LA Times: Toyota US Chief Defends Electronics

Full testimony can be found here:

Response by Toyota and NHTSA to Incidents of Sudden Unintended Acceleration

 

I'm thinking Lentz doesn't grasp the nature of Toyota's hardware containing software. The fact that one can flash a lot of hardware makes the two pretty much the same.

 

With all due respect Hill, this is a totally nonsensical statement.

By "hardware containing software" ... are you referring to the embedded code that is normally referred to as "firmware" ... which is, as I understand it, a set of computer instructions contained within a CPU that cannot be changed? Or are you referring to the field programmable software code, similar to the code that has been the subject of re-flashing in the recent Prius III recalls related to the braking anomaly?

With respect to the hearings, I honestly think Toyota should have had an engineering expert on the various Toyota control systems present in the hearings, to assist Lentz in explaining the technical aspects. I don't care if the politicians get lost in the technical details, that would be a plus; illustrating clearly as no other forum could the stupidity of members of Congress getting themselves involved in this highly technical area.

 

Take it for what it's worth...

NHTSA Has No Software Engineers or EEs To Analyze Toyotas - The Car Connection

 

Sorry, I was typing before I thought. Yes, in the strictest sense hardware is the physical equipment you can touch that contains instructions/code. The lines are blurring as to what is/isn't a device that has changeable code, and my point was simply that if Lentz is anything like the exec's at my company, he'd be hard pressed to describe the difference, or any other controllers on cars. I may be wrong, but before he worked for Toyota, I think he was a professor for a Community College teaching business related classes ... accounting, finance, marketing and the like. I don't think electronics & electrical engineering are his forte' ... that's all.

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Well, the Gen II Prius definitely does not have a brake override system. For a company to claim that it is focused on safety features of its products, not having a brake override on all of its products sounds a bit hollow.

 

The better to defeat any attempts to analyze the safety systems.

 

It's starting to sound like we need a completely independent and expert assessment of the reported sudden acceleration problems (and fast).

What about a well instrumented university lab since Toyota will likely not trust a US Government lab?

 

There are private sector test facilities that are up to the challenge; the problem is in what they are supposed to test and how deep do they dig into the systems. Based on Lentz' refusal to rule out further problems with the cars, problems with the electronics are still on the table.

 

I'm so confused.

 

Take a car out for a test drive on a street with no traffic. Start to apply pressure on the accelerator pedal with your right foot. Then with the left foot apply pressure to the brake pedal while keeping the pressure on the accelerator pedal with your right foot. If the accelerator pedal control is not cut out (meaning the engine is either shut down or in a non-hybrid car goes to idle) and the brake pedal is given control so the car can be brought to a stop, the car does not have brake-throttle override installed.

My 2007 Touring edition does not have the brake-throttle override function. I haven't bothered to test the Gen III Prius. My 2010 BMW 3 series has the brake-throttle override function.

 

As long as pressure is being applied to the accelerator pedal, the engine is wanting to propel the car forward. Apparently by applying the brakes, the computer(s) that is/are controlling everything senses that more torque is needed (as if I were going up a hill) and keeps the engine running in combination with the electric traction motor (there were two energy flows - engine to traction motor and battery to traction motor when I tested the function earlier this a.m.).

The only way the car stops is by releasing the accelerator pedal and then the brakes take over.

 

Then your Prius is unique in having no regenerative braking ability, quite apart from the hydraulic braking feature.
Looks as though a shop visit is required.

 

Out of curiosity, how does the Prius have regenerative braking when the accelerator is being pressed? I was under the impression that regenerative braking occurred as a result of the accelerator being released, which 'told' the computers to turn the traction motor into generator mode (with depressing the brake pedal 'telling' the computers to generate more electricity)? At least that is how things appear to work when the car is driven 'normally' (with the right foot controlling the accelerator and brake pedals, and only on one pedal at a time).

 

+1

in fact, without even stomping the brake as hard as I can ... using only 50% of my strength (while holding the gas pedal to the FLOOR) our prius will SKID to a stop. Just that simple. Don't contradict it if you haven't tried it, and if it's not the case, take it to the dealer.

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+1, full of hooey.

Brake with the accelerator on and it will stop. Doesnt make sense for it not to. In the basic block diagram of electronic control there should be a "if braking then brake, else if accelerating..." where braking always has precedense. Just from a common sense standpoint, and it holds true.