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Discussion Starter · #1 ·
OK.. I wanted to start a topic on this subject.. cause I know I have seen other people talking about this same problem on other boards (thank god I fund this one! its GReAT!) :) :D


I own a 2001 Prius Old style... 60.000miles


But I have heard it reffered to as the 'Big Hand'



it's basicly you'll be driving down a highway at a steady speed.... probably using both engines..

when with out releasing any pressure on the gas pedal.. you notice the car loosing accleration power..... kind like a 'big hand' has come up behind your car and grabbed hold and held it back a bit... then lets go ... goes away... like magic...


you might feel that several times.. then one time its happens really noticably and the BIG red warning light comes on and the car wont acclerate very well at all.. it'll still move.. but you press on the gas pedal and it just wont push ... kinda like it might be only using one engine and not both.. cause I could still hear the gas engine churning.


stop turn on and off the car several times and 'poof' the warnign lights go away the car drives fine and the dealer finds no error codes..


This has happend several times over the summer...

untill one time it happend and the check engine light stayed on..

This time the dealer
found error codes...

so they replaced the 'computer' and the fuel injectors and adjusted some valve?

Replaced the 'ECM'?? ?I dunno what that all means.. (ALL COVERED BY WARRENTY!! yay! :)

But I just got it back today .

SO I am crossing my fingers and hopeing this works..

but I was wondeirng if other people have experienced this before?

what happened?

and what does the 'computer' controll and whats a ECM?
 

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classic "Big Hand" doesn't leave any codes.

however, when it does get bad enough to leave a code, it's usually from:
http://autos.groups.yahoo.com/group/toy ... 018-02.pdf
TSB EG018-02
Sept. 12, 2003, Master, Hybrid & M.I.L. "ON" P1120, 2001-2002 Prius. (symptom: low engine power output (similar to big hand syndrome). fix: replace accelerator pedal assembly.)

The fuel injectors you talk about is probably from:
http://autos.groups.yahoo.com/group/toy ... 006-02.pdf
TSB EG006-02
Mar. 1, 2002, M.I.L. "ON," Engine Misfire P0300/01/02/03/04, 2001 Prius, replaces TSB EG007-01. (May need valve clearance adjustment, replace fuel injector assembly/spark plugs, and replace Engine ECM)

(There are more than a dozen computers in the Prius. The ECM is the Engine Control Module.)

I'll also note that often driving on bumpy roads (like cobblestones) or using a high octane gasoline is known to leave the same engine misfire error codes...

Another TSB that is similar to your description:
http://autos.groups.yahoo.com/group/toy ... 006-01.pdf
TSB EG006-01
May 4, 2001, HV ECU High Speed Coordination Control Logic Changes (engine surging, replace HV ECU), 2001 Prius
 

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Discussion Starter · #3 ·
I m looking at the invoice and the code I see is

eg1002 FUel injector assembly R&R (all)

What does R&R stand for ? replace and repair?

IS there a website with all error codes?
 

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Discussion Starter · #5 ·
And the roblem continues...

Blah.. so today.. 3 days after i got it back from the shop.....

The check engine light pops on again!!


but this time no big hand or red triangle..

just the check engine light..


OH man.. I have a feeling this problem wont be under warrenty and I'm gonn have to pay mucho buckos.. i have a bad feeling..
:(
 

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Discussion Starter · #7 ·
hello,
So I just heard back from the shop and it is indeed the pedal and it will cost around 500$!

So now.... I don't know.... Is this a potentially car damaging problem? If I don't fix it it won't break my car right? it'll just do that weird big hand thing... every now and then? I mean I can live with that as long as it doesn't damage my car...


I mean I have a choice of paying the 400$ to do the 60,000 mile tune up maintenance That I haven’t done... Or paying the 500$ to fix the pedal...

I can't afford both.. .

but if the pedal problem isn't damaging.. too my car... yet not maintaining it is....

I would rather maintenance it.. first.. the fix the pedal when I get the extra cash...


What should I do!???? Is this a car damaging problem?
 

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You can probably get the pedal assembly from parts for around $300. Try a few dealers or search this site for postings from dealers willing to do mail order. Installation is incredibly simple. It took me 8 minutes to find the right socket wrench (I had put it in the wrong toolbox), then 2 minutes to pop off the connector, remove two bolts, position the new pedal, reinsert two bolts and pop the connector back on. Total time: 10 minutes. And I'm not very good at working on cars.

