battery in key fob, 2012 Pruis v (lowercase v)

The batteries last 3-4 years. Remove metal key from the side of the fob, use end of blade to pry open fob case, remove enclosed circuit module, open module, replace CR2032 battery, close module, replace in fob case, close case, replace metal key. Voila.

 

Don't be fooled! I noticed similar behaviour with my SmartKey - occasionally the system would not unlock/lock on the passenger side, and so I replaced the batteries in both FOBs (seemed to made sense since they were the same age), but about a week after that, I noticed the 12V battery was starting to fail, so I had the dealer do a load-test, found it bad, and so replaced it - there have been no problems ever since, so what you're seeing might be the first signs of a failing auxiliary (or Management (as the dealer calls it)) battery. Good luck!

 

I just changed the battery for my 2013 Prius v. It was a CR 1632. Not a 2032.

 

Absolutely right! My error. CR1632/ECR1632

 

Here's a link to a good 1 min video on how to change out the battery.

.
My wife drives our Prius v (lowercase v for the Prius v wagon)most of the time. She told me that the car was not automatically sensing the key fob (dome lights didn't come on, the car didn't unlock when she touched the handle) when she tried to use it first thing in the morning. We live in Southern California so while it's January, it's still in the mid 40's in the morning so I didn't think the temperature was a factor.
Once she activated the remote manually, the car seemed to "wake up" and act normally for the rest of the day. After reading some of the other posts, I'm starting to suspect the 12v auxiliary battery...thoughts?
Here's another bit of weirdness. My first thought when she told me about the car not responding to the fob was that the battery in the key fob was going bad, so I tried to replace them. I had some new CR1632 batteries still in the wrapper so I swapped them out and the remote fails completely. I put a volt meter on them and they read 3.3volts , they are made by "Panther Power". The Panasonic CR1632 batteries that I'm replacing read 2.7 volts. Does anyone know why the "Panther Power" batteries wouldn't work. BTW this happens in both of the fobs we own.

 

Did you check the battery polarity, as installed?

 

Nice vid, but when I changed the batteries in my FOBs (Gen II with SKS) I took care to make sure the batteries were clean (i.e. weren't covered in my greasy fingerprints), and I still found that the basic problem was a failing 12V battery (see threads passim) - hope this helps - Wil

 

Also, I think when the fob batteries are getting low, there'll be an in-dash warning. That's what happens on our regular 3rd gen, anyway.

 

No "low fob battery" warning on the 2012 v Five. Just stops working...

And ironically, the fob whose battery I didn't change a while ago just turned up dead this morning. Now changed.

 

Interesting... according to the manual on page 60 you are supposed to get an interior 15-second long beep to let you know the battery in the fob is dying...

That said, it is always best not to rely on such things...

I wonder if anyone has considered hiding a spare fob battery under their bumper in one of those old magnetic key hiders... (yes, I know you could store it in the car and use the mechanical key to get in, but the idea of hiding it under the bumper amuses me)

 

On 3rd gen Prius there's a text warning. Surprisingly specific and to the point; typically the car's warnings are uselessly vague.

 

Indeed. According to the manual, there are supposed to be DRLs, too... Just sayin...