News about Toyota’s throttle and now braking problems have been filling the nation’s headlines.
The company had to recall 2.3 million vehicles and halt sales of 8 popular models of new cars. The problem identified is that the throttle can get stuck in an unintended acceleration leading to loss of control, accidents, and death. Toyota has engineered a fix for the sticky throttle involving installation of a small steel beam that increases pedal resistance. These are now just being outfitted to recalled vehicles by dealers, but may not tell the whole story.
Another problem we reported previously, is also surfacing more intensely and surrounds braking failure occurring in the 3rd generation 2010 Prius. In this case, if a driver goes over a bump or pothole, the brakes can seem to disengage again leading to loss of control. This too has resulted in accidents. Over 100 complaints about this have been lodged in the US and Japan.
Though there is no recall of the Prius yet, both the Japanese and US governments have launched investigations.
In both cases there may be an underlying theme.
Modern high tech vehicles rely on electronic controls to interface between the driver and the mechanical endpoints. In the case of the accelerator, sensors measure the movement of the pedal and send an electronic signal to a control unit that operates the throttle. In the Prius brakes, electronics and software monitor pressure on the brake pedal and wheel speed, and use the information to utilize regenerative braking whenever possible and friction braking when needed.
One unifying theory is that there may be failures in the electronic control units for these functions. These failures potentially could be caused among other things by electromagnetic interference from other electronic components in the car. US transportation secretary LaHood indicated that though Toyota denies it is the electronics at fault, those components will become the center of a new investigation.
So while all of this negative publicity is resulting in massive losses for Toyota in sales, quality perception and customer loyalty, and equivalent gains for competitors including GM, it may really be a wolf in sheep’s clothing.
After all, no car in the world will rely more on electronic controls than the Chevy Volt. If Toyota couldnt prepare for the disaster they are now faced with in a high volume car like the Camry or the third generation Prius, can GM be sure the Volt will operate perfectly in just a few months based on the behavior of 80-odd preproduction prototypes?
“We should have no issues,” says GM Volt executive Tony Posawatz.
UPDATE: On Thursday Toyota issued a statement claiming the Prius brake problem was a software glitch involving the switch from regenerative to friction braking at the same time as anti-lock brakes kick in. They claim to have corrected the code in late January but haven’t decided how to manage the older cars. A recall hasn’t been ruled out.
This entry was posted on Thursday, February 4th, 2010 at 12:01 am and is filed under Engineering. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.
+42
Feb 4th, 2010 (12:04 am)May the great state of Michigan once again become the car capital of the world.
Go GM!
Go Volt!
+2
Feb 4th, 2010 (12:15 am)Having the throttle, “ignition” and gear selector all as inputs to the computer isn’t a good idea.
Hopefully GM is smart enough to make at least one of them a pure hardware device… for example if you have the ability to kill the power contactor for the batteries under on/off switch control then you have a sure way for people to kill the vehicle.
+11
Feb 4th, 2010 (12:28 am)I could be crazy, but isn’t it a WOLF in SHEEP’s clothing?
Because it’s a potential bad thing disguised as a good thing?
Either way, just goes to show the importance of GM’s rigerous Volt testing, and CONTINUED Volt testing.
+5
Feb 4th, 2010 (12:32 am)I think this is the reason the Volt is scaling up so slowly. But I don’t think there will be a problem. The 2nd Gen Prius never had any problems, in fact it’s been the model of vehicular reliability. Even the 3rd Gen’s alleged braking issues are probably more psychological with changes in braking pressure etc. when hitting pot holes than a real problem.
I think the serial hybrid engineering in the Volt should be a lot simpler than the cuckoo clock complexity of the parallel hybrid system in the Prius.
+27
Feb 4th, 2010 (12:36 am)And thus the reason why GM says they will only produce 10K vehicles the first year.
If GM really wants to find any bugs, all they have to do is put 500 vehicles into the hands of people like us on this site to put these cars through some real world testing. Within 100 days, any problems will come to the surface with enough time to have them corrected before the general release of the car.
If the testing is being done by the design engineers, they are going to baby it, even if they don’t realize it. As outsiders, we would not have those concerns. And with all the different types of people and driving styles that are represented on this site, I think the Volt would have a pretty tough time hiding any major or even minor faults. Because they would have a common meeting place to discuss (gm-volt.com, of course!) what they are seeing and how the car and it’s sub-systems are performing.
So come on GM!!! If you really want to see if your car is ready for prime time, feel free to give us a call.
If the car passes our testing, you might consider increasing the production of the first year’s production run!!!!
If called upon, I would proudly step forward to do my duty and help the Volt cause. (Shameless plug, I know…) Trust me, 100 days of driving around the roads in Youngstown, Ohio would be a real torture test, and if it survives that, you will know you have properly done your job!
So GM, I triple dog dare you to let us be your test fleet!!!
NPNS
+16
Feb 4th, 2010 (12:37 am)It’s amazing what a year can do… A year ago GM was in really bad shape and Toyota was aiming for #1 spot. Now Toyota is plagued with serious quality/safety issues: sticky pedal, bad brakes in Prius, and rusty chassis in Tundras and Tacomas. GM might be able to pay its debt back by June 2010. Toyota seemed to have been concerned more with quantity than quality lately… I hope GM will learn a valuable lesson from the technical problems that face Toyota now and offer a mature Volt product!
+7
Feb 4th, 2010 (12:46 am)“In this case, if a driver goes over a bump or pothole, the brakes can seem to disengage again leading to loss of control.”
This particular issue sounds _really_ familiar…
There is a similar issue that early model wrx drivers have been chasing for years. The wrx ABS will go into “ice mode” when you hit the right bump. Several unverified reports from supposed bosch engineers claim that the wrx got a bad ‘tune’.
In ice mode, you still have braking, but at a much reduced rate. To some, it feels like the brakes have disengaged.
Those of use who autocross or rallycross the wrx’s have learned to pull the ABS fuse or you _will_ end up in the weeds as you go to brake and you get an anemic response with it’s characteristic noise.
Regards.
+8
Feb 4th, 2010 (12:52 am)Will there be bugs in the Volt’s software: Yes. Over time, they’ll get ironed out – I remember reading somewhere that software bugs have a log-normal distribution, which means, that it takes a while for them to get ferreted out.
Happily, though, there are software design techniques (and rules) which can minimize the impact of the bugs when they assert themselves. When I was working at JPL, I sometimes talked with the people in a related group did the software for the Deep Space Probe. The remote agent software (which helped the probe make independent assessments and decisions millions of miles away from the earth) was automatically generated from a graphical state transition diagramming environment. Viewing and simulating the state machine graphically really helped work out the bugs before the probe was flown. And, it was a huge success. Of course, that’s one technique out of many, it’s hard to say what GM will do. I guarantee, though, they have processes in place that will produce very solid code.
+4
Feb 4th, 2010 (12:52 am)Expected, to fail, may be GM has to design pcbs with redundancy, Create redundancy paths , get high quality components, make software support redundancy , test them and use Onstar to monitor every component failure and do software updates as and when needed and notices for customer for board replacements etc. Its a big project ahead for GM. Even training the existing automobile technicians is also a big job.
One idea for GM is to start Certifications ( like GM Certified EV Associate, GM certified Voltec power train professional , GM Certified 2 mode power train professional, GM certificated Electroc power train Expert etc – like cisco levels with labs )
+9
Feb 4th, 2010 (12:56 am)“After all, no car in the world will rely more on electronic controls than the Chevy Volt. If Toyota couldn’t prepare for the disaster they are now faced with in a high volume car like the Camry or the third generation Prius…”
The Volt was subjected to Death Valley and Pike’s Peak testing last year. And is currently getting another work over in the Arctic. The recent quality oversight at Toyota drives home the importance of real world testing. This being actual plug to workplace, plug to school, long haul field trips, and random natural occurrences.
The intense testing effort at GM is encouraging.
=D~
+2
Feb 4th, 2010 (12:58 am)There has never been and never will be a perfect car. However, it’s quite clear that cars today are far better than they were 20 years ago, and cars 20 years from now will be considerably better than those on the roads today.
As for electric controls being the source of all these problems, since electric controls are everywhere it’s not surprising that they’ll be implicated in a lot of issues. But this hardly means they are the source of the problems. The Audi 5000 was alleged to have had unintended acceleration problems and it had a direct mechanical link between the gas pedal and the throttle vane. When it and other cars moved to electronic throttles most of the unintended acceleration claims disappeared.
The Volt will have problems but the problems will probably show up in the most unexpected places. The big problem for the EV-1 were the tires.
+11
Feb 4th, 2010 (1:00 am)Off Topic: I hope this works out better than certain other triple-dog dares.
I see the first comment is after midnight. Obviously I’m not the only person who checks this site (well, the RSS feed) about eight times a day for new posts!
*sigh*… I think I need a 12-step program.
+5
Feb 4th, 2010 (1:13 am)Just shows how naive some of us have been in wanting the Volt release schedule moved up. Sure we might be willing to take the risk but is GM and their lawyers? More importantly our heirs?
It would seem that it might be a good idea to have some sort of redundancy in the throttle and brake controls. I would think that a drive by wire system is most likely to fail with a zero or full throttle signal. Zero throttle not such a big deal. Full throttle – you gots a problem! So put a secondary switch that engages at the top 5% of throttle. If the computer sees full throttle from the analog switch but not full throttle from the discrete switch – shut her down!
+6
Feb 4th, 2010 (1:45 am)Probably preferable to floored, yes, but I’ll still play devil’s advocate.
What if you just happen to be crossing over a highway or a train track, traffic is coming soon, and you’ve already committed… and then the throttle goes unresponsive? Rut-roh!!
OK, now I’m just getting a little fussy. Time for bed. Night all!!
