicle tests confirmed that one particular dead task would result in loss of throttle control, and that the driver might have to fully remove their foot from the brake during an unintended acceleration event before being able to end the unwanted acceleration."
They're just talking about normal software code ... again, most programs hang together by fragile threads - the slightest hiccup somewhere, and the whole lot collapses; equivalent to having a 10 storey building, and a kid dislodges a small pebble in the concrete foundation ... and down she coooomes ...
Fact: all software is defective, all software has bugs; any program that is closely scrutinised will be found to be riddled with problems, and weaknesses - it comes down to the level of reliability one can live with ...
With software controlled aircraft the solution that negates many problems is to have two completely independent software teams write identical, equivalent systems, in terms of the functionality. They are completely isolated, no cross pollination allowed; then the final results are run on independent computers - and they must agree on the outputs at all times. The chances that the same dumbness occurred in two totally separate environments, to give identical results, is of course dramatically lower ...
Fact: all software is defective, all software has bugs; any program that is closely scrutinised will be found to be riddled with problems, and weaknesses - it comes down to the level of reliability one can live with ...
With software controlled aircraft the solution that negates many problems is to have two completely independent software teams write identical, equivalent systems, in terms of the functionality. They are completely isolated, no cross pollination allowed; then the final results are run on independent computers - and they must agree on the outputs at all times. The chances that the same dumbness occurred in two totally separate environments, to give identical results, is of course dramatically lower ...
Looking for a single number for long life?
--- Keep it well under 125C. Under 105C is best for no heat related issues.... including parameter changes.
Software issue? It always comes down to the expertise and experience with the OS etc. A large company can afford to hire the best programmers. If major SW issues exist, it would be seen as a problem at the top.
THx-RNMarsh
THx-RNMarsh
Last edited:
- Status
- Not open for further replies.