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

Check Hybrid System after blown 12v fuse

Discussion in 'Prius c Technical Discussion' started by Pri3C, Mar 20, 2021.

  1. Pri3C

    Pri3C Active Member

    Joined:
    Apr 4, 2020
    171
    122
    0
    Location:
    Midwest
    Vehicle:
    2014 Prius c
    Model:
    Two
    I got this inverter from Amazon to power a few things on road trips. Last night I plugged it into the “cig” slot to test and it blew the fuse right away. So I located and replaced the fuse and the 12v plug is working again. I didn’t drive the car, just turned it off after confirming it had power. Today I go to turn on the car, it goes to “ready” but then I get the “Check Hybrid System” message. I haven’t ran the codes yet, but I’ll do that next and post soon. Hoping it’s just the 12v battery. Any insight or help would be very much appreciated :(
     
  2. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

    Joined:
    May 12, 2018
    6,686
    6,375
    1
    Location:
    Pennsylvania
    Vehicle:
    2018 Prius c
    Model:
    Two
    No obvious link between these events.

    Cig lighter receptacle under the dash is only good for about 120W, and with inverter inefficiency that might only be 100W for real.

    You can wire in another receptacle with heavier feed wire to support running that inverter at full load.
     
  3. Pri3C

    Pri3C Active Member

    Joined:
    Apr 4, 2020
    171
    122
    0
    Location:
    Midwest
    Vehicle:
    2014 Prius c
    Model:
    Two
    Thanks for your reply. I think it’s possible there is a link as it happened right after this event
     
  4. Pri3C

    Pri3C Active Member

    Joined:
    Apr 4, 2020
    171
    122
    0
    Location:
    Midwest
    Vehicle:
    2014 Prius c
    Model:
    Two
    Dr. Prius gave me a P0A0F code. Attaching a screenshot from the app showing the voltage readings today. I’m not going to start it again, except to maybe get it out in the street for a AAA tow. @Leadfoot J. McCoalroller you may be right about this being a coincidence.
     

    Attached Files:

    #4 Pri3C, Mar 20, 2021
    Last edited: Mar 20, 2021
  5. Pri3C

    Pri3C Active Member

    Joined:
    Apr 4, 2020
    171
    122
    0
    Location:
    Midwest
    Vehicle:
    2014 Prius c
    Model:
    Two
    Well I guess I’m in this alone then, but I’m going to keep updating this thread with my progress.

    I tested my hybrid battery on Dr. Prius when I bought this car last April and it gave it 88% life expectancy, but I do remember it mentioning something about a weak block, so there may be something there to address (not sure if I’d be up to that).

    According to this video, hybrid battery failure on its own will not cause the P0A0F code the Dr.Prius app gave me yesterday.. so I’m going to clean the MAF sensor first, and if that doesn’t work I’m going to order a cable and hopefully install the techstream software to get more details about what’s going on, instead of rushing to tow it to the dealership tomorrow.

    I inspected my engine pretty good with a flashlight today (just wiped it clean recently, too) and see no signs of rodents.

    When I had this car inspected last year they told me the car had no code history, and I take very good care of it.
     
    #5 Pri3C, Mar 21, 2021
    Last edited: Mar 21, 2021
  6. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

    Joined:
    May 12, 2018
    6,686
    6,375
    1
    Location:
    Pennsylvania
    Vehicle:
    2018 Prius c
    Model:
    Two
    You're not completely alone, I don't know anything about the app you're using though, so that part is all you. :whistle:

    It says you've got a weak block or two. There isn't a lot you can/could have done about that. Keeping the cabin cool (use lots of AC) and keeping the battery cooling fan clean is all it takes to dodge most battery problems.

    Any chance the warranty is still in effect there? In some states that's 8 years/100k miles.
     
    Bazzle and Pri3C like this.
  7. Pri3C

    Pri3C Active Member

    Joined:
    Apr 4, 2020
    171
    122
    0
    Location:
    Midwest
    Vehicle:
    2014 Prius c
    Model:
    Two
    Thanks for hanging in there with me @Leadfoot J. McCoalroller !

    I checked the fan yesterday and it’s looking pretty clean and clear to me. Vacuumed it last April, but maybe I can take the top part off and go a little deeper with the cleaning.

    I do run the air (usually on low is all I need) pretty consistently in the warmer months.

    If it ends up being the hybrid battery, I will definitely be looking into a warranty claim if one is possible. I bought it used from a Toyota dealership, but the battery should be warrantied through 2022 or 100k, like you said. The car currently has 65k miles on it.
     
  8. topshot

    topshot Member

    Joined:
    Feb 9, 2017
    141
    56
    0
    Location:
    Midwest
    Vehicle:
    2015 Prius c
    Model:
    Three
    0.05 voltage difference between max and min voltage seems pretty good to me, especially of that age.

    Might look into fuel pump operation such as this person (who had run his battery dead while using an inverter). Perhaps a relay got damaged before fuse could blow?
     
  9. Pri3C

    Pri3C Active Member

    Joined:
    Apr 4, 2020
    171
    122
    0
    Location:
    Midwest
    Vehicle:
    2014 Prius c
    Model:
    Two
    Thank you for the link and suggestion @topshot

    I can’t seem to find a fuel pump relay that’s listed as working with my 2014 model. This one says it’s compatible with 2019 & 2018 Prius C, but when I select 2014 it tells me it doesn’t fit. Oh well, I suppose the part number will be on the relay if I need to replace it. Thanks again.

    I’m going to clean the MAF sensor tonight. Hopefully I can do a scan for codes via techstream by midweek.
     