+1
Feb 4th, 2010 (1:49 am)Thanks to everybody for your comments, I feel more educated now. Thats the reason why I’m addicted to this blog. If I may add some personal input, I would advise to use cross redundancy in the drive by wire system, this decreases the probability of failure of a circuit by one half, but I’m pretty sure the GM engineers know this, what bothers me is that the Toyoya engineers seems to have forgotten their probability courses.
Best regards,
JC NPNS
+1
Feb 4th, 2010 (1:59 am)Well, GM really needs to get it right. Contrary to popular belief, it’s not totally impossible to make software work. The problem comes about with the attitude to the way software is created vs. the way hardware is created. Many companies take a rather cavalier attitude to software because they think it’s cheaper to change. But it isn’t. If Toyota is truly having a software problem (and I think it is likely at least in Woz’s “accelerating while on cruise control” issue) it’s not going to be any cheaper than a hardware problem. Probably much more expensive, in fact.
Feb 4th, 2010 (2:10 am)True. But hopefully not bugs that make you feel that you could die at any random moment.
“The company had to recall 2.3 million vehicles and halt sales of 8 popular models of new cars.” – I don’t know how every one else is feeling but the scale of this feels almost surreal to me.
No, they haven’t not even close, that’s the scary part. It’s the unknown and essentially unknowable interactions amongst the infinite iterations of supply chain and process and environment that fortunately, rarely turn up this type of result.
+3
Feb 4th, 2010 (2:19 am)Really?
With eight models and millions of vehicles on the road since 05, shouldn’t Toyota have long since had this behind them by that methodology.
+3
Feb 4th, 2010 (2:25 am)#4
“Even the 3rd Gen’s alleged braking issues are probably more psychological with changes in braking pressure etc. when hitting pot holes than a real problem.”
Actually the new issues are with the regen braking actually disengaging when the car is using them and hits a bump, thus feeling like your brakes broke. From my impression the problem would fix itself if you simply pressed the brake pedal harder to engage the friction brakes, or let go of the brakes alltogether and applied them again freshly. Not that that’s an acceptable solution.
+2
Feb 4th, 2010 (3:00 am)PriusChat members are attempting to understand the 2010 Prius brake issue…see link below
http://priuschat.com/forums/gen-iii-2010-prius-technical-discussion/75438-2010-brake-system.html
+2
Feb 4th, 2010 (4:28 am)I also think it has to do with ABS/TC.
Here’s a similar discussion on the Tesla Motors Club forums and it mentions the 2G Prius having similar complaints:
http://www.teslamotorsclub.com/tesla-roadster/3398-nhtsa-complaint-wrt-regen-tc.html
The automatic reduction of braking force by the ABS/TC because of a loss of traction (hitting a bump in this case) seems to be quite common even in ICE cars. You will feel a short period (less than half a second) of reduced braking force, but it comes back when the tires regain traction. In your case, in competitive driving, this might be less safe, but in normal driving it should actually be safer since it allows the wheels to regain traction.
The only thing different for hybrids and EVs is in addition to normal braking, you also lose regen braking for some time. In the Tesla Roadster, it’s a split second, and according to a commenter, in the 05 Honda Insight it is a bit longer. The Prius likely does something similar.
+1
Feb 4th, 2010 (5:03 am)This ABS vs Pot holes and rough roads is indeed an old issue.
Ever try a panic stop with ABS on snow or gravel/dirt?
In most cases, you are better off throwing the vehicle sideways.
Me? Give me an on and off switch for the ABS please.
Besides, If I want ABS, I’ll just pump my brake pedal 60 times per second.
-Paul
+2
Feb 4th, 2010 (6:06 am)So if you are right Jeffhre, I advise all the current car engineers to revise this elementary exercise :
A particular circuit in a security system of a plane , car, truck, … only operates correctly if both components C1 and C2 are not faulty. If only one of them is faulty the security system is out of order. C1 may be faulty with a probability (k), (0 < (k) < 1) and C2 with a probability (z) (0<(z) <1). The defects of C1 and C2 are assumed independent.
a) The basic circuit links C1 and C2 in series.
Solution :The probability that the circuit is out of or order is (k)+(z)-(k).(z) = p, 0 <p<1
b) Assume you double the circuit for a better security. So you have two similar circuits in parallel the a circuit and the b circuit, with 4 components : Ca1 is linked to Ca2 and Cb1 is linked to Cb2. Solution :The probability that the circuit is out of or order is p².
c) You may dramatically increase the probability of non failure of the circuit by not using parallel redundancy but cross redundancy, using the same four components but linking Ca1 to both Ca2 AND Cb2 and linking Cb1 to both Ca2 AND Cb2.
Solution :The probability that the circuit goes out of or order is p^4. (the fourth power of p).
That is theory, in practice one usually say that the probabilty of failure is at least halved to take into account other non modelized factors.
I hope that helps.
JC NPNS
Quelle est la probabilité que le circuit tombe en panne ?
+1
Feb 4th, 2010 (6:15 am)Lyle reversed the metaphor, because it could be worse if it happens within the Volt. I’m pretty sure it was intentional and clever.
Be well,
Tagamet
Let’s Just Get The ***VOLTS’* * * Wheels On The Road!!**********NPNS
Feb 4th, 2010 (6:19 am)DITTO! *USE* us GM!
Be well,
Tagamet
Let’s Just Get The ***VOLTS’* * * Wheels On The Road!!**********NPNS
+1
Feb 4th, 2010 (6:22 am)The first step is recognizing and admitting a problem (lol).. Where do I join?
Be well,
Tagamet
Let’s Just Get The ***VOLTS’* * * Wheels On The Road!!**********NPNS
Feb 4th, 2010 (6:26 am)Agreed! And all the more reason for a trial fleet chosen from our members!
Be well,
Tagamet
Let’s Just Get The ***VOLTS’* * * Wheels On The Road!!**********NPNS
Feb 4th, 2010 (6:31 am)Would be great to see TAG offered a Project Driveway Volt. I’m pretty sure GM wouldn’t approach me with the offer. Not going to give details. Folks who have been here over the last year probably know why.
BTW: Lyle, Don, Dan, statik, Laura, and Mike deserve consideration.
=D~
+2
Feb 4th, 2010 (6:33 am)Hi JC,
nasaman, in typical NASA fashion has been lobbying for redundancy in all of the Volt systems for a long time now. I hope that GM has been listening to some of the suggestions from this site, (although I’m sure their engineers would be of a similar mind).
Be well,
Tagamet
/Off to work
Let’s Just Get The ***VOLTS’* * * Wheels On The Road!!**********NPNS
+7
Feb 4th, 2010 (6:38 am)I am not remotely worried about this in the Volt.
GM has been killing themselves with testing.
I would be very surprised if this is not the most reliable car they have ever built.
Feb 4th, 2010 (7:05 am)I think that most of us would crawl through broken glass for the chance!
Be well,
Tagamet
Let’s Just Get The ***VOLTS’* * * Wheels On The Road!!**********NPNS
Feb 4th, 2010 (7:06 am)From your lips, To God’s ear!
Be well,
Tagamet
Let’s Just Get The ***VOLTS’* * * Wheels On The Road!!**********NPNS
Feb 4th, 2010 (7:15 am)To answer the question, yes I think the probability is high and there will be issues and recalls involving electronics. Its inevitable. High voltage, variable speed variable load asyronous motor, regen braking, gas engine-driven generator–these are all technologies that are new for GM, many of which are farmed out to out-of-house suppliers.
Insulated wiring, phase monitors and proper filters to protect against electro-magnetic interference-again, all new variables for a traditional manufacturer with little technical experience. Metal components can weld /fuse with other metal as a result of stray voltage. Choice of the type of ceramic bearings in the electronic drive motor. These kind of failures could be catastrophic.
The first generation Volt will have many more issues then future generations.–Lee
+1
Feb 4th, 2010 (7:27 am)If I were Andrew Farah, in these very moments I would urgently arrange further reviews of all the FMEAs(*) that were (hopefully seriously) done up to now, at least for the Design and for the Manufacturing Process.
(*)Failure Mode and Effect Analysis
+5
Feb 4th, 2010 (7:33 am)And let me add this.
Before this car, I swore I would never buy another GM car. Period.
Now, I want to be first to drive off the lot with one.
I have so much confidence that GM is building the Volt as a very reliable car.
Feb 4th, 2010 (7:37 am)I honestly don’t think so. They have too much at stake here. They can’t handle another failure. All the testing and retesting they are doing is going to help a long way. They want to restore confidence in their brand of cars. They need to become a shining beacon of American ingenuity.
They need to overcome negative perceptions. They know this.
This car will be immaculate.
+3
Feb 4th, 2010 (7:38 am)will the Volt be able to be remotely programmed?
It sounds like the problem that Toyota has in fixing the brake problem is getting all the cars into the shop so that they can be reflashed.
The current Tesla Roadster can be reprogrammed remotely (wireless). If the Volt has On-Star, I would think that the software updates could be done remotely as well?
Any discussion of whether this feature will exist?
Feb 4th, 2010 (7:39 am)This is one of the biggest problems GM and other car makers face.
With ignitions that are no longer hard wired to the spark plugs, shift levers that are no longer connected to the transmission, and now brakes that are no longer connected to the calipers, there is a lot of room for disaster.
Lets face it, most of these components are not even made by the car company themselves. The components are built by 3′rd parties that supply the auto industry and the individual car companies have little control over the manufacturing process. Toyota’s gas pedal problem is a part manufactured in Elkhart, IN. While these problems always existed in the auto industry, at least as a car driver, you could shut off the key or shift to neutral if the gas pedal got stuck. Not any more…….
+3
Feb 4th, 2010 (7:45 am)jeffhre #18 says:
“Really?