If you don't replace the pedal, the frequency of occurance will slowly increase. At some point, the "big hand" will be accompanied by the "triangle of doom". When this occurs, you have almost no power available, even at full pedal. It wouldn't clear up for me until I came to a complete stop with foot off the pedal. Sometimes I even had to turn it off then back on.

So you don't have to replace it immediately, but it will eventually become so annoying that you will replace it.

There's been some speculation on the prius-technical-stuff yahoo! group that you might be able to clear up the problem a bit by the following procedure: Prior to starting the car in the morning, fully depress and release the pedal around 30 times. Only do this procedure once. If it turns out to be helpful, once should be sufficient. If it turns out to increase the problem you don't want to do it any more.

Let us know if this has any noticable effect on frequency. If you do end up replacing the pedal, there's a guy on that group that would love to have the old one for experimental purposes (they're trying to discover a cheaper solution).
 

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the pedal

Hi Sonikbaby, I guess I'm the guy Robert mentioned. I received an apparently failed pedal from another Prius driver, and did several things in an attempt to repair it. Since I have driven with that pedal only 1000 miles but with no sign of problem.

I also carry in the trunk my original pedal and the tools described by Robert, just in case I might need to do a roadside swap.

Also this week I have seen a similar message from Abigail on PriusChat. I offered her my pedal, in exchange for her sending me the bad one. Perhaps not my smartest business decision ever? I think her plan is to buy the new pedal, and I pay to get the failed one shipped here for more evil experiments.

So we might discuss. By the way, are you Abigail? Starting to get confused here. At least I'd like that old pedal, if you decide to buy.

Used pedals may be available from salvage yard networks (like LKQ), or

http://www.ozgrl.com

What next, then?

DAS
 

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Discussion Starter · #11 ·
Yes I am abigail... :)


you guys are making it sound like it is REALLy easy to replace this>???

Ok I am totally CAR STUPID...


Do you think I could do this though? My dad has alot of tools...

If I had instructions I might be able to do it I'm good at following directions...
 

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Discussion Starter · #12 ·
Oh an NO my car has not been in the shop for a year...


but after taking it back there over the past year for this problem.. THEY have FINALLY pin pointed this solution... and I think that this is probally the correct one...



they already did the EVU fix where they replace the computer... and that didnt work...

and they replaced the catalitic converter thing in the exhust system..

that didnt stop it..


So now this better stop it
 

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big hand

Yeah it's pretty easy to remove and reinstall the pedal assembly. You've got the tools and can follow instructions. It would help to be somewhat small and flexible (this is not my best qualification).

If we are talking about you opening up the pedal and doing the cleaning things as did I, that would require more detailed instructions, and here a digital volt-ohmmeter would come in handy. You might wish to reset the angular adjustment.

So tell us your plan, sonik abigail. New pedal, used pedal, fixit yourself, or the Tochatihu swap?

DAS
 

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Discussion Starter · #14 ·
Oh i just don't know! Where am I going to get instructions???

Can you post them up on here????? Please?? So that me and my dad can do it?

Thanks
 

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accel pedal

OK, coming soon, I am going to get the pictures together and add another message below. But here's the disclaimer:

I am sure that you folks could do these steps as well as I have, and if your pedal were wrong in the same way, this should fix it. But mistakes happen, and there is a chance that you will find something different inside. In other words, I can't guarantee the outcome. Proceed at your own risk, batteries not included, etc etc.

Have you tried to find out what a used accelerator pedal assembly (APA) would cost?

But since you may be rarin' to go there, the first steps should not require photos.

1) Identify the cable connector attached to the APA. Depress its locking tab on the left-hand side and disconnect it.

2) Remove the two, 10-millimeter bolts that connect the APA to the Prius. Pull the whole thing out. If you wrap your left hand around the top of it and let the bottom bolt-channel poke into your left forearm, you can "floor it" with your right hand and enjoy watching the clever mechanism move.

3) DON'T adjust in any way, the two smaller (7 millimeter, 9/32 inch works) bolts on the side of the APA. We'll talk about those later. If you don't have a digital volt-ohm meter, you STILL won't get to adjust them.

Next message coming soon. Need breakfast now.

DAS
 

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accel pedal

Continuing the steps, let's see if I can intersperse attached images.

NOTE: The next section refers to changing the potentiometer angular adjustment. It should not be needed, unless the two nuts have come loose, and its position has slipped. Unfortunately, it would be hard to know this without a digital volt-ohm meter. Lacking this thing, leave those nuts alone (you are permitted to tighten them). But how can any proper nerd can survive without such a meter (often available for but $20)?

