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A puzzle for you guys (constant 12 volt drainage)

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by SSimon, Jun 14, 2022.

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  1. SSimon

    SSimon Active Member

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    Hi there,

    Long story made short: an auto body shop worked on our '06 prius that had theretofore been running like a dream. I drove off their lot from a simple bumper replacement and the car dash lit up like a Christmas tree. I posted previously with the codes and there were no answers here at Prius chat. Fast forward to current and the car's 12 volt battery continually drains and has to be replaced very sporadically. Sometimes it'll stay charged for 6 months, sometimes longer or sometimes it needs to be replaced more frequently.

    Here's the repair invoice for the body shop's repairs and the diagnostic report that the body shop ran.

    Any ideas what the body shop could have done wrong that would cause the 12 volt to continually go dead?
     

    Attached Files:

    #1 SSimon, Jun 14, 2022
  2. PriusCamper

    PriusCamper Senior Member

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    Unless there's other symptoms or codes its' not related to all the work the auto body shop did... It's a common problem on Prius and you can buy an aftermarket inverter cooling pump for $30 and clamp the hoses and swap it out in an hour or so. Easy fix!
     
    #2 PriusCamper, Jun 14, 2022
  3. SSimon

    SSimon Active Member

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    Why didn't the Toyota techs mention this repair to me? They find nothing wrong with the inverter (not sure if that is the same thing as the inverter cooling pump). Edit: there were subsequently other error codes for which no one on here was able to identify a certain cause.
     
    #3 SSimon, Jun 14, 2022
  4. PriusCamper

    PriusCamper Senior Member

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    That's what your error code indicates... Please go back and look through your paper work. That screenshot of P0A93 usually means to simply replace the pump. But it seems like they're taking a wait and see if symptoms return approach and want to try bleeding air out of the system first.

    Get yourself one of these: https://www.ebay.com/itm/265484403768 so you can use a phone app like Dr. Prius or others to read codes and clear red triangle so you don't get stuck on the side of the road.
     
    #4 PriusCamper, Jun 14, 2022
  5. rjparker

    rjparker Tu Humilde Sirviente

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    Your 12v parasitic draw concern requires a measurement to determine if a problem exists. If it is an excessive drain then further diagnostic steps are required. Usually by isolating circuits via fuses, either by disconnecting or by measuring millivolt drops across fuses.
     

    Attached Files:

    #5 rjparker, Jun 14, 2022
  6. SSimon

    SSimon Active Member

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    We've already been stranded with tow service necessary. What will that device do for me if I'm somewhere far and the car dies out?

    Here are the notes from Toyota and the various codes the car threw since this issue started:

    BATTERY ~|~CUSTOMER STATES VEHICLE WON'T TURN ON. NEC TO JUMP STATRT WAS TOLD THERE IS A DRAW ON BATTERY ~|~SHORTED ~|~198000 BATTERY WOULD NOT HOLD A CHARGE, REPLACED BATTERY TO START. AFTER PARASITIC DRAW TEST FOUND AMPERAGE UNDER 0.050 AMPS WHICH IS WITHIN SPEC ACCORDING TO TIS. ONLY ABNORMAL THING SEEN WAS TERMINALS ARE WORN OUT, WOULD RECOMMEND REPLACING TERMINALS.PA

    BATTERY ~|~CUSTOMER STATES VEHICLE DIED OUT WHILE DRIVING. PRIOR TO VEHICLE TURNING OFF, THERE WAS A HIGH PITCHING WHINING NOISE. SEVERAL M.I.L'S AND MASTER WARNING LIGHT WERE ON. THE DISPLAY AND LIGHTS WERE FLASHING (ON DASH). A "THERE IS A PROBLEM WITH THE TRANSMI ~|~BATTERY FAILED TEST ~|~197467 C-C/S VEHICLE DIED WHILE DRIVING;NUMEROUS MILS CAME ON ALONG W/ A WARNING BUZZER C-AUXILIARY BATTERY FAILED LOAD TEST W/ BAD CELL -CUSTOMER SUPPLIED VIDEO OF CONCERN HAPPENING -REPLACED AUXILIARY BATTERY & TEST DROVE VEHICLE FOR APPROX. 40 MINUTES

    BATTERY ~|~GUEST STATES THERE WAS A HIGH PITCH NOISE AND A BUNCH OF LIGHTS CAME ON ON DASH WHILE DRIVING FOR ABOUT 10 MINUTES, PLEASE CHECK AND ADVISE ~|~DCAQW86UG7WFW0 ~|~186436 REPLACED BATTERY WARRANTY CODE DCAQW86UG7WFW0 PARTS WARRANTY 12/26/2018 RO 923515 MILEAGE 168079

    GUEST STATES AFTER STOPPING TO FILL TIRES UP WITH AIR, PUT VEHICLE IN REVERSE AND ALL LIGHTS CAME ~|~GUEST STATES AFTER STOPPING TO FILL TIRES UP WITH AIR, PUT VEHICLE IN REVERSE AND ALL LIGHTS CAME ON ON DASH AND THERE WAS A HIGH PITCH SCREECHING NOISE PLEASE CHECK AND ADVISE ~|~ ~|~185255 SCANNED VEHICLE FOR CODES, FOUND C1241 AND P0A08 PRESENT. BOTH CODES CAUSED BY LOW VOLTAGE IN HYBRID AUXILIARY BATTERY. TESTED BATTERY WITH HAND-HELD TESTER, BATTERY TESTING GOOD AT THIS TIME. TESTED BATTERY WITH GR8 (TOYOTA TEST), BATTERY PASSED.

