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2002 Prius P3009 P3000 and others

Discussion in 'Newbie Forum' started by jtholt, May 27, 2017.

  1. jtholt

    jtholt New Member

    Joined:
    May 27, 2017
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    Vehicle:
    2002 Prius
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    About a year ago the HV battery was failing. We had the battery rebuilt. They reconditioned and replaced the failing cells and cleaned everything up. The person who did the repair said that the cables were in near perfect condition. Now there are new codes. I have the following:

    P0420 (Pending)
    P1436 (Current and History)
    P3000 (Current)
    P3009 (Current)
    C1202 (Current)
    C1259 (Current)

    Any help diagnosing the HV code would be great.

    The problem is the triangle will go away after a few drives and may not come back for a few weeks. So it seems that the HV problem is intermittent. I have no idea how to diagnose it

    I have the freeze frame data from the diagnostic software if any of the data would be useful.
     
  2. ChapmanF

    ChapmanF Senior Member

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    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    P0420 - an impending issue with the effectiveness of your catalytic converter

    P1436 - an issue with the bypass valve just in front of the catalytic converter (these have been known to seize up, if not worked back and forth with some anti-seize lube early in the car's life ... a shiny new one is included in the Toyota front exhaust/catalytic converter assembly.

    P3000 - A code the HV ECU will set, simply to say "the Battery ECU has told me there's a problem." It can have an INF code, which is the HV ECU commenting on what was going on at the time the Battery ECU told it there was a problem.

    P3009 - A code from the Battery ECU (this will be the one it told the HV ECU about, causing the HV ECU to log the P3000). This code means a leak somewhere in the electrical isolation of the HV circuits (both the HV + and - are supposed to be completely isolated from the chassis, and the Battery ECU monitors for any leaks). The leak can be in the battery, the cabling, or the transaxle; you can search the Gen 1 forum for posts on easy ways to tell (in brief, clear the code, then check whether it comes back in IG ON, or not until READY, or not until READY and in gear).

    C1202 - This code is from the brake ECU. Check your brake fluid level. If the level is ok, check the level warning switch. :)

    C1259 - Also the brake ECU. This code just means "the HV ECU has told me there's a problem." This, of course, is second-hand gossip from the Battery ECU telling the HV ECU there's a problem.

    So, you've got an impending exhaust issue, you need to check your brake fluid, and you have an HV electrical leak to track down. The other codes are just repeating gossip.

    Electrical leaks right at the threshold of detection may come and go with humidity, etc., leading to the intermittent behavior you're seeing.

    Of all the places the leak could turn out to be, you'll probably be happiest if it's in the battery; that might be fixed with a thorough washing of all the modules and case. If it's in the wiring or transaxle, you'll probably end up having to replace something.

    Note you should be doubly careful doing any kind of work on the HV system when the ECU is reporting a voltage leak. The designed-in safeties and interlocks normally protect you very well, when everything is isolated the way it's designed to be. There are more wild cards when there is known to be a leak, and especially before you know where it is.

    -Chap
     
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