With eight models and millions of vehicles on the road since 05, shouldn’t Toyota have long since had this behind them by that methodology.”
===============================
The problem with your statement is that we really do not know when Toyota found out about these problems, and if they just decided it was not important enough to fix…… Large companies do those types of cost analysis projections all the time. Action is only being taken now, becuase it is such a huge public relations nightmare, IMHO.
+1
Feb 4th, 2010 (7:47 am)==================
Dave: I am really hurt that I am not on your list……………….
+3
Feb 4th, 2010 (7:47 am)A series hybrid is much simpler to electronically control than a parallel hybrid, just as fuel injection is much simpler to control than an electronically controlled carburator (remember the late ’70′s and ’80′s).
Feb 4th, 2010 (7:55 am)The old saying goes: “you live by the sword, you die by the sword”
This is the disadvantage of the modern trend in automatic brakes (ABS) and automatic steering.. the occasional failures are spectacular but overall you get better safety.
Reputable auto manufacturers know how to solve/prevent these issues… and the best solution to many of these problems is reliable parts/software that are re-used across different car lines. Unfortunately the Volt will pioneer many new parts and processes.
You know the press will jump with both feet on any story like these, and the Volt will suffer from them also… bad news sells newspapers.
Is ABS braking required by the government?.. I really prefer simplicity in my cars.
Feb 4th, 2010 (8:18 am)Hi Tag, thanks
Bis repetita placent, I’m sure Nasaman can have influence on many.
Best regards,
JC NPNS
+1
Feb 4th, 2010 (8:21 am)Would be great to see TAG offered a Project Driveway Volt. I’m pretty sure GM wouldn’t approach me with the offer. Not going to give details. Folks who have been here over the last year probably know why.BTW: Lyle, Don, Dan, statik, Laura, and Mike deserve consideration.=D~ (Quote)
———————————————————
And don’t forget that zipdrive person. I like him/her. And of course -ME!
+2
Feb 4th, 2010 (8:22 am)While total vehicle integration will reach a new high and complexity on the Volt, it’s important to note that electronic sub-systems have been in production on GM cars for some time now. The electric steering system has been on the Chevy Cobalt since it went into production. My Colorado pick-up has the same fully electronic throttle that was introduced on the Corvette. It operates flawlessly and the fleet is many years old now. Completely self contained electric anti-lock brake systems began with the TEVES system used by GM on their higher end cars (My Olds Touring Sedan) since 1988. Stability and traction control actually ought to be easier to accomplish on an electric power train. I think the articles we’ve seen on this site has shown that GM is spending an inordinate amount of time and resources on integration. Look how much has gone into operation of the generator, most of us who understand it’s function would probably have been happy with just about anything. But GM really is worrying the details.
+3
Feb 4th, 2010 (8:34 am)(Whew!), (I signed up 4 shops yesterday for L-1 advanced processsor training and was really “vegged out” by the time I got in, so, no post).
GM will be monitoring every Volt automatically in real time with OnStar to the precision of 10 to the fourth power of sensitivity and immediacy.
The entire key here is the real time (up to every four thousanths of a second or so) monitoring, of, for example, each prismatic cell, to the one-onehundreth of a volt, reported through the Controller Area Network both in a “fast priority” without reporting limitations (class “C” or even a “D”), or “not as fast priority” in a routine “non-examining” way (class “B” rate), if you will (only several times a second, perhaps).
OnStar is the totally opposite end of the reliability-monitoring spectrum as compared to ***not*** having OnStar at all.
This is not an advertisement on my part for GM, it is just plain ***fact***.
This series of Toyota tragedies ought now make this completely clear if anyone is concerned about ‘privacy issues’. None of us should be. Privacy issues have nothing to do with OnStar until someone takes your car. That thief is going to jail, and, OnStar is going to help put him there, period.
Toyota apparently has had this problem since 2007, and, the sheer numbers of them out there was a logistical nightmare. As well, Toyota became encumbered with a “double bind” situation,
“Damned if you do [a recall] and damned if you don’t [do a recall].”
Apparently, Toyota collectively chose the latter, which clearly has become far more damning by a magnitude of at least 3 (1000 times worse).
This is what any excessively accumulated sense of power can do to the human psyche, from being in charge too long.
Or, if suddenly someone underqualified is granted the tools of excessive power (via nepotism) (ahem), where they either already have a narrow and shortsighted and totally unqualified set of viewpoints (God help us all for another Katrina, and, God save us from self-annointed heretics who influence anyone responsible to not give care in time), or, if the position of power has been held far too long beyond their self discipline to remain self-critical. (It is just not only a matter of **overt** pretentious humility).
Corprate power, political power, legal power, heretical religious power on the TV, and many other forms of it, supposedly are subject to the limits of the voting out of the entrenched self-corrupted who have neglected their self-critical responsibilites.
Technolical advancement beyond the managerial-span-of-control of those entrenched in “almighty-power-incorporated”, when overly-protected by the corporate veil, ought to be prosecuted toward removal from those positions.
Abuse of power or the neglence of the wise directions of it must be voted out, (or critically overtly condemned in person, face to face). This is what makes a democracy work. A (family or religious) non-democratic corporate hierarchy (automotive or heretically-religious), un-selfexamining and un-selfcriticing, which causes loss of life, directly or by complicit influence (respectively), ought to be prosecuted out of that deadly position of leadership, to, for example, be permanently censured off of TV in the public interest).
Per the Volt,
Real time reporting via the OnStar holds the complete confidence that any problem, even something we might perceive as infinitesimal, can be seen by the GM automated monitoring not just in a split second, but to the speed of the communications rate on board, a lot faster than that.
And, as thorough as GM datastream availabilities are, for us independent technicians out here in the aftermarket, your Toyota’s and all other makes would not be as easily understood by your favvorite independent tech had it not been for the exceptional openness of those datastreams that GM lets us have out here with the Genisys scan tool (with the GM logo as well as the other OEM logo’s in it, proving the analysis software comes from GM et al. (at an affordable cost for us too.) )
But then again, I expect that the independed shops wil not be needed at all for Votec for the first ten years at least. You will just not need us at all.
+4
Feb 4th, 2010 (8:50 am)Now, if Toyota can also admit there are problems with high acceleration during cruise control use. We have a 2007 Camry Hybrid that accelerates at full throttle (excessively) in order to get back up to speed after coasting downhill. Last year, Toyota said it was “normal”.
Time to trade in my Camry Hybrid for the Volt……
+13
Feb 4th, 2010 (9:05 am)Quite frankly I believe that Toyota got sloppy and too content. So did GM, Ford and Chrysler in the 1970′s and 80′s. Now its Toyota’s turn at falling from grace.
Detroit’s resurgence is upon us and the Volt and related cars will lead the way.
Make sure the code works, the bugs are gone and check, recheck, and test, test, test.
I’ll take mine in black this fall, thank you!
+7
Feb 4th, 2010 (9:14 am)Toyota’ s problem with its throttles is just poor engineering.
Engineers can design for redundancy in critical systems.
Essentially “man rating’ an NASA rocket consists of making critical components ‘ triply redundant’. Designing critical systems for a nuclear power plant is an example of routine use of ‘parallel triple redundancy’. but as you can imagien its more csotly ot do so.
That sounds really technical but what it means is something we all do, but is formalized as a design rule. For example: when its raining, many people wear a raincoat,AND take an umbrella,. That is ‘parallel double redundancy’,if you use both or ‘serial double redundancy’ if you use only one but carry the other in reserve unused, in case of a very severe rain. .
Another example, you have a tire, and a spare tire, and yet another spare tire, in case the the spare goes flat simultaneously. That is ‘serial triple redundancy’. If you go further, and make the original, the spare, and the spare for a spare tire, all mounted and ready to go like a’ dualie or triply’ on a Pickup truck. That’s ‘parallel triple redundancy’.
The Volt EREV architecture is a ‘serial doubly redundant’ system. GM felt people would fear running out out of juice. So they supplied a built in charger/engine for the basic BEV of a VOLT. That relieves ‘range anxiety’ and is an example of ‘serial double redundancy’.
You can do similar things in s/w, and s/w + h/w combinations. All you have to do is decide to pay the cost and do it..
From what I understand Toyota engineers kept their old mechanical throttle linkages on their cars for a few years, in parallel, with the new electronic throttles. as a sort of half-assed redundant system.
Under price pressure to gain the benefit of electronic throttles, and reduce costs, they decided the old mechanical throttle was no longer needed as a redundant system. So they discontinued it. But they were left without redundancy in a critical system.
And a very infrequent bug did show up.
Feb 4th, 2010 (9:15 am)Test the living daylights out of the Volt. It must be absolutely perfect, or at least as perfect as possible with manufacturer testing.
+2
Feb 4th, 2010 (9:18 am)This issue reminds me of the movie “Fight Club” where Jack’s (Ed Norton) job as an insurance adjuster forced him to calculate potential costs of customer lawsuits for faulty products vs. the cost of the company actually performing a recall to fix the faulty equipment (I think his faulty part was a seatbelt bracket)…
…great movie…
+1
Feb 4th, 2010 (9:18 am)______________________________________________________
Woz’s Prius Rant:
Video of a frustrated Woz talking about his Toyota Prius software issues…you have to love this guy…
http://gizmodo.com/5462806/a-frustrated-steve-woz-talks-about-his-toyota-prius-on-video
GM,
Consider putting Woz on the Gen1 Volt short list…
______________________________________________________
+5
Feb 4th, 2010 (9:22 am)“If Electronics are to Blame for Toyota’s Vehicle Failures, What Does this Mean for the Volt?”
It means absolutely nothing.
