Won't start (brake switch? 12v is fairly new)

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by berderder, Dec 28, 2024.

Tags:
  1. berderder

    berderder Junior Member

    Joined:
    Jun 27, 2020
    69
    19
    1
    Location:
    Connecticut
    Vehicle:
    2014 Prius
    Model:
    Two
    Hey all,

    I'm thrown by a couple things going on here.

    A couple weeks back I was getting engine knocking. Getting chillier out and I did the typical didn't-let-my-engine-switch-off-after-parking-before-turning-off-the-car thing that makes the engine knock when you start up the next day. That was to be expected, happens every winter. Only this time oddly I got a check engine light later that evening on my way back home.

    Just a day or so later it got below freezing for the first time of the year. Prius would not start, no lights, no nothing. Stiff brake pedal. I unplugged the 12v and charged it at home with a peripheral charger thing. Solid green light (although doesn't tell health of battery). I bought this current battery probably 3 years ago and put normal say 10k/year commuter miles on it.

    Probably has nothing to do with it but I was messing around with a free backup camera a friend gave me and was messing with the brake lights, etc. As I was saying not getting any lights, brake lights included.

    Switched out the fob battery for main and spare TWICE. I thought maybe the cheap ones I bought online were dead and switched in some duracell ones. The car is like a brick, red lights on fobs flashing, no response from car, have to manually unlock. Very dim dome lights, that's the only thing. Apparently 12v fully charged.

    I've only recently learned about the brake switch which I can see being a possibility. The brake is very heavy/stiff and I've tried making the startup condition for it by pressing harder/retrying etc. Don't know a lot about fuses by just initial glance they don't look burned out or anything. Any thoughts?
     
    #1 berderder, Dec 28, 2024
  2. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    57,967
    39,994
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Check the 12 volt battery voltage, with a multimeter, car off.

    what’s the miles?
     
    #2 Mendel Leisk, Dec 28, 2024
    berderder and Brian1954 like this.
  3. ASRDogman

    ASRDogman Senior Member

    Joined:
    May 29, 2018
    6,887
    3,627
    0
    Location:
    Florida
    Vehicle:
    2010 Prius
    Model:
    Two
    "peripheral charger thing"????
    You need a volt meter. You can get one from walfart for about $15.
    I would guess from what you've written in perhaps you've damaged or
    disconnected something why trying it install the camera.
    For some reason you're not getting any power to the car, likely the 12v battery.
    Depending on where you got the battery, you should still have a warranty on it.
    Is a Toyota battery? If not, there's no telling how long it will last.



     
    #3 ASRDogman, Dec 28, 2024
  4. berderder

    berderder Junior Member

    Joined:
    Jun 27, 2020
    69
    19
    1
    Location:
    Connecticut
    Vehicle:
    2014 Prius
    Model:
    Two
    160k miles. I'll try the multimeter, I had to pick one up
     
    #4 berderder, Dec 28, 2024
    Brian1954, Mendel Leisk and ASRDogman like this.
  5. ASRDogman

    ASRDogman Senior Member

    Joined:
    May 29, 2018
    6,887
    3,627
    0
    Location:
    Florida
    Vehicle:
    2010 Prius
    Model:
    Two
    If you get a new battery, make sure you charge it with a 5amp or less AGM Charger
    for at least 6-12 hours. They don't come charged because they will sit on the shelve
    for months and months....
     
    #5 ASRDogman, Dec 28, 2024
    berderder likes this.
  6. berderder

    berderder Junior Member

    Joined:
    Jun 27, 2020
    69
    19
    1
    Location:
    Connecticut
    Vehicle:
    2014 Prius
    Model:
    Two
    Lol yeah for some reason I wasnt finding the words for the at home charger you can hook the battery up to. Only needed a half hour until it went from blinking to solid green (fully charged), but my understanding is that it doesn't mean the battery is in good health. The thing about the backup camera though is that was months ago. I agree though I'm thinking I need to try a new 12v. It feels like I just put down $250 for OEM battery not that long ago but I guess it has been 3-4 years
     
    #6 berderder, Dec 28, 2024
  7. ASRDogman

    ASRDogman Senior Member

    Joined:
    May 29, 2018
    6,887
    3,627
    0
    Location:
    Florida
    Vehicle:
    2010 Prius
    Model:
    Two
    The Toyota battery has a 7 or 8 year warranty. There should be a sticker on it.
    But look for your paperwork.
    After charging, it should read at the very least 12.5 volts.... 12.8 is better.
    the tenths of volts may not seem like much, but for a Prius, it is.
    And just because the voltage is good, with a load, it could drop. So hook up the meter
    and then turn the lights on. If it drops below 12 volts, the battery is a gonner.

     
    #7 ASRDogman, Dec 28, 2024
    berderder likes this.
  8. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    57,967
    39,994
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    A fresh off a charger can read falsely high; you want to check a day or two later. Much better assessment is with an electronic load tester; most automotive retailers selling batteries have them and will test for free.

    If EGR systems never been cleaned, and with rough starts, could be head gasket. Very likely actually. Stsrt with boroscope inspection of the combustion chambers, preferably with cooling system pressurized, looking for coolant.
     
