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Smart key system no longer works like it used to...

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by second time's a charm, Jun 10, 2008.

  1. second time's a charm

    second time's a charm 2 Prius Family

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    We've had our 2008 Prius for a little over 2,000 miles now. We had a 2007 Prius, but my husband made a dumb driving move and had an accident. We were shocked when they told us it was totalled....So out we went and bought another one, just like the other one. I've always loved how the smart key system works, and not having to actually take the keys out of the purse to drive, or lock and unlock the doors.

    Now, here's our problem. My husband did another dumb thing (he's just full of tricks!) and somehow left the car with the auxiliary power left on. Less than 3 hours later, the battery was dead. We called AAA, and they jumped the car. We drove it around for about 15 minutes, and also left it running for a little while, too.

    The problem now is that the smart key system doesn't really work properly. The only thing we can still do is to start the car with the keys still in the purse or pocket. We can't lock the doors anymore with the black buttons, and we actually have to get the keys out and hit the unlock button to get into the car. We were thoroughly spoiled with how the system worked. My question now is: HOW DO WE GET THE SMART KEY SYSTEM TO WORK THE WAY IT'S SUPPOSED TO??? I thought about taking it to a dealership, as I'm sure someone there knows how to help us. I would rather, tho, be able to fix it ourselves. I read the manuals, and couldn't really find any answers there.

    CAN SOMEONE PLEASE HELP US???

    Thanks, second time's a charm
     
  2. morpheusx

    morpheusx Professor Chaos

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    he most likely must have turned off the smart key with the button that is labeled "key" underneath the steering wheel. If its only one of the keys that does this it is possible that the battery in the FOB may somehow already be low.

    I just re-read your post and if you can still start it, but can't lock it one of the doors isn't shut all the way most likely the trunk hatch.
     
  3. brick

    brick Active Member

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    Low voltage does screwy things to electronic systems. And any time you run a battery flat there's a chance that it's still not completely charged, or even that it has been damaged. One option is to drive it around for a few more days and see if it improves. If you want to be more proactive, get out the multimeter and see if the battery is producing the ~12.5V that it should be. (If open circuit voltage it's below 12V after having driven the car or left it in "ready" for 45 minutes or so, that's cause for concern. Just make sure you wait a while after shutting down to check the voltage or you will get an artificially high reading.)

    You haven't done anything that would damage the system as far as I can tell.
     
  4. richard schumacher

    richard schumacher shortbus driver

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    Ditto that. Go slam all the doors and the hatch and see if it works again. If not, try the other fob. If not, push the SKS button near the steering wheel *once* and try the fobs again. If not, replace the fob batteries.

    Your husband should get his own car to mess up.
     
    1 person likes this.
  5. second time's a charm

    second time's a charm 2 Prius Family

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    I know it has nothing to do with all of the doors being shut. They've all been checked and re-checked. This problem happened over a full week ago. It doesn't matter which fob - they both don't work. I don't think that button under the steering wheel has been touched, either, but I'll give it a shot tomorrow morning, just in case.

    We were thinking that since the electronic system was out for awhile, the smart key system has to be re-set or something. Is that a possibility? Not that we know how to re-set it, anyway :(
     
  6. Patrick Wong

    Patrick Wong DIY Enthusiast

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    No, that should not be required. The Smart Key ECU can be programmed by the Toyota tech to recognize up to five fobs. Once programmed to recognize a fob, that memory (in principle) should remain although 12V battery power is disturbed.

    I am with the other posters who suggest that you first ensure that your 12V auxiliary battery is in good condition. (What was the total duration of "15 minutes plus a little while"?) When the battery has been discharged to the point that you require a jumpstart, you need to keep the car READY for a couple of hours to ensure that the battery has fully charged.

    Once you have done this, and you have confirmed that the Smart button near your left knee (when sitting in the driver's seat) is set so that the system is on, then if you still have problems a dealer visit is in order.

    Good luck.
     
  7. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

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    it aint the doors... it would not lock under any circumstances if a door was open... i would check the SKS button first then replace the batteries.
     
