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

Get check engine light off, C2300 + P1116 + C1231: Repairs Needed

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Gabriel Begin, Nov 13, 2024 at 1:21 PM.

  1. Gabriel Begin

    Gabriel Begin Junior Member

    Joined:
    Jul 31, 2023
    2
    0
    0
    Location:
    Santa Cruz, California
    Vehicle:
    2009 Prius
    Model:
    Two
    I have a 2009 prius with 285k miles; she has been a reliable car. Me and my wife just had new tires installed.

    I was debating whether or not to let her go, but I found a prius specialist in the bay area and had him inspect her. What he told me agreed with my general sense of things: the car is in great shape for it's age and mileage, but a few things need some work. The registration is due in a few weeks, and I need to get the check engine light off to pass smog in california. He gave me a quote for the repairs he said we necessary to get the check engine light off.

    I know a fair bit about the key pieces of owning a prius and how it works, but am really just a well researched amateur at best. I've done a lot of searching online, but couldn't find any precedents that were similar to my specific situation. I was hoping to get another opinion on the accuracy of his assessment. Any help other knowledgeable members could offer is much appreciated!

    Full Details

    About a year ago, the check engine light would start to turn on intermittently, and now mostly stays on. When this mechanic checked the codes he showed me on his phone and this is what came up on his reader:

    (For some mysterious reason, the battery was low and I had to jumpstart the car with a battery pack right before this appointment)

    C2300
    Actuator system malfunction

    C2318
    Low voltage error (power supply malfunction)

    P1116
    Coolant temperature sensor circuit stuck for coolant heat storage system

    P1121
    Throttle / pedal position sensor / coolant flow control valve position sensor circuit stuck

    C1231
    Steering angle sensor

    C1241 0
    Low battery positive voltage or abnormally high battery positive voltage

    C1242
    Open circuit in ig1/ig2 power source circuit

    According to him, these are the needed repairs and what he quoted me to replace these parts with used / after market parts. According to him, if we repaired the first two there's a good chance that would get the check engine light to turn off.

    Steering Angle spring - 200
    Heater Storage - 425
    Abs brake actuator - 1k


    He and his son owned a well reviewed repair shop in the south bay called hybrid experts, they seem reliable and honest and are well reviewed online. That said, I did get the sense at times that he wasn't telling me the whole story.

    Thanks for any help you can offer!
     
  2. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    10,361
    1,790
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    Before we start the silliness a picture of your dash on a normal daily drive You should have orange lights and possibly a red triangle on Is that what you have? I can't see it from here I can make my car generate these codes easily just by playing with the battery and doing things I just had all these codes on my 2007 yesterday on purpose. You're 12 volt needs to be passed by an authority that knows what they're looking at the 12 volt needs to have AH backing up it's 12V claimed output etc. many Prius folks don't tell whole story. Most people have forgotten most of the stories about this car because they're so reliable in the first 15 years of their lives they've required no work Just tires batteries and a little old lady to sit in the seat and point it. Now 15 years in they're inundated with generation 3s Toyota tacomas Lexus h whatever's and these cars have forgotten about so they have to pull a manual and things out again that they haven't looked at in a long time just for this model because they're not the same as the newer stuff that got the Prius and some trouble the generation 3 mainly everybody's attention is kind of on the threes and the fours and the twos are kind of left alone but every so often the two shows up in a shop and everybody has to run back to their old things to look at to work on this car so you kind of want to be careful in that A lot of times you'll know more about the car than the person you're taking it to that's kind of a serious statement
     
  3. dolj

    dolj Senior Member

    Joined:
    May 14, 2012
    7,854
    3,965
    0
    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    Only the three codes above from your list should be considered for now. (Note: the first two cookie-cutter text phrases are what P1121 means in some other cars, as P1xxx codes are manufacturer-specific codes. It is sheer laziness on the part of the code reader manufacturer to use such a catchall technique.)

    As far as the other codes, you need to sort out the 12 V situation, whether to charge up an otherwise good battery or replace the failing 12 V battery. Testing the battery will give you the direction on that. Once the battery is sorted, you can clear the codes and see which (if any) 12 V-related codes come back.