Finally - lights from Brake Booster/Pump failure

Discussion in 'Prius v Technical Discussion' started by wafwat, Jan 4, 2026.

  1. wafwat

    wafwat Junior Member

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    So I had previously posted back on December of 2024 that I notice my brake booster//pump starting to run every 30 seconds or so. Well today it finally lite up the "Christmas tree" on the dash. We were driving down the interstate and I had cruise on and it disengaging and started flashing/beeping. Got home and the brake booster/pump is now running every 3 seconds.

    The car has 119,575 miles and it's in service date is September 2016. SOOOO we made it in time to hopefully qualify for the "CUSTOMER SUPPORT PROGRAM 23TE07"

    Made a Service appointment on line already and hopefully I'll get to talk to someone before bringing the car in. My local dealer makes it hard to talk to someone on the phone... Guess AI is taking over... uggg...

    V

    IMG_8536.jpg
     
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  2. rjparker

    rjparker Tu Humilde Sirviente

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    Don't reset anything or cycle the 12v
     
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  3. ChapmanF

    ChapmanF Senior Member

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    Naturally, don't clear any trouble codes or try to reset anything.

    But it would be good to look at what trouble codes you have. If you haven't got a scan tool that can show them, you can use this method:

    Blink (a/k/a Flash) Codes – How to. | PriusChat

    The 23TE07 program only applies if you have certain specific trouble codes. The "PRE-COLLISION SYSTEM" warning showing on your MID would explain cruise disengaging and probably has trouble codes too, but those would be different from the ones relevant to 23TE07.

    If you pull the codes yourself and confirm they do or don't qualify you for 23TE07, then you don't have to have blind trust in the dealer to make that call for you.
     
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  4. wafwat

    wafwat Junior Member

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    Went to my local Auto Shop and they hooked up their super duper AUTEL scan tool and found that it did indeed have code C1391. It also had B15EC... no clue what that is...

    Oh and AutoZone and O'Reilly's free scan tool service are "poop".... they found NO codes even thought the dash is lit up like a "Christmas tree"....

    Off to the dealership tomorrow....

    V
     
  5. ChapmanF

    ChapmanF Senior Member

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    Your car has around two dozen ECUs in it. The AutoZone and O'Reilly's scan tools probably are able to talk to at least one or two of them. If you had happened to have codes from those ECUs, those tools would have shown them. They just didn't show the codes from the ECUs of interest here.

    Well, like any B1 code, it is manufacturer-defined; you'd have to find out from a Toyota Prius v repair manual, because in other cars, manufacturers could freely use that same code to mean completely different things.

    Toyota Service Information and Where To Find It | PriusChat

    [​IMG]

    I don't have a 2016 v repair manual handy to look at. In my 2010 repair manual, that code has to do with the backup battery for the "safety connect" cell-phone-based mayday box. (Remember it's a manufacturer-defined code, so nothing prevents Toyota reusing the code for something else in a different model. But maybe it means the same thing ... if you have such a "safety connect" feature in the car.)

    The "safety connect" feature in my 2010, anyway, depended on 3G cell service, so it's no use now anyway.
     
    #5 ChapmanF, Jan 5, 2026
    Last edited: Jan 5, 2026
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  6. bisco

    bisco cookie crumbler

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    all the best with a no cost new actuator!
     
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  7. rjparker

    rjparker Tu Humilde Sirviente

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    Yes free is the way to go
     
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  8. wafwat

    wafwat Junior Member

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    Car is fixed!!! And it was covered!!! Dropped it off yesterday morning and got a call from Service Advisor at 4pm cst that it was ready. I was surprised!!! We went back down and picked it up. He said that when we spoke on Monday and I explained the issue and supplied the bulletin number he ordered the parts that day, Monday. So they had them in hand yesterday.

    Also, thanks to @rjparker and @ChapmanF for your detailed posts!!! You both are invaluable resources to this forum!!!

    V
     
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  9. bisco

    bisco cookie crumbler

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    great news, congrats!
     
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  10. geoffdaddy

    geoffdaddy Junior Member

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    In our case, our brake booster pump/accumulator was clearly on its way out. We could hear the pump run intermittently while sitting at a traffic light. I took it by our local dealer who confirmed my suspicions that it was related to the TSB. He said, "unfortunately, there's nothing we can do until we get the christmas tree indications on the dash that are mentioned in the TSB... Toyota won't cover it otherwise." I tried a number of things to get the system to trip, hard stops, etc. Our fortunes changed when my wife was on her way to drop our kids off at school and hit a patch of loose sand that had washed onto the road from a new residential neighborhood road construction...that was enough to trigger briefly the traction control system and light up the dash. My wife called me frantically and I told her, "it's fine but DO NOT SHUT IT OFF! Drive straight back and meet me at the Toyota dealer as soon as you're done... LEAVE IT RUNNING!" We got to the dealership and I found the tech that helped us before. "Yep! That's what we needed to see!" We had less than a month and less than 500 miles left on the warranty, and Toyota covered it all!
     
  11. Viviparous

    Viviparous Junior Member

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    I have the same problem with my 2014 Prius. I hear what I think is the brake actuator. It comes on rather continuallly, perhaps every few minutes when the car is running, and for a few minutes when the car is turned off. But when I complained to the service department, they ran a diagnostic that showed that the brake actuator was working fine. And there are no codes and no Christmas Tree lights on the dash. I was told to just wait for check engine light before contacting them. That’s why I got the 4-year extended warranty from the dealer; I don’t know if it would be covered under a Toyota warranty given the high mileage and age of my car.

    But, so far, the Prius has been paying for itself in terms of fuel economy. I only have to fill up once a week, typically around $40 (gas is expensive here in California).
     
  12. rjparker

    rjparker Tu Humilde Sirviente

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    It has to code first. Same goes for the hybrid battery when dealing with any warranty even though frequent cycling is a brake booster warning and low mpg is a hybrid battery sign.

    I believe it takes several minutes of booster pump running to code unless it fails completely first.
     
  13. Mendel Leisk

    Mendel Leisk MMX GEN III

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    a month or two back I was trying to call our nearby Mazda dealership, which is right next door too, and part of the same company as, their neighbouring Toyota dealership.

    i managed to muddle it up, inadvertently phoned the Toyota place, talking to receptionist under impression it was Mazda. I tried to explain to “her”, an issue with our son’s Mazda CX-5, and asked about warranty coverage. She kept asking if the car had been serviced by them, and saying warranty wasn’t applicable.

    out of the blue, it occurred to me, she’d used the same word-for-word expression three times… I asked “are you AI?” She responded, “yes I am”, and went on to assure me she could handle most queries.

    anyway, I asked if I could talk to someone human, she put me through, and in a moment or two realized my gaffe.

    (the above quote took about 60 seconds to show, I’d pretty much given up, was going to copy/paste)