  8. wchardin

    wchardin Senior Member

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    Also if it was an open door, the car would do the long, loud beep.
     
  9. second time's a charm

    second time's a charm 2 Prius Family

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    Patrick - thank you - it IS probably the fact that the battery isn't up to par - we had it running after the jump only about a total of a half hour. We have been driving it ever since, and I have always noticed that the battery's blue bars (on the screen) are always lower than they used to be (only three of four bars, and sometimes only a few PURPLE bars).

    If this is the problem - how do we correct it?

    Oh, and the beep we hear when trying to lock the doors with the black button is a long single beep.

    I MISS BEING ABLE TO APPROACH THE CAR, AND THEN JUST TOUCH THE HANDLE TO OPEN THE DOORS

    :eek:hwell: :Cry: :eek:hwell:
     
  10. Patrick Wong

    Patrick Wong DIY Enthusiast

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    The MFD screen is showing the traction battery state of charge. This is unrelated to the 12V auxiliary battery. Perhaps this is low because you are using the air conditioning a lot, and are not driving the car very fast?

    Regarding the Smart Key, have you already tried pushing the button under the steering column once to see if you can turn that feature back on?

    The long single beep is an error message. I have heard that beep when the car thinks that a Smart Key fob is still inside the passenger cabin. Have you accounted for all fobs, and ensured that they are all out of the car before you lock it?

    When checking all doors to ensure they are shut, have you also checked the hatch and the hood to make sure they also are shut. With the hatch, if you leave the hatch light switch so that the light is on when the hatch is open, then when you shut the hatch, the light should go off. If the light doesn't go off, that is proof that you need to slam the hatch with more force.
     
  11. second time's a charm

    second time's a charm 2 Prius Family

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    That's a GOOD POINT!! Actually, my husband's keys are missing, and have been almost since the battery incident. :glare: Maybe that's the answer?!? We keep assuming that his keys are lost somewhere in the house, but maybe they ARE in the trunk area somewhere - we have several things in there that could be covering them up. But, would we be able to lock the car at all with the keys in there - we're only locking it with the lock button on the key fob. (Maybe it's not even locking then??)

    More stuff to investigate after work today. We work in the same State building, but not in the same departments. ;)

    Thanks for the continued brainstorming. I will keep you posted!
     
  12. Danny Hamilton

    Danny Hamilton Active Member

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    There are several people giving advice who seem to be ignoreing this comment from you. If it is true that you don't need to insert the key into the slot on the dash to start the vehicle, then the button under the steering column is most certainly not the issue.

    This leaves a few components:

    1) The fob might be transmitting a weak signal that can be picked up by the antenna in the vehicle when starting the car, but not strong enough to be picked up by the door antennae when trying to open the door. This could be caused by a low battery charge in the fob. Replacing the fob battery would fix this cause. However, since the problem began suddenly on a relatively new vehicle after the vehicle 12V battery was drained, I doubt the fob battery is the problem. Keep it in mind though just in case.

    2) The antennae in the doors may be disconnected or damaged in such a way as to prevent sensing the fob's presence. Since the SKS was working prior to the drained vehicle 12V battery, and the vehicle has not been involved in an accident, I doubt this is the problem. Keep it in mind just in case.

    3) The fully drained 12V battery may no longer be providing the full expected voltage. The low voltage condition may be interfering with either the door antennae ability to sense the proximity of the fob, the handle sensor ability to sense the presence of your hand, or with the control logic that determines that the door should be unlocked. I would be surprised if discharging a relatively new 12V battery a single time would create such a low voltage situation. If you have the ability to check the voltage of the 12V battery after the vehicle has been shut off for an extended period of time (such as overnight), I'd recommend checking it. Otherwise, a trip to the mechanic may be in order.

