1. Attachments are working again! Check out this thread for more details and to report any other bugs.

2015 Prius Check hybrid system, won’t start

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Therapydoc, Apr 18, 2023.

  1. Therapydoc

    Therapydoc Junior Member

    Joined:
    Feb 22, 2022
    28
    11
    0
    Location:
    MO
    Vehicle:
    2015 Prius
    Model:
    Four
    2015 Prius that was running great until this morning. Went to start it and I could not get it out of accessory mode. Tried pushing harder on brake pedal and cycling it many times and never would get the ready light. I believe the start button usually lights up green when brake pedal is pushed but I don’t get that green light. Only orange light when accessory turns on. I don’t have the red triangle of doom. I have brake lights that come on so don’t think it would be brake position sensor. Had 12v battery checked and it’s good. I pulled all the fuses and they are fine and all big fuses appear to be okay. I held remote up to start button with Toyota emblem up and tried that with both remotes to no avail. Decided to load it on a trailer and while preparing to push it on I tried to start one more time and I get the ready light somehow. Went ahead and loaded on trailer to take it somewhere but is there anything I can check to see what’s going on.

    since it started, I do have check hybrid system in Notification Center and check engine light.

    Ordered a obd reader and should be here soon to get codes.
     
  2. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,501
    8,413
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    If a car didn't have any symptoms/problems when you shut it down, then the next morning it won't start usually leads me to the 12v battery. Are you sure the connections are good and tight?
     
  3. Therapydoc

    Therapydoc Junior Member

    Joined:
    Feb 22, 2022
    28
    11
    0
    Location:
    MO
    Vehicle:
    2015 Prius
    Model:
    Four
    yup I double checked all the connections, even wiggled everything under the hood to make sure. I took the battery to two places yesterday to have it checked bc I was really hoping that was the issue but both said it was good. One said it was on last quarter of life but currently good. I tried to jumpstart the car with my truck to no avail.

    isn’t the light on the push start button supposed to turn green when you push on the pedal? Mine is not lighting up at all when pedal is pushed until it goes into accessory mode then it’s orange.
     
  4. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
    Jun 6, 2008
    8,277
    4,908
    7
    Location:
    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    So now you ger Ready? It is good to go.
     
  5. Therapydoc

    Therapydoc Junior Member

    Joined:
    Feb 22, 2022
    28
    11
    0
    Location:
    MO
    Vehicle:
    2015 Prius
    Model:
    Four
    attempted to start it again this morning and I’m not getting it ready light anymore again.

    here’s the lights that are on
     

    Attached Files:

  6. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    10,090
    1,738
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    Yes you need code reading DTC codes are in storage if your code reader says they're not it's not the car it's the code reader You will get the code somehow and then you'll go from there That's just the way it has to be when you have 21 computers and all these sensors in a vehicle there has to be intelligent troubleshooting process is followed or not and then things get really lengthy. So if you have lots of time you can go around and round and be lengthy If not then you may choose another route.
     
  7. Brian1954

    Brian1954 Senior Member

    Joined:
    Jan 31, 2021
    1,008
    362
    0
    Location:
    South Central PA, USA
    Vehicle:
    2011 Prius
    Model:
    III
    How old is your 12V battery?

    Do you have a voltmeter to measure the 12V battery? If so, what is the measurement using the voltmeter?

    If the battery is on the last 1/4 of its life, it should be replaced. Check battery prices at your local Toyota dealer and Walmart now sells the battery for about $160.

    Posted via the PriusChat mobile app.
     
    #7 Brian1954, Apr 19, 2023
    Last edited: Apr 19, 2023
  8. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
    Jun 6, 2008
    8,277
    4,908
    7
    Location:
    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    Agree you may have low voltage on 12v.
     
  9. MikeDee

    MikeDee Senior Member

    Joined:
    May 9, 2013
    1,561
    593
    0
    Location:
    San Francisco Bay Area
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Plus
    When my 12v was low, I got a message specific to the 12v, not the hybrid system.
     
