Battery display bounces like a rubber ball!

history: 05 original owner has 24500 miles normal 50+MPG warm weather lately 48MPG. Never had a problem. TILL NOW!

I ran my Prius out of gas (Short ver. unresolved fuel gauge issue) 1/2 miles from gas and dealer (talk about luck!). I refueled, (10.47gal.) ICE started on 1 bar. recharged some and went to dealer to have check engine light cleared. Dealer said all they did was clear the check engine light. Only code was I ran out of gas!

130 Miles later... back at dealer. MPG at 39 and going down! ICE runs all the time. Can't do stealth for more than 100 feet. Battery gauge bounces like a rubber ball, 8 bars to 2 bars. Dealer says the computer does NOT show any problem. They don't know why the battery indicator is jumping around but EVERYTHING IS OK! I have another appointment this Saturday with another eXpert! SOC =64 %, Delta state of charge 87%.

Any one have any Idea at all??

 

I should have given more detail on the speed at whitch the battery indicator changes. It will go from 8 bars to 2 bars in say 1 miles or less! Driving the same places I did before the change occured and nothing like this ever happened. I don't think I ran the battery to low because it still had 1 bar and it did start the ICE. If I sit in park with the battery at full 8 (which was a rare occurance before) in 2.5 min it will be down to 6. This is with NOTHING on at all not even the radio. It makes these wild swings all the time now. Dealer sayed the Delta SOC was an indication of the health of the Hybrid battery and that 87% was good for a car with 24K mikes.

 

<div class='quotetop'>QUOTE(galaxee @ Dec 28 2006, 02:20 PM) [snapback]367723[/snapback]</div>

No only about 1/2 mile still had 1 bar left. ICE started OK and recharged. I read the post Trouble Codes. It sounds pretty scarry. I can't see how a 1/2 mile trek on flat ground at low speed could damage the battery.
I did call national support and they are going to have a senior rep call me possably before my Saturday appointment with the dealer.
I am pleased with the responce I recieved from Toyota national support. They do sound conserned and want to get this fixed.
I will let you know what happens.

Thanks for the help. :huh:

 

The plot thickens!!!
National service called me. They suggested a TSB EG047-04 and told me something about the ECU being able to make the gas pump shut off early by closing some valve. This could account for the fuel gauge issues. They seemed to be pretty good, but no solid answer. They were going to suggest reprogramming the ECU and Hybrid controller. They had called the dealer and would call them back before I go on Saturday.
Well I went to the dealer. We took a drive and the service tech is very good. He did agree that there is something wrong with the way it acts and the battery SOC meter. He said he had NEVER seen 8 bars on the display. We went from 2 to 8 bars several times just driving around the Mall parking lot. He spent probably 2 hours doing research and checking everything he could think of in the cars computer. Wrote a page of notes and called a national Prius instructor that he knew. ( National service will not be back until Wednesday) They are stumped!?! My service guy will be making more calls next week (he said he will call me no later than Thursday) to people in engineering. He did find 3 communication errors that didn't make sense. My system has the newest software and revs. The battery is in grate shape. The computer is no help!! I guess this will be one for the school books!
I will keep you posted..

 

My next appointment with the dealer is on Jan 10. They have talked with engineering and will need my car for at least a full day. They want to do tests from a cold start on.

 

I took my car in on the 9th and picked up my loaner car. I got it back on the 11th. What I was told by the local tech was they replaced the "high voltage battery computer IN the battery"? I didn't know there was a computer in the battery! Anyway the national service lady called and talked to my wife and she said they replaced the ECU. She said they normally repair them but they wanted to see what went wrong. I think what she meant was they could reprogram it but they replaced it. It works great again! I have only part numbers on the service ticket no meaningfully part names. If anybody is interested I can post the part numbers for you. The national service lady said she wold call me back on Tuesday. I will ask her more specific question when she calls and let you know.
Thanks for your input.