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

  1. David Mc

    David Mc Junior Member

    Joined:
    Aug 22, 2019
    3
    0
    0
    Location:
    Indiana
    Vehicle:
    2004 Prius
    Model:
    One
    Driving the other day and all my warning lights came on. Car seem sluggish and after stopping i shut the car off and tried to start it again,nothing. The ready light wont come on at all so I had it towed home. The ready light not coming on seems to be something new for me as I've had main battery issues before and replaced it just 5 months ago along with the 12v. Main is a Greenbean replacement.
    Thanks in advance for any advice
     
  2. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,464
    8,377
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    You would need to check the codes on the car to know the problem. If you experienced sluggishness and the car didn't just shut down while driving, then you most likely have a HV Battery issue. If the car just shut down without the sluggishness feeling, then you would most likely have an inverter pump that shorted.

    Either way to eliminate the inverter pump issue, you can check the engine compartment fuse marked "AM2", if that fuse is blown, then your inverter pump has failed. I do not think this is the case as you mentioned the sluggishness.

    The car not starting again may mean it's a P0AA6 error, which is usually a high voltage isolation error (like a leaking module in the battery pack). You can start the car if you disconnect the 12v battery and reconnect. That reset should allow you to start the car 1 time, and then it'll get disabled again.
     
    #2 JC91006, Aug 22, 2019
    Last edited: Aug 22, 2019
    Aegean, Skibob and SFO like this.
  3. Skibob

    Skibob Senior Member

    Joined:
    Sep 14, 2018
    2,912
    1,494
    0
    Location:
    Northern California
    Vehicle:
    2006 Prius
    Model:
    N/A
    If you find it is the battery, you disconnect the 12v and it starts, at least you will be able to drive it to a mechanic or the dealer, and pay for a diagnostic that says the battery is bad. You won’t have to have it towed there. Then you can get a replacement under your warranty. Bet you didn’t know about that part of your green bean warranty.
     
    JC91006 likes this.
  4. sam spade 2

    sam spade 2 Senior Member

    Joined:
    Mar 31, 2018
    7,035
    2,780
    0
    Location:
    USA
    Vehicle:
    2017 Prius c
    Model:
    Four
    Things need to be tested.
    Starting with the 12 V battery.
    Things that are "new" sometimes fail too.
     
  5. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    call greenbean
     
  6. TMR-JWAP

    TMR-JWAP Senior Member

    Joined:
    Aug 12, 2016
    6,058
    5,783
    0
    Location:
    Columbia, SC
    Vehicle:
    2007 Prius
    Model:
    Touring
    A bit of clarification...and this is assuming the dash indicators lit up brightly and the 12v is fine.

    The best thing you could do right now is to get the actual codes read. Preferably with a hybrid capable scanner, so it reads TRUE codes.

    If the dash was lit with warning lights, the AM2 fuse is intact. Loss of the AM2 results in total loss of the dash and MFD. They go BLACK.

    If the car will not "ready" even after cooling off, then it's not the inverter cooling pump. If the car will go ready after cooling down, then it likely was an inverter over temperature issue.

    If the 12v battery is disconnected for a minute or two, it will reset the ECU codes. If the car will "ready" following this, then there's a good chance there's an HV isolation issue, with the battery typically being a leading cause. Unfortunately, there's always other causes possible.

    But...the best option, if possible, right now is to get an accurate code reading...if not possible, then disconnect the battery and see if the car will go.
     
    Skibob likes this.
  7. David Mc

    David Mc Junior Member

    Joined:
    Aug 22, 2019
    3
    0
    0
    Location:
    Indiana
    Vehicle:
    2004 Prius
    Model:
    One
    whats the best way to disconnect the 12v,pull the plugs or the neg terminal?
     
