Strange One Beep after Turning Off

[gladfelter]

Hi All,

I just started getting one beep after turning off the power to my 2004 Prius. There are no warning lights or any other indication that something is wrong. It isn't because I opened the door before turning off the power, the door is closed when this happens. I looked through the manual and on the web and I cannot find any information about this. Has anyone else have experienced this? Any help would be greatly appreciated.

Thanks,


Dave

[Patrick Wong]

Hi Dave,

I'm wondering whether your fob battery might need to be replaced. Another possibility is that your 12V auxiliary battery might need to be replaced - especially if the original equipment battery is still in place.

[gladfelter]

Thanks Patrick,

I just a hour searching the forums and I found another owner who confirmed one of your theories:

http://priuschat.com/forums/care-mai...-question.html

I second his comment that beeping isn't a very informative way of warning of a problem!

Anyway, he said that his problem was due to the aux battery. I haven't made any modifications to my Prius, so it seems likely it is either the key fob or the aux battery. I haven't had any decrease in the performance of the fob that I am aware of and I haven't had any starting problems or other indications of battery problems.

Should I just take the car in to the local Toyota dealer? Is there an engine code they can read, can they test these maintenance-free lead-acid batteries ... or will they just be guessing?

Thanks again,


Dave

[Patrick Wong]

Hi Dave,

Since you have very cold winters in your area, I suggest that you replace the 12V battery as a preventive maintenance measure now - even if you had no strange beeps or other symptoms.

If you can do this yourself then you can save the dealer tech labor rate. The correct battery will cost ~$160 at your dealer's parts dept.

I have seen some posters who have paid for their dealer tech to do a load test - the battery passed the test but it was still bad. So why pay for an inconclusive test...

[TucsonPrius]

Replace the fob battery. If you read your manual, you'll find this is the indication as to when the fob battery is weak.

I know this because not 4 weeks ago, I had the same happen.

Thanks,
Shawn

[john1701a]

Originally Posted by gladfelter

Has anyone else have experienced this?

Yup. It was the FOB battery getting about to kick the bucket.

Now the change process (with photos) is documented in the User-Guide.

.