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It there a write up for diagnosis of Power Booster failure/ABS light+step by step repair??

Discussion in 'Generation 1 Prius Discussion' started by twinturboguy, Jan 21, 2015.

  1. twinturboguy

    twinturboguy Junior Member

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    Hi everyone New Owner Here

    Yeah I got a 2002 Prius 190K The other day and I think I did good on it?
    Body is good, good AC, Great Quiet/comfortable Suspension, Hybrid system works very good I think.
    Transmission seems fine.
    I got it for $1100 :D (tell me if thats good deal)

    Its drivable but bit dangerous because it has abs light and brake light on. Its hard to stop.

    No service records but I told them I would give them $150 if they get me proof of the Hybrid Battery being changed(they claimed it was done 35k miles ago at 190k now) and other service records as they said they threw them out...

    Everything seems to be working flawless. (i don't know how accurate the Read out for MPG avg is but its been saying 43-50ish) (we didn't drive it that much yet)


    So I need help how to troubleshoot the issue, as the Dealer wants $119 I think just to check it out.
    We removed all the wipers and top section where rain hits (guard whatever its called)
    It looks pretty horrible to remove and replace that Power Booster as the AC lines need to be removed.
    We also have code reader we use on our 2003 Echo and we going to test if it can read codes on prius. (there is no check engine light on the prius)

    Any advice would be more than appreciated.
    Thanks
    J

    Just randomly after dealership and back. We started the Car and the Screen Says PS And ABS light flashes. The PS on Screen went away but the ABS is flashing instead of just being on.
     
    #1 twinturboguy, Jan 21, 2015
    Last edited: Feb 28, 2015
  2. ChapmanF

    ChapmanF Senior Member

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    We won't know whether your $1200 was a good deal until after finding out what the brake repair sets you back.

    As you saw under the cowl if you looked closely, in this car the master cylinder, the ABS actuator, and the brake accumulator/pump are three separate units mounted in three different places on the firewall, and one thing they have in common is that replacing any of them will soak up serious labor. You haven't said enough about what codes are reported, or what exact symptoms you have, to make many predictions yet about where the trouble is.

    Getting the brake codes should be your first order of business. You can do it with a good Prius-aware scan tool (MiniVCI often discussed in this forum would be a good choice, as it will also allow you to run the actuator bleed sequence when needed). In a pinch, you can also get the brake codes by jumpering the Tc and CG terminals at the OBD-II connector and counting the blinks of the ABS light. Those will give you two-digit blink codes, which are translated to normal OBD-II DTCs in the service manual at techinfo.toyota.com.

    If it happens to turn out that the accumulator is your problem, you can find a recent thread on here (last several months, I think) where someone was able to replace that unit without disturbing the A/C lines. Spent about ten hours as I recall.

    But before putting in those kinds of hours, of course you'll want to be sure where the problem is.

    Hope this helps,
    -Chap
     
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  3. twinturboguy

    twinturboguy Junior Member

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    Thanks for you reply. Yeah I was saying I tried to plug it in. I got my cheap scanner from Costco that seems to read any check codes when plugged into our Toyota echo or our Mazda mpv. But when we plugged into the Prius with abs and brake light. I assume there is no engine code so it maybe only reads check engine light but not brake lights. No codes found it says.

    How much and where do I get scanner for this Prius?

    Also to note I don't think we are leaking any kind of fliud what so ever.

    Before I purchase this. Is this a good one to buy? Will this read brake codes on my laptop?

    As my scanner has only read check engine and has not been able to read codes off my Prius with flashing abs and brake light.
     
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Look om Amazon.com for Mini VCI, price ~$30 or less. You need a Windows XP or Windows 7, 32 bit OS laptop to run the software. Mini VCI will provide you essentially the same Toyota Techstream diagnostic power as the Toyota dealer tech enjoys, and can be used with all Toyota models.

    Consult techinfo.toyota.com to obtain factory repair manual info, including the meaning of the DTC which you will retrieve, how to troubleshoot, how to replace the brake actuator assembly etc.
     
  5. SWprius08

    SWprius08 SoCalprius

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    Patrick just hooked me up with this mini vci for less than $30 and it works good. Here is the link which he recommended and I got
    ofcourse I had a old XP laptop sitting around which I was able to bring back to workable life by replacing its battery and fan so it worked out good. But if you don't have a laptop then to get a used one will add up significant cost, not sure if it might be better to get a different scanner for that cost. Just looked up ebay and found a descent XP laptop (dell latitude known to be robust) for about 85 bucks that has a return policy of 14 days, here is the link Dell Latitude D610 Windows XP Pentium M 1 8GHz 335MHz 512MB RAM 55 8GB Laptop | eBay
     
  6. twinturboguy

    twinturboguy Junior Member

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    I found on on Amazon and bought it. Trying make this the most budget troubleshooting/repair ever possible lol.
     
  7. ChapmanF

    ChapmanF Senior Member

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    I'll add here that when you get onto techinfo, there's one important manual you might not think to look in. The main thing is the service manual (volume 1 and 2, where volume 1 has the diagnostic info including trouble codes, test methods, etc., and volume 2 has how to take the stuff apart and replace it). But some people find those volumes frustrating at first because they both assume you know how the stuff is supposed to work in the first place.

    That's the exact information that's in what's called the New Car Features Manual, also on techinfo. It comes out for every new model, so you should look up the one for year 2001 and pay special attention to the section on how the brake system works, because there are some things about it you probably wouldn't guess.

