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2005 prius will not start but 12v battery seems to be working

Discussion in 'Gen 2 Prius Technical Discussion' started by geo2000, Dec 22, 2019.

  1. geo2000

    geo2000 New Member

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    Good day all. My prius will not start. My smart key works because it unlocks and locks my 2005 prius. Also, my head lights, brake lights, emergency lights, dome lights all work. However my prius will not start. When I put the smart key in the key slot and press the brake pedal then press the power button, the prius will not start. Also, I notice the power button light does not come on almost like it does not sense the smart key at all. But like i have mentioned before the smart key unlocks/locks the car doors. I changed the battery on the smart key but the prius still will not start. Any advices are well appreciated.
     
  2. bisco

    bisco cookie crumbler

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    worth taking a deeper dive into the 12v. how old is it? check all the connections.

    also, make sure the brake lights are on when you push the start button.

    did you lose the rfid chip when you changed the fob battery?
     
  3. sam spade 2

    sam spade 2 Senior Member

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    "Seems to be working" is not good enough. The battery needs to be tested.
    Then....have you tried the spare remote ?
    You HAVE a spare remote......right ??
     
  4. geo2000

    geo2000 New Member

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    Good day everyone. I did have the battery checked at auto zone. They said it was fine. Like I said the smart key works. The brake lights work. Head lights work. Dome lights work. I checked all fuses they are good. However when I press the power button it will not even engage in assessory mode. The power button light does not even light up like it does not sense the sense smart key even though it works to unlock/lock the car doors. Unfortunately I do not have a spare smart key. Before I invest in a new battery and/or smart key I like to know if there is any fuses or relays or something that I should look at that powers the starter button. As I've mentioned before the power button does not seem to sense the smart key.
     
    #4 geo2000, Dec 23, 2019
    Last edited: Dec 23, 2019
  5. geo2000

    geo2000 New Member

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    Also 12v battery is about a year old from toyota so I do not think that is the problem but I could be wrong. Also can a smart key malfunction even it still unlocks/locks the car doors?
     
    #5 geo2000, Dec 23, 2019
    Last edited: Dec 23, 2019
  6. SFO

    SFO Senior Member

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    When was the last time this vehicle was driven?
     
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  7. geo2000

    geo2000 New Member

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    5 days ago. Also the 12v battery is holding its charge. It's reading at 12.4.
     
  8. TMR-JWAP

    TMR-JWAP Senior Member

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    Some questions...

    Is the FOB case original or has it been changed at some point due to wear and tear on the buttons etc?

    If it was changed, are you certain the RFID chip was swapped from the old one to the new one?

    If is was changed and the RFID chip forgotten, then the slot will never work with that fob, ever. Along with this, the Smart System would stop working if you accidentally pressed the KEY button located on the dash under the steering wheel.

    So try pressing the KEY button to see if your smart system starts working again..

    There's also the possibility that the AM2 fuse has blown. When the AM2 opens, all you'll get is the door ajar, the "blinking car with the key inside" symbol on the dash and the small green lights on each side of the key fob slot. Everything else will appear dead
     
    #8 TMR-JWAP, Dec 24, 2019
    Last edited: Dec 24, 2019
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  9. sam spade 2

    sam spade 2 Senior Member

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    12.4 is NOT fully charged......if that reading was taken with no load.
    What's the voltage with the door open and the headlights ON ?

    And yes, the "door opening" function is different than the code that is read to enable starting.

    A locksmith might be able to help.......but I strongly suspect that you will need a Toyota dealer.
    And the cost might be more than the "blue book" on a 2005.

    AND.....for others reading this, THIS is exactly why it is so important to have TWO FOBS.
    If the only one you have is lost or fails, the cost to get it running again is a LOT.
     
  10. TMR-JWAP

    TMR-JWAP Senior Member

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    I just installed one of my spare Toyota SKS batteries (S46 model 325 cca) into a car to help someone out a couple days ago. The battery was 12.32 volts and tested at 400 cca.

    A brand new battery will be around 12.7-12.8ish, but that will lower as the battery ages. 12.4v still has a lot of life remaining as long as the battery is aging normally and doesn't have any abnormal problems.
     
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  11. geo2000

    geo2000 New Member

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    Thanks for all responses. I deeply appreciate it. Regarding fob, it is an original key. The only change I have made on the smart key is the cell battery. The rfid is still entacted. Regarding the 12v battery, it still 12.4. I have not worked on the car for the past 3 days because it has been raining over here. So I just don't think it's the 12v battery but I could be wrong.
    As far as the am2, where is it located? I like to change the fuse on it. TMR-JWAP's systompyn descriptions of am2 looks like my problem except for door a jar. Like I've mentioned before my smart key unlocks/locks the car. Thanks for all your help.
     
  12. geo2000

    geo2000 New Member

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    Another question, does the power button sense the fob key even though 12v battery is a little low? I am noticing the power button light not sensing the smart key whether red, orange or green. Also, not engaging to accessories mode.
     
  13. bisco

    bisco cookie crumbler

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    did you push the sks button under the steering wheel, as tmr suggested?
     
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  14. geo2000

    geo2000 New Member

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    Yes I pushed and unpushed sks button. No response.
     
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  15. bisco

    bisco cookie crumbler

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    i would tackle the am2 fuse until you get another response. look in the under hod fuse box, not sure if it's marked or not.
    you should be able to find threads here and pics. check youtube as well.
     
  16. sam spade 2

    sam spade 2 Senior Member

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    Maybe not............

    That piece of information is mostly worthless UNLESS you tell us under what conditions you measured it.

    If it was with no load, IE everything in the car OFF, it might indicate a bad battery.
    OTOH, if it was with the door open and the headlights ON, you should be able to rule out the battery for the time being.

    You need to pay attention to ALL of the responses that you get.
    The whole/best advice often is not in any one single reply.
     
  17. bisco

    bisco cookie crumbler

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    post #4, o/p had the battery tested at autozone
     
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  18. ChapmanF

    ChapmanF Senior Member

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    No worries there. If the number 12.4 comes up in the context of "can you help me judge the exact condition of my 12 volt battery?" then there's a wealth of state-of-charge charts and other wisdom to be applied to that question.

    If the same number comes up in the context of "is this number the reason my car is doing X?" the answer is no. 12.4 is plenty to run the car. Around 9.5, some of the ECUs will start logging codes that mean "hey, d'you know your voltage got down around 9.5?" Below 7 or 8, I've usually found the car won't start.
     
  19. prius_deep

    prius_deep Member

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    will it go into READY mode?

    pics please.





    if so[READY]; what do you mean by it will not 'start'?

    do you mean the ICE is not starting?
     
  20. George W

    George W Active Member

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    As Bisco asked, did you step on the brake pedal b4 pushing Power button?