Toyota to replace 2004-2009 Prius gas pedals, give new all-weather mats

Yes, many have done so and reported back to other threads here on PC.

That is your perception.

Mine? Coming from a manual transmission, I had to retrain myself to NOT shift to neutral for gliding after finding the Owner's Manual warning against it -- in normal, not emergency situations.

No problems or difficulties occurred during the week I was shifting to N against the recommendation, which is intended to prevent damage in a certain uncommon situation (rolling down steep hills with engine off and gaining a lot of speed, going over a certain threshold). This particular mechanism cannot happen while the engine is running, and even if it could, is less serious than being in a runaway car.

 

That thread went on a bit and I would recommend starting with this post that includes a photo of the run-away car:
http://priuschat.com/forums/gen-ii-...mmanded-acceleration-issue-23.html#post841524

I enjoyed the thread because we got to cover a lot of Prius sub-assemblies. We did have to deal with some attitude problems but once folks realized we were 'on the hunt,' things progressed nicely. <wink>

Bob Wilson

 

Shifting to neutral would be fine if the problem is a stuck pedal, but I'm not sure if it would work if it's an ECU problem. Unlike a traditional automatic, the gears are never disengaged so neutral is simulated by running MG1 to counteract the ICE.

If the ECU has failed, it might not correctly do this.

However, if Toyota secretly knows it's an ECU issue, the only explanation for the pedal/mat recall would be that Toyota can't identify it but wants to be seen as doing "something". It's a pretty expensive something, though. I would think an ECU flash would cost a lot less than replacing everyone's accelerator pedal, so Toyota would do that instead if that would fix it.

I'm actually okay with the recall even though you "should" keep your mat anchored. You should also never press "Park" while you're driving 60 mph, but the Prius "fixes stupid" anyway and fails to destroy the parking pawl if you do.

Toyota's design is different than other cars -- I looked at my friend's Mazda and there's about 3/4 inch between the bottom of the pedal and the floor. The Prius pedal touches the floor, so something under could conceivably get it wedged.

Could the mat come unhooked without me noticing? Probably. Could the car wash fail to hook it down and I fail to check it? Probably. If that makes me stupid, so be it.

 

I'm more concerned about brake override than the floormats and accelerator pedal on my Prius. But apparently the brake override doesn't apply to the Prius.

My mat is hooked and can't move. I don't want a sawed off accelerator pedal, because I'm short and concerned about reaching it. Right now, everything is perfect.

Why fix what ain't broke? And maybe create problems for some?

When you see all the hate nuts on the internet, you wonder about believing the claims of a few people highlighted in the media. I would exclude that Lexus 350 in California, which was a brake issue.

Is there a law about hooks on driver mats? There should be--for all cars. I've had this problem of mat creep in the past with other cars with no hooks. Also with replacement mats. But not with my Prius.

If the government doesn't have a law about secure driver mats--that's the problem.

 

Re: Gas Pedal--Re-call ?

I'm thinking I may just take my angle grinder to the old pedal ... zip zip ... debur debur ... and save Toyota the trouble.

collaterally be prepared to hear this: "Hey, ever since I stopped using my brake pedal as a foot rest ... my brake pads last longer, & folks no longer shake their fist at me when they pass" ... "Woah"

.

 

Re: Gas Pedal--Re-call ?

perhaps for good R.R.? ... as well as double redundancy?

That's why I use the big toe driving method ... mentioned in earlier threads from time imortal ... it helps improve mpg's too.

No ~ just because your PRIUS is ok, doesn't mean all Toyota & Lexus vehicles are designed the same. Right? After all ... the fatality involved a 272hp Lexus (what's that ... more than double the Prius' hp ? ), and who knows how many different fuel delivery types there are between the dozens of models, and a half dozen design years of both Toyota & Lexus.

.

 

Re: Gas Pedal--Re-call ?

And: "... my gas mileage suddenly jumped higher."

 

Neutral is simulated not by running MG1 in any pattern, but by de-powering it so it freewheels. This kills all power flow out of the ICE.

Historic evidence suggests that the majority of incidents are likely caused by driver error and mat interference. A simple ECU reflash will not solve these, leaving the major causes still in place.

Clearing those two causes off the table will make it far easier to identify any additional problems that remain.

 

You first have to decide whether unintended acceleration incidents exist that are not attributable to driver error. If you believe that all incidents are due to driver error, then no action needs to be taken and you can blame all incidents on "stupid" drivers. This is the philosophy that both NHTSA (according to LA Times) and Toyota seems to have been operating under until the San Diego Lexus crash was documented via passenger cellphone.

