new battery / smart keys NOT working

I suggest that you replace the fob battery to make sure that a worn battery is not an issue.

If the system still doesn't work, then find the SMART button located near the steering column, and press it to see if that helps to activate the system again.


If the SMART system still doesn't work, then you'll have to seek dealer assistance. Note that the SMART and immobilizer ECUs are programmed to recognize the fob, not the reverse.

 

someting that i just found out im ordering the 2010 iv with solar roof...but if the key dies then its got a key that slide outs to OPEN the doors but WILL NOT start the car...so if the key is dead you can get in the car but it will not start...

 

Actually, the smart key is a very short range passive transmitter. If you hold the powerless smartkey up to the power button it will be powered by the car in order to transmit it's authentication. It reminds me of the contact-less badge that my company and many others have to use at work to open doors. So, you just hold your key up to the power button very close and then press power. It should work without a battery. That is my understanding at least.

 

I just started having this problem today. Smartkey will not lock or unlock the car. Tried two batteries and nada. Made sure button under the steering wheel was in proper position. NADA. I can the start the car okay with putting the fob into the key slot so no problem driving the car, but it is PITA to get the little key out to open the door.

Just out of curiosity, I tried what the above poster said and it did not work for me. The only way the car will start is with the fob in the key slot.

1) Have the prices on new smart keys come down at all? Am I looking at $300 to $500 for a new one?

2) Also, in researching the problem here, someone mentioned a red light on the fob. Where would that red light be?

Thanks.

 

To the right of the "lock" button. When you push either the "lock" or the "unlock" button the red light flashes.

 

Thanks. I just tried it and no red light.

 

It's getting complicated around here...

The Gen2 (2004-2009) has a switch on the lower dash that can disable the proximity function of the smart key. The Gen3 (2010+) doesn't have the switch, although it will turn the proximity function off if the car is left unused for several days.

The Gen2 has a slot in the dash. The Gen3 doesn't have the slot, but it has a similar function when the key is held near the Power button. The reason both Gen2 and Gen3 have these functions is to handle the situation when the battery in the key loses power. When the key battery isn't working, the keyslot/Power button transmits enough power to the key for it to send its identification. The range is only a few inches.

Both Gen2 and Gen3 keys have a red LED that lights up when a button is pressed on the key. The LED also lights up when the key is recognized near the outside of the car when the car is turned OFF and locked.

There are two different Gen2 systems. The basic one has a black logo on the back of the remote. It does not have the proximity functions. The smart remote (SKS) has a silver logo on it, which indicates that it has the proximity functions. All of the Gen3 systems sold to date have the SKS system.

If the red LED doesn't flash when a button on the remote is pressed, then the battery isn't providing enough power. It could be dead, inserted backwards, or corrosion could be interfering. The remote is quite durable, so it's very unlikely that it would be damaged by dropping. If it gets wet, that could could be a problem. If it was just clean water, waiting for it to dry should be enough. Salt water is damaging, and will have to be rinsed out with clean water at the minimum.

The car warns of a weak remote battery by sounding a single beep when the car is powered down.

When the 12 volt battery in the car gets weak, all sorts of strange things can happen, including problems with the smart key system. The 12 volt battery typically lasts about five years. If you have to replace the 12 volt battery in the car, it would be a good idea to also replace the batteries in the remotes.

All Gen2 and Gen3 remotes have a small physical key. It can be used to lock/unlock the driver's door. It cannot be used to start the car.

 

I had a new 12 volt put in 2 years ago (3 1/2 years after purchase). I, or someone, left the interior lights on and started draining the battery. Then all kinds of funny things happened and people here and the dealership said to replace it, which was done.

I'll try getting another battery for the FOB. The two I tried were from the same packet and have been in the glove compartment for a while. I know it is inserted correctly. There is an excellent video on how to do it on Youtube. Guy at the Toyota replaced one battery in the FOB and then I replaced that battery with the second one.

 

I had one smart key not working and replaced the battery, but still it was not working, then I noticed that the red led was not responding when I pushed the button, so I went through a stack of batteries and found out that the new ones do not work 3.28V, but the ones that had 3.1V worked, so it looks the electronics works not if the battery voltage is above 3.1V. So the solution was to discharge the battery to 3.1V and now the Smart key works. (Operating range is 3.1V-2.9V for the Smart Key 2004 model)

 

i replaced the smart key battery and it didnt work after i changed it out. red light on key was blinking and everything. apparently the key is connected to the 12v battery. If you go to your trunk where your 12v battery is and disconnect the black wire for a few moments, after you reconnect the wire, the key may start to respond again to locking and unlocking the car. Thats what i did and it worked for me.

 

My SKS hasn't been working for several days.

After fiddling around with procedures to re-activate SKS and pondering batteries and all that ... I found the cause.
I was using an extra set of keys for my wife's car to move it. I left the extra keys, which included my extra Prius fob, in the center console.

The SKS will not function when there's a fob inside the car.

 

This should have been obvious when you try to lock the car and it won't let you and give off a long beep when you try

 

Locking and unlocking works normally. No long beep or anything strange, except for the lack of SKS.

 

With the Smart fob in your pocket, if you push the little black square button on the door handle to lock the car, the car should have rejected your request to lock and the beep should occur.

If you use the Smart fob lock button to lock the car, that command would be accepted without a warning that you have a fob in the car.

 

If you're sure the battery is good but the red LED doesn't light on the fob there are two possibilities. 1) the fob is toast, you broke it our it got dropped in water etc. 2) The fob thinks one of the buttons is depressed. Try and unstick all buttons with xacto knife or similar, the red panic button often gets stuck in the down position, this prevents the other buttons from working and drains the fob battery rather quickly. All buttons should have a tactile "click" and illuminate the red LED when depressed regardless of where the car is.

 

I made an account here just to say, "Thank You!" My panic button was stuck in after I was using the knife on my keychain to fix sprinklers, so I thought it was water... but after reading your post I checked the buttons and sure enough. One was stuck. Popped it out and back in, good as new!!

Thanks

 

Hi!
I had the same problem and I followed the advice posted replace battery n key button... and nothing.

I noticed that the panic button on smart key was stuck. Undid the button, viola!! It works now!! I'm able to unlock/lock remotely. I haven't try keyless entry but I'm sure it will work.

 

Thanks, I also unstuck my panic button and the red light started working again, so that did the trick. My batteries were dying very quickly, so having the button pressed down was likely draining the battery quickly like you said, so thanks hope the batteries last a while now!

 

This saved my day mate. Thanks heaps!!!