smart key lock button not working

Discussion in 'Gen 2 Prius Technical Discussion' started by Backyardbill, Oct 1, 2020.

  1. Backyardbill

    Backyardbill Junior Member

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    2007 Prius
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    1. Unlock works: push button and the little red led on keyfob flashes, opens doors.
    2. Alarm works: push button and the horn starts blasting
    3. Lock button does nothing: not red led, no doors lock
    4. Touch inside of front door handle and the doors unlock
    5. Touch outside button of front door handle and the doors lock
    6. Inside car: press GO with brake peddle pressed and the Prius goes ready.

    I removed the keyfob section covering the lock and unlock buttons. Same results as 1 and 2.

    I'm thinking it is a bad Lock button switch on the circuit board.

    Anyone else have or had this problem?

    Any help will be appreciated. and a circuit diagram would be helpful!

    PS: I have basic electronics skills and can solder boards like the Prius keyfobs. However I only have one key and really don't to risk screwing it up.
     
  2. Prodigyplace

    Prodigyplace Senior Member

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    Step 1 Get a second key fob programmed. If you totally kill your one good fob it is much more expensive to recover. They need to reseed the digital keys in the car first.
     
  3. Backyardbill

    Backyardbill Junior Member

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    Unfortunately, I can't. I Need the lock button to do the reprogram.
     
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  4. dolj

    dolj Senior Member

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    I think you are right and yes, p[lenty of people have had this problem, with one or the other of the buttons. Usually, foreign matter gets in once the membrane cover deteriorates and lets dust and grit in.

    I would crack open the fob case remove the PCB, spray it with electronics contact cleaner while gently using a soft brush to clean it. Check the operation of the push switches for an audible and tactile click when pressed. For any switches where you do not get a good click, you may need to inspect its base with a magnifier and if necessary use a needle to gently dislodge any foreign matter.

    If none of that works, then you are left with buying a new (or two) key fobs and having an accredited auto locksmith or the dealer do a key reset and reseed to add the new key(s) to the car.
     
  5. Backyardbill

    Backyardbill Junior Member

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    Good idea on hitting the PCB switch etc. with the electronics spray. I have MAF sensor cleaner. And before anything else, I will try to program another used key I bought a while back on eBay, using this method


    Thanks for the reply.

    10/02/2020 10:25am followup: I was able to get the used keyfob from eBay to be programmed to start the Prius by putting the key in the slot! Next I will try cleaning the PCB of thr main smart key.

    10/02/2020 1:50pm follow up: I drenched MAF cleaner on the lock button, clicked button several times, blew out the switch with compressed air, and repeated this process several times. and VoilĂ ! The lock button is working again. Now to program the immobilizer stuff on the eBay key.
     
    #5 Backyardbill, Oct 2, 2020
    Last edited: Oct 2, 2020
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  6. Backyardbill

    Backyardbill Junior Member

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    10/03/2020 11:14am final follow up: I didn't realize that immobilizer can not be programmed in a used (from another Prius) keyfob, even using TIS (without some getting some special "code" from Toyota). So, at least I have a backup way of starting the Prius. I called Toyota of Richardson and they want $30 to cut a blank door key.
     
  7. Backyardbill

    Backyardbill Junior Member

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    10/06/2020 final final followup: So I called A-1 locksmith to see if they could cut a metal key. Yes, for $40 plus tax; bring in Prius, title, drivers license, and $40 they will order the key. Then when the key arrives at their store; being in the car and stuff as before, and they will cut the key. $40? forget it. Today, while at Home Depot, I walked up to the key cutting machine and the operator was there. I asked him can he cut this Prius key. He said he can try. The (Hillman) machine read the key and #35 blank displayed. He had the blank and cut the key. When I got to the parking lot I tested the key: it works! Out the door cost: $5.21.

    So to sum everything up: if you like me just need a backup key set, buy a used smartkey from eBay or wherever, do the chicken dance to registered to your (gen2) Prius, and get a key cut at Home depot. I hopes this helps others.
     
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  8. dolj

    dolj Senior Member

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    It is a known solution, and if this solution does what you want then great.

    If it were me, I still want another fully functional key fob. When you need to make another fully functional key, it is so much easier and cheaper to make another key now than waiting until after your only fully functional key dies. That hybrid back-up will be of no help making another fully functional key.
     
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