Anyone else fuel gauge when filling up not show full untill a little ways down the road? It only shows about 3/4 for a while and eventually later on it'll show full, like a half hour later or after turning engine on and off. Just curious if this normal.

you must be idleing while fueling

If you fuel up while idling it will do this. Takes time to get the air out and for the sensor to read full IIRC... This is normal. Try is without the truck running and it should not do it..

I turn mine off when fueling - it's the law here in Orygun and the attendants look weird at me when I sit there idling after a long drive <G> - so haven't experienced this particular glitch before. Mine doesn't exactly register 1/4 full when it's at that stage but best I can calculate, it's only a gallon off.

I know that not all GM fuel gages/sending units are directly linear, however. My ImpalaSS ('95 - last of a breed until GM pulls their head outta their a$$ and gets back to the market they dominated for so long) would register full for almost 100 miles, then drop suddenly to 3/4. Then it was linear, registering what was in the tank correctly, until 1/4. When filling up I found that at 1/4 I still had 8 - 9 gallons to go on a 24 gallon tank. Found a fix through a car club and installed what they called a "Fuel Minder" electronic board. It, and don't ask me how it did it, corrected the glitches and my gage registered correctly through the whole range.

Weird, huh?

Mine does the same thing. It takes forever to read full. I always fuel while ideling. So, like the others are saying, maybe it wouldn't do it if the truck was off during fueling.

I shut the motor off when fueling and never have had this happen. Always full when I start it back up...

Since you mention I've only noticed it after fueling when idling, well that answers that question. :thumb:

does the same thing to me and my 06

That is a safety built into the logic of the level sensor and fuel indicator circuit. The fuel level should only go up while the car is off.

30 minutes seems to be a GM baseline for resetting error codes on the level sender system so the first post seems dead on.

If it didnt work like that everytime you hit a bump your fuel gague would bounce.

while we are on this topic.......... the fuel guage on our 05 LLY has not worked since we bought the truck. It has dual fuel tanks and a dump body. The dealer said gm knew about the problem and their temporary fix was to bend something on the sending unit????? Well it works for a week and then it goes back to reading empty all the time, no matter what the tank level. Anyone else had this problem or know of a fix?

We Have had the same problim at work there is 4 (2-04's, 2-05's) Dealer cant tell me why the just keep replacing the sending unit?? the 2 04's are now out of warrenty and noow the drivers just fill up every morning

yeap thats what we do now too. Makes me wonder exactally who is working on problems like this.

mine takes almost 30 miles to go up after idling when fueling not a problem even my 04 was the same way. It is gm's way of making the guage smooth when driveing on un level or bumpy ground when the fuel is sloching around in there.

I noticed the same thing when running while fueling. I will shut down next fuel stop and see if it takes the same time to read full.

Its called an anti-slosh circuit. The reason it takes so long to read full is the same reason the fuel gauge doesn't fly all over the place when you are driving over bumpy terrain. The fuel sender reading is displayed immediately on the gauge on startup.

Same thing... and i just love putting in 20+ gallons when it reads 1/2 full :rolleyes: