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From: john on 27 Nov 2009 21:51 This is getting interesting. There were engine surge problems from the beginning of drive-by-wires that Toyota issued TSBs to fix. That was unexpected engine surges between 38-42 MPH on light throttle input: "Although Toyota says it knows of no electronic defects that would cause a vehicle to surge out of control, it has issued at least three technical service bulletins to its dealers warning of problems with the new electronic throttles in the 2002 and 2003 Camry. The throttle systems on six-cylinder engines can cause the vehicle to "exhibit a surging during light throttle input at speeds between 38 mph and 42 mph," according to one of the bulletins that was published by Alldata, a vehicle information company. The solution provided to dealers was to reprogram the engine control module." http://www.latimes.com/business/la-fi-toyota-throttle29-2009nov29,0,5254584.story
From: Kevin John Putzke on 28 Nov 2009 08:22 "john" <johngdole(a)hotmail.com> wrote in message news:a19e56e7-b0df-4891-b542-4f31a23c31bc(a)x5g2000prf.googlegroups.com... > This is getting interesting. There were engine surge problems from the > beginning of drive-by-wires that Toyota issued TSBs to fix. That was > unexpected engine surges between 38-42 MPH on light throttle input: > If only you had the cash to purchase a Toyota. Too bad. Continue taking public transportation. You are an IDIOT.
From: Don Stauffer on 28 Nov 2009 10:17 john wrote: > This is getting interesting. There were engine surge problems from the > beginning of drive-by-wires that Toyota issued TSBs to fix. That was > unexpected engine surges between 38-42 MPH on light throttle input: > > "Although Toyota says it knows of no electronic defects that would > cause a vehicle to surge out of control, it has issued at least three > technical service bulletins to its dealers warning of problems with > the new electronic throttles in the 2002 and 2003 Camry. I wonder if they consider software an electronic defect. If the computer operating system allows multi-tasking, and if they use a lot of conditional branching, it is possible to write software that cannot be deterministically verified, only statistically. Aircraft flight control software has developed deterministic rules for software. I wonder which way the car computers are. I'll bet too that the car computers are not redundant. Military aircraft are usually triple redundant, commercial stuff quad redundant. Expensive. I have a Prius so this is not just idle curiosity with me.
From: Vic Smith on 28 Nov 2009 10:58 On Sat, 28 Nov 2009 09:17:33 -0600, Don Stauffer <stauffer(a)usfamily.net> wrote: >john wrote: >> This is getting interesting. There were engine surge problems from the >> beginning of drive-by-wires that Toyota issued TSBs to fix. That was >> unexpected engine surges between 38-42 MPH on light throttle input: >> >> "Although Toyota says it knows of no electronic defects that would >> cause a vehicle to surge out of control, it has issued at least three >> technical service bulletins to its dealers warning of problems with >> the new electronic throttles in the 2002 and 2003 Camry. > >I wonder if they consider software an electronic defect. If the computer >operating system allows multi-tasking, and if they use a lot of >conditional branching, it is possible to write software that cannot be >deterministically verified, only statistically. Aircraft flight control >software has developed deterministic rules for software. I wonder which >way the car computers are. I'll bet too that the car computers are not >redundant. Military aircraft are usually triple redundant, commercial >stuff quad redundant. Expensive. > >I have a Prius so this is not just idle curiosity with me. The whole idea is a loser to me. Mechanical linkages are well proven. What about short circuits, bad tracings, etc? (I know squat about electronics - except they sometimes fail.) The programming part regarding safety is pretty much a no brainer, as somebody mentioned - touching the brake always says shut down the throttle. But even that is subject to switching pulses and microscopic pathways. I especially don't like the idea of the ignition switch being disabled or bypassed. To think that Murphy's law won't kill somebody is pretty arrogant. KISS is always the best option where safety is concerned. A TPS is perfectly adequate to tell the CPU what the foot is doing. The foot should be in total control. Putting this electronic junk in to avoid floorpan holes and some linkage is no different than saving 20 cents per car on that Pinto gas tank design if people end up dead. Really sucks when Beta testing is being done at the risk of lives. Haven't been following this closely, so I may have something wrong. But I'll be sure to look for a mechanical throttle on my next car. If that's not available, I better be able to shut down with a key/switch. Otherwise I'll stick with older cars. --Vic
From: in2dadark on 28 Nov 2009 21:09
On Nov 28, 10:58 am, Vic Smith <thismailautodele...(a)comcast.net> wrote: > On Sat, 28 Nov 2009 09:17:33 -0600, Don Stauffer > > > > > > <stauf...(a)usfamily.net> wrote: > >john wrote: > >> This is getting interesting. There were engine surge problems from the > >> beginning of drive-by-wires that Toyota issued TSBs to fix. That was > >> unexpected engine surges between 38-42 MPH on light throttle input: > > >> "Although Toyota says it knows of no electronic defects that would > >> cause a vehicle to surge out of control, it has issued at least three > >> technical service bulletins to its dealers warning of problems with > >> the new electronic throttles in the 2002 and 2003 Camry. > > >I wonder if they consider software an electronic defect. If the computer > >operating system allows multi-tasking, and if they use a lot of > >conditional branching, it is possible to write software that cannot be > >deterministically verified, only statistically. Aircraft flight control > >software has developed deterministic rules for software. I wonder which > >way the car computers are. I'll bet too that the car computers are not > >redundant. Military aircraft are usually triple redundant, commercial > >stuff quad redundant. Expensive. > > >I have a Prius so this is not just idle curiosity with me. > > The whole idea is a loser to me. Mechanical linkages are well proven. > What about short circuits, bad tracings, etc? > (I know squat about electronics - except they sometimes fail.) > The programming part regarding safety is pretty much a no brainer, as > somebody mentioned - touching the brake always says shut down the > throttle. > But even that is subject to switching pulses and microscopic pathways. > I especially don't like the idea of the ignition switch being disabled > or bypassed. > To think that Murphy's law won't kill somebody is pretty arrogant. > KISS is always the best option where safety is concerned. > A TPS is perfectly adequate to tell the CPU what the foot is doing. > The foot should be in total control. > Putting this electronic junk in to avoid floorpan holes and some > linkage is no different than saving 20 cents per car on that Pinto > gas tank design if people end up dead. > Really sucks when Beta testing is being done at the risk of lives. > Haven't been following this closely, so I may have something wrong. > But I'll be sure to look for a mechanical throttle on my next car. > If that's not available, I better be able to shut down with a > key/switch. Otherwise I'll stick with older cars. > > --Vic- Hide quoted text - > > - Show quoted text - Not crazy about DBW either. They seem to be installing 'more' hazards in cars instead of eliminating them. I wonder if the Kia forte is DBW.. |