replace Key Fob Battery?

Odd, I had the same problem. Only, the CR2032 I had was kind of old (it measured ok with no load, but under load, it totally sucked.)

1) take the battery out, measure the voltage with a 1k load (ermm. get a cheap DMM from harbor freight or something, they have a cool battery test feature that is very useful. It's also a really useful tool that can save your butt sometimes...)
-- if you don't want to do this, buy another known good battery.--
2) Clean the battery and contacts.
3) reinstall the battery (don't put the cover back on just yet.)
4) push the lock button.
5) does the led on the upper right flash? if not, take the battery out and repeat #3.

my theory: this happened to me, I replaced the battery with a 'known good' source. I'm not sure whether the CPU inside the FOB actually reset properly or decided to challenge me.. It took several power cycles to get it back up. Just make sure to press the button and look for the LED to blink before wrapping it back up..

At this time it might also be a good idea to clean the o ring area so that the fob remains waterproof.

 

I'm replacing the one FOB battery at 4 years and 4 months. (November 2003-March 2008) I think that's pretty good. Our 2nd (lesser used) FOB CR2032 battery is still going.

 

I've had my 2005 Prius since Oct 2004, and the fob battery finally died in Dec 2008. Early signs included the Smart Entry being less responsive (resulting in embarrassing tugs at still-locked doors). =]

 

Well since we're reviving 5yr old ancient threads, there's the alternative to the fob. You change the battery for both functions for this baby. Sold in Japan. Only $400 U.S.



For those of us not affected by the soft economy, a must have.

 

What kind of battery is that?any idea about the cost.
thanks

 

When I bought an used 2004 Prius car last December 2008, I replaced the battery for my only one FOB because I don't know how old is the battery. It cost 3 dollars at Radio Shack. Then I bought two more used FOBs from eBay for 20 dollars each, I also replaced both batteries too and reprogrammed both FOB at 52 dollars each. Wise choice I have made!

 

My fob batteries are the original ones with my 2005 Prius. I have noticed recently that the car beeps when I shut it off. Is this the way the indicates a low fob battery? Where can I get new fob batteries and will they work without any reprograming? Thanks!

 

Did anyone send you a reply? The same thing happened with my 05 prius. The car beeps when I shut it off and not the smart entry (fob) no longer works.

 

You can get a new battery at Radio Shack or any store that carries button cell batteries. A low fob battery is indicated when the fob LED no longer flashes when used. There is no need for reprogramming.

Tom

 

Getting the fob open can be a pain. Remember that the cover slides off parallel to the longest axis of the fob, it does not pull away from the fob. A pointed object can be helpful getting it started. Then you will need a very small (jeweler's or eyeglasses) screwdriver to open the watertight cover for the battery. A new battery costs about $4. A dealer will happily charge you about $50 to do the job.

 

I have a 2005 picked up in May of '05... used one key fob pretty much exclusively. In early Dec 2009 it started acting the same way, then one day, wouldn't open the door. Luckily the other fob works. Just changed out the battery on the one, have to wait for the wife to bring back the car to try it... (She had no gas so stole my car today, LOL)

 

I just changed the battery for a friend of mine. It was actually pretty easy and I was pleased to see that the '05 Prius used a common 2032 battery. I actually had one in my toolbox. Just FYI, the '10 Prius uses a 1632 battery, as do most of the new Toyotas and Lexuses. These batteries are a little harder to find and I ended up going to the dealer.

 

I had two keys and both batteries wore out after 4 years, 10 months. The hardest part for me was sliding off the back cover. I tried doing it by hand numerous times.

I finally had success by inserting a very small flathead screwdriver right under the sliding catch in the FOB and twisting the screwdriver to force the cover backward, away from the catch.

If you have two FOBs, watch when buying the batteries. That particular battery often is sold in a two pack with a small economy in price over the single pack.

 

I just discovered that it is 100 times easier to slide the cover off the FOB with your thumb on the Toyota logo, and NOT on the ridge at the end the cover!

 

My Prius has been responding erratically of late, so I just changed mine today. Three and 1/2 years.

 

Mine just hit 5 years today. Replaced (both fobs) with Panasonic CR2032.
Note - the jewelers Phillips screwdriver is a 1.6mm.

Radio Shack also carries a replacement CR2032.

 

5 years and ours just went out this week...reading the first few posts made it simple to open it up...Pull the key out and keep the key release slid over then slide the back off and its open.....came off real easy on ours..didn't have a tiny screw driver so I used a sharp knife, screws came out super easy...I might as well change all the batteries since one went the other might go soon...thanks prius chat...

 

batteries came 2 in a pack. i did one and figured i'd wait on the other because i rarely use it. but within a few months, that one died too.

 

Is this the record?! My 2004 Prius fob battery (mine since the day it rolled off the truck) died today. The battery is 9 years and 6 months old (not a smartypants key, though).

 

Mine started occassionally not working so I recently replaced the battery in both fobs. Good again. But the panic button hasn't worked on either fob since we bought the car 10 months ago. Any ideas?