Toyota Crisis Worsens, Cars Pulled From Rental Fleets, A Million More Cars Recalled

[dieselgeek]

Re: Toyota Crisis Worsens, Cars Pulled From Rental Fleets, A Million More Cars Recalled

It has EVERYTHING to do with fly by wire.

Damping is not needed on fully mechanical throttle linkage.

the problem is mechanical, friction issue - unless I am missing something here? that can happen with a CABLE throttle just as easily.

A pedal position sensor is the same thing as a throttle position sensor - but they aren't saying the failure is in the potentiometer, so, how is this a drive-by-wire problem?

[squirrel]

Re: Toyota Crisis Worsens, Cars Pulled From Rental Fleets, A Million More Cars Recalled

No, the part that is sticking is the damper in the pedal assembly. This is a built in friction device, which is NOT used on any cable or mechanical linkage. It is used on the fly by wire system because the pedal will be too springy feeling without it....there is not the mass of the rest of the mechanical system to slow the pedal return down.

I've never heard of any mechanical throttle control system with a damper in it, or any that have stuck because of excessive friction. There are plenty of other failure modes though....you're probably too young to remember the engine tie down straps in late 60s chevys

[dieselgeek]

Re: Toyota Crisis Worsens, Cars Pulled From Rental Fleets, A Million More Cars Recalled

No, the part that is sticking is the damper in the pedal assembly.

Which is a mechanical part? nothing electronic about that. Thus, not part of the "fly by wire" system at all. It's a mechanical dampener.

I've never heard of any mechanical throttle control system with a damper in it, or any that have stuck because of excessive friction.

I sure have. Seen it at Maxton, at Bonneville, and the drag strip MANY times. Throttles stick all the time due to worn out cables (friction), worn throttle shafts (friction), etc.

I can see MAYBE saying the problem is "because there is DBW on the car" but the problem you discuss is mechanical. There's nothing electronic about that issue. So I don't see how it's a problem with DBW, it's a problem with shitty engineering of a mechanical piece.

[squirrel]

Re: Toyota Crisis Worsens, Cars Pulled From Rental Fleets, A Million More Cars Recalled

Which is a mechanical part? nothing electronic about that. Thus, not part of the "fly by wire" system at all. It's a mechanical dampener.

The damper is a part that is NOT NEEDED on a mechanical system, it is a mechanical part that is only used on fly by wire systems. It is part of the fly by wire system. There are other mechanical parts in the system too, that can fail in interesting ways...like the throttle body servo. This is not the KISS principle in action here, by any means.

I can see MAYBE saying the problem is "because there is DBW on the car" but the problem you discuss is mechanical. There's nothing electronic about that issue. So I don't see how it's a problem with DBW, it's a problem with shitty engineering of a mechanical piece.

I never said it was an electronic problem, I said it was a DBW problem. The DBW system has MORE mechanical parts in it than a purely mechanical system! There are more opportunities for the mechanical designers to screw up, BECAUSE they introduced electronics into the system.

[dieselgeek]

Re: Toyota Crisis Worsens, Cars Pulled From Rental Fleets, A Million More Cars Recalled

so, that seems more like a HAMB opinion than an engineering opinion. It could just as easily be a bad bushing on a throttle cable and I bet you that it would fail more often than the DBW setup. If you're trying to imply that DBW is more failure prone than a cable throttle - even though I prefer cable throttles - I would have to disagree...

[Brian Lohnes]

Re: Toyota Crisis Worsens, Cars Pulled From Rental Fleets, A Million More Cars Recalled

How many millions of vehicles were recalled due to mechanical throttle cable or linkage failures?

[squirrel]

Re: Toyota Crisis Worsens, Cars Pulled From Rental Fleets, A Million More Cars Recalled

No, that's an engineering opinion. The more parts there are in the system, the more there is to go wrong.

[TheSilverBuick]

Re: Toyota Crisis Worsens, Cars Pulled From Rental Fleets, A Million More Cars Recalled

I have to agree with Squirrel on this one, the DBW system is complex with much more opportunity for things to go wrong, which isn't the same as WILL go wrong. They've proven themselves reliable enough, hasn't GM used them on the 3800 engine since 1998 or so? Other manufactures may have been using them in bulk before that even.

The simplicity of a cable throttle really minimizes opportunity to screw up the engineering.