  10. Therapydoc

    Therapydoc Junior Member

    Joined:
    Feb 22, 2022
    28
    11
    0
    Location:
    MO
    Vehicle:
    2015 Prius
    Model:
    Four

    Battery showed 12.2 volts when I checked it. I took it to O’Reilly and Autozone and they both tested it good. Testing on 12v setting on multimeter
     
  11. Therapydoc

    Therapydoc Junior Member

    Joined:
    Feb 22, 2022
    28
    11
    0
    Location:
    MO
    Vehicle:
    2015 Prius
    Model:
    Four
    Had former Toyota mechanic tell me to try cleaning cooling fan for batteries so going to try that later today also.
     
    Kasra likes this.
  12. MikeDee

    MikeDee Senior Member

    Joined:
    May 9, 2013
    1,561
    593
    0
    Location:
    San Francisco Bay Area
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Plus
    You need to read the codes and go from there.
     
  13. Therapydoc

    Therapydoc Junior Member

    Joined:
    Feb 22, 2022
    28
    11
    0
    Location:
    MO
    Vehicle:
    2015 Prius
    Model:
    Four
    also would it have started with jumping it off my truck if the battery was bad?
     
  14. Therapydoc

    Therapydoc Junior Member

    Joined:
    Feb 22, 2022
    28
    11
    0
    Location:
    MO
    Vehicle:
    2015 Prius
    Model:
    Four
    Ok that’s on this afternoon list also. Will put them up when I get them
     
  15. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,501
    8,413
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    I've actually seen this happen before, it's not really the fan that's clogged, but the actual filter. That filter is located on the right side next to the rear seat. If you shine a flash light into that filter area, you'll probably see it completely clogged with lint/hair
     
    Therapydoc likes this.
  16. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    56,262
    39,031
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    How did you test it? Multimeter with car off? Dash displayed voltage?
    Did these 2 places only check volts then? Or volts and CCA tested with an electronic load-tester? The latter is worthwhile

    If it's showing 12.2 volts, in a simple voltage test, with the car off, that's not "good", more like near-dead.
     
  17. MikeDee

    MikeDee Senior Member

    Joined:
    May 9, 2013
    1,561
    593
    0
    Location:
    San Francisco Bay Area
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Plus
    That should have allowed the car to start if the 12v had an insufficient charge.
     
    #17 MikeDee, Apr 19, 2023
    Last edited: Apr 19, 2023
  18. Therapydoc

    Therapydoc Junior Member

    Joined:
    Feb 22, 2022
    28
    11
    0
    Location:
    MO
    Vehicle:
    2015 Prius
    Model:
    Four
    That was with car off on multimeter. The two places load tested it with their machines. When jumped with truck was reading 12.7
     
    Mendel Leisk likes this.
  19. Therapydoc

    Therapydoc Junior Member

    Joined:
    Feb 22, 2022
    28
    11
    0
    Location:
    MO
    Vehicle:
    2015 Prius
    Model:
    Four
    Update!!! Got home and cleaned the fan screen and battery cooling fan really well and boom I get my green light and it goes right into ready mode without issue. Knock on wood, that was easy fix.

    checked for codes and it showed no fault codes at all which is weird. Even past history only showed from when I pulled fuses and checked them all.

    You’d think Toyota would have made that screen accessible from the seat side and not have to completely disassemble the rear of the car.
     
  20. Therapydoc

    Therapydoc Junior Member

    Joined:
    Feb 22, 2022
    28
    11
    0
    Location:
    MO
    Vehicle:
    2015 Prius
    Model:
    Four
    Well it happened again. No check hybrid system this time though and no codes. Wife took it to a meeting and when she went to leave it happened again. No green light when brake pedal pushed to get into ready mode. I’m at a loss. Any ideas ? It worked fine for about 5 tries before she left. Does the ignition switch in these ever go bad ?