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Issues after ac compressor changed

Discussion in 'Gen 2 Prius Technical Discussion' started by caramel_cookie, Apr 1, 2017.

  1. caramel_cookie

    caramel_cookie New Member

    Apr 1, 2017
    Victoria, Australia
    2006 Prius
    Hoping to get some help with my 2006 prius. I have just recently had a reconditioned ac compressor put into my prius however, not long after my car has warning lights coming on.

    Before I get into more detail note - the HV battery has under 12 months ago had a battery with reconditioned cells put in and was tested and running fine.

    I got:
    • Master warning light
    • Brake system warning light
    • Hybrid system warning light
    What happened next - manage to get my car home and run diagnostics and I get High Voltage fault code POAA6. Turn the engine off and next thing I get is that the car won't go into READY mode.

    Mechanic number 1 - cleared the codes and told me its fine to go not. Drove the car for 70 kilometres with the ac going and again, same warning lights came back on. Ran diagnostics and same error code POAA6 and again won't READY after I turned the engine off. I still recon it's the AC compressor that was put in. I decided Mechanic 1 didn't really know what he was doing so got someone else.

    So - off to MECHANIC 2. MECHANIC 2 cleared the codes and I did stress to them that I think it's the ac compressor but told me it was fine and doesn't physically appear to have an issue. Drove it, warning lights came own, same code came up and won't READY again. MECHANIC 2 came back a second time told me he was certain it was the 12V battery this time around

    My mechanic ran tests on my 12V aux battery and said that he think it might be that as it was reading low. I didn't think that was the issue since it was reading 11.8 to 12.1 at the time but since it was old anyway, we replaced the 12V battery.

    You'd think 3rd time luck right, but no. Around another 70 kilometers, the same warning lights, the same POAA6 code.

    What do I do now? FYI I'm an asian girl with a retired mechanic dad so I know bits and pieces about cars. But no-one wants to listen. I do just bite the bullet and take it to a dealership or does anyone know a good hybrid mechanic in Australia, victoria who will actually listen?
  2. uart

    uart Senior Member

    Sep 7, 2009
    2005 Prius
    Hi Cookie. That code is a high voltage isolation fault, basically a ground fault somewhere in the high voltage system.

    The compressor in the Prius aircon operates from the HV battery, so given that the fault codes appeared very soon after the compressor replacement then yeah, it's very likely that there was a fault in the replacement compressor.

    Having such a recently refurbished HV battery does muddy the waters somewhat though. The isolation fault could also be in the HV battery or the transaxle as well. I think that there may be a subcode under the POAA6 that can perhaps narrow it down a bit.
  3. strawbrad

    strawbrad http://minnesotahybridbatteries.com

    Aug 9, 2011
    2005 Prius
    You could try unplugging the big orange cable to the AC compressor. That will take the AC compressor out of the system. Disconnecting and reconnecting the 12 volt battery will allow the car to restart once after the P0AA6 appears. There is a test for determining the source of the high voltage leak. Since your car still takes 70 kilometers to produce the code the test will be ineffective. Once the problem returns immediately the test will work.