Fuel Tank Gauge Didn't Reset

jchu · 12-24-2004, 07:57 PM

In preparation for a 500 mile road trip (and to make sure I cleared Oregon where there is no self-service refueling by law) I topped off the Prius fuel tank. At the time it was down to 6 bars. After filling up. the gas tank gauge REFUSED to reset despite several restarts that night and 2 the next morniing. Paranoid, I hit the reset on the energy screen (wasn't sure it would reset either as I remember that doesn't happen if the tank isn't empty enough to start with) so as to track miles on the tank at least. The fuel gauge never reset but seemed to wait until the tank matched the fuel gauge to continue downward. Ultimately, it did seem to reach the single bar state at the appropriate time but until I knew for sure it was very unnerving to wonder if it would get back in sync with the actual gas in the tank.

Thoughts Anyone?

**efusco** · 12-24-2004, 10:03 PM

There's a minimal amount of fuel that must be added for the reset to occur. If you still showed 6 bars at fill up you probably didn't add the nominal amount (whatever that is) for the auto-reset to occur.

ceric · 12-25-2004, 02:44 AM

I recall that the manual says, at least 4 gallons of fill-up to trigger the Auto-Reset of Average Mileage value.

jchu · 12-25-2004, 08:40 PM

Guess I thought that that only applied to the Energy Screen of the MFD. Didn't think that it applied to the gas tank guage as well. Live and learn.

**efusco** · 12-25-2004, 10:32 PM

<div class='quotetop'>QUOTE(jchu\";p=\"59905)</div>

Quote:

Guess I thought that that only applied to the Energy Screen of the MFD. Didn't think that it applied to the gas tank guage as well. Live and learn.[/b]

Huh! You're saying that you filled up but the guage didn't show you to be full? I think you threw us off with the "reset" thing since the guage just changes levels. I would think you should still have the guage show full if you were actually full....no matter the amount added...but maybe not.

Canuck · 12-25-2004, 10:37 PM

"gauge"

jchu · 12-28-2004, 11:54 PM

Evan,

Yes, I meant the gauge for the gas tank NOT the energy screen display of the MFD.

Sorry that wasn't clear in the first post. I had filled the gas tank to brimming and got 450 miles out of it in coldish weather before I hit one bar, but the fuel gauge did not ever reset from 6 bars to 10 bars. Instead, it seemed to wait until I had burned up 5 bars worth of gas to start going down.

What made me paranoid was that when I started, I wasn't sure that the gas tank gauge would ever read right for that fill.

**efusco** · 12-29-2004, 10:00 AM

Hmmm, weird....hadn't heard of that happening before. I'm curious if it will ever do that to you with a full refill (like from 1 bar or 1 flashing bar)....if it does it certainly may be malfunctioning.

Frank Hudon · 12-29-2004, 12:06 PM

happened to us on the wife's 2k1 the day we traded it in. Gas gauge showed 1 bar and was probably ready to start flashing so I put about 4 gallons in and it never climbed 1 bar for the whole trip out to the dealer, about 25 miles. I figured that it was just a quirk. Since we never just put a bit in, always refilled to the top, we never really noticed this quirk before. I wouldn't worry as the gauge is a computer and it didn't start to drop till you were well into the trip the next time this happens you'll remember it's normal.

HTMLSpinnr · 12-29-2004, 12:10 PM

I've had this happen where I was one bar down, and I actually nursed 2-3 gallons into the tank to make it from AZ to SoCal. This was before I had the tank TSB done. The gauge never reset, but stayed put until presumably the fuel level dropped below 9/10 or 3/4.

Hasn't happened since.

12-24-2004, 07:57 PM	#1
jchu Join Date: Mar 2004 Location: Nampa, ID Posts: 1,063 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	Fuel Tank Gauge Didn't Reset In preparation for a 500 mile road trip (and to make sure I cleared Oregon where there is no self-service refueling by law) I topped off the Prius fuel tank. At the time it was down to 6 bars. After filling up. the gas tank gauge REFUSED to reset despite several restarts that night and 2 the next morniing. Paranoid, I hit the reset on the energy screen (wasn't sure it would reset either as I remember that doesn't happen if the tank isn't empty enough to start with) so as to track miles on the tank at least. The fuel gauge never reset but seemed to wait until the tank matched the fuel gauge to continue downward. Ultimately, it did seem to reach the single bar state at the appropriate time but until I knew for sure it was very unnerving to wonder if it would get back in sync with the actual gas in the tank. Thoughts Anyone?