Feb 4th, 2010 (9:24 am)Agree with the comments that folks on the list should be testers. Michigan would be a good location with it’s unpredictable weather and debateable status as the “pothole capital of the world”. State government is talking about cutting highway funding to keep our status safe. The first link is to a pothole contest held a couple years ago, the second discusses potential federal highway revenue losses due to lack of matching funds.
http://www.wilx.com/home/headlines/15744242.html
http://www.crainsdetroit.com/article/20091206/FREE/312069963#
+5
Feb 4th, 2010 (9:31 am)I agree 100%!!!!
Poor Toyota quality is not a sign that GM will have poor quality.
Toyota seems to have endless very poor quality. 3 recalls now for the run away problem. And clearly noone knows if the problem is fixed. (I would sell a Toy if I had one) Now a toy that won’t stop.
To think the Volt will have problems because Toyota has very poor quality control seems saying because a cheap off brand electric game from China breaks that my Compaq computer is going to have problems.
Bottom line Toyota is not building the Volt. So how can poor Toyota quality cause poor Volt quality?
+2
Feb 4th, 2010 (9:38 am)Daaaagwoood, come out to playyyayyy. Dagwood, why so sad, broke brakes got your tongue, or your Toyota heavy stock portfolio got you down?
Feb 4th, 2010 (9:38 am)Wow – very well explained ! You must be an academic of some kind ( or perhaps, you SHOULD be an academic ) – no disrespect intended !
Feb 4th, 2010 (9:52 am)Hopefully with OnStar any software fixes could be downloaded to the Volt – like when Microsoft downloads a Service Pack fix for Windows overnight to you computer. Or is this oversimplifying things?
+6
Feb 4th, 2010 (9:57 am)As a professional gremlin hunter in electronic circuits, I suggest using as much solid state controls as possible. If i had a dollar for everytime the problem was a loose wire, i could have retired years ago.
Regarding the code, KISS. Overcomplex code is just asking for problems.
+2
Feb 4th, 2010 (10:00 am)And… At 1/2 hour to repair, that’s 1.15 million man-hours. Where the heck are they going to get this volume of skilled labor outside their factories? What are they going to do about the quality of repair in a field-installed environment? Surreal indeed.
Chrysler and others are using the brake system to disengage throttle. The acceleration and braking systems are interlocked to override any logic problems.
Mechanical linkages have just as many problems with the amount of wiring etc under the hood. I worked on a Lincoln one time with a throttle sticking issue. A wiring harness had slipped out of it’s loom and was hanging up the linkage.
+4
Feb 4th, 2010 (10:00 am)Central Alberta Canada Volt Tester available for Hire.. No salary required….
I would give daily reports including the +’s and -’s and also could compare the Volt with my 2010 Fusion Hybrid…
Out here…. temperatures are from -5 C to -40 C in the winter all the way up to + 27 C ish in the summer . The roads vary from an interstate highway type to narrow pot holed gravel roads…and everything inbetween…
The Ideal testing ground….
Volt tester available now…. GM Call me….
+2
Feb 4th, 2010 (10:02 am)Torture test the Volt! Drive it into potholes 100 times a day or something. Let it cook in the Arizona sun for a month and then drive it. Let it freeze in northern Canada for a month and then drive it. Heat the Volt up to Arizona summer temperatures one day and then freeze it below zero the next day … back and forth for a couple of months. Just to see what happens.
GM’s test engineers should think of all the scenarios the Volt would deal with in the real world. Hills, mountains, gravel roads, salty roads, twisty roads, dirt roads, muddy roads, dusty roads, bumper to bumper traffic, speed bumps, sidewalk curbs, driving in the water of creeks and rivers that have overflowed, etc. Test all the electronic equipment, connectors and cables rigorously for electromagnetic interference and heat problems, etc. They should probably have a checklist of about 100 scenarios that the Volt might encounter in real world driving. Check each one of them off. Then repeat them again and again.
GM just can’t afford to have any big surprises with the Volt in the first few years. Once the Volt is on the roads, they need to keep on testing them too. Some of these Toyotas don’t start having problems until they have been on the road for 3-4 years and have plenty of miles on them.
TEST, TEST, TEST
TWEAK, TWEAK, TWEAK
OPTIMIZE !!
+2
Feb 4th, 2010 (10:02 am)______________________________________________________
#41 Jason M. Hendler Said:
“A series hybrid is much simpler to electronically control than a parallel hybrid, just as fuel injection is much simpler to control than an electronically controlled carburator (remember the late ’70’s and ’80’s)…”
____________
Is the Volt a true simple Series Hybrid or is it as BillR speculates http://gm-volt.com/forum/showthread.php?p=36228#post36228 a more complex 2-Mode Series/Parallel Hybrid?
As I mentioned in yesterday’s topic thread (#128 comment), I find it interesting (perhaps telling?) that the 2Mode presentation http://www.che.ncsu.edu/ILEET/phevs/plug-in_2008/1A-1_GM%202-ModePHEV%20VUE.pdf provided in BillR’s forum post shows a clear graphic of not only the Saturn 2Mode VUE but also the Chevy Volt.
Perhaps Lyle can get a definitive response from GM as to if the Volt is a classic Series Hybrid or a 2Mode Series/Parallel Hybrid.
______________________________________________________
Feb 4th, 2010 (10:25 am)Having been in the wireless industry for 17 years, I can say with authority that signal propagation is very unpredictable. (Thus, dropped calls for no engineering reason.)
I don’t have the complete confidence that Dan has and I don’t believe for a second that OnStar can do real-time telemetry at computer speeds. The best you can do is pick up the pieces later.
Feb 4th, 2010 (10:34 am)Stas, thank you. Even an idiot such as myself can fully understand this.
Great explanation!
Feb 4th, 2010 (10:36 am)47 J Bell Now, if Toyota can also admit there are problems with high acceleration during cruise control use. We have a 2007 Camry Hybrid that accelerates at full
throttle (excessively) in order to get back up to speed after coasting downhill. Last year, Toyota said it was “normal”.
Time to trade in my Camry Hybrid for the Volt……
Hi J Bell, we own a 07 Prius and I have to agree with the Toyota Rep. on your complaint.
My 2 reasons are 1. Since you said you were coasting down hill and then the cruise control excellerated excessively to get back up to cruise speed tells me you either turned the cruise off while going down hill or you lowered it several mph while going down hill. Either way when you reset the cruise to go faster, thats what the car is going to do. 2. As you should know with the CVT The engine will normally increase in rpm just like a car that drops down a gear or two to accelerate quicker does. Sometimes with the CVT it may sound like the engine rpm is excessive when accellerating but that is normal with CVT’s. It’s no different than passing a vehicle on the freeway and an automatic transmission drops down a gear or two when you are trying to pass another vehicle. We are also considering buying a Volt or bev eventually but not because we are not satisfied with our Prius. We have had 0 problems with our car except having the bumper drag on the end of our driveway. Respectfully, BLIND GUY
+2
Feb 4th, 2010 (10:57 am)Up until last year, I had a car with no ABS. Now, I have that feature in my new car.
I hate it.
It might be good in some circumstances to have that but most of the time it’s a pain in the neck.
Wish I could disengage the thing easily. It should be mandatory to be able to disengage it at will. I know I don’t need that crutch to drive my car.
Feb 4th, 2010 (11:05 am)Well said. I totally agree.
+1
Feb 4th, 2010 (11:08 am)Eugene (#6),
Toyota has also had a huge problem with “Engine sludge”. Here’s an interesting article about it:
http://www.consumeraffairs.com/news04/2007/01/toyota_sludge_settlement.html
+2
Feb 4th, 2010 (11:19 am)Ouch. Please don’t compare GM to Microsoft. You’re gonna scare us all : -)
+1
Feb 4th, 2010 (11:20 am)Stas Perterson (#49) +1, Great explanation. Thanks.
There is a Washington Post article that describes a redundant safety measure called “Brake override” that many auto manufacturers implement, but Toyota does not. It’s very interesting. Take a look:
Toyota did not install brake override systems despite complaints
http://www.washingtonpost.com/wp-dyn/content/article/2010/01/28/AR2010012803971.html
+2
Feb 4th, 2010 (11:22 am)We’ve done this gig before. Many times. I’m pretty sure GM is not taking any such offer at this time. But nice try anyway.
Feb 4th, 2010 (11:24 am)Me neither. But they can surely find a use for OnStar other than that.
+4
Feb 4th, 2010 (11:25 am)Wow! This article just gave me an idea of how a company, fearful of the Volt, could de-rail its rollout. Cause FUD (fear, uncertainty & doubt) by sabotaging a competitor’s electronics. Make GM management second guess their Engineers due diligence and delay the rollout.
It could happen; the Volt is a game changer.
Change is not welcomed by everyone, especially those profiting from current practices.
NPNS!
Feb 4th, 2010 (11:31 am)_______________________________________________________
The action by Toyota would therefore have been completed after 100 days had elapsed following the sale of the first 500 vehicles.?
+5
Feb 4th, 2010 (11:36 am)Good morning —I’m a bit late to the party today. I’ve reviewed all posts here so far and find several noteworthy….
- Noah Nehm’s #8
- Jean-Charles Jacquemin’s #15, 23
- Jacksunny’s #34
- Dan Petit’s #46
- Stas Peterson’s #49
- Kdawg’s #59
And Tag, you‘re certainly right in saying in post #29 “(nasaman) has been lobbying for redundancy in all of the Volt systems for a long time now.” In fact, one reason I flew to NYC for VoltNation a couple years ago was to “preach” extensive redundancy, fail-safe designs and Failure Mode, Effects, and Criticality Analysis (FMECA) to anyone from GM who would listen. I caught Andrew Farah there & we discussed the subject in detail —I can assure anyone here that he understood & agreed that these design & analysis disciplines are vitally important and must be enforced on all suppliers as well as throughout GM itself.
More than 20 years ago GM acquired Hughes, one of the world’s largest and most experienced spacecraft suppliers. Many Hughes engineers became heavily involved in developing highly-reliable automotive systems such as ABS. The Hughes acquisition gave GM a head start over most other competitors in applying fail-safe, highly-reliable design practices to automotive components and subsytems. As I said to Farah 2 yrs ago, all his team had to do was to enforce these high-reliability disciplines throughout the Volt program —and I have no doubt they have done and are continuing to do so.
Feb 4th, 2010 (11:47 am)Thank you Stas, you’ve managed to make this very clear for some one who hasn’t seen the terminology nor the math behind the theory for more than 20 years.
+1
Feb 4th, 2010 (11:55 am)I think Toyota’s problem has to do with chooseing less expensive parts instead of using best part for critical application. This is totally my guess without direct facts to back up my opinion. I hope GM listens to engineers instead of bean counters when it comes to deciding on appropriate parts, especially high use critical parts. I was glad to hear that the engineers have feathered the power to the traction motor from a stop to help avoid wheel spinning. I never thought I would say that. With the high torque from 0 I could see how it could be a problem on any slippery roads having the traction motor always fighting the traction control and giving the feeling of confusion from your car’s response. I would love to be an observer of the Volt engineers tweeking the volt.
+1
Feb 4th, 2010 (11:57 am)Y’know, it’s funny that you can’t disable ABS. I’ve never seen a car with a manual switch for that. On the flip-side of the coin, every car I’ve ever seen with Traction Control… those all DO have a TC on/off switch. Go figure.
Feb 4th, 2010 (11:59 am)It may have helped me in 1989, today it just confuses the heck out of me!
+2
Feb 4th, 2010 (12:00 pm)Having the worlds largest proving grounds and real world test facilities … Milford proving grounds 126 miles of test roads of all types… and other facilities like the corrosion lab… I would say if there is a way to test for it … GM is doing it to the VOLT.
+2
Feb 4th, 2010 (12:00 pm)I would hope that the “New GM” is smarter than Toyota and has a great desire to make good and sound automobiles. We have as Ford and Chrysler made junk in the past which I don’t think the Volt will be.
Keep thinking clearly and go for quality and good workmanship. That means that the employees on the assembly line need to be quality orientated.
+6
Feb 4th, 2010 (12:05 pm)For sure, this has to be a clarion wake up call for the whole industry. I think that anyone who produces a system of this complexity had better be ready for a bug or two to surface, usually at the most inopportune time. Remember the NASA/JPL guys who sent the probe to Mars a few years ago? Somebody typed in miles instead of kilometers, or some such, and the thing missed the whole planet, or pretty close. Nobody’s perfect.
Thank goodness this one happened to Toyota, and not to GM. Next time it could be the opposite. I would suggest to GM that they spend their energy thinking about how to handle such a contingency better than the arguably bungled way Toyota has behaved/is behaving here. This as opposed to giving out “incentives” to terrified Toyota owners, and appearing to gloat. “Pride goeth before a fall” and “What goes around comes around” apply equally across the board.
-2
Feb 4th, 2010 (12:07 pm)The disable for the ABS is called the emergency brake.
But using it while ABS is needed defeats the purpose.
Drive Safely.
NPNS!
Feb 4th, 2010 (12:17 pm)I think if I disable the traction control on my Impala, I’ve disabled the ABS too. Maybe someone who’s know what their talking about can correct me if I’m wring
+3
Feb 4th, 2010 (12:18 pm)#19
I heard a local Toyota dealer, who supposedly sells the most Priuses of any dealer in the U.S. make this exact argument last night. No doubt true, but a pretty shaky response to scared, non-technical, customers IMHO, LOL. “Just step on the brake harder”. True, but a tough sell when the panic is on.
In the early days of ABS, there were numerous reports of accidents for a similar reason. People would slam on the brakes for the first panic stop in their new ABS car. When they felt the pedal pulse for the first time, they would panic and take their foot off. Bang!
My S-10 is so light in the back that the ABS deploys when you hit a bump under any sort of moderate braking. Maybe it’s just a low end system, but the cycle rate is so slow that it does feel like a momentary loss of braking. I guess it actually is, come to think of it. My response is to stand on the pedal even harder, but I can see how it would be disconcerting to someone who doesn’t understand what is going on.
I’m the last to apologize for Toyota. But I think that the Prius is fine if you really do just stand on the brakes like you mean it. It seems like a driver education problem as much as anything. Unfortunately (fortunately?), it looks as if they are well on the way to botching this one as badly as the throttle thing. There is a great object lesson here for GM, et al. Learn from your competition’s mistakes, and figure out better way to respond.
Feb 4th, 2010 (12:24 pm)This Toy fiasco could’ve happened to anyone. That’s just the nature of high capacity manufacturing. When you build mass excellence, you can also build mass failures. ESPECIALLY when you rely on outside products.
Mass production eventually will “relax” specs or reduce testing cycles to increase numbers. Do you really think Toy tested every piece of the gas pedal that came from the third party? Hell no. That would slow down stock inventory and numbers. Do you think they tested the part for 5 years (Avalon affected years 2005-2010), I highly doubt it. So do you really think GM will test all the PCB’s in the Volt for any more than 5 years? They haven’t yet have they? But they are still releasing within 3 years right? OK maybe 4.
The point i’m trying to make is this crap pops up when you least expect it and you can’t predict it. Somewhere in every mass produced product there could be a 750 million piece semiconductor of a specific Lot # that might fail because the furnace temp during the baking and doping period dropped to below .98 of the lower control range for 2.75 milliseconds and may cause the semiconductor to fail in normal operation. Regardless of the cause or who made the product, the final product mfgr is responsible. You don’t call Seagate for support if your hard drive fails in your Dell PC do you?
IE, sh|t happens, you just have to brush yourself off an move on.
Personally, the peeps I work with that have cars affected still have loyalty to Toy and laughed at the GM $1,000.00 credit for a Toy and said it’s GM’s desperate attempt (insert rolling eyes). IMHO, GM should’ve took the high road on this one. “Kickem while their down” usually means even if it happens to them (GM) and no matter how small and Toy does not reciprocate the action, it’s even worse.
/Whew….. long post. I think i’m done for the day……..L8!
//I think it’s the random piece/part failures that really piss most of the people off, i.e, a knob here, a tranny there, a power window switch here, a leak there. These big recalls almost always means just one thing. And no I don’t own a Toy.
+2
Feb 4th, 2010 (12:25 pm)Driving 6 months of the year on snow/ice, I think ABS is a great and would never turn it off (same goes for traction control). Usually the cars i see in fender benders or in the ditch are older ones w/out these features. There are also people who don’t know what ABS is, and that their car has it, and try to pump their brakes to stop.
+3
Feb 4th, 2010 (12:36 pm)You are talking about a manufacturing defect which should be the responsibility of Quality Control. I think the problem is a design flaw, not manufacturing.
I think Kickem while they’re up/down/wherever is SOP for the auto industry (even between domestics). How many Asian car ads show a big American Truck/SUV running out of gas or getting crappy gas mileage, but fail to mention these same American car manufactures have high mileage cars as well. Its called sales/marketing and everyone is suppose to be a big enough boy or girl to make their own opinions after seeing/hearing the ads. I get more upset when Goverments unfairly get involved in the market, like when Japan would not allow US cars to be bought in the Japanese cash for clunkers.
+1
Feb 4th, 2010 (12:37 pm)Wouldn’t it also be just as effective to throw the car in neutral as well then hit the brakes?
So what if you blow the engine, at least your alive.
Or does that make too much damn sense? Let me know if it does so I can add more Kahlua in my coffee.
Feb 4th, 2010 (12:38 pm)Toyota is trying to manage sticky throttle, faulty brake system, and tire wear issues. Honda is fairing better. Both have battery hybrids which have been on the road for some time now. In some cases the batteries have been in use for ten years. Wonder how these are holding up?
_______________________________
First Numbers (from 2008) on Hybrid Battery Failure:
For years, sporadic anecdotes about hybrid battery failures have been reported by individual hybrid drivers. But finally, the automakers are reporting the first numbers about the likelihood of batteries failing after the warranty expired.
With more than 100,000 Honda hybrids on the road, the automaker told Newsweek that fewer than 200 had a battery fail after the warranty expired. That’s a 0.002 likelihood. Toyota says its out-of-warranty battery replacement rate is 0.003 percent.
Most hybrid-producing automakers offer a warranty on hybrid components for the first 100,000 miles. In California and other states using California’s stricter emissions laws, the warranty is extended to 150,000 miles.
_______________________________
Ten years equals 3650 cycles. Add 24% for periodic twice daily recharge. The total is 4500 cycles in ten years time under very heavy use. Wonder how many cycles the T battery of the Chevy Volt has been through at the test lab? How are things looking?
=D~
+3
Feb 4th, 2010 (12:46 pm)#79
Years ago, when ABS was pretty new, I got to drive a Corvette with such a switch. I’m an amateur race driver and, like most, I was certain that I could modulate the brakes better than any !@#$%^ computer. Chevrolet had set up a rainbird on a big parking lot. They challenged us to drive up to a cone at a certain speed, put on the brakes, and avoid another cone on the wet asphalt. With the ABS off, you would invariably lock the wheels and run right over the cone. With the ABS on, you could nail the brakes as hard as you could, and steer right around the cone. It made a believer out of me, and I have never forgotten it.
It is a great system for emergency stops. The biggest problem I see is that people still don’t understand the dynamics, and fail to just nail the pedal with all their strength, even when it’s the best thing to do.
