Strange Combination Meter Issue?? Just The Speedo is Missing

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by cre8er, Jul 16, 2020.

  1. cre8er

    cre8er Junior Member

    Joined:
    Sep 4, 2016
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    Location:
    Usa
    Vehicle:
    2007 Prius
    Model:
    ----USA----
    Symptoms:
    1: Speedometer on Combo meter is missing
    2: VSC, ABS, Skid Lights On
    3: Can't shift into gear or drive
    4: Ready light is red
    3: After a while the red triangle hybrid battery codes come on.
    4: Clearing codes with techstream and resetting with battery disconnect works exactly once, then the same symptoms always come back.
    5: Also the CD changer is failing the System check on the center display and won't eject CD's

    It should be noted that this all started with a normal failure of the combo meter where it turned off and the car would not shut-off. That problem has never returned and I have replaced the 100uF capacitor on the combo meter display board.

    The weird thing is that everything works great the first time you turn it on after reset, hybrid batter cells look good, no codes, Techstream looks happy, no symptoms at all. The instant you turn it off and back on again, this issue comes back.

    I've read about every combo meter thread and every mention of no speedometer and no one has a resolved issue or solution.

    Techstream codes:
    ABS/VSC/TRAC - C1259
    C1310
    Air Conditioner - B1421
    Hybrid Control - P0AA6

    The standard P0AA6 Hybrid code doesn't come on until after a while and I'm well versed in diag of the battery pack. All 14 cell blocks are within .2V of each other and charge and discharge normally. I have replaced multiple cells (6) in this pack.

    Open to all suggestions and troubleshooting tips.
    See attached Techstream report
     

    Attached Files:

  2. cre8er

    cre8er Junior Member

    Joined:
    Sep 4, 2016
    2
    0
    0
    Location:
    Usa
    Vehicle:
    2007 Prius
    Model:
    ----USA----
    After more diag, here is what I have decided:
    It is in fact a Hybrid Battery Issue.
    The P0AA6 is a subcode 1: 526 Subcode 2: 612 error
    The fact that it coincided with a combo meter failure is a cooincidence.

    We are gonna get some new cells in and pull the battery.
    Things to check with the 612 subcode:
    1: Leaking battery cell
    2: Hybrid Battery Main Relays (Check ohms on switch side and check for open continuity on the power leads)
    3: Connections at the Hybrid Battery ECU. I've been told to inspect the harness pins carefully for burning & corrosion.

    I will report back.
    This is my girlfriend's car so a lot of what I was going on is what she has explained to me, It took all day to decide this is probably the real issue.
     
  3. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    15,013
    7,689
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    Location:
    Los Angeles, CA
    Vehicle:
    2010 Prius
    Model:
    V
    There is nothing wrong with your speedometer, the car is just not starting because of P0AA6.

    So if you disconnect the 12v for 10 seconds and try to start again, it should start the car and your speedometer will appear. This will only work once since you have the P0AA6 error code.

    Chances are you have a leak in the HV battery, possibly a module you put in to fix it. That P0AA6 could be in many areas, but HV battery is where I would look first (since you messed with it)
     
    Raytheeagle likes this.
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