4) Under the cable connector you disconnected you will see these six pins (first image)

I define those six pins as follows, with the APA in its normal (pedal at bottom) orientation:

1 2
3 4
5 6

There are two separate potentiometers/variable resistors inside the case (you will see those later). Toyota calls them "main" and "sub", and so shall we. Measure the resistance of main between pins 4 and 5. Write down the number of ohms. A value of about 470 ohms would be typical with the pedal not pressed down, and about 2000 ohms with the pedal fully depressed (which you accomplish with the left-hand holding-trick described in the previous post, which puts circular dents in your left forearm).

Measure the resistance of sub between pins 1 and 3. Write down the number of ohms. A value of about 900 ohms would be typical with the pedal not pressed down, and about 2300 ohms with the pedal fully depressed.

If your main and sub resistances are unlike the typical, or if the nuts were initially not tight, or if it looks like the whole assembly has slipped all the way to one end, now is the time to loosen the nuts. The whole thing will slip to one end, because it is spring-loaded. Find the angular position that best matches the typical ranges noted above, and tighten the nuts down in that position.

There is a faint possibility that you have now completely fixed the problem, and need not proceed to cutting etc. I don't know, because I have not received a bunch of failed APAs. People are supposed to be sending me those...

NOTE: All will follow the steps below. Please read them ALL before deciding that you wish to proceed. Once you cut, you are COMMITTED.

It is time to start cutting!

5) Put an abrasive wheel on your Dremel moto-tool, or similar. I have no idea how to open the potentiometer box without such a tool. The (obvious) plastic lip must be cut off, but the box and its lid must not get mangled too badly.

see attached second image:

The lip has been ground away, and after removing little burrs, lift off the lid. Inside it looks like, see attached third image:

Upper thing is the "potentiometer box", with 4 three-fingered contact wipers; and 6 springy gold-colored contacts. Below is the "lid", with 4 curved resistive tracks and 6 contact pads. Now, you know what everything is. Just because the potentiometer box in the image is detached from its APA, does not mean that you should do so. Stay on track...

6) Inspect the three-fingered wipers closely, ideally use a magnifier. If they are clean, fine. If they are dirty, clean them with 70% isopropyl alcohol (drugstore item) on a q-tip.

7) Inspect the springy contacts closely, ideally use a magnifier. This is where I noted a small amount of corrosion. Suggest you CAREFULLY rub each of them with sandpaper, emery board, or similar. Then clean each with alcohol on q-tip.

eight) Having finished with the potentiometer box, proceed to the lid. Wipe each of the curved trackes with q-tip/alcohol. You will probably note "dark substance" transferred to the q-tip. Do not wet-wipe them more than twice; the goal is NOT to remove the conductive plastic material! Finally, wipe the tracks with dry q-tips.

9) With emery board or similar, CAREFULLY rub the surfaces of the six contact pads within the lid. This will make them appear much more silvery and shiny. Goal is just to shine them up, not to remove any chunks. Clean each with alcoholic q-tip, dry each with q-tip. You should have gone through at least a dozen q-tips by now. Done, except for reassembly.

10) Now get out your tubes of epoxy cement. I used JB Weld 5-minute epoxy (car parts store item). Similar should be OK, but not something that takes a long time to harden. Somebody is going to have to hold the lid in place during the hardening, or invent build a holding-and-lid-pressing device that does not get in the way of where the epoxy goes.

11) Now practice what gluing people call "dry-fitting". Put the lid into position and feel it snap into the correct position with your fingertip. Learn what this feels like; you will NEED to achieve it accurately once the epoxy is mixed. If you epoxy the lid into the wrong position, the APA will not work, for sure. I found it very useful to have the ohm meter attached (as described above) to confirm the correct position. I know it's possible to do with just the fingertip feel, but I wish you'd just get the darn meter!

12) Mix the epoxy (following package instructions)! Position the lid correctly with your fingertip! Smear the epoxy over all the area where you ground off the lips. Make sure that the epoxy extends both onto the lid, and part-way down the side of the potentiometer box. Do not get epoxy on the 6 external contact pins, nor anywhere near the 2 angular adjustment bolts or their tracks.

13) Continue to maintain the lid in that perfect position with finger, or with the hold-in-place device you invented and built after reading (10) but before performing (11). Incidentally, this is the best reason for using 5-minute epoxy. Nobody wants to stand there for 2 hours. Realize that the 6 springy contacts inside are trying to lift the lid out of its perfect position, and nothing but your finger prevents that.

14) After the epoxy is hard, remove your finger from the lid. Of course this presumes that the finger is not epoxied in place.