    HY AUX.BATTERY ~|~BATTERY FAILED LOAD TEST AND NEED REPLCEMENT ~|~MEASURED AT 176CCA AND RATED FOR 275CCA ~|~REPLACED HYBRID STARTING/AUX BATTERY WITH OEM REPLACEMENT

    Does any of this change your opinion of what could be wrong with the car?
     
    #6 SSimon, Jun 14, 2022
  7. SSimon

    SSimon Active Member

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    I will ask Toyota if the performed this.
     
    #7 SSimon, Jun 14, 2022
  8. PriusCamper

    PriusCamper Senior Member

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    Nothing concerning in any of that writing other than they're usually more eager to take more money from you than this... As for the OBD2 device, it will allow you to read the error codes yourself, take a screenshot of them and text it to your nearest car nerd friend or google it, then clear the code and if code doesn't come back keep driving. There's limits to this problem, mostly heat related, but in general you can keep clearing it till you get home or get to a repair shop, which is way less hassle than waiting for a tow truck.
     
    #8 PriusCamper, Jun 14, 2022
  9. rjparker

    rjparker Tu Humilde Sirviente

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    Your subsequent writeup says they measured the parasitic draw and it was under 50ma. It also says they replaced the battery. Perhaps many times.

    What is hard to decipher is what happened when. Early in the text it was normal, later they say a replacement battery was installed. Try to tell us what happened when in sequence.
     
    #9 rjparker, Jun 14, 2022
    Last edited: Jun 14, 2022
  10. TMR-JWAP

    TMR-JWAP Senior Member

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    Does your Prius have SKS (where you can start the car while the fob is in your pocket) or does it require you to put the fob into the dash slot in order to start the car?
     
    #10 TMR-JWAP, Jun 14, 2022
  11. Georgina Rudkus

    Georgina Rudkus Senior Member

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    Eric of South Main Auto is not working on a Prius, but the technique he used to find the phantom drain might be helpful to the OP.

     
    #11 Georgina Rudkus, Jun 14, 2022
  12. bisco

    bisco cookie crumbler

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    in the meantime, consider a jump box
     
    #12 bisco, Jun 14, 2022
  13. SSimon

    SSimon Active Member

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    Apologies. I’ll log into Toyota tomorrow and repost in sequence.
     
    #13 SSimon, Jun 15, 2022
  14. SSimon

    SSimon Active Member

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    will do. The Toyota technician recommended a trickle charger, too.
     
    #14 SSimon, Jun 15, 2022
    bisco likes this.
  15. SSimon

    SSimon Active Member

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    The car does start with the key in our pocket.
     
    #15 SSimon, Jun 15, 2022
  16. SSimon

    SSimon Active Member

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    Excuse my ignorance, but if the battery does how does clearing the codes keep the car running?
     
    #16 SSimon, Jun 15, 2022
  17. rjparker

    rjparker Tu Humilde Sirviente

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    He is saying some problems and their codes disable the car or put it in a limp home, limited power mode. You "could" override a serious overheating or similar problem temporarily by clearing the code. However when these kinds of things happen its usually better not to risk the consequences. For example the inverter could overheat and it shuts the car down to protect itself. The inverter might cost $2,500 and create a week of downtime. Fixing the root cause would be far better.

    But your demonstrated problem is repeated failed 12v batteries. When a 12v battery goes bad, a side effect can be erroneous codes. There is a possibility that your wreck has caused an intermittent parasitic draw or direct short that kills batteries but is not there all the time.
     
    #17 rjparker, Jun 15, 2022
  18. PriusCamper

    PriusCamper Senior Member

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    It's based on amount of time it takes for car to notice the problem again... On one extreme the red triangle comes up again in one second or faster and it's time for a tow truck. On another extreme you'll clear the code while still driving and it will be many weeks before it comes back again. Somewhere between these too extremes is where the health of your hybrid system currently is.
     
    #18 PriusCamper, Jun 15, 2022
  19. PriusCamper

    PriusCamper Senior Member

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    You're lucky. I tried to do chicken dance with second unworking Fob I bought my 2007 with and lost that function. Been putting the fob into the plug ever since... Still trying to figure out how to get it back!
     
    #19 PriusCamper, Jun 15, 2022
  20. TMR-JWAP

    TMR-JWAP Senior Member

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    Well, that means you have a car with SKS.

    As stated in your paperwork......
    |~MEASURED AT 176CCA AND RATED FOR 275CCA ~|~REPLACED HYBRID STARTING/AUX BATTERY WITH OEM REPLACEMENT

    Then you have the wrong battery installed in your car. The battery you have (275cca) is the battery for a car without SKS. Your battery is supposed to be the S46B24R battery rated at 45Ah and 325 cca.

    Personally, I would start my troubleshooting with fixing the obvious first, and put the correct battery in it.
     
    #20 TMR-JWAP, Jun 16, 2022
    SFO and PriusCamper like this.
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