Help Diagnosing Unintended/Uncommanded Acceleration Issue

I am sure that is what he meant. That's what he stated earlier in the thread. It's typical to make an error like that in the most important part of the problem description, sending everyone back to the drawing board. Hopefully he will edit the post.

Tom

 

Power supply problems are another source of intermittent problems. It would be a good idea to have the 12 VDC auxiliary battery tested and make sure all of the leads and terminals are free of corrosion. However, a failing auxiliary battery typically shows other symptoms.

Bob Wilson

 

Delete me

I agree with bwilson #69, I don't want to add to the noise in this thread.
I will be watching this thread, since I am interested in the findings, but I haven't had the problem so... nothing really to contribute.
Seems we are not allowed to delete our own posts here... will a mod help?

 

If you look at the data posted earlier in this thread by Chogan2:

http://priuschat.com/forums/care-ma...-me-unintended-acceleration-2.html#post841445

I am more likely to have an "unintended acceleration" event in my Ford Explorer than in my Prius. (It hasn't happened in either vehicle so far) Frankly, I'm a little more concerned about a meteor dropping out of the sky and vaporizing my whole neighborhood. That would suck.

 

This will happen if you press the power button with your foot off the brake. Sometimes I do it trying to power up the car too quickly.

 

Oh, you mean like certain Ford vehicles where the cruise control cancel brake switch was directly tied into the brake line, and always live? So when the switch shorted out, the damn vehicle burst into flames? I know the following is an ambulance chasing lawyer site

Ford Fires - Cruise Control Switch Fire Recall List, Ford Fire Recall Lawyer

but according to the NHTSA stats, you have a much better chance of losing a Ford to an engine/switch fire, than having a Prius suddenly turn into a Dodge Challenger SRT-8 and wildly accelerate down the road

My gripes with my Prius were mostly minor, except the TC. I'm currently looking at a new 2009, and a used 2009, as a replacement, and have no concerns whatsoever

 

User 'pnerd' has other issues and no original contribution to the acceleration problem. 'pnerd'', reading about someone else's report is NOT an original contribution.

We have seen a number of 'post and run' reports by those with NO interest in problem diagosis. Yes this accelerator problem is rare but this is one of the best documented cases.

One of the reasons I often suggest the Yahoo Group 'prius technical stuff' is not only the resident expertise but also their ability to focus on the problem and not be distracted by peripheral issues. So please, focus.

Bob Wilson

 

We have two affected Fords: the Explorer and a Class A motorhome. The motorhome was recalled for this, the Explorer wasn't even though they both have the same switch which fails at a near 100% rate after ~ 5 - 10 yrs. I replaced the switch in the Explorer after the CC stopped working and I discovered that the master cylinder was almost empty due to the switch leaking profusely.

The difference: For the Explorer, the switch is only powered with the key on. Apparently, Ford considers it acceptable if the truck bursts into flames while being driven or the brake fluid leaks out of the master cylinder; they only recalled the vehicles that spontaneously combust while sitting in the garage or driveway.

 

I appreciate your willingness to work through the problem. Rare, intermittent problems are the most vexing.

I think we can rule out static electricity as the air was likely at a high humidity level.

The _HYPOTHESIS_ of an ECU involvement sounds promising but the engine ECU can not be ruled out nor the bus between the hybrid ECU and engine ECU. It does sound like a vexing transient so I'm keeping an open mind.

What is your laptop operating system and does it have a stereo microphone input? If so, see about getting a copy of Audacity, which allows the laptop to record the microphone inputs, hopefully stereo but monoral is better than nothing.

Also, do you have a 'plug-in' power adapter that can convert the 12 VDC cigarette lighter voltage into the 40-50 watts the laptop would need? What we're talking about is having the laptop become a data logger. If nothing else, have it record the engine noise but if we can use two channel, then we can look at other signals such as some way to record accelerator pedal position.

I understand that you are not 'wires and circuits' technical but I think we come up with configurations that are well documented and confirm what is going on. We'll also need to understand if this will be a 'commuting' laptop that visits the car with you or one that stays in the vehicle.

Also, does your laptop have USB interfaces? The reason I ask is there are OBD 'mice' that plug into the diagnostic bus and can be used to record all transactions. This is an advanced technique that has the potential to provide a detailed record of any error events.

Bob Wilson

 

OK, that explains EVERYTHING! ound:

Sorry, couldn't resist. I'm in Software QA/Software Process Engineering (CMMI, ISO-9000, AS9100, Six Sigma). I always have to pick on PMs (I were one once myself).

 

Some days, the spouse is really giving you heck ... layin' into you ... and on those days I kinda look forward to that meteor slamin' into me be it 1 : 1,000,000 odds or not. So don't be minimizing my meteor.

 

I'm not trying to kill anyone's dream, I'm just sayin.

 

Sad to see how owners have to debug what seems to be a very serious issue on their own without any support from the manufacturer. Hope such things as hardware and software diagnostics, software reload, and even a "black box" for recording all system parameters for a few days will soon become normal for all drive-by-wire vehicles. Unfortunately, somebody may have to get hurt first before it is implemented.

 

I use Car Code OBD-2 on a laptop. It will record trip data via obdII and can be synched with GPS programs as well. I haven't had any chronic problems. I purchased it to see what was going on in system during the hills, etc. on my daily commute.