Intermittent Lights and Codes

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by hoosierprius81, Jan 18, 2021.

  1. hoosierprius81

    hoosierprius81 Junior Member

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    2008 Prius
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    I have a 2008 Prius with ~178k miles on it. I bought it fairly cheaply with ~165k miles on it. It has treated me well and no issues thus far. However, about 2 or 3 weeks ago, I was driving to a friends, and about 100 feet out, the red triangle and a lot of other lights pop up. I baby it into his driveway. I do some research and someone on here recommending checking the oil. I check the oil and it is lower than me (unbeknownst to me it has been burning oil). So, I do an oil change. I had lost my code reader so I was not able to reset the codes, so after a few hours of driving time, the lights all go away. The lights were off for about 3-5 days and then they come back on. So then I start to think this isn't just because of low oil. I check oil anyway and the oil is fine. I get the car home and on my way home, the lights go off. When I got home, I ordered another OBD2 reader (Blue Driver) to replace the one I lost. So while I was waiting on the reader to get to me through the mail, I have to keep driving it because it is my only mode of transit. The lights came and went at an unpredictable interval and pattern. So when I got the OBD2 reader in the mail, the lights came on the next day. So, I scan it, and get codes P0AFA (hybrid system voltage low) and P3000. I have looked on here and on other places and theories and fixes are all over the place. I have read a lot of places that if it truly is the battery the lights would stay on all the time.

    So, does anyone have any ideas on what I should do next or how to proceed?
    Much appreciated.
     
  2. SFO

    SFO Senior Member

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    Here is the workup for DTC P0AFA : https://attachments.priuschat.com/attachment-files/2019/02/161942_2006_Prius_RM_-_DTC_P0AFA_Inspect_Proc.pdf

    Here is the workup for DTC P3000 with the INFs 123, 125, 603 : https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/Prius%20Service%20Manuals%202004/%E4%BF%AE%E7%90%86%E6%89%8B%E5%86%8C/04pruisr/05/21bpm/3000123.pdf

    Here is the workup for DTC P3000 with INF 388 : https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/Prius%20Service%20Manuals%202004/%E4%BF%AE%E7%90%86%E6%89%8B%E5%86%8C/04pruisr/05/21bpm/3000388.pdf

    Here is the workup for DTC P3000 with INF 389 : https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/Prius%20Service%20Manuals%202004/%E4%BF%AE%E7%90%86%E6%89%8B%E5%86%8C/04pruisr/05/21bpm/3000389.pdf

    As you can tell, having the subcode / detail code (aka INF) for the above DTC P3000 might be helpful is tracking down the issue.

    Do you have a DIY mechanical attitude, or would you be relying on someone else to sort out the above issues for you?

    If you feel like digging in, have a look at the HV battery ECU and sensing cable for corrosion :

    [​IMG]

    If you see nothing there, then pop the lid on the battery and take a quick look inside.

    Best not to drive it, or be slow and careful if you do. No sense in making the situation worse before you can sort it out.
     
    Raytheeagle and JC91006 like this.
  3. mr_guy_mann

    mr_guy_mann Member

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    You may want to try another app such as Dr Prius or Hybrid Assistant which should let you retrieve the secondary (INFormation) code to help narrow down what to look at.

    Posted via the PriusChat mobile app.
     
  4. hoosierprius81

    hoosierprius81 Junior Member

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    Thank you for that! I am not opposed to doing some DIY digging of my own. I am looking into getting a reader compatible with Dr. Prius so I can get the INF codes. I am new to the Prius world, so where would I find the HV Battery ECU?
     
  5. SFO

    SFO Senior Member

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    Here is a decent guide (for installing the HA Prolong reconditioning cable) that can be used to find your way, follow the pictures up to step #14 (removing the hybrid battery junction cover), and you should be able to find the ECU and associated cable after that.

    If disconnecting the 12v, you may need to clean the MAF sensor (unless already cleaned) as the mapping will reset to factory default.

    If you like videos, there should be plenty out there on how to remove / replace / rebuilding a HV battery.
     
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