Now we have this pedal shortening and floor mat replacement program, which implicitly assume that the driver is unaware enough to allow the mat to freeze the pedal. However we know that Prius, when working properly, will stop when the brake pedal is depressed, regardless of the accelerator pedal position. Hence the Prius part of the recall program will cost Toyota ~$60 million (600K 2G US Prius x $100 each) yet yield little payback in terms of safety improvement.

If you believe that at least some incidents are due to equipment failure, then you need sufficient data to determine the cause of the incidents, so that you can take remedial action. The rest of this msg assumes that you are in this camp.

Regarding Prius: each ECU is responsible for reporting its own errors. The diagnostic capability of each ECU is not complete so occasional glitches are reported in PriusChat and other user forums that the dealers cannot immediately resolve. No ECU is responsible for monitoring the overall health of the system and recording problems.

In hindsight, it would have been very nice to have an ECU whose only function is to monitor the overall system and store data of interest, such as vehicle speed, brake and accelerator pedal position, engine RPM, etc. In other words, a scaled-down version of the Toyota diagnostic laptop used by the dealer, embedded in the car. This would help to prove whether the unintended acceleration was due to driver error.

Then, it would also be nice if that ECU had the power to force failsafe operation if it noticed illogical events, such as the driver depressing the brake pedal hard, while the car continued to gain speed. Failsafe means that the ignition or fuel system would be cut while warning lights and buzzer would come on. Failsafe also means that this emergency system shutdown is not dependent upon proper function of other ECUs such as the hybrid vehicle ECU.

Lacking perfect information about the failure, dealer service philosophy also needs to be examined. The current service philosophy is that an appropriate DTC has to be logged or the failure has to be experienced by the dealer tech before Toyota will authorize warranty repair. This is reasonable for most failures.

However, when an intermittent failure with life-threatening implications happens, then a different philosophy needs to be adopted. Don't replace one part at a time, expecting the customer to bear the risk of another failure. Instead, replace all parts that could be involved and be done with it. See my posts here:
http://priuschat.com/forums/gen-ii-prius-main-forum/11798-brake-failures-04-prius-6.html

My dad had an unusual brake failure with his 2007 Prius and had to return three times to the dealer before the problem was finally resolved.

Also see this string which discusses more brake failures:
http://priuschat.com/forums/gen-ii-prius-main-forum/19415-brake-failure-2005-prius-8.html

Regarding unintended acceleration, assuming that the fault is not due to driver error, then there are a limited number of Prius components that could cause that problem:

1. hybrid vehicle ECU
2. engine ECU
3. throttle control motor
4. accelerator pedal

There have been 40-50 NHTSA complaints about this. Lacking perfect diagnostics and data, it would have been far more effective (from a cost and safety perspective) for Toyota to replace all four parts at once (assuming the car wasn't already totaled in an accident) for those cars registering the complaints; than to buy new floor mats and accelerator pedals for 600,000 US 2G owners. Or, buy some of the cars back from the owners and have Toyota employees drive them for a period of time as their personal vehicles, to see what happens. Pay a bonus of $50K to the first employee who can figure out the root cause, etc.

Recall the recent LA Times story where one Prius owner experienced unintended acceleration three times, and finally the accelerator pedal was replaced. She reasonably (IMO) felt that was an insufficient response, gave up and traded in her car for a BMW.

 

Hi Patrick,

Although neither of our Prius will be affected by the recall and I was aware enough to recognize the unsecured, driver side floor mat in our 2010 was a potential problem, I think there is enough information to justify the recall:

1. Reputation - the Ford "Pinto" memo echos today. No vendor can afford to be seen as selling a vehicle with a known safety defect (or weakness.) It would completely consume their advertising budget for no effect. The ~$60m advertises a safety commitment to preserve the value of Toyota TV, newspaper or magazine advertising efforts.
2. Shifting to "N" is not taught as a safety technique - our own sampling of 52 responders had ~30% reporting they hadn't practiced shifting to "N". I only knew it was OK because of my Pulse and Glide testing and hadn't realized the safety aspect.

Granted, the number of runaway incidents in the NHW20 has been fairly small, depending upon who is asked, but the costs from these incidents, especially when life and property are at risk, more than makes up for the small numbers. But I remain puzzled that the ZVW30 is not included.

We have had at least one report is that application of the ZVW30 brake defeats the accelerator. I'll do some testing this afternoon to see if I can replicate this observation. If so, it will be a good thing.

Bob Wilson

 

I just finished reading through this thread with great interest. There is article in today's LA Times about the possibility of this being an electronic issue rather than a simple floor mat/accelerator pedal is too long issue.

(Sorry, TonyPSchaefer, didn't realize I was in violation)

Here is a snippet from the article, the link to the article is below:

"What's more, said Huei Peng, director of the University of Michigan's automotive engineering program and a What's more, said Huei Peng, director of the University of Michigan's automotive engineering program and aat a modern car is susceptible to are not detectable by the car's fault detection system.