    #9 Pri3C, Mar 22, 2021
    Last edited: Mar 22, 2021
  10. topshot

    topshot Member

    Joined:
    Feb 9, 2017
    141
    56
    0
    Location:
    Midwest
    Vehicle:
    2015 Prius c
    Model:
    Three
    There should be a secondary code that may provide a little more info on why the engine won't start (or remain running). It wasn't clear to me if yours actually does start and then dies after 10-15 seconds. If it does start then it wouldn't be a fuel pump relay.
     
  11. Pri3C

    Pri3C Active Member

    Joined:
    Apr 4, 2020
    171
    122
    0
    Location:
    Midwest
    Vehicle:
    2014 Prius c
    Model:
    Two
    Yes, the ICE came on like normal for 10-15 seconds on Saturday morning, then stopped and displayed the hybrid system warning message. I started it 2-3 times, and I’m not going to do it again until I’ve scanned for codes and ideally have a fix in place.

    Right now I’m betting this is somehow connected to the power surge I caused, but we’ll see. Just trying to chalk this up to being an opportunity to learn more about the car and hoping it’s something I can manage on my own.
     
    #11 Pri3C, Mar 23, 2021
    Last edited: Mar 23, 2021
  12. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

    Joined:
    May 12, 2018
    6,686
    6,375
    1
    Location:
    Pennsylvania
    Vehicle:
    2018 Prius c
    Model:
    Two
    Good catch. I think I already established that I'm not good at interpreting the dr. prius app, but if there was any doubt...
     
  13. Pri3C

    Pri3C Active Member

    Joined:
    Apr 4, 2020
    171
    122
    0
    Location:
    Midwest
    Vehicle:
    2014 Prius c
    Model:
    Two
    Since my cable for the techstream software didn’t come today, I decided to disconnect the 12v & hybrid batteries and clean the MAF sensor. No luck for any quick fixes there, unfortunately. I feel like almost every single error light is on when I start the car, ICE comes on for a second, then the hybrid system warning.

    Hopefully I can get the codes tomorrow and a better indication of what the issue is, or I’ll be towing it to the service center on Monday
     
  14. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

    Joined:
    May 12, 2018
    6,686
    6,375
    1
    Location:
    Pennsylvania
    Vehicle:
    2018 Prius c
    Model:
    Two
    Well, people wouldn't stop driving them when just the one light came on, so they changed the artwork to make it scarier. Many car brands did the same starting around 2010.
     
    Pri3C likes this.
  15. Pri3C

    Pri3C Active Member

    Joined:
    Apr 4, 2020
    171
    122
    0
    Location:
    Midwest
    Vehicle:
    2014 Prius c
    Model:
    Two
    Ok I managed to get Techstream up and running today and checked Hybrid Control & Engine and ECT for codes:

    Hybrid Control:
    P0A0F: Engine Failed to start

    Engine and ECT:
    P0353: Ignition Coil “C” Primary/Secondary Circuit

    There are other codes displayed, but P0353 is the only code with the blue icon next to it on the left (please see attached image and you’ll understand what I’m talking about), so this means it’s only showing an error for coil C, right?

    Reading more about the issue here, I think it’s possible that when I plugged that stupid inverter into the 12v socket and the fuse blew, it shorted the wiring connected to this coil.

    Any other insights on how to proceed?
     

    Attached Files:

  16. Pri3C

    Pri3C Active Member

    Joined:
    Apr 4, 2020
    171
    122
    0
    Location:
    Midwest
    Vehicle:
    2014 Prius c
    Model:
    Two
    Can someone with a little Techstream knowledge tell me the significance of the blue icon to left of the code in the images I’ve attached? I did a few searches and found no answers. Is it highlighting the bad ignition coil? I swapped coils this morning and the icon moved to the new coil.

    462DD9B1-B1E5-4F6E-A69D-E192C3942BF4.jpeg
     
  17. Pri3C

    Pri3C Active Member

    Joined:
    Apr 4, 2020
    171
    122
    0
    Location:
    Midwest
    Vehicle:
    2014 Prius c
    Model:
    Two
    I finally got my car to the Toyota service center on the most appropriate of days (April 1), because this fool apparently pulled the fuse for the ignition coils and put it a back in a blank slot. Yup, that’s it, that’s all that was wrong with my car. Initially I thought the fuse box I needed to access was the one under the hood.. so yeah.. I feel like a total idiot.

    Oh well, live in learn. At least it’s been a very educational week and a half.

    Now I know how to:

    Clean the MAF sensor.
    Change ignition coils and spark plugs (didn’t do the plugs but I know I can swap 'em out with no problem)
    Change the engine air filter
    Clean the throttle body
    Change the 12v battery (I removed it to charge and had it tested at Autozone.. it’s a 6.5 year old battery and it’s still good!)
    And I have techstream.

    I got 53 mpg on the way home. Happy “Christine” is alive and well again and ready for spring!
     
    Bazzle likes this.
  18. topshot

    topshot Member

    Joined:
    Feb 9, 2017
    141
    56
    0
    Location:
    Midwest
    Vehicle:
    2015 Prius c
    Model:
    Three
    I'm quite curious how your ICE ran for even 10 seconds at a time without any spark.
     
  19. Pri3C

    Pri3C Active Member

    Joined:
    Apr 4, 2020
    171
    122
    0
    Location:
    Midwest
    Vehicle:
    2014 Prius c
    Model:
    Two
    Wish I could give you an answer. It definitely kept starting up, no power to move the car, then dead with the “check hybrid” message.
     
  20. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    23,064
    14,970
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    Prius engines crank at the same RPM conventional cars' engines idle, so to most ears, cranking in a Prius sounds like starting, and an engine that cranks for ten seconds and gives up because it never started is reported on PriusChat as "started every time, ran for ten seconds, then died" by nearly absolutely everybody, as the vast number of threads here with close variations on that wording will confirm.
     
    Pri3C likes this.