[TheSilverBuick]

Re: Toyota Crisis Worsens, Cars Pulled From Rental Fleets, A Million More Cars Recalled

How many millions of vehicles were recalled due to mechanical throttle cable or linkage failures?

I don't know, but it seems Toyota is making up for the DBW in one fell swoop :P

[Brian Lohnes]

Re: Toyota Crisis Worsens, Cars Pulled From Rental Fleets, A Million More Cars Recalled

Dealer fix announced:

Metal shim will be placed on the friction layer to stop problem. They are testing it now.

[squirrel]

Re: Toyota Crisis Worsens, Cars Pulled From Rental Fleets, A Million More Cars Recalled

they'll give it the 500,000 mile test tonight, right?

[IRONHEAD]

Re: Toyota Crisis Worsens, Cars Pulled From Rental Fleets, A Million More Cars Recalled

Fly by wire is a bad joke, eh?

If the problem is "mechanical" as described above, then the problem has nothing to do with "fly by wire" - come on Mr Engineer ;)

then why don't YOU go tell toyota what the issue is..
D/G heres your chance.. go tell um YOU know the fix..
as seen as a group of engineers can't or won't(lawyers) enlight'n the masses..

[dieselgeek]

Re: Toyota Crisis Worsens, Cars Pulled From Rental Fleets, A Million More Cars Recalled

How many millions of vehicles were recalled due to mechanical throttle cable or linkage failures?

the best question in this whole post. Who knows the answer to that?

I still disagree that the Toyota throttle control in question has more parts, or has more to go wrong, than a typical cable throttle.

Who here has taken apart an APPS system anyways?


The throttle pedal turns a simple potentiometer (the ones I have seen, have a pair of pots). The potentiometers have THREE wires: a ground, a power supply (5 volts), and a signal return into the ECU. That's HALF of the "throttle control" and already, no pulleys, cables to worry about bending (or adjust), etc.

The second half of the control, which wasn't even the issue in the Toyota case, is a servo in the TAC module, with a pair of inputs to control it. It's controlled just like the Idle Air Motors on GM cars, 4 wires (two circuits, one to open and one to close). The ones I have seen, double up on these andphysically can't "overcenter" like Captain Genius thinks.

I still say, it's incorrect to claim that the DBW setup is guaranteed to fail more often than a manual, cable driven throttle control. I think that it's been proven already, as well (but not sure about that). Nobody here can cite how many recalls happened with cable throttles... so... sounds to me like there's not enough info here to jump to conclusions.


And besides, the failure on the toyotas (if this information is indeed fact) is MECHANICAL. They're replacing something that regulates friction in the pedal. Pretty lame, if you ask me, to call this a "drive by wire" problem when what's happened is simply a failure of a pivot or hinge point. Yeah it sucks for the families who are losing their loved ones, and SCREW toyota for cheaping out on parts and releasing something so problematic, BUT - it seems really lame to me to be writing this off as a "DBW is too high tech and fails more" kind of problem when nobody here has facts to back that up.

Carry on!

[IRONHEAD]

Re: Toyota Crisis Worsens, Cars Pulled From Rental Fleets, A Million More Cars Recalled

SORRY d/g NOT buy'n it..
my pedal stuck on my s10.. put foot under it and pull up..
fixed, car was stop able..
try that in a throd by wire.. if it's not an issue in the pedal .. your s.o.l. and it's not gonna help..
the cable worked fine for 100 years..
this clearly does not.. and now.. will never be trusted no matter the make..

[dieselgeek]

Re: Toyota Crisis Worsens, Cars Pulled From Rental Fleets, A Million More Cars Recalled

SORRY d/g NOT buy'n it..
my pedal stuck on my s10.. put foot under it and pull up..
fixed, car was stop able..
try that in a throd by wire.. if it's not an issue in the pedal .. your s.o.l. and it's not gonna help..
the cable worked fine for 100 years..
this clearly does not.. and now.. will never be trusted no matter the make..

can you read? in the toyota case, pulling up on the throttle pedal would have stopped the car. At what point will you stop following me around?

It kills me that they'll let a troll like you stay here, but get rid of someone like Franklin, who can (a) write a coherent post and (b) isn't lying or making up huge BS stories 99% of the time

You probably didn't even own an S10. Why waste your time with one when you can drive McLaren F1s 220mph on the highway, eh?