Keep Losing Contacts/Stored Information

HI B...B...,

My guess is that you need to check the 12 V battery. What it could be is when your starting the car, its dropping down below what voltage is needed to maintain the memory. The concensus here is that If the 12 V battery is below 12.0 V, after a day of resting , before starting the car, it should be replaced. During a startup, it will be momentarily pulled somewhat lower in voltage. After startup, the inverter is running, and it will pump 14.0 Volts into the 12 V battery.

3 years is a bit short for the 12 V battery to be going. But, not if you let it get drained a time or two, accidentaly. Or, if during this time you had the car in Phoenix, or other hot place.

Now, one would think in this day and age they would use NOVRAM (NOn-Volatile Random Access Memory). But apparently not...

 

Yes, I am resurrecting a old thread. My apologies.

This is an issue in our 2011 Prius and has been during our 3 years of ownership. So I doubt it is a V12 battery issue.

It has happened enough times and weather does not seem to be a factor, meaning I doubt it is related to how hot it is outside.

Boulder_bum, did you get your issue resolved?

Thanks,

 

With out taking any measurements of the 12V battery w/ a DVM (Digital Volt Meter), was time on the clock always maintained, when the phone contacts/radio presets were erased? I'm assuming that the phone contacts are stored into the radio's memory. If so, then there is something wrong with the radio and/or memory wire portion.

Assuming you took it to the dealer, what did they do? Did they not replace the head unit (AKA radio) at least once? Did they not measure the battery voltage to make sure its ok? If they did either, or both of these, then:
1) there maybe be a crack/loose connection of the 12V memory wire connection at the circuit board. The problem is intermittent, and you only notice when you try to start the car. When the car is ON and you are driving, memory is being retained because the radio is on. When you turn the car OFF, the wire or connection at the circuit board may be open (no connection-memory lost) or closed (connection-memory will be saved), due to road conditions.
2) there maybe a short somewhere in the radio wire harness itself, specifically of the 12V memory wire itself.

 

The older Prius models have a bluetooth that is "always searching" for a connection. So if you turn your bluetooth off and then back on again it will find the phone and connect automatically. Works great and a full-proof system of connection.The 2011 Prius searches for the connection at start up (when you turn the engine on). If the phone is "on" it finds it and connects.

However, if the phone is off (or the bluetooth is disabled on the phone) the connection is lost. If the bluetooth is turned on after the car is started, the bluetooth in the car does NOT search for a connection. You have to manually press "connect" and then press the phone you want to connect, and it will then search and find the phone and download the contacts and speed dial.