Fluctuating fuel gauge

Several fillups here, and I've never seen that behavior. Once that bar dropped out at 80-100 miles, it never returned.

 

Same with me. My Gen II never did that.

It seems to happen when the car is inclined to the left. I park at home with the right wheels on the sidewalk, so I see them blocks re-appear quite often.

 

Mine just did it yesterday. Filled up a few days ago and put on 40 or so miles. Then yesterday drove it on a 40 miles trip. After about 70 total miles on the trip odometer, it dropped the first bar (pip, I think you folks call it). My MPG since fillup was 50.2.
Then over the next 20 miles or so, the top bar would appear then dissapear about 8 times every couple minutes. I wasn't going up/down grades, so the tank sending unit should not have been moving much. So - hmmmm - not a big deal, but, an early warning of an issue?

 

I've seen it a few times, enough to speculate about a pattern. It seems to be just when the tank is still relatively full. Once you've consumed the first 2 gallons, it settles down and doesn't happen anymore.

So just the top 2 pips show that behavior. The rest are rock solid. The refill point (for me is 500 miles) is extremely consistent.
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Not necessarily. I've see mine do it on the third pip from the bottom. No big deal. Regular gauges have moved up and down for years.

 

Mine fluctuates as well and I assume it is due to the lack of enough baffling in the tank, pretty normal in many cars, but not as noticeable in cars with an analog gauge. My 05 rarely dropped and returned a bar due to the bladder in the tank which the 2010 does not have. Also, the number of pips is greater in the 2010 than the more coarse gauge in the previous generation and was a source of complaints from a lot of customers. It is certainly not enough to complain about....

 

It's just a hypothesis. There's no where near enough data yet to for any of us to draw a conclusion yet. We know something is amiss. Scope is between full and half, so far.

Focus has always been on how to make "near empty" more accurate. Has anyone seen fluctuation at that point?

Also, has anyone checked if the fluctuation influences the distance-to-empty value?
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As I said above mine occurred with the third bar from empty. As I also said I don't see it as any problem at all. It soon disappears again with no effect what-so-ever.

 

I missed that, sorry. And yup, mine duration was short and had no effect either. I think it corrected itself the next time the Prius was started.
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Mine lasted about 5 miles before it disappeared again. No restart.

 

I bought my Prius III about a month ago. I had driven about about 490 miles since last fillup, and my last pip began to flash. I drove another five miles to reach the first gas sttion. I was surprised to find that the car took only 9.6 gallons. (BTW this was my third fillup). Earlier two times the car took just over 8 gallons. That means that there were still 2+ gallons of gas in the tank. Does this make sense? Why does the flashing pip comes on with so much gas (15-20%of the tank) still in the tank? Could it be that the tank is not filling up fully?

 

Thanks for the response. Next time I will not get nervous when the flashing pip comes on. Generally, I try to fill with two pips left.

 

Update to this earlier post. Yesterday I observed this behavior. A pip disappeared at the 75 mile mark, then reappeared at the 81+ mile mark, while I was at a stop light on a downhill slope.

 

Happened to me twice so far on the first tankful. First it went from 10 -> 9 -> 10 at about 75 miles, and this morning it went from 4 -> 3 -> 4 (at about 360 miles, it stayed at three for about 20 minutes of driving and went back to 4 after I parked it at the store then got back in).

 

My bet is that it happens to everyone, but some just don't notice it. How could it not happen? Gas in the tank is going to move around somewhat in any kind of driving and the fuel level sensor in the tank couldn't have any way to compensate for that. IMO, Edmcm2000, 2010 w/ Solar