15) Wait as long as the epoxy package says. While you're waiting, try to clean up those 6 (external) contact pins that mate with the cable connector. Probably they are not dirty or corroded, but there is nothing else to do during this interval.

16) Reinstall the APA. Tighten the two 10-mm bolts about as firmly as possible, with your hand 4 inches down the socket wrench handle. That's probably about 15 foot pounds of torque, but no way in heck to get a torque wrench into there. Notice how hard it is to wiggle into the correct position to do all this. This is why Toyota techs charge $50/hr and up.

17) Reconnect the cable connector. Then pull it off and reconnect it again. And again. In effect, your are completing the connector-cleaning process. Might as well do it now; you've already wiggled yourself into position.

Last step) Crawl out. Start the car! You should see no error codes. Depress the pedal (in "P") and the engine speed will increase slightly. Still no error codes! Release the pedal, engine returns to idle speed. Congratulations, you have repaired the APA (probably). Go for a drive. Maybe to the hardware store to buy "epoxy remover" to get that stuff off your fingers.

DAS

PS: the images are all at the bottom, and appear in the reverse order. I did my best, you do the rest. PM me if you want to exchange phone numbers to discuss confusions. If Toyota extended the warranty on this (like on the steering), we would not have to do all this. But I still like them.
 

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tochatihu - are you still collecting "bad" accelerator pedals?

This week driving to work I thought that I might be having the start of the big hand syndrome (BHS) on my 2001... But I shook it off as all being in my head as the topic was just on my mind after several other posters on this and other Prius groups mentioning it lately.

Kind of felt like the lack of acceleration that I had on my previous car (mercury mystique/mystake), which had a leaky seal on the transmission (low fluid, and the transmission wouldn't shift or at least not easily).

This morning on the way to work, it happened again at about the same place as the other times this week... I'm just cresting a hill at around 45MPH, change into the newly-created right (3rd) lane, and begin to coast a bit to get down to 30-40MPH as there's a bunch of traffic lights ahead... (The location is on rt. 9 right by the Jordan's Furniture and Walmart light in Framingham/Natick, MA.) I start slowing down below the speed I'd like, so I press down on the accelerator pedal a little... BEEP! and the Master Warning Light (red triangle with exclamation point in it on the dash) and the highlighted red box on the MFD is the Hybrid Vehicle Warning Light (exclamation point on car outline) come on. No MIL (check engine light). I'm now at about a steady 20-24mph, but I have the accelerator pedal floored. (I didn't check, but I believe I was still in D and hadn't gone into N - I wasn't playing with radio stations, and flooring the accelerator in N would normally rev the engine, but that didn't happen here...) Since I was only a few lights to work, I kept driving... Most of it was electric-only, but occasionally the gasoline engine would come on. (I have a CoastalETech engine run indicator.)

I chickened out after a bit, and pulled into the Crown Plaza hotel parking lot. Pulled into a space, parked, and rebooted. On the 4th reboot, the warning lights went out. I then do the very short drive to work (essentially the other side of the parking lot).

I tried calling for an appointment with my dealer for tomorrow (Friday), as that's my usual day off. The earliest appointment is on Tuesday (ok, I can swap my day off for next week), but... I tell them of my lights, and they say that my car should be fine to drive! I tell them that I have to wait for my car. They tell me to bring the car in at 7:30, and they'll get around to it sometime during the day... They couldn't pinpoint a time closer than that. Not much of an appointment, if you ask me... Now I have to find myself a nice book or two to bring with me...

Anyhow, since it's probably EG018-02 (accelerator pedal), should I ask for the old part for you? I know that the TSB is for 3 years/36,000 miles, but I've got the extended warranty, so hopefully all I'll have to pay (if anything) is an $85 diagnostic fee.
 

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accel pedal

yes yes yes, please I would like a pedal. Two pedals. Many pedals. I need some "stock" to establish a pedal exchange program.

Since the pedal (serviced as described in the messages here) has performed correctly here for almost 2000 miles, I am leaning towards the idea that it is repaired. Still don't know which thing done to it was the meaningful thing - that's were additional pedals would help.

Haven't seen anything from SonikBaby. Did I post too much detail?

DAS
 

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If the part is not replaced under warranty, you are entitled to have it back. However, if it is replaced under warranty, the warranty underwriter can request it.
 

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"I've got the extended warranty, so hopefully all I'll have to pay (if anything) is an $85 diagnostic fee."

If you paid for the extended warrantee, why do you have to pay this fee?
 
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