Run Away Prius a Hoax

F.) Toyota decides to "invent" a problem, a fairly MUNDANE problem, as "cover" for a reflash that in actuality fixes a much more serious flaw that Toyota/NipponDenso doesn't want to disclose to/for public scrutiny.

That better..??

 

Not really.

 

Well, 2010 represent a new redesigned generation of Prius.

From what I recall, they made ABS in charge of the traction control (instead of hybrid ECU in gen2). Anyone can correct me if my statement below is inaccurate....

In gen2 the hybrid ECU has to protect MG1 as well as deal with the traction control. This created a conflict of interest and ECU favored protecting MG1 by cutting off power to the wheels. This resulted in poor performance in snow. Toyota tweaked it in 2006+ model to allow some wheel spin but owners asked for more (better design).

For gen3, the traction control responsibility was moved to ABS. Gen3 now has the separation of duty.

Ford Fusion hybrid also had the same issue which they fixed it around the same time. It went unnoticed due to the media fixation on Toyota. You gotta realize that we are dealing with the latest high tech cars with the latest concepts and architectures. They are being developed to improve from the previous generation. No one has done these stuffs before. It is not easy as non-hybrids (cookie cutter).

Your conjecture and suggestion that they are trying to hide something is an insult to the engineers (both Toyota and Ford) leading these technology in the hybrid field. Cut them some slack.

 

Because of the Sikes SUA episode most of my research has centered on the 2008, with the 2010 as sort of a tagalong due to the ABS "refresh".

For the 2008 the skid control computer has exclusive control of frictional braking so I would assume that means it is now, as of 2010, really the ABS/TC computer. When braking is initially applied it is the skid control computer that computes how much braking is being asked for and then asks the HSD computer how much of the total it can supply via regen braking.

Insofar as hybrid systems design is concerned in my opinion the Ford engineers are simply "followers" so any denigration I hand out is not directed at Ford.

What most bothers me is the extremely sloppy, horrible, sensor monitoring firmware programming that Dr. Gilbert uncovered and which apparently everyone is ignoring.

 

Everybody is ignoring it because Dr. Gilbert re-wired and manipulated it to make it sloppy by overriding the built-in safety checks.

 

"..by overriding the built in safety checks..."

No, Dr. Gilbert did not in any way override the factory built-in safety checks, they simply did not function as the factory documentation shows that they should have.

According to the factory documentation the firmware sensor montoring routines are constantly checking the two gas pedals sensors against each other for validity. If any of these checks fail an MIL code should be entered and the system put in "limp home" mode. I can go back and look up the specific codes if you like.

There is a code to be "set" if the monitoring firmware detects that the two gas pedal sensors appear to be shorted together, their output voltages within 0.20 volts of each other. There is a second and third code to be set if the sensor output voltage is outside of the normal operating range. When Gilbert shorted BOTH sensors to 5 volts to create the engine runaway condition both of those codes should have been set. Instead of the engine runaway, provided the firmware were operating as designed, specified by Toyota themselves, the engine control system should have immediately dropped into "limp home" mode and both codes set.

Sloppy programming, DAMN sloppy programming.

 

Dr.Gilbert "emulated" a floored gas pedal using electrical signal rather than physically. Exponent was able to reproduce it in Mercedes, BMW, Honda, Subaru and Chrysler vehicles as well.

I guess going by your definition of "sloppy programming", the entire industry is pretty damn sloppy. We live in a very dangerous world. Yeah right!

 

You might as well give it up. His mind is closed. Remember this article?
Toyota Hybrid Horror Hoax - Forbes.com
Then read the comments.

 

http://pressroom.toyota.com/pr/tms/document/GILBERT-Evaluation_of_the_Gilbert_Demonstration_1_.pdf


From Exponents document, above...

"..Figure 1. A 200 ohm resistor is apparently placed between the output signals of the two pedal position sensors...."

Note the word "apparently"....??!!

I had assumed that the "short" Dr. Gilbert placed across the two sensor signals had just enough resistance, accidental and unintentionally, that a voltage difference greater than the monitoring system was checking for, 0.020 volts (only 20 millivolts), remained between the two signals.

I think that what Exponent is saying here is that in order to replicate Dr. Gilbert's experiment BUT NOT trigger the monitor they had to use a 200 ohm "short" between the two sensors.

Given that the two sensor output voltages should ALWAYS be displaced by at least 0.80 volts (factory document), using a difference voltage as low as 20 millivolts is unreasonable if one wishes to truly detect short between the two sensors.

Apparently (there's that word again) Exponent assumed a 200 ohm short since that's the resistance they had to use in order to NOT to trigger the firmware monitoring test.

From Exponent, again.

"..To bypass setting the DTC code on the 2007 Camry Exponent slightly modified the parameters of Dr. Gilbert's demonstration...."

"...By carefully engineering the modification.."

Carefully engineering the modification...


Yes, using empirical engineering method to select a shorting resistance that provided "just enough" signal shorting to still allow a voltage difference above the detection threshold.

In other words the 200 ohm resistor wasn't small enough, low enough in resistance, to "fool" the 2007 Camry's firmware sensor monitoring system, so Exponent chose another value.

First they "ASSUME" Dr. gilbert used a 200 ohm resistor with absolutely no evidence of that (granted, either way), now they modify their own assumption to fit the new case.

And yes, you can "short" the two signals together with just enough resistance to still remain above the minimum voltage difference detectable by the monitoring firmware. And now, if you wish, provided you carefully select the resistance of the "short", connect the one sensor to the 5 volt reference to create a runaway engine "without" setting a DTC.