  8. David Mc

    David Mc Junior Member

    Joined:
    Aug 22, 2019
    3
    0
    0
    Location:
    Indiana
    Vehicle:
    2004 Prius
    Model:
    One
    I pulled the am2 fuse and checked it and it was good. Then pulled the 12v plugs and drove to Advance auto to get it scanned,no codes found. Went for a 25 mile drive and no lights. Scratching my head as to what happen. Any thoughts?
    Also thanks guys for all the imput,didnt know about the fuse or that disconnecting the 12v would help get going for awhile. I Learned something.
     
  9. TMR-JWAP

    TMR-JWAP Senior Member

    Joined:
    Aug 12, 2016
    6,058
    5,783
    0
    Location:
    Columbia, SC
    Vehicle:
    2007 Prius
    Model:
    Touring
    David,

    Unfortunately, disconnecting the 12v is a two edged sword. It will clear all codes and sometimes get the car going again, but once the codes get cleared, you have no way of finding out what they were until it happens again.

    Glad to hear you're rolling again.

    Don't forget this from post #6

    If the 12v battery is disconnected for a minute or two, it will reset the ECU codes. If the car will "ready" following this, then there's a good chance there's an HV isolation issue, with the battery typically being a leading cause. Unfortunately, there's always other causes possible.
     
  10. sam spade 2

    sam spade 2 Senior Member

    Joined:
    Mar 31, 2018
    7,035
    2,780
    0
    Location:
    USA
    Vehicle:
    2017 Prius c
    Model:
    Four
    What are these "12 V plugs" that you are talking about ?
     
  11. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    23,073
    14,980
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    Gen 1 and Gen 2 had handy unpluggable connectors at the battery positive clamp. Went away in Gen 3.

    I'm with TMR-JWAP ... happens again, read the trouble codes before erasing them.
     
  12. lunacyworks

    lunacyworks Member

    Joined:
    May 13, 2015
    114
    41
    7
    Location:
    SF Bay Area
    Vehicle:
    2008 Prius
    Model:
    II
    Unfortunately, I just had this issue too. I was swapping out the tranny fluid for someone else and they used my car and let the 12v battery die (left light on).

    I replaced the 12v battery and thought everything was fine. Now a couple days later getting
    p0aa6 -526 subcode (was also getting 612)
    c1310
    c2124
    b1271

    Thought there was a losse connection when swaping out 12v. But now having combo meter issues as well.

    I pulled the disconnect on the HV battery and had a look for any leaks but didn't see anything. Also looked under hood at inverter and connection.

    The strage thing at 149k I had a very similar issue and replaced the 12v and took it to the Toyota dealership at first they said tranny, hv interver, battery all needed to be replaced. Then a day later they claimed nothing was wrong.

    This was of course near the Grapevine in California and it happened on the way down the pass. I figured if there was anything wrong with the car that would make it show up. Anyway it's been 2 years and now the car is 230k and first time this problem.

    I have attached my scan files here: There are 3 times, the scan from a bad 12v, the scan right after the new battery was installed and the person drained it again (yes 2 times in a row) they were confused by the Door option on the light and they own a Prius ! (Although their cabin light was blown.). The last is today after the issue cropped back up again.

    I am pretty sure all the other codes are just results of the primary. To me I think it's a loose connection somewhere since the Combo is on an off and I just started used the smart key option (turn on the button under the steering wheel).

    At this point, the next step is to pull the combo meter and replace the problematic cap to remove it as an issue source. I think i have a good working one around somewhere anyway. After that pull all the cables to the inverter (oh the pump and inverter was replaced at 150k as preventative ) measure.

    Other things that happened that caught my attention.
    1. I have a dash cam that was unplugged, I had just plugged it back in when 1 minute later this issue popped up.
    2. A day ago after i thought everything was fine and the car was running fine. I put the rear cover storage back in the car. The next time I tried to start I had issues.

    So the one thing all these things have in common is I could be causing a communication problem in the system and some wiring is just marginal and I am pushing it over the effective noise limit and causing communication issues on the CAN bus.
     

    Attached Files:

    #12 lunacyworks, Aug 30, 2019
    Last edited: Aug 30, 2019