Smart Key System wackiness

Does this happen with one fob or both fobs? If only one, try another fob battery.

Your symptons are indicative of a low fob battery or possible bad fob.

 

A replacement fob is expensive and then you need the dealer to program car to accept fob.

I would try another battery first. Unless you have a voltmeter and can test the battery to verify that it is OK. Batteries have a shelf life and it is not unusual to get an out of date battery.

Most dealers have a device that can test the fob. Some auto parts places like Advance Auto and AutoZone also have the fob testers.

 

Did the problems happen right after the fob battery was replaced?

One or some of the buttons on the fob may be "pressed" by the case or circuit board being out of alignment when the case was reassembled after the battery was replaced.

Try taking the fob apart. Then carefully reassemble taking care that everything is lined up properly.

SCH-I535

 

I'm also having odd problems with my remote/key fob for a 2008 Prius. The Smart key function stopped a couple of weeks ago, but the lock/unlock kept working. I got a new battery that worked the lock/unlock -- not smart key function -- which lasted for about a week. I replaced the battery again with same result: lock/unlock with no smart key works for a few days then dies. I replaced the battery a third time -- same result again. I checked the 12 volt battery and it's fine. I knew the on/off key button on the steering column had to be set properly since the remote works briefly with a new battery (I checked it anyway). The red LED light on the remote works with each new battery. So -- is this a bad remote/key fob or do I have a problem with the receiver (or whatever it's called) in the car that communicates with the remote? Thanks.

 

There are reports of buttons on the fob sticking. New fob batteries sometimes are weak because of the shelf life. How do you know the 12V is not weak? The lock/unlock working for a week each time seems to indicate the fob battery is dying, indicating a possible stuck button. The SKS not working ever sounds more like a 12V or a sensor maybe?

 

Did you ever get this figured out? I just bought a 2006 Prius with the same exact problem.... FOB eating up a battery every few days and then the smart system functionality isn't working at all. What was your solution?

 

Get a replacement keyfob case. Be sure to transfer the transponder chip as well as the circuit board over to the new case.

At least one button is degraded, causing it to be stuck ON. Wears out a battery in about a week or two.

 

this did the trick!