    #8 Mendel Leisk, Dec 28, 2024
    berderder likes this.
  9. berderder

    berderder Junior Member

    Joined:
    Jun 27, 2020
    69
    19
    1
    Location:
    Connecticut
    Vehicle:
    2014 Prius
    Model:
    Two
    Thanks a lot, checking soon with the multimeter and will look into warranty. I'll report back what happens. @Mendel Leisk it's funny you mention EGR, I was just trying to get this sorted before holidays
     
    #9 berderder, Dec 28, 2024
  10. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    57,967
    39,994
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Every 50k miles is about the longest I'd go between EGR cleanings. Leaving it late in the day like 160K, then cleaning it, is analogous to brushing/flossing once every 6 months, just before dentist visit.
     
    #10 Mendel Leisk, Dec 28, 2024
    berderder likes this.
  11. berderder

    berderder Junior Member

    Joined:
    Jun 27, 2020
    69
    19
    1
    Location:
    Connecticut
    Vehicle:
    2014 Prius
    Model:
    Two
    So the engine knocking I mentioned I think was what first brought EGR cleaning to my attention. I first noticed when I spent 3 months in Vermont during the winter 3 or 4 years ago. After parking the prius, if I didn't idle and wait for engine turn off completely before turning off the car, it would produce the knocking sound the next morning on startup (this is to say, if temperatures are very cold like 10-32 deg F). This has been it's behavior consistently during the winter months, but I definitely need to do the EGR cleaning anyway. Wish I did at 50k and 100k like you did. And of course I had that check engine light all of a sudden so we'll see.

    BTW the battery is reading 2.5 volts lol. The "full charge" on trickle charger I did was I think 4 days ago.
     
    #11 berderder, Dec 28, 2024
    Mendel Leisk likes this.
  12. ASRDogman

    ASRDogman Senior Member

    Joined:
    May 29, 2018
    6,887
    3,627
    0
    Location:
    Florida
    Vehicle:
    2010 Prius
    Model:
    Two
    2.5 volts? After 4 days? May it RIP.

    Unless, did you mean to type 12.5v? Then, it's marginal....

     
    #12 ASRDogman, Dec 29, 2024
    berderder likes this.
  13. berderder

    berderder Junior Member

    Joined:
    Jun 27, 2020
    69
    19
    1
    Location:
    Connecticut
    Vehicle:
    2014 Prius
    Model:
    Two
    Yeah unfortunately 2.5v. Kind of surprised, extreme cold could do that maybe? Pretty sure it's only about 3 or 4 years old..
     
    #13 berderder, Dec 29, 2024
  14. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
    Jun 6, 2008
    9,121
    5,526
    7
    Location:
    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    Likely culprit that killed your battery

    Very illogical. Dim dome light means low 12v battery.

    Don't "knock" yourself too much about the egr is the devil myth, especially on a 2014 which is likely to have updated rings and pistons (build date after Feb 2014).

    They all run great until 150k miles (Canadian 100km is actually 62k miles).

    Most likely you have something drawing way too much current when the car is shut off. Excessive parasitic draw. Typical good is 30ma (thousands of an amp). An aftermarket camera could be drawing ten to a hundred times more, strangling your 12v battery and causing an early death.

    The bad part is a new battery, oem or not, could fail quickly as well if there is an excessive parasitic draw.

    I would have the current draw tested after you get a new battery.
     
    #14 rjparker, Dec 29, 2024
  15. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
    Jun 6, 2008
    9,121
    5,526
    7
    Location:
    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    Is that like cleaning the house and making the bed before the cleaning lady shows up?
     
    #15 rjparker, Dec 29, 2024
    Mendel Leisk likes this.
  16. ASRDogman

    ASRDogman Senior Member

    Joined:
    May 29, 2018
    6,887
    3,627
    0
    Location:
    Florida
    Vehicle:
    2010 Prius
    Model:
    Two
    Well, that's your issue... Take it back to Toyota and get a replacement.
    You should also check if you left any dome lights on.
    Or if you tapped into something that has power going to your back up camera consistantly.
    If you don't drive much or very far you might was to invest in a battery maintainer, or
    one of these:
    MHPOWOS 12V 50W Portable Solar Panel Charger For Car Battery Automotive Motorcycle Boat Marine RV Trailer Snowmobile - Walmart.com

     
    #16 ASRDogman, Dec 29, 2024
  17. berderder

    berderder Junior Member

    Joined:
    Jun 27, 2020
    69
    19
    1
    Location:
    Connecticut
    Vehicle:
    2014 Prius
    Model:
    Two
    Good thoughts on the backup camera. It was actually just a trial run to see how easy it was to remove the trunk door paneling and to route the camera cable. Didn't actually plug anything in.

    But guess what. The battery is sweating. Either it was this entire time or I just noticed. Didn't get a good photo because I got rid of it at Autozone as soon as possible. That active perspiration/condensation kind of look like a cold glass of water. It was sitting upright in my other car for several hours so it wasn't rain water or something.

    It makes me think when I took the trunk paneling off to practice installing the backup camera whether I introduced a leak. There was a little bit of water, maybe half a cup you know near the water plug in the battery well but I think that's fairly normal. Didn't see water anywhere else. The only other thing that comes to mind is the first day of real cold weather. I commute with a different car and drive this prius like on a weekly rotation so maybe just a few days of being parked and that cold snap....

    Unless I seriously messed up with the trickle charger. Not that I'm aware of
     
    #17 berderder, Dec 30, 2024
    ASRDogman likes this.
(You must log in or sign up to post here.)