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battery warning, put prius in park, not neutral, to charge?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by sanma0, Dec 12, 2021.

  1. sanma0

    sanma0 Junior Member

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    hello,

    I hope you've all had a nice weekend. powered up 2009 prius 112k miles, last oil change 4,500 miles ago, no previous issues, to go to the gym today. immediately was greeted with an error message, warning sign on the dash, as well as warning noise when I put the car in drive that the prius must be put in park, not neutral, to charge the battery.

    so I went back, powered the car down, put it into signal check mode. 12.3/12.4 volts without any load; when I put it in accessory mode, 11.8/11.9 volts was the reading. when driving, the car was at 14.1. judging by the accessory mode reading, I assume the issue is that the battery needs replacing; would that be correct?

    thank you so much!

    edit: provided photos of the voltage. would it be of any use to drop by advance auto and have the battery load measured?
     

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    #1 sanma0, Dec 12, 2021
    Last edited: Dec 12, 2021
  2. ChapmanF

    ChapmanF Senior Member

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    The warning message you saw is about the traction battery, not the 12 volt battery.

    The warning is just to make sure you're aware that being in Neutral disables charging of the traction battery. It's ok to be in Neutral for short periods when it makes sense, but you should soon shift to any other position to make sure the traction battery does not discharge too far.

    Little bit of Prius nomenclature: "accessory" mode is what you were in for the first photo; the second one must have been "ON" mode. You get to "accessory" with one power button push, no brake. A second power button push, no brake, takes you from "accessory" to "ON".

    When you push the power button with the brake, you go to READY mode, where you can drive the car, and the 12 volt bus rises to 14-ish.

    If you had not been in accessory mode for the first photo, the display screen would have been dark; you need to be at least in accessory mode for it to power on.

    The voltages you report for the 12 volt battery look quite reasonable to me. There is a bit of load in ACC mode, and 12.3 there is not a matter for great concern. When you proceed to ON, there is more load added, and 11.9 then wouldn't bother me much either, depending on what items in the car were turned on.
     
    #2 ChapmanF, Dec 12, 2021
    Last edited: Dec 12, 2021
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  3. sanma0

    sanma0 Junior Member

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    thank you! I wasn't sure why it came up, as I did not move the gear into neutral. before starting it up today at 5:30pm, I had last driven in ~22 hours ago. edit: would this be indicative of a computer issue? my other thought might be that engine oil may be a contributor—I'm due for one in ~450 miles; should I get this done asap?

    I've included a picture here I just found of the warning light, as I just went for a little spin and the warning did not come on again. here are the new readings on the signal check:
     

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  4. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    Toyota is required to have a neutral position on the shifter. You are never required to use it, and, in general, you never should.

    In N no engine power goes to either motor/generator, so they make no electricity. In some car washes you can run out of HV battery power before you finish the carwash, don't use those carwashes.

    (If your accelerator gets stuck open, it is a good time to shift to N)
     
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  5. ChapmanF

    ChapmanF Senior Member

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    If that happened to me, one time, I would gravitate to the dead-simple explanation that I might have somehow knocked the lever into Neutral without realizing it. I might make a note-to-self like, if this happens again, pay extra attention to whatever I was just doing, and get a picture of the PRNDB on the dash as well as the message on the MFD. (Too bad the PRNDB isn't visible in the photo you've posted here.)

    As for it being "indicative of a computer issue", well, never say never, but humans are a lot more complicated, and have memory and behavior glitches a lot more of the time.
     
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  6. sanma0

    sanma0 Junior Member

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    woops, thank you for clarifying! I'm hoping to test the car again in about an hour to see if the same neutral/park error message comes up.
     
  7. gromittoo

    gromittoo Active Member

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    The car is a 2009, so it is not a Prius v. As a gen 2, it might have the "Extra Info Screen" on the instrument cluster. The picture of the error message might be showing the Instrument Cluster, not the MultiFunction Display (A.K.A. MFD).
     
  8. ChapmanF

    ChapmanF Senior Member

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    I don't remember Gen 2 having an "extra info screen", though Gen 3 does have the MID.

    The fingerprints on the first photo in #3 make it look like the MFD. (Also, I think I'm seeing one bright segment of the VFD speedometer reading up barely above it.)

    People don't usually get many fingerprints on the combination meter, as it isn't touch sensitive, so no real reason to poke at it, and it is so far away to reach.
     
  9. gromittoo

    gromittoo Active Member

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    I never had a Gen 2. Many Gen 3 Prius's had the Extra Info Screen (Higher Trim Levels), but the none of 2012 - 2014 Prius v's had them. I believe the picture displaying the error message is of an "Extra Info Screen", While the others photos showing diagnostic are on the MFD. However, since I have never driven a Gen 2 I could be wrong.
     
  10. ChapmanF

    ChapmanF Senior Member

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    With respect, I think that happened this time; I believe the MID was new with Gen 3.

    Even the latest, greatest 2009 Gen 2 still had the conventional combination meter with the VFD speedometer display and a bunch of indicator lights, no MID.

    nomid.png
     
  11. nancytheprius

    nancytheprius Active Member

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    The same warning also pops up if the driver's door is not completely closed and you go in Drive
     
  12. gromittoo

    gromittoo Active Member

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    I stand corrected. The message that would appear on the MID (if equipped) on a Gen 3, must appear on the MFD on an earlier gen.

    Note that on my 2013 Prius v which has no MID, does not display that message at all. My 2017 Prius v which has an MID displays a similar message on the MID.
     
  13. Another

    Another Senior Member

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    Are you saying that putting a Prius in N for the two minutes or less it takes to go through a car wash is not advised?
    I’ve never seen a drive through car wash that doesn’t require the car to be in N.
     
  14. nancytheprius

    nancytheprius Active Member

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    in the worst case scenario, you can drain your battery too much. I’ve been thru one and my battery was at 2 bars by the end of it. If your car wash is only 2 minutes then you’re probably wasting your money on it. overall, if you turn off AC and monitor the mfd you’ll be fine
     
  15. ChapmanF

    ChapmanF Senior Member

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    Yeah, I wouldn't say I've ever worried about it, but I would try to have the bar graph on the high side before going in, and turn off the A/C and most other optional loads while going through.

    I've mostly been using the spray-it-yourself wash with my Gen 3 though (not because worried, just to clean better). There was a roll-through I used to use more with my Gen 1, and I didn't have to think about the A/C in that case because it wasn't electric.
     
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