    4) One of the fobs are still in the vehicle. This would prevent you from locking the doors from outside the vehicle while the vehicle is off. If you are certain that when the vehicle is off you can lock the doors from outside the vehicle with the buttons on the fob, then this is not the problem. On the other hand, if you are simply assuming that the doors are locking when press the buttons on the fob, then you need to verify this. If the doors are not actually locking then I highly recommend searching the vehicle for the missing fob before taking any other steps. You also might want to try starting the vehicle while leaving your fob in the house. If the vehicle starts, then you know for sure that you have a fob lost in your car. Of course if it doesn't start, that doesn't mean that you don't have a fob lost in the car. You might still have a fob lost somewhere far enough away from the antenna in the center console as to prevent starting the vehicle.
     
  13. qbee42

    qbee42 My other car is a boat

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    You can lock a working fob in the Prius by using the manual lock button on the other fob. You can't lock a working fob in the Prius using the external lock buttons, unless the fob is located in such a way that the Prius can't tell it's in the car. It's possible to do this, but it takes a bit of work to get the fob in just the right spot in the back. Of course, if the fob batteries are weak, that's a different story.

    Tom
     
  14. Danny Hamilton

    Danny Hamilton Active Member

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    Hmm, not sure why I thought that wasn't possible. I'm going to have to try it now when I get home just to prove to myself that you're right. Assuming you are, then I'd have to recommend searching that car carefully for that spare fob. I'm almost ready to lay a bet down that the fob is in the car.
     
  15. qbee42

    qbee42 My other car is a boat

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    I do this when my wife has the fob in her purse, but doesn't want to take her purse out of the car. It's not the best practice from an anti-theft standpoint, but it's easier than replacing my wife.

    You can't lock a working fob inside of a running Prius without using the metal key. Perhaps that is what you remembered.

    Tom
     
  16. KayakerNC

    KayakerNC Member

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    If this is true, it proves once again, that the Prius is generally smarter than the owner. My wife is pretty sure that my Prius is smarter than me.
    Of course, she is certain that she is smarter than me too.

    :kiss:
     
  17. Danny Hamilton

    Danny Hamilton Active Member

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    :doh: You're right. That's probably what I was thinking of. Sorry about the mistaken advice. Anyhow, let us know if it turns out the fob was in the car. We'll all be wondering now.
     
  18. second time's a charm

    second time's a charm 2 Prius Family

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    This discussion is getting more and more interesting - and I'm learning more and more interesting factoids! I searched the hatch area, and, no fob. My husband will have to check the back seat and under the seats, because I have back injuries. Now that I think of it, tho, the car won't start unless I have my keys in the car, so it's probably not the cause. I'm going to go out and check in a few minutes.

    Here's another 'kink' in this whole thing. There is ONE place where the doors will still unlock by touching the handle - it's the hatch handle. This is what makes this issue so frustrating :eek:.

    ANY IDEAS NOW??

    I'll keep you posted, as usual.....
     
  19. qbee42

    qbee42 My other car is a boat

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    Yes. If the fob is in the hatch area, you can't start the car without another fob. The Prius knows the difference between a fob in the driver's area and a fob in the hatch area.

    When you say you can still open the hatch by touching the handle, do you have the fob with you? There are separate antennas for different areas on the Prius: Driver's door, passenger's door, hatch, inside front, inside hatch. My suspicion is that the hatch antenna is still working, but the other ones are not. Does this problem happen anywhere you park the Prius? We want to make sure it's not just a problem in your garage.

    Tom
     
  20. Betelgeuse

    Betelgeuse Active Member

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    OK. So I just went out and played with my SKS.

    I get a single medium-length beep (~2 seconds) if I throw my keys in the car and I try to lock the car by hitting the black button. This is relatively long, but it's significantly shorter than the long beep that you get if you try to lock the doors when a door is ajar (~10 seconds). It does not matter if you have the (second) fob in your hand or not; you'll get the medium-length beep if the car senses a fob inside.

    I can't properly explain the hatch behavior. I think that non-functioning door antennas (i.e. Tom's idea) or a flaky battery (Patrick's idea) have the best chance of being true. Have you tried the locking button on both doors? I'd be surprised if both the driver's and passenger's door antennas failed at the same time. If the passenger's side doesn't work either, the battery may be the culprit.

    However, before you make take any drastic steps, I'd find the other fob to make sure it's not causing the trouble.