Motor Trend and the Toyota Accelerator Problem

A friend tells me that some months ago that Motor Trend had an article about the Toyota accelerator problem that claimed Toyota was not at fault. Govt. and other data did not support the claim they were at fault. Anyone know which issue?

Here’s the web article.

For more info google ‘Toyota government study’, lots of articles.

They were at fault for the accelerator pedal design problem that led to unintended acceleration and also for the floor mat issue that led to UIE as well. But there was no electronic design flaw in the throttle found.

Thanks.

jt, I’m unaware of any investigation that found them at fault for other than the floor mat problem. Can you clarify?

JT, I am with MB on this one. Toyota had a recall and installed shorter accelerator pedals to solve the problem, but I am not sure that means it is their fault. I thought it ended up being a problem with the floor mats.

I had a scary moment in my mother’s motorhome with the floor mats, and I don’t blame GM. Fortunately, I know how to shift the thing into neutral and bring it to a stop.

Toyota admitted that the accelerator pedals were sticking because of excess friction within the assembly - that was what the whole metal shim was about. They recalled millions of vehicles for that problem - did you all forget about that one?

We have a vehicle at work that was a part of the recall (a Camry hybrid). They didn’t install a metal shim. They installed a shorter gas pedal.

eraser1998 beat me to it. Remember that wear in the pedal assembly from one manufacturer that led to the pedal sticking? It resulted in 2.3 million Toyotas recalled in the US. Vehicles that used the Denso pedal assembly were not involved.

Whitey - because vehicles, even supposedly identical ones, may use parts from varying sources and have varying levels of trim, the recalls that your particular Camry may have had may be completely different from the recalls other Camrys had. For example, if you had the Denso pedal, it would not have been recalled for a shim, but you may have received a notice to have its pedal shortened…

As an example, some people told me I was lying when I said my 97 Taurus was never recalled - and they provided me with info on a recall on a transmission servo cover to “prove” it. The problem was that recall affected AX4S transmissions only. I had an AX4N transmission. If you had the 4S, you had a 12-valve engine… but the 4N was used with both 24-valve and 12-valve engines… so there were plenty of base Tauruses recalled for the servo, but also plenty of base Tauruses that were never recalled, because they had the newer, better transmission.

Our Lexus ES-350 never got the Pedal Recall. The Lexus used a different manufacturer for the Accelerator pedal then the Camry plant used.

“Our Lexus ES-350 never got the Pedal Recal. The Lexus used a different manufacturer for the Accelerator pedal then the Camry plant used.”

All Lexus cars are built in Japan and use the Denso pedal assembly. The North American manufacturer that supplies all NA-built TMC vehicles was the only one with the problem.

Well, Toyota tells you that the Densos had no problem, at least.

However, we have a Camry in our family that had a Denso pedal that, while it didn’t show the exact same runaway symptoms that spurred the recall, did fail and led to a surging idle… That wasn’t a problem with excess friction, but of a failed sensor in the pedal.

The Camry Hybrid and the ES-350 both have the Denso accelerator assembly. The campaign procedure is the same for both, to cut 1" off the bottom of the accelerator pedal with a saw, then sanding the pedal smooth. A new pedal assembly is available if the customer is dissatified with the “chop”.

2007 to 2010 Lexus ES-350’s also receive a Engine ECU update to include a brake over-ride to cut engine power if both the accelerator and brake pedals are pressed at the same time.

http://www-odi.nhtsa.dot.gov/acms/docservlet/Artemis/Public/Recalls/2009/V/RCRIT-09V388-2937.pdf

If it is standard practice for manufactures to use a brake over-ride feature in the event of a accelerator/brake input correlation failure, is the lack of this feature not a defect?

“If it is standard practice for manufactures to use a brake over-ride feature in the event of a accelerator/brake input correlation failure, is the lack of this feature not a defect?”

It is a risk reduction feature. A defect exist where there is a direct link to a system failure of some sort.

We did get a floor-mat recall. But I’m not sure it was ever an issue. The floor mats in the Lexus have little hooks on them to keep them in place. They can be a pain to remove the mat for cleaning and then putting them back. I suspect that some people are removing the hooks and just letting the mat rest on the carpet…This will allow the mat to slide forward and interfere with the gas pedal. We’ve never removed the hooks so it’s not an issue for us.

I remember reading that the run-away problem with the state trooper in his ES was caused by installation of the wrong floor mat, that somehow a set of RX350 mats were installed.

It was the 2007-2010 ES 350 that was recalled. And you are correct that the mats were not firmly hooked in place and the driver’s floor mat moved into a position where the gas pedal could get stuck on it. All that Lexus would do is to attach the mats properly,as you have done, and cut the bottom of the gas pedal off to prevent interference.

“And you are correct that the mats were not firmly hooked in place”

I wouldn’t expect the floor mats to remain in the vehicle after a severe crash, roll over and fire.

"If it is standard practice for manufactures to use a brake over-ride feature in the event of a accelerator/brake input correlation failure, is the lack of this feature not a defect? "

Not necessarily - but it is certainly a sign of failure to properly perform a Failure Mode, Effects, and Criticality Analysis…

Any well-engineered system will have an FMECA done on it… as part of that, you should always examine the idea of “what happens if … fails”… and so when you consider the throttle position sensor in the gas pedal, you should ask what happens if it fails such that it sends a throttle open signal or a throttle closed signal. Pure logic says that if it fails in a throttle open position, the car will accelerate and be hard to control. So you either have to guarantee that failure mode never occurs, or provide backup systems, since the effect of the failure has a critical safety issue. On the other hand, if it fails closed, you have a ticked off customer, but they aren’t hurt.

So since you can’t tolerate an open failure, you MUST either eliminate the possibility of that happening, or provide backup systems that mitigate the effect of a failure. That is what a brake override does - it eliminates the critical nature of the failure.

So is it a defect? Not exactly, but it is a sign of a poorly engineered product, IMO.