12-25-2004, 02:44 AM	#3
ceric Senior Member Join Date: Oct 2004 Location: Fremont, CA Posts: 1,040 My Car: 2005 Prius Model: Package: #6 Thanks: 0 Thanked 43 Times in 16 Posts Friends: 0	Re: Fuel Tank Gauge Didn't Reset I recall that the manual says, at least 4 gallons of fill-up to trigger the Auto-Reset of Average Mileage value.

12-29-2004, 12:06 PM	#9
Frank Hudon Senior Member Join Date: Jan 2004 Posts: 4,144 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	happened to us on the wife's 2k1 the day we traded it in. Gas gauge showed 1 bar and was probably ready to start flashing so I put about 4 gallons in and it never climbed 1 bar for the whole trip out to the dealer, about 25 miles. I figured that it was just a quirk. Since we never just put a bit in, always refilled to the top, we never really noticed this quirk before. I wouldn't worry as the gauge is a computer and it didn't start to drop till you were well into the trip the next time this happens you'll remember it's normal. __________________ You can quote me on this, People who drive vehicles that idle at a traffic light, are idiots. mine 2k3 avg. 5.36 for 46,915Km Best tank 4.4L per 100K 64.2 Imperial 53.4 U.S. gallon, MiniScanner, SilverStars, block heater, winter lips, in as of Oct 15, out on April 25. In again on Sept. 21st. her's 2k4 "B" avg. 6.01 for 42,317 Km Best tank 4.02L per 100K, CAN-view with OBD11 module and flashloader, SilverStars, 06 Chrome grill bar, Michelin HydroEdge, upper and lower grill blocker,upper out as of April 7, lower out on April 28. In again on Sept 21st.

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12-24-2004, 10:03 PM	#2
efusco Troll Slayer Join Date: Nov 2003 Location: Nixa, MO Posts: 17,228 My Car: 2004 Prius Model: Package: #9 Thanks: 49 Thanked 249 Times in 148 Posts Friends: 37	There's a minimal amount of fuel that must be added for the reset to occur. If you still showed 6 bars at fill up you probably didn't add the nominal amount (whatever that is) for the auto-reset to occur.

12-25-2004, 08:40 PM	#4
jchu Join Date: Mar 2004 Location: Nampa, ID Posts: 1,063 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	Guess I thought that that only applied to the Energy Screen of the MFD. Didn't think that it applied to the gas tank guage as well. Live and learn.

12-25-2004, 10:37 PM	#6
Canuck Senior Member Join Date: Aug 2004 Location: Vancouver Island,BC,Canada Posts: 585 My Car: 2008 Prius Model: Package: B Thanks: 0 Thanked 0 Times in 0 Posts Friends: 1	"gauge"

12-28-2004, 11:54 PM	#7
jchu Join Date: Mar 2004 Location: Nampa, ID Posts: 1,063 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	Evan, Yes, I meant the gauge for the gas tank NOT the energy screen display of the MFD. Sorry that wasn't clear in the first post. I had filled the gas tank to brimming and got 450 miles out of it in coldish weather before I hit one bar, but the fuel gauge did not ever reset from 6 bars to 10 bars. Instead, it seemed to wait until I had burned up 5 bars worth of gas to start going down. What made me paranoid was that when I started, I wasn't sure that the gas tank gauge would ever read right for that fill.

12-29-2004, 10:00 AM	#8
efusco Troll Slayer Join Date: Nov 2003 Location: Nixa, MO Posts: 17,228 My Car: 2004 Prius Model: Package: #9 Thanks: 49 Thanked 249 Times in 148 Posts Friends: 37	Hmmm, weird....hadn't heard of that happening before. I'm curious if it will ever do that to you with a full refill (like from 1 bar or 1 flashing bar)....if it does it certainly may be malfunctioning.

12-29-2004, 12:10 PM	#10
HTMLSpinnr Gen III Forums Moderator Join Date: Dec 2003 Location: Surprise, AZ (Phoenix) Posts: 4,072 My Car: 2010 Prius Model: IV Package: Solar Roof Thanks: 215 Thanked 437 Times in 196 Posts Friends: 18	I've had this happen where I was one bar down, and I actually nursed 2-3 gallons into the tank to make it from AZ to SoCal. This was before I had the tank TSB done. The gauge never reset, but stayed put until presumably the fuel level dropped below 9/10 or 3/4. Hasn't happened since.