Phone Pairings Deleted

I lost all my phone pairings today.

My wife and I have both our phones paired to the Prius since we got it December 2005, and our current phones have been paired with it for 18 months now. I normally use the car, but when she uses it, we press the off-hook switch on the steering wheel, settings on the screen, select phone, choose her phone, then OK.

This morning, we went through the exact same process and we had her phone connected. We wanted to call someone so I pressed the off-hook switch again to get to the phone screen, but it won't display. Pressing the off-hook switch did nothing. We couldn't get any response.

I restarted the car (weird saying that for a car), and the off-hook switch is now back in order. However, the phone cannot be connected anymore. None of the registered phones are there! The bluetooth name of the car reverted back to the factory setting which is "HANDSFREE."

She was running late so I re-registered her phone, and she was able to connect. Unfortunately she won't have any speed dial access because all of those are empty as well.

Has anything similar happen to you? Where does the Prius store the phone book data? If there is a hard drive involved, it may be a sign of corruption. Whatever it is, I hope it doesn't break the wallet

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Info:
2006 Prius, both phones are iPhone 3G

 

4 years 6 months. I got it Dec of '05, and the battery's never been changed; well, never been brought up by the dealers for replacement, at least.

 

I followed the instructions from the first link. My battery seems to be in good order. It never dipped below 12.0 in any of the tests. I'll use this to check weekly. It really is an old battery after all.

Besides the battery, is there anything else that might be the culprit?

 

You might be right. I tried checking again last night, and on the third part (where I press on the brake pedal to put the car in "Ready") the voltage dropped to 11.8. I released the brake pedal and it went back to 12.1. Stepped on it again, 11.8. Since it's almost 5 years old, I think it's not unreasonable to replace the battery this time. But for $165? Ouch! Gotta grin and bear it, I guess

Thanks for the replies, guys.