    Cheers,
    -Chap
     
  8. twinturboguy

    twinturboguy Junior Member

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    Thanks. Its most definitely the Brake Booster for having such a hard pedal with Poor Brake performance. But maybe the codes can pin point the exact problem and save lot extra hours of labor and maybe its easier solution.
     
  9. ChapmanF

    ChapmanF Senior Member

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    I'm glad you're having the hard-pedal symptom. (Ok, maybe not glad exactly, but compared to other variations...) Do you ever hear the accumulator pump run? (Normally it's the whirrrrrrrrrrrrrrrrrr-CLICK sound under the hood when you first turn the key on and it's been sitting a while, or you've pumped the brake several times.) If you hear it run, for how long does it run?

    Is the alarm buzzer sounding? (Hmm ... I've just discovered I can't make mine sound, even by pumping the accumulator totally flat. More random troubleshooting for Chap for some warm day.... What on earth goes wrong with a buzzer?)

    You can always get your brake codes by the light-blink method, even while waiting for your MiniVCI to show up....

    -Chap
     
  10. twinturboguy

    twinturboguy Junior Member

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    I dont get a buzzard. (hopefully no one disconnected it)

    But i got check that tomorrow.
    No check engine lights and everything runs really smooth just hard pedal.
     
  11. ChapmanF

    ChapmanF Senior Member

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    Have you tried leaving some carrion under the hood for a coupla days?

    How about the sound of the brake pump running? Do you ever hear that whirrrrrrr-CLICK under the hood when first turning the key on?

    Getting a little OT, in my car there doesn't seem to be anything wrong with the buzzer itself ... taken out and with 12 volts applied, it makes a pretty convincing buzz (more like a high B♭ beep really). So maybe I don't completely understand the conditions for the ABS ECU to activate it? The manual just says low accumulator pressure, but I don't hear it even after pumping the brakes to the point they go rock hard. Anybody know more about the actual conditions for the buzzer to sound?

    -Chap

    By the way, this is what the buzzer looks like, in case anybody else needs to get it out; in place it's hard to see the clip that holds it in place or how to squeeze it (I'd use longnose pliers if there's a next time). The + terminal is the one near the keyway (bottom, in this photo).
    buzza.png
     
    #11 ChapmanF, Jan 22, 2015
    Last edited: Jan 22, 2015
  12. twinturboguy

    twinturboguy Junior Member

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    I thought buzzard is more of a serious warning to no longer drive the car.

    I only had car for like 2-3 days now. We just try to test things and we went through all the fuses today.

    I didn't get check anything with pump yet.
     
  13. ChapmanF

    ChapmanF Senior Member

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    There are some contributors on here with repair shops of their own, so it won't surprise me if one of them chimes in with the actual answer for what conditions are needed to sound the buzzer. Page DI-444 only says "the brake warning buzzer sounds while the accumulator pressure is abnormally low" but mine isn't doing that, so either there's a more complicated set of conditions, or my car has some issue in the warning circuit (not the buzzer itself).

    It's probably mostly off-topic for your issue. The best information from your car will be the codes (either by scantool or by light-blink method) and whether you hear the accumulator pump.

    -Chap
     
  14. ChapmanF

    ChapmanF Senior Member

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    Aha ... there's a matrix on p. DI-360 showing which codes can sound the buzzer, and then the specific diagnostic pages for those codes show the required conditions to set them. For example, it doesn't set C1252 unless the pump run exceeds 5 minutes, or C1256 unless the low-pressure switch is asserted for 60 seconds. I probably just didn't persist with my test long enough.

    [Edit 1/23/2015: Yes, turns out nothing was wrong with my buzzer, it goes off just fine if I create the right conditions: start with IG OFF and deplete the accumulator by pumping the brake until it goes rock hard; then turn IG ON and keep pumping the brake rapidly to make sure the electric pump can't catch up; after 60 seconds of that treatment the BRAKE and ABS lights and buzzer come on. Then you can stop pumping and they all go dark and silent again as soon as the pump has brought the pressure back up. Odd they would build such a long delay into a brake alarm....]

    Again, a bit off-topic for your situation, but since I raised the buzzer question here I thought it'd be good to have the answers here in case somebody else reads it.

    -Chap
     
    #14 ChapmanF, Jan 22, 2015
    Last edited: Jan 23, 2015
  15. twinturboguy

    twinturboguy Junior Member

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    Yeah thats cool. Cant wait for my Plug in Mini vc
     
  16. twinturboguy

    twinturboguy Junior Member

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    Very Horrible problems. I am getting the issue that it doesn't connect correctly. They give me some super out of date 32bit windows software which i have no computers with 32bit.

    I am trying to find away to get 64bit version. Any help please! I am so pissed with the new technology! Why can't cars be the way they were! lol
     
  17. SWprius08

    SWprius08 SoCalprius

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    while researching i had found some people who had figured out a way around. Check youtube "Connect mini vci 64 bit" or something like that.
     
  18. ChapmanF

    ChapmanF Senior Member

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    Sorry you're having trouble with it - those kinds of problems really spoil my mood.

    If you don't want it to slow down the solution of your brake issue, you might use the blinkenlight method to get your brake codes just to know what they are.

    Cheers,
    -Chap
     
  19. twinturboguy

    twinturboguy Junior Member

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    Yeah I am working on Mini vci. Hopefully I get somewhere today with it. (i fixed the registration issue, as it wouldn't let me login) Now its just matter of getting the device cooperate with the program as it says cannot connect to vim.
     
  20. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I tried the workarounds suggested in the Toyota Tundra forum and it didn't work for me so I had to buy and load Windows 7, 32 bit OS to get Mini VCI to properly function. That OS doesn't cost too much if you look around, newegg.com for example.