"When there's no error code, it doesn't mean there's no error," Peng said.specialist in vehicle control systems, many of the kinds of electronic errors that a modern car is susceptible to are not detectable by the car's fault detection system.

"When there's no error code, it doesn't mean there's no error," Peng said."
Click on the title below to take you to the full article, it includes diagrams.

Motorists, experts say throttles, not floor mats, to blame for sudden acceleration in Toyota, Lexus models

 

On a flat, isolated road, I floored my wife's ZVW30 (2010 Prius) and once the engine was fully reved and vehicle accelerating over 55 mph, I pressed the brake with my left foot:

• surge power - there were a couple of brief, ICE surges
• braking was obviously very effective - I came to a stop fairly quickly

I need to repeat the test going down an 8% grade at 65-75 mph and will document it with a cell phone camera. However, I suspect the brake-accelerator interlock mechanism is in the 2010 ... and it works. I don't remember reading about it in the "New Car Features." Since our car was manufactured in April 2009, I suspect it is in all 2010 Prius.

Next test, to find out if it can it handle an 8% down grade at 65-75 mph. This is interesting because the gravity assist is an independent source of energy and the faster the car is going, the greater the power. If the car stops with the accelerator floored going down an 8% grade at 75 mph, the 2010 does not need to be in the recall. Yes, I will take an IR thermometer and measure the brake temperature as soon as it stops. ... <wheeeeee>

Bob Wilson

 

The recall is still usefull for the Prius: if you release the gas pedal, also a Prius-owner expects the car to decelerate, not continue to accelerate. So, to prevent the pedal to be kept down by a floormat is a good thing.


The Prius has allready the brake override system, so it doesn't have to be equipped with it.

That lady which was not satisfied and bought a BMW: Is she a specialist or a guru? What authority does she have, that her dissatisfaction proves that there is something else wrong?

 

Ok, back from the downgrade test with our ZVW30. No problem at all.

First pass too much traffic.

Second pass, hit the brake too hard and the dog was thrown from her seat. Do this test with gradual application. These are great brakes!

Third pass, the first inch or so, no effect ... then they work and work well. Within seconds the 2010 dropped from 89 mph to middle 50s. Complete control and the ICE spun down. Releasing brake pressure and the ICE was roaring again.

The ZVW30 does not need to be fixed with a brake-accelerator interlock. We'll need some photos with rulers to understand if there is a "crap in the gap" problem.

Bob Wilson
(aka test Prius pilot)

 

I disagree with the assertion that the Prius has the brake override system for two reasons:

1) We know that Prius, when operating correctly, will slow down when both the brake and accelerator pedals are simultaneously depressed. However there are a number of NHTSA complaint reports of unintended acceleration with Prius, where the complaint states that the driver had depressed the brake pedal. In some cases the brakes suffered heat damage while in other cases it was asserted that bystanders saw the brake lights on. It appears that the system was not working for those drivers.

2) If in fact Prius was equipped with a "brake override" system, I would expect Toyota to publicize that fact. Instead, the recent Toyota press release is silent about Prius.
Toyota Vehicles : Toyota Announces Details of Remedy to Address Potential Accelerator Pedal Entrapment / Toyota

The New York Times says that a smart gas pedal (aka brake override system) will be installed on Camry, Avalon, and Lexus models, and other recalled models where technically feasible. So maybe Toyota just hasn't gotten around to looking at the Prius yet. The Camry/Avalon/Lexus likely received first priority due to the visibility and sales volumes of those models.
Toyota Says Cars to Get Smart Gas Pedals - Wheels Blog - NYTimes.com

Regarding the unintended acceleration incident that happened 3x and the eventual replacement of the accelerator pedal, I personally wouldn't be satisfied with that unless a physical flaw in the pedal could be pointed out to me. After all, that pedal only consists of a couple of Hall-effect sensors and a return spring.

 

Hmm. I wonder why the new ones are plastic?

And will it feel different? Have to get in the habit of putting your foot in a different position?

 

Electronic Brake Distribution.

 

Movie from 2010 Prius, ZVW30, braking test. The accelerator was flat on the floor as soon as the speed increased over 70 mph. You'll notice during braking a couple of 'spurts' of ICE but they were brief. The brakes were in control. I don't think the ZVW30 needs to be in the recall unless there is a need for accelerator pedal clearance changes.

I noticed the ZVW30 new car features discusses the lighter weight, hollow assembly. I wonder if that is what the NHW20s will be offered.

Has anyone tried this test with an NHW20?

Bob Wilson

 

I believe that in the other Toyota models, they will build the same type of brake override system as the Prius has.

I don't think Toyota will build an extra failover system in case the Prius brake override doesn't work.