Feb 4th, 2010 (12:48 pm)+1
Feb 4th, 2010 (12:50 pm)#87
Amen. +1
+1
Feb 4th, 2010 (12:53 pm)#90
I was talking specifically about the brake issue with the Prius. When it comes to the bigger throttle issue with all of the other cars, you are absolutely right. And the engine won’t blow anyway. I’m 99% certain that they all have rev limiters built into their engine electronics by now. Unless that doesn’t work either, LOL.
+1
Feb 4th, 2010 (12:56 pm)“One unifying theory is that there may be failures in the electronic control units for these functions. These failures potentially could be caused among other things by electromagnetic interference from other electronic components in the car.”
This is impossible. If Toyota uses sensors with discrete output signal (0-24V) and executing mechanisms controlled by discrete input signal (0-24V), cables do not need ANY protection from electromagnetic fields. Even large industry electric motors (100+ kW) do not interfere with 0-24 signal.
If Toyota uses analog or digital sensors and mechanisms, shielded cable is more than enough to protect the signal.
Electric control system is 100 times more reliable than mechanic one.
Feb 4th, 2010 (1:01 pm)#23 said: Quelle est la probabilité que le circuit tombe en panne ? (What is the probability that the circuit goes down? [Thanks to Google]) Things are a bit more involved than that. First, there’s a discernible reliability partition between software and hardware. The wisdom back in the stone age was to minimize (trade-offs) software for hardware to increase reliability. This has evolved to where VLSI IC hardware rivals cpu/software complexities.
Add to this the several dozens of sensors needed. Then add to those sensors; cable harnesses, connectors, and EMI/weather-proofing enclosures. And yes, all this needs super duper stable power supplies (I do, among other things, DC metrology engineering.) You start to see the difficulties of testing new designs. Since military and space requirements mandate seven-nines kind of reliability; the auto industry has ready design models. Case in point.
GM doesn’t fare well so far in car ratings. Most of these ratings place GM generally in the middle of the pack (of about 30 models). So GM needs to look past Toyota’s debacle and clean up its own house. This is one area where getting back its dealers is a must. Otherwise GM will be swimming uphill.
Feb 4th, 2010 (1:15 pm)this depends on sensor type
+1
Feb 4th, 2010 (1:17 pm)Also, people who DO have ABS, but who think they’re retro-rockets and will stop you on *any* surface. That’s just not true.
Feb 4th, 2010 (1:19 pm)I aggree for the most part, however encoders and high-speed counters are very susceptible to noise unless shielded properly. This could be the case (or loose connections). There’s always software too. I’m interested to see what the investigation reveals.
Feb 4th, 2010 (1:19 pm)Just a cursory and laconic review of US auto sales in Japan would reveal that this measure is an example of economic ( ‘parallel triple redundancy’) overkill.
Back OT, did Toyota’s Japan based accelerator pedal suppliers face the same problematic results?
Feb 4th, 2010 (1:23 pm)How do you swim uphill? Waterfall? Did you mean upstream?
(j/k)
Feb 4th, 2010 (1:33 pm)Overcoming multiple metaphors in one sentence expresses the monumental difficulty of the task
Feb 4th, 2010 (1:35 pm)WOW That was schocking. Anyone thinking of buying a Toyota should read that first. Thanks for posting the link.
Feb 4th, 2010 (1:36 pm)You are correct about fly-by-wire being a future problem for automotive manufacturers.
However, the stuck gas petal problem that Toyota is experiencing uses the very procedure you mention to stop the accellerating vehicle: shift to neutral, steer the vehicle of the road and shut off the engine!
Happy trails to you ’til we meet again.
Feb 4th, 2010 (1:50 pm)#101
I don’t think so. I heard a Toyota dealer interviewed on NPR yesterday. He said that the first thing they do is check the name of the manufacturer on the unit. If it’s a Denso, it’s good to go. Also, if the serial # of the car shows it was made in Japan, good to go also. I think that the service bulletin statik posted yesterday reflects this.
+1
Feb 4th, 2010 (1:54 pm)jeffhre #75 Says: “The action by Toyota would therefore have been completed after 100 days had elapsed following the sale of the first 500 vehicles.? ”
===========================
No, the knowledge that there was a problem may have been available in that timeframe. Taking action to correct it is on an entirely different schedule. I do not pretend to be an expert on this whole Toyota situation, but my understanding is that there have been reports about the accelerator pedal problem for several years, but that it was ignored. Now that there is extreme public and governmental pressure, it is being corrected.
To compare that to my inital statement from post #5, reports of problems on this site would be the pressure applied to GM to correct the issues before the general release of the vehicle. There would be a common source of information, and many different people to see if any reported problem could be duplicated. I think that is a fair assumption, if GM would decide to use people from this site as a “test fleet”. Would it find every single problem that may occur? Absolutely not. Would it help in the testing process before the release? YES!
JMHO
+2
Feb 4th, 2010 (1:57 pm)#99
True that. I’m not trying to oversell it. The coefficient of friction is what it is, ABS or no. Plus, every time it cycles, it turns off the brakes for that little instant, and the stopping distance lengthens that little bit. I’m just saying that I’m willing to admit that it can modulate the brakes better than I can.
Feb 4th, 2010 (2:00 pm)So if their Non US Suppliers parts don’t have this problem, why does the US supplier? If engineered by Toy then they should be the same product / same problem? No? Yes? I would think they would be but I aint gonna make any assumptions. I had a hard enough time understanding the fix.
+2
Feb 4th, 2010 (2:02 pm)Electronic sub-systems have been around for a long time for basically any manufacturer. I think the fear of electronic systems is just people don’t understand them. If you look over the history, I think mechanical systems have been much bigger causes of problems, safety or otherwise. If you look at Toyota this time, you will see the two biggest safety problems (the loose floor mat and sticky pedal) are found to be mechanical problems. There has been no evidence of the current issues being a result of electronic systems; so far it is just people projecting their fear and starting these rumors.
In this case, it seems the issue is just lag from the ABS, which can happen in any car (and sometimes this lag can’t be avoided because even with an instantaneous responding system, it has to wait for the traction to return), and maybe the additional loss of regen braking makes it seem worst in the Prius. For entirely electrically driven cars like the Volt and the Tesla, it should actually be easier to do ABS and TC. People who have driven the Roadster say it is the quickest responding TC they have experienced (no lag, stuttering whatsoever), I imagine the same for the Volt.
Feb 4th, 2010 (2:06 pm)If I’m not mistaken, there was an Audi model that had the feature of being able to disengage the ABS using a simple button a few years back but it was a high-end luxury sedan.
+1
Feb 4th, 2010 (2:08 pm)Emergency brake does not disengage the ABS. At least not for the front wheels.
Feb 4th, 2010 (2:11 pm)#109
The $64 ($640?) million dollar question, LOL. There was a headline in the LA Times over the weekend to the effect that CTS says that Toyota engineered the part, and it’s their fault. I thought that I read somewhere that Toyota had accepted the responsibility. Of course, I suppose that such a statement could become inoperative at any time, LOL. Kind of like a staffer explaining what the politician “really meant”. Many lawyers will bill many hours figuring this one out, IMHO.
As to the fix, I never did understand it. It looks like eyewash to me, but then I’m not a big Toyota fan, in case you didn’t notice. Take a look at the link at #104. It speaks volumes about their attitude and MO. Worse than the sticking throttle debacle, IMHO.
+1
Feb 4th, 2010 (2:14 pm)I’ve experienced the “brake problem.” It’s just regenerative braking, same as any other engine braking. You’ll feel it in the volt too, it’s just the fraction of a second it takes for the friction brakes to kick in as you hit a pothole. You loose your brakes for that split second because 1 of the 2 tires currently applying braking looses traction. It’s an extremely simple concept, but so many people are uneducated on the physics of the automobile now days. Everyone wants to drive fast and follow too close.
They’re just responding because they are being forced to by people complaining who are unfamiliar with the technology. The only likely real fix is customer education when people buy their car.
+1
Feb 4th, 2010 (2:15 pm)Off Topic, but here is Bladderman, er, I mean Nasaman’s next car, coming in the end of 2011.
http://media.opel.com/content/media/intl/en/news/news_detail.brand_opel.html/content/Pages/news/intl/en/2010/OPEL/02_04_Ampera
-2
Feb 4th, 2010 (2:25 pm)“can GM be sure the Volt will operate perfectly in just a few months based on the behavior of 80-odd preproduction prototypes”
80 volts in test for a few months is not comparable to over 1,000,000 priuses all over the wolrd more than a decade.
GM would be super lucky if it does not have to recall the Volts within the first year even the first month.
My 2 cents
Feb 4th, 2010 (2:30 pm)There are stringent EMI (electrical noise) compliance requirement standards in place. For both what’s emitted by a car’s circuitry and its related susceptibility. However, these standards do not necessarily cover cross EMI pollination within the vehicle’s electrical boundary. In other words, one poster claims 24 V circuitry is immune to EMI by virtue of its signal to noise. That’s likely to be the case but inter-circuitry generating the 24 V to start with is certainly vulnerable.
+1
Feb 4th, 2010 (2:38 pm)#114
True that! +1
Modern cars have so many gee-whiz systems on them that I bet half the owners don’t understand many of them. Or care. Me included. But when somebody slams on the brakes, and then lifts off in panic because the pedal pulsed, it’s a disaster. There really does need to be a way to teach the buyers about this stuff. And NO, they won’t read the 200 page owner’s manual.
+1
Feb 4th, 2010 (2:40 pm)According to CNN, Toyota didn’t ensure that the parts were identical. It sounds like a cost cutting measure….
http://money.cnn.com/2010/02/01/autos/toyota_mistakes.fortune/index.htm?postversion=2010020119
Feb 4th, 2010 (2:41 pm)#115
LMAO! +1 Thanks. I guess that makes me “Anti-Bladderman”, hehehe.
We know every rest stop in the state of CA, and that’s a fact.