Or, if you like, you could short the one sensor to a reference voltage right at the maximum of the normal operating range, the engine would go WOT, but no DTC would be set.

"...Exponent was able to rewire the pedal sensors and achieve engine revving without setting a DTC...."

Yes, so could anyone, by empirically selecting the shorting resistance.

And finally:

"...Exponent also evaluated how vehicles made by other manufacturers would respond to the same rewiring that Dr. Gilbert showed in his demonstration. Every vehicle from other manufacturers tested by Exponent could be induced to respond with a sudden increase in engine speed and power output, although the parameters of the rewiring changed slightly from vehicle to vehicle. These demonstrations in no way indicate a defect with any of the vehicles tested (including the Toyota and Camry).

...although the parameters of the rewiring changed slightly...

NO SHxx, SHINOLA..!!

....no way indicate a defect with any of the vehicles...

Avoiding a public REBUTTAL by other manufacturers, "this".

But I still find myself puzzled that this worked, so far...

 

Oh, thanks for the link to the Exponent document, MANY thanks.

I had heard, and read, that Exponent was all to willing to prostitute themselves for money, but until seeing this document I had no idea. Strickly a PR document, even a junior engineer could rebutt most of this in a court of law.

 

I've got to agree with the sloppy programming, a code should at least be entered in the condition. Exponent did not say if the other cars logged an error code. Exponent did not convince me at all in their document. They seemed to skate around issues, but I believed before and after that the situation is very unlikely.

In the cases of Mercedes, BMW, and Chrysler a small application of brakes will halt the throttle condition. Heavy application of brakes would halt the condition in 2008 prius would also halt the condition. Making all these cars safer than the gilbert tested car even with the sloppy programming of error codes. 2008 Avalon will not even log brake application in edr in the case of a crash. Plenty of sloppy programming, some is more dangerous than others.

 

The problem isn't sloppy programming. If the two signals remain in the proper range, the software doesn't see any problem, so there is nothing to report.

Perhaps a better statement would be to say that the system should be more robust so as to better detect and log shorting and out of bounds values. A larger signal offset is only one of the ways this could be accomplished.

Tom

 

The European and Japanese cars have had rear disc brakes since 2004. There has not been, to my knowledge, any Skid Control firmware update for 2004-2009 model year, second-generation cars - certainly there has been no recall. I don't know whether the software is different between a car fitted with rear drum brakes and one with rear disc brakes - I'm not going to dismantle my car to find out the part code on the Skid Control ECU, which is behind the steering column. It's possible to view it, and the firmware version number, with the TechStream or MasterTech scan tool if anyone has access to it.

The firmware update for the 2010 cars must not be applied to a Gen 2 Prius, it's not compatible. The brake system has been physically reconfigured for the new model and appears to have a different number of sensors, with some solenoid valves having been renamed.

The firmware update for the 2010 cars is being applied to European and Japanese Gen 3 models. The UK recall notice is here.

The most obvious and most likely and most logical explanation is the one that Toyota have given.

 

I watched the videos and I believe they said none of the other vehicles logged error codes.

 

I agree.

However, there are some whose livelyhood seems to depend on creating suspicion and doubt and dishing out mis-information. Some of them are even present on this board.

 

Then what do you think the 200-ohm resistance placed by Dr. Gilbert himself between the output signals of the two pedal sensors is doing?

The manuscript says "As shown in Figure 1, a 200-ohm resistance was apparently connected by Dr. Gilbert between the output signals of the two pedal position sensors."

Your research fails. How much are they paying you to astroturf?

 

Look at the chart in Figure 7. It clearly shows that the variables must fall within the red vertical bar for Gilbert's demo to work. The "typical contact resistance" and "typical wire insulation resistance" show that the red bar is highly unlikely to be achieved accidentally, therefore, logically, the Gilbert situation, although not impossible, has a probability of damn near nil of happening in a real-world situation.

 

Wow, you're one of the readers who got caught up by the Exponent SMOKE SCREEN.

The wiring insulation breakdown or resistance, nor the connection contact resistance or breakdown isn't the subject matter any knowledgeable engineer would first address. Engineer knowledgeable of integrated circuit design and fabrication anyway.

If the condition Dr. Gilbert "simulated" is to occur it would more likely than otherwise result from a failure internal to the hall effect sensor integrated circuits.

That 0.02 volt minimum "short" voltage is beyond belief for any hardware engineer and/or even any real time process control programmer having read the specifications of the redundant sensor gas pedal.

0.40 volts would have been my choice. If that resulted in too many failure codes being set in the field, in use, I would damn well start looking at "why" rather than widening the tolerance voltage.

Note that Exponent never tells us what resistance was used in testing other manufactuers sensor monitoring systems, only that the value was empirically, experimentally, determined. They could have using 10 Megohms for all we know.

And even if one assumes the 200 ohm resistance was used to "fool" the firmware sensor monitoring routines that still doesn't explain how the monitoring system did not detect the short to the 5 volt supply/reference. 5 volts is well out of the normal operating voltage range of the sensors.

Exponent even admits that they had to add another resistor in line with the connection to the 5 volt supply/reference in order to not exceed the operating voltage range when they added that "short".

TWO-FACED, at best.

 

I have no problem with that wording, and it is more specific and accurate. I was just repeating the previous posters words. I did add another example of incomplete programming, a spot in the log for an important value data is missing. I would say that the way the system logs data leaves doubt as to whether there are software or electronics problems. For Toyota to be believable on the issue more robust logging needs to be added, or the number of reports of unintended acceleration need to fall.

 

There will always be doubt as to software or electronics problems. Even with all of the logging you could ever imagine.

And even if there were cameras watching every car and the driver's feet, people would still report SUA incidents.