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

Driver Door Actuator / 12v Aux Battery Issue?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by scottjm, Dec 2, 2019.

  1. scottjm

    scottjm Junior Member

    Joined:
    Dec 26, 2017
    14
    2
    0
    Location:
    Omaha
    Vehicle:
    2010 Prius
    Model:
    Two
    I have a 2010 Prius with just over 140k miles. So far, this has been a very low-maintenance vehicle.

    Last week, I noticed my driver door wouldn't lock with the key fob, driver door / finger thing (exterior), nor the door lock button on the inside of the door. It would lock manually.

    I troubleshot this issue a bit using forums online and it seemed to be the door lock actuator. I also saw on some forums that replacing the 12v Aux battery may resolve the issue so I started there.

    I replaced the 12v Aux battery as my 2010 Prius had the original 12v Aux battery (manufactured in 2009!), I was pretty impressed it lasted that long. Before I did - I checked it on the display (by pressing and holding the "info" button, putting the vehicle in ACC mode, and turning on/off the headlights 3x). The battery read ~10.8-10.9v. I took my car to a local Autozone where they tested it and their diagnostic tool said to replace it. So, I replaced it with one of their Duralast Platinum Battery. I then drove my vehicle to my hotel and parked it on Wednesday night last week (I'm at training for work). The vehicle sat in the hotel parking lot over the long Thanksgiving weekend.

    This morning (Monday), I went to unlock my door and nothing happened. None of the doors unlocked. I used the hard key (please correct my verbiage/term) to open the driver door. The battery was dead. I noticed that the interior dome lights were on but extremely dim. I got a jump (it didn't seem to work on the connection at the fusebox under the hood and I had to go through the back door to the battery itself with the jumper cables as the lift gate wouldn't open since it needed power) and it worked when I connected the jumper cables directly to the battery terminals.

    After driving it around a bit, the door now unlocks / locks using the key fob and outside finger lock thing (again - please correct my verbiage / term).

    Over the weekend, I ordered a new actuator but am unsure if I even need to replace it.

    My hunch as to why the battery was depleted was that the car was trying to lock the driver door all weekend, but don't know much about the subject.

    Do you guys have any other ideas as to why the battery died, or if I did anything wrong with any of the above?

    Interested to hear your thoughts!
     
  2. tankyuong

    tankyuong Senior Member

    Joined:
    Nov 9, 2012
    1,555
    659
    0
    Location:
    Central MO
    Vehicle:
    2012 Prius c
    Model:
    II
    Parasitic drain
     
  3. NutzAboutBolts

    NutzAboutBolts Senior Member

    Joined:
    Mar 5, 2013
    1,478
    1,553
    0
    Location:
    Bay Area
    Vehicle:
    2012 Prius
    Model:
    Four
    if everything worked before the old battery was replaced, then its just a battery issue. Does all the door lock and unlock with the key fob? any car accident history?
     
  4. scottjm

    scottjm Junior Member

    Joined:
    Dec 26, 2017
    14
    2
    0
    Location:
    Omaha
    Vehicle:
    2010 Prius
    Model:
    Two
    Thanks for the reply! What is that? Is it normal to happen on a brand new battery (manufactured a month ago)?
     
  5. scottjm

    scottjm Junior Member

    Joined:
    Dec 26, 2017
    14
    2
    0
    Location:
    Omaha
    Vehicle:
    2010 Prius
    Model:
    Two
    All the doors lock / unlock now. The vehicle was in a collision a few years ago when someone ran a stop sign. Front drivers side panels needed replacing.
     
  6. tankyuong

    tankyuong Senior Member

    Joined:
    Nov 9, 2012
    1,555
    659
    0
    Location:
    Central MO
    Vehicle:
    2012 Prius c
    Model:
    II
    Means something is draining battery when it shouldn’t when engine off
     
  7. NutzAboutBolts

    NutzAboutBolts Senior Member

    Joined:
    Mar 5, 2013
    1,478
    1,553
    0
    Location:
    Bay Area
    Vehicle:
    2012 Prius
    Model:
    Four
    probably just a bad battery, some stores battery just needs a good charge by driving around for a long time since the battery has been sitting on the shelf for a while. Sometimes it’s just a bad battery that was bought and just need a replacement.
     
  8. scottjm

    scottjm Junior Member

    Joined:
    Dec 26, 2017
    14
    2
    0
    Location:
    Omaha
    Vehicle:
    2010 Prius
    Model:
    Two
    okay. I think have Autozone check it.
     
  9. scottjm

    scottjm Junior Member

    Joined:
    Dec 26, 2017
    14
    2
    0
    Location:
    Omaha
    Vehicle:
    2010 Prius
    Model:
    Two
    I’ve noticed (after driving about 50 miles) that my MPG has gone down from ~49 mpg to ~44 mpg. Would this issue be contributing to this?
     
  10. Hasib

    Hasib New Member

    Joined:
    Nov 29, 2023
    11
    1
    0
    Location:
    Kabul
    Vehicle:
    2010 Prius
    Model:
    N/A
    Auxiliary battery 12 volt with 28Ah

    Hello I hope everyone is doing well,
    I have Prius 2010 model, sometimes my prius become wild like it’s not going in ready mode the dashboard says: “Auxiliary battery
    (For starting) Insufficient charge Please check the instruction manual” even though the lights are not dim but after to three attempts my speedometer become blurry and weak also my internal lights and one side of the speedometer which shows traction battery become blank and after some time it came back.
    but when I unplug the positive terminal from 12 volt battery after 2 or 3 times attempting it finally works (ready mode). Is that a problem of 12 volt battery? If it is so why when I unplug the auxiliary battery and sit for 5 minutes then I plug back after 2 or 3 attempts it finally get In ready mode? My auxiliary battery is 28 Ah. Some people told me that it’s getting winter and cold the battery is old and you need to replace it. For example last night I was on a wedding party and I parked the car in open parking it did the same thing then I unplugged the 12 v battery terminal and sit for few minutes then plug it back and got in ready mode. But when I came back to my apartment and my parking is in underground of the building and when Woke up in the morning it get in ready mode probably my parking is warm I have no idea. Do you guys think it’s my 12 v battery? Any advise is appreciated
    Thanks…
     
  11. ASRDogman

    ASRDogman Senior Member

    Joined:
    May 29, 2018
    5,783
    3,114
    0
    Location:
    Florida
    Vehicle:
    2010 Prius
    Model:
    Two
    It's better to disconnect the negative cable.
    How old is your battery? Is it a toyota battery?
    What is the voltage? After sitting and before opening the drivers door?
    What is it when you disconnect the negative terminal?

    28ah's sound very low. If they battery is 6-7 years or older, probably time for a new one.
    Toyota's OEM one is the best, but there are others. Just make sure you charge it at 4amps
    or less for about 8 hours. Stores do not charge them, they just sit on the shelves until sold.