Feb 4th, 2010 (2:49 pm)To me what it means for the Volt is that GM has to be on top of things ASAP and be proactive in keeping fires that pop up from getting out of control. Fact is, cars wear out; parts wear out. New tech, new design concepts bring new risks with unforeseen hazards. When those hazards come up, GM needs to be ready to jump on them and contain them. Toyota erred badly in that they took too long to face the reality that hit them. I don’t know if it was arrogance, poor organization, or a combination of the two, but the fact is they are losing consumer respect for their slow responses which bordered on denial.
I’m wondering if Onstar could be used by GM to monitor control systems of each car during its lifetime. I haven’t read any of the other posts, so maybe this has already been discussed. But if it could be done, GM would really have something that would make a Volt owner feel much more secure than they could be without it.
+3
Feb 4th, 2010 (2:51 pm)ICAM. GM should have taken the high road. By offering those incentives to Toyota owners, all they did was make themselves look desperate. And gave credence to the idea that the only reason anyone would look at a domestic car is because the competition messed up.
Besides, it increases the resale value of used Toyotas. At least in the short term. And that should be the last thing they’d want to do.
Feb 4th, 2010 (2:53 pm)BillR Says:
February 4th, 2010 at 2:15 pm
Off Topic, but here is Bladderman, er, I mean Nasaman’s next car, coming in the end of 2011.
http://media.opel.com/content/media/intl/en/news/news_detail.brand_opel.html/content/Pages/news/intl/en/2010/OPEL/02_04_Ampera
(Quote)
The extended range seems to be about the same as the Volt 500 kilometers = 310 miles . Sorry I’m not sure what you meant in this post if it wasn’t about more range.
Feb 4th, 2010 (2:54 pm)http://www.msnbc.msn.com/id/35214248/ns/business-autos
Prius is officially recalled.
Feb 4th, 2010 (2:58 pm)What’s ICAM?
+1
Feb 4th, 2010 (3:08 pm)Me too then…if there’s still room. Will they serve Volts there?
Feb 4th, 2010 (3:10 pm)IMHO, that happens in every manufacturing facility. Especially if you have more than one supplier of one part. Many many times drawings were “Redlined” to make alterations or “Retrofit” a part to make it work. That’s why manufacturers all go through that ISO9000 certification and other crap like that> They are then placed under the impression that they will always be in compliance as long as there’s a paper trail of the changes. Many times we would receive parts from a supplier that were wrong because they didn’t get the “Redline” of the newest drawing and the parts were electrically wrong. It’s not the suppliers fault. It’s not the mfgr’s fault it’s just timing. Many of you who were in manufacturing can relate. Once your load of 9,000 parts get in that you already paid for and they come in wrong, do you scrap the entire PCB set if all you have to do is solder one or two jumper wires to redirect RF or DC buss lines? Hell no, you make the change and document it and move on.
Ever open an electronic gadget? Open a few of the same model and you’ll see these random jumper wires and some will not have them. All the minor revisions are items that nobody can predict and there’s no way to ever do so. Everything or anything can be a failure. It’s just all a matter of time.
Feb 4th, 2010 (3:11 pm)Hey Dave, you deserve one too. You’re a great forum contributor and I always look forward to reading your posts.
+1
Feb 4th, 2010 (3:12 pm)I guess my soon is right about me turning into an “old fart”. I just don’t get this “high road” argument. you read this thread and it sounds likd GM has people in trench coats standing on street corners dealing drugs or worse. I haven’t seen any big national add campaing for this rebate. In fact it I hadn’t heard about it here I wouldn’t have even known it existed. Any time there is a (series) of major recalls there will be a certain number of people that will want to dump the car. If telling a potential buyer that the car they are wanting to dump is worth an extra grand is taking the low road I don’t see it. There’s been no public gloating over Toyota’s problems from GM that I’ve seen – maybe I nee to get out of my cave more.
+2
Feb 4th, 2010 (3:12 pm)This is exactly why GM is currently going through the painstakingly long process of testing and software validation. We people on these forums all the time going “What’s the problem? Put it on the road already!” But what they fail to realize is there is a protocol that MUST be followed to insure the finished product is going to function correctly and in complete safety.
When Lyle posted some threads a while back showing Volts being driven through a 3-foot deep pond, some people responded “What’s the point? Nbody will be driving their Volt through 3 feet of water!” BUT someone certainly WILL and GM couldn’t afford to have the High Voltage source becoming a serious hazard in that event, especially since this battery “loads” into the chassis from the bottom.
In this respect patience is a virtue.
JMO
WOT
+1
Feb 4th, 2010 (3:20 pm)Blind Guy,
Nasaman prefers the styling on the Ampera to the Volt.
This press release states production will begin at the end of 2011, one year after the Volt. Also, it looks like the EU will look at incentives, infrastructure, common standards, and other policies to promote EV’s.
I also like the last paragraph:
“We are honored by Minister Sebastian’s invitation to show EU Industry Ministers how Opel intends to lead the way in the electrification of the automobile,” says Gherardo Corsini,.Director, Electric Vehicle Implementation, who will attend the event. Corsini has been integral in developing the technology that makes the E-REV propulsion possible.
Feb 4th, 2010 (3:22 pm)It’s shorthand for “I couldn’t agree more.” One of my friends uses it a lot, and I must have picked it up without realizing it. Sorry about that…
I knew there was a reason I hate texting!
+1
Feb 4th, 2010 (3:36 pm)I think they’re actually more concerned with getting as many of the potential new customers that are “up for grabs” as possible. So, this campaign is actually directed more against Hyundai, Honda, and Ford, than it is Toyota. At least, IMHO.
I haven’t seen GM do any gloating either. But it just looks bad to offer incentives the minute another company has problems.
Besides, there are more than enough conspiracy theories floating around. And, at least, IMHO, GM is playing into their hands by making it obvious that they expect to gain sales from Toyota’s problems.
Feb 4th, 2010 (3:50 pm)I really do need to get out of my cave more often. By the way is Nixon still president?
Feb 4th, 2010 (3:52 pm)#131 Bill R Thanks for the explaination, it just didn’t occur to me about the style difference, daaah.
+1
Feb 4th, 2010 (3:55 pm)Not sure if anyone has already posted this but …
Looks like a Toyota dealer in California messed up bad by not fixing this high profile customer’s problem quicker. Apple co-founder Steve Wozniak has been plenty mad about the problems with his 2010 Prius. He says the accelerator would kick in when he put it in cruise control. He said it looks like a software issue to him.
http://online.wsj.com/video/apple-co-founder-on-his-toyota-frustrations/5ED6E1B3-2E0F-4825-BD94-D84A57D64662.html
That’s a wee bit concerning because I usually relax and crank up the stereo when I’m on the open road using cruise control. Imagine some woman fighting with her kids in the back seat and then the accelerator kicks in. Not good.
I bet there’s some highly stressed Toyota engineers working hard this week. I’m sure they’ve been getting flogged every day by upper management to fix this nightmare.
I bet GM will be working extra hard on the Volt to make sure this doesn’t happen to the Volt. Let’s hope so. People have high expectations for the Volt. I bet there will be plenty of high profile tech guys like Steve Wozniak who buy a Volt. Plenty of people in Hollywood too. If they drive a Prius now, you can bet that a lot of them will get a Volt at some point … especially if Jay Leno puts in a good word for the Volt and the reviews are good by the car magazines, etc.
Feb 4th, 2010 (4:00 pm)Sorry Noel, I wasn’t trying to suggest that you were
Feb 4th, 2010 (4:04 pm)If Nissan is rushing the Leaf to market, I would say that computer issues would be an even bigger danger for them.
Feb 4th, 2010 (4:10 pm)That could very well be true. The question is why weren’t they aware enough or agressive enough to correct the problems on the production lines instead of letting defective vehicles roll out for years. Even if their analysis showed it would not be cost effective to repair the vehicles already on the road or to initiate a recall, new ones could have been built without problems.
If they had only used the Denso units in place of the CTS parts would this have happened? There were millions of these vehicles and only one their suppliers, CTS for these parts, seems to have these deleterious effects on Toyota accelerator contols. Of the billions of daily trips taken in thes vehicles there have been only a few handfull of complaints. Even as a potentially fatal problem, this has vexed Totota for years.
And what, just as a hypothetical supposition, will occur if the same problem happens years later with vehicles that used the Denso parts?
+1
Feb 4th, 2010 (4:17 pm)I disagree.
The Leaf is a simple BEV. Just the electronics to interface with driver and batt pack BMS and charger.
The Volt has the same BUT also has the genset which means it requires more computer apps to monitor the Genset when it’s in use, start the Genset when it’s needed, “Blend” the power of batt pack and Genset when needed, “Blend” the regen braking from regen to mechan, etc…. There’s way much more to the Volt. To add more to the complexity, from BillR’s post, it shows the Volt will have 4 clutches to help “Blend” the required power of the ICE/Genset/Batt pack.
Feb 4th, 2010 (4:19 pm)What, Woz is blaming the software guys…Say it ain’t so!
Feb 4th, 2010 (4:34 pm)There’s no going back. Electronic controls are here to stay. From cars to jet aircraft, our lives now depend on the proper functioning of incredibly complex software.
Feb 4th, 2010 (4:37 pm)Paging Nasaman, you have been ZINGED!
Feb 4th, 2010 (4:39 pm)… just wait until cars start driving themselves …
Think that’s far-fetched? Have a look at Lyle’s next post …
+1
Feb 4th, 2010 (5:01 pm)The downside is that anything engineers design as ‘fool proof’ will ultimately be compromised by a smarter or more persistent fool.
Feb 4th, 2010 (5:31 pm)Software is always the hardest part of any embedded system – especially when there are multiple processors programmed by independent groups that must work together.
