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VSC ABS (!) Brake Warning lights + Buzzer

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by hmd, Apr 6, 2018.

  1. hmd

    hmd Junior Member

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    I had my snow tires replaced yesterday with All Seasons and tonight the ABS, Brake VSC, (!) warning lights + buzzer came on. Brake were mushy. This 2004 Prius has 222K on it, but it was completely checked over when I bought it a few thousand miles ago.
    Can I assume that the tire changing may have messed up the brakes somehow? Best to take it back to the tire garage? Doubt they can check Prius codes, though. Suggestions, please!
     
    #1 hmd, Apr 6, 2018
  2. Elektroingenieur

    Elektroingenieur Senior Member

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    That’s possible. You could give the tire shop a chance to fix the problem; without more information, it’s hard to say if it was their fault.
    Someone needs to read out the codes. That someone can be you—even without a Toyota Techstream diagnostic system or other special equipment—if you follow @ChapmanF's postings that explain how to check brake-related codes by shorting the TC and CG pins of the DLC3 (OBD II) connector and counting the blinks:

    brake, (!), ABS, and VSC lights on | PriusChat

    3 Brake warning lights come on - no codes stored? | Page 2 | PriusChat

    Edited to add: If you’ve already noticed that the brakes aren’t working correctly, keep in mind that some brake problems get worse with successive applications of the brakes. If you’re not certain this won’t happen, consider having the car towed, rather than driving it to be repaired.
     
    #2 Elektroingenieur, Apr 7, 2018
    Last edited: Apr 7, 2018
    valde3 likes this.
  3. hmd

    hmd Junior Member

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    ONE more point: The tire shop also did a front end alignment.
     
    #3 hmd, Apr 7, 2018
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    1. I think you should measure the voltage across the 12V battery when the car is IG-OFF. Then measure the voltage again when the car is READY and report the results.

    2. If the warning buzzer is on, that means the brakes are seriously impaired and the car should not be driven in that condition. You should have the car towed to your Toyota dealer for diagnosis.

    3. I do not think that the installation of tires and wheel alignment is related to the brake system problem since you apparently were able to drive away from the tire store without any issues.
     
    #4 Patrick Wong, Apr 7, 2018
  5. hmd

    hmd Junior Member

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    Here's an update (Thanks for suggestions everyone):
    Took car back to tire shop and they said that codes pointed to a problem with brake actuator system. Now it's at the Toyota dealer and they had a Toyota tech look at it, but they're claiming that they still can't identify THE issue--their codes are not pointing directly to the actuator. They say they need to check wiring, and they're having problems finding the correct wiring diagrams for the car. Supposedly a formally trained Prius senior tech will be looking at it on Monday. They did say that the battery (small) was low and needed recharging. If a particular part is faulty wouldn't a code indicate that the specific "part" has failed?

    I feel I'm getting double-talked, so I'd appreciate any suggestions/thoughts from those who've been down this road (bad pun).
    TIA
     
    #5 hmd, Apr 7, 2018
  6. Patrick Wong

    Patrick Wong DIY Enthusiast

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    If you post the diagnostic trouble codes which the Toyota dealer tech retrieved, then we can discuss the significance of those fault codes.
     
    #6 Patrick Wong, Apr 7, 2018
  7. ChapmanF

    ChapmanF Senior Member

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    In general, no. You can see here for more of a discussion on what trouble codes usually can tell you, and can't tell you, and why.

    The typical detection condition for a DTC will be something like "signal ____ at time ____ was expected to be ____ but actually measured ____." That's very useful information, but still often demands a fair understanding of the system involved in order to know where to go with it and what to check next. Of course, that's what the Repair Manual helps a lot with.

    -Chap
     
    #7 ChapmanF, Apr 7, 2018
  8. hmd

    hmd Junior Member

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    The saga continues:
    The Toyota dealership claims I need a new actuator and that it will cost $1,700+ and 7 hrs. for installation at $115 per hour. I called Toyota to see if they would extend the warranty for this part, which they have done previously, but I don't qualify because of the mileage and year of the car.
    The dealer also said that there's an issue with a fuse and that they'll have to replace the fuse block assembly. They claim to have had trouble finding the correct wiring diagrams and the shop tech is calling Toyota tomorrow to confirm that they're using the correct diagrams.I asked them why their diagnosis has taken so long--especially since the tire shop came up with the same diagnosis after half an hour. Their answer was that they (Toyota) discovered other issues, fuse, battery low) as well. (That was another 2-3 hours.)

    I can't afford any of this. Are there quality aftermarket actuators available? Open to any suggestions and thoughts. Arrgh! TIA
     
    #8 hmd, Apr 9, 2018
    Last edited: Apr 9, 2018
  9. Patrick Wong

    Patrick Wong DIY Enthusiast

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    You potentially could buy a used brake actuator and have an independent tech install it. However you will need to find someone who specializes in Toyota hybrids.
     
    #9 Patrick Wong, Apr 9, 2018
  10. hmd

    hmd Junior Member

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    I'm checking around for local dealers who specialize in Toyota hybrids. Someone suggested that I consider a used part. What do you folks think?
    The Toyota part number is 44500 47091. I've found (used) actuators which claim to work with the 2004 Prius, but Is there a listing of listing of actuators which indicates which part numbers are compatible? Thanks.
     
    #10 hmd, Apr 10, 2018
  11. jm98

    jm98 Member

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    There is no guarantee that used actuator will be good... Since Toyota can't produce/sell this replacement parts at reasonable cost its best to file complain with safecar.gov.
     
    #11 jm98, Apr 11, 2018
  12. 3prongpaul

    3prongpaul Hybrid Shop Owner, worked on 100's of Prius's

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    If a dealer says they cannot find the proper wiring diagram for a Prius they are lying to you or are computer illiterate.

    All dealers subscribe to Techinfo.Toyota.com and can retrieve wiring diagrams for any Toyota.

    ANYONE can purchase a 2 day subscription for Techinfo and view/download any wiring diagram or service manual chapter you want.
    Cost is $15 for 2 a day subscription.
     
    #12 3prongpaul, Apr 14, 2018
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