new battery / smart keys NOT working

[monolisp]

Hi there,

I am hoping someone can help me with my 2005 prius with smart keys. I started having trouble with the electronics (slowly the smart keys stopped working) along with some other strange phenomenon. I took the car to the dealership and they told me I needed to replace the aux battery in the rear. I did so, replacing with an OEM from Toyota dealership. The trouble is the smart keys still do not work with the car and I am wondering if there is anything I am missing? Do they need to be reprogrammed after the installation of a brand new battery? Has anyone had any similar problems? I had the bettery tested by another shop and they confirmed that it was indeed bad. Any help would be greatly appreciated!

[Patrick Wong]

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.

[HelpSaveMotherEarth]

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...

[JasonPro]

Originally Posted by HelpSaveMotherEarth

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.