I’d feel much better if there a mechanical linkage between the brake pedal and the wheels that would over-ride the ‘gas’ pedal if you pressed hard enough.
Feb 4th, 2010 (5:51 pm)47 J Bell Now, if Toyota can also admit there are problems with high acceleration during cruise control use. We have a 2007 Camry Hybrid that accelerates
at full
throttle (excessively) in order to get back up to speed after coasting downhill. Last year, Toyota said it was “normal”.
Time to trade in my Camry Hybrid for the Volt……
Hi J Bell, we own a 07 Prius and I have to agree with the Toyota Rep. on your complaint.
My 2 reasons are 1. Since you said you were coasting down hill and then the cruise control excellerated excessively to get back up to cruise speed tells
me you either turned the cruise off while going down hill or you lowered it several mph while going down hill. Either way when you reset the cruise to
go faster, thats what the car is going to do. 2. As you should know with the CVT The engine will normally increase in rpm just like a car that drops down
a gear or two to accelerate quicker does. Sometimes with the CVT it may sound like the engine rpm is excessive when accellerating but that is normal with
CVT’s. It’s no different than passing a vehicle on the freeway and an
automatic transmission
drops down a gear or two when you are trying to pass another vehicle. We are also considering buying a Volt or bev eventually but not because we are not
satisfied with our Prius. We have had 0 problems with our car except having the bumper drag on the end of our driveway. Respectfully, BLIND GUY
J Bell you might want to check out post #136. If your car continues to accellerate even after you reach the cruise speed set, then you would have a problem. However if your car levels off once reaching the set speed then I don’t think theres a problem. There are some people that would complain if the car gradually went to the set speed because they would be afraid the car wouldn’t merge quick enough. Anyway good luck, BTW are you J Bell from the Diamondbacks?
+1
Feb 4th, 2010 (5:55 pm)Two days ago Toyota stock was downgraded. Yesterday it was upgraded. Today it has again been downgraded.
Ford is in the news today with it’s own “braking” problems. Watch for a Toyota upgrade in the morning.
Conclusion: Manipulation is running rampant. Do your own thinking.
=D~
+1
Feb 4th, 2010 (6:18 pm)I heard a lot of times there is no better then home made food.
It should make seance, always home made cars it is a little better.
Feb 4th, 2010 (6:20 pm)#148
Good advice IMHO. +1
Puts me in the mind of the old “Saint James Infirmary Blues”:
“Oh, when I die, please bury me,
In my ten dollar Stetson hat,
Put a twenty-dollar gold piece on my watch chain,
So my friends’ll all know I died standin’ pat.”
Feb 4th, 2010 (6:21 pm)#149
Amen! +1
Feb 4th, 2010 (6:46 pm)I hope GM is designing in a “brake override system” into the 2011 Volt. This would have prevented the issues with brakes for the Prius. It needs a “fail-safe system against unintended acceleration.”
http://www.businessweek.com/news/2010-02-04/toyota-pedal-recall-may-spur-u-s-to-require-new-brake-systems.html
Feb 4th, 2010 (7:26 pm)That’s likely.
Feb 4th, 2010 (7:37 pm)Interesting. At the same time that regenerative braking makes us less reliant on friction braking, with the expectation that brakes will be longer lasting and have less wear and maintenance – the complexity leads to another layer of circuitry and control.
+1
Feb 4th, 2010 (8:14 pm)Amen!! +100
and a great big boo hiss to anyone starting to feed the FUD on electronic controls.
Flown on an airliner lately? Controls are all electronic. 100′s upon 1000′s of flights every day take off and land without incident.
Is this to say electronics are never a problem? Heck no. But lately all I see if knee-jerk fear applied to the electronic control systems. People who should know better and news site looking to bolster rating by shouting “Scary!! Scary!! Electric throttles!!! Scary!!”
Feb 4th, 2010 (10:12 pm)The great conspiracy debate “Volt is not a serial electric” continues.
Feb 4th, 2010 (10:24 pm)Somehow I doubt it’s the electronic hardware itself. Electronics are pretty darn resilient. Software on the other hand can be a nightmare. It gets to a certain level of complexity and start doing unexpected things.
Feb 4th, 2010 (11:32 pm)Lyle asks: “What does this mean for the VOLT?” If the problem is in software, then it can be fixed in the lab and downloaded to every car while it’s charging.
The Segway PT/HT is now over 7 years in use. The first owners were all trained by Segway trainers before they could take possession of their Segway. It wasn’t until years later when they were rented to the general public that the major problem surfaced that required a recall. It was a renter who ran the battery down to dangerous levels and tried to make it go fast when there was little power left. But the Segway PT has “black box” technology that stores all the internal data during an mishap. They were able to analyze the data and develop a software upgrade that solved the problem. (BTW, the reason for the high cost is the dual redundancy throughout its design.)
It is very critical that the VOLT have stored data to help GM engineers know exactly what occurs when a problem exists. The feedback will enable them to solve problems when the vehicles are rented. The sooner they get them to Hertz, Avis, Enterprise and others, the faster the unknown problems will be solved. It would also allow many of us to rent a VOLT and enjoy a lengthy test ride before purchase.
Feb 5th, 2010 (4:59 am)Thanks BillR,
Now it seems that this EU summit by the Spanish Presidency was inspired by the Better Place model, read page 6-7 in the Zapatero (Spanish Prime Minister) before the EU Parliement on Jan 20th 2010 in Strasbourg : (http://www.eu2010.es/comun/descargas/noticias/en_Parlamento_Europeo_20_enero_10.pdf)
“The third sphere, the economy or sustainable industry. I will only put forward one example of what we feel is a development priority within the context of the fight against climate change. We would like to foster, along with the Commission, a development plan for electric vehicles. The automobile industry is going to undergo great changes and it is already immersed in that great transformation.
If we place a decided wager on this industrial area as Europeans with a joint, shared vision and with a common strategy for electric vehicles, we will contribute to reducing our energy dependence. We will also contribute to the fight against climate change and to the technological innovation that will, without doubt, be opened up by the electric vehicle, which will, moreover, be directly linked to Information and Communications Technologies.”
Best regards,
JC NPNS
Feb 5th, 2010 (5:15 am)Right Nelson, look at the banks,
JC NPNS
Feb 5th, 2010 (9:40 am)Jeffhre, I have leaned everyday of my adult life that it is never too late to learn, and I still have a lot of pleasure to play with problems of elementary probabilities.
Best regards,
JC NPNS
Feb 5th, 2010 (9:53 am)I’m sure all have noticed that the test vehicles we’ve seen in the videos, etc. all have a big red/yellow switch prominently mounted on top of the dashboard. I recognize this as an Emergency Stop or ‘E-STOP’ switch, common on machine tools and industrial machinery. It presumably is a hard-wired cutoff to the drive electronics. Makes sense for testing, but I assume this will NOT be in production models….
Feb 5th, 2010 (10:44 am)Can’t help but think that a two motor all wheel drive version would give the ABS more options in situations like this. And of course performance should be improved to boot.
Feb 5th, 2010 (10:55 am)What I like to call both end drive – see the production intent Audi e-tron and Ferarri 599XX and a whole bunch of concepts.
Feb 5th, 2010 (11:36 am)#162
I dunno, it sounds like a pretty good idea today!
Feb 5th, 2010 (12:19 pm)Back on topic:
It means anywhere from an additional $25 to $150 in costs for the Volt, and all GM products, it would seem:
http://www.bloomberg.com/apps/news?pid=20601087&sid=aeVrqDdBHWCg&pos=7
Feb 5th, 2010 (3:48 pm)This is also the first sure sign that full hybrids are now firmly in the hands of plain jane US mainstream consumers:
http://www.hybridcars.com/safety/sorting-out-hybrid-brake-issue-safety-issue-or-different-feel-26604.html
Feb 5th, 2010 (6:04 pm)But now you have introduced another failure mode. When that secondary switch fails, you lose throttle control, which could be fatal if you have just pulled out in front of a truck.
In a critical aerospace application, we will typically have 3 sensors. They “vote,” and when one fails, it disagrees with the other two, so the controller can tell which input to believe.
But that’s probably overkill in this case. I’d stick to the current single sensor design, make reliability a priority, and push on the brakes in the rare case when the throttle sticks.
Feb 5th, 2010 (6:43 pm)The components and their arrangement in the system are only part of the reliability story. The probability of a system failure is also time dependent. With redundant systems, you need to deal with the problem of the backup system failing passively (without indication) such that it is not available when you need it.
In aerospace, we typically reduce exposure time by ensuring that there is either a way to indicate failures of redundant systems, or by making the redundant systems frequently swap modes from active to passive (just to make sure that they still function). When that is not possible, the operator gets stuck with a scheduled maintenance requirement to exercise the redundant systems.
So if component C1 has a failure rate of 1E-6 per operating hour, but it can fail passively, then the exposure time is the desigh life of the product. Let’s assume 1E4 hours for an automobile (300,000 miles at 30 MPH average). Thus, the probability of C1 being failed is increased to 1E-2. That’s 1 chance in 100; not good at all if the consequence is severe!
However, if the failure of C1 is indicated (e.g., “Check Engine” light) and we assume that the operator gets it repaired within 100 operating hours, the probability of C1 being failed is only increased to 1E-4. Dramatically better!
Feb 5th, 2010 (6:55 pm)There is a way. In aerospace, we track parts by part number and serial number. We know which parts got what changes, so when something goes wrong, we know which parts are affected (and which airplanes they were installed on).
I’m not saying that it would be cost effective for automotive production, but it is possible.
Feb 5th, 2010 (7:00 pm)I do not understand how there could be a cost advantage to replacing a $10 throttle cable with a sensor, a servo, and all the wiring and software needed to make them work together.