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Discussion Starter #1
Ok i got a 06 CC and the sticker on the tank says 26 gal. With my truck almost on "E" It will only hold 16-17 gallons... This happens everytime i fuel up. Guage seems to read fine( Moves all the way from "F" to "E" smoothly). Anyone have any insight to this... Im just curious if its normal or not. I have a friend with an 08 Dmax and he has the same concern so i figured id ask. Thanks guys
 

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Yes-- that is a known problem, and no easy fix for it. Some just go by miles traveled and then fill up from that.

There is a way to "fix" the sender unit. You have to find someone with EFI and buy a license. They can re-scale the sender with that program.
 

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Discussion Starter #3
well the problem is i have no idea how far i can really go bc i just got the truck a few weeks ago and it was doin it when i got it.... Elaborate on this EFI "fix" is a permanent fix?
 

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It is a permanent fix because it basically allows you to recalibrate how the sender is interpreted by the gauge.
 

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Basically you have a sensor in the tank and a table that is programmed with the number of gallons based on the voltage input signal. From some research it appears some of the issue is a limit on the swing of the sensor itself and the remaining issue is the table. A tuner can go in and change the input table to read more accurately the number of gallons at the bottom of the tank.

I believe GM programmed this intentionally to avoid the average user from running out of fuel. Running out of fuel in our trucks is slightly more complicated then running out of fuel in a comparable gas engine truck. This issue is of course compounded with the small factory tank.

Hand calculate your mileage over a few tanks and then take the lowest mileage you see. Subtract a few mpg for cushion and say you have a 22 gallon tank. I wouldn't run more then 4 gallons low. 22 x mpg = distance per tank.
 

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Discussion Starter #6
Running out of fuel is not something i want to do which is why i am kinda concerned with pushing the limit with it... Im not a big fan of driving with the Low fuel light on thinking ive got around 10 gal. left. I know what to do if i run outa fuel bc this isnt my first diesel... Just not the best thing to do. but filling up when i could have another 150 miles to go is kinda aggravating sometimes if yah know what i mean.
 

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I have an 08 and I am having the same problem . The Service Manager is looking into this. He has had several owners come by with this issue. This is a GMS/CHEVROLET problem that needs to be addressed at the manufacture level, so go online and log your concern to get this issue fixed. GMC is a good company that does the right thing. It just takes a LOUD voice to be heard.
 

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Same here on my 04, it is at 15 gallons used and is close to E. I am really not sure about pushing this?

Has anyone with EFI Live been able to find somone to fix this??
 

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GM will not fix this issue. Mine has done this for a while, and even the GM Customer Service reps on the forum do not offer a solution for this. If your truck has a "Fuel Used" button in the DIC, then I would keep a watch on that and see how accurate it is to the fuel used versus how many gallons you put in when you fill up. If it is true, then go by that and fill up at around 22 gallons or so. My low fuel light comes on at 15.5-16.0 gallon used, and I also have a 26 gallon tank. I just go by DIC and fill up at 22 gallons used and have not had a problem. It is a nuisance but GM did not think this out very good.
 

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I often wondered about this...slap on E and 18gals filled it up to the brim. That's a lot of diesel left in the tank...a LOT.
 

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I have an 08 and I am having the same problem . The Service Manager is looking into this. He has had several owners come by with this issue. This is a GMS/CHEVROLET problem that needs to be addressed at the manufacture level, so go online and log your concern to get this issue fixed. GMC is a good company that does the right thing. It just takes a LOUD voice to be heard.
Please keep us posted on your progress, if you have any concerns or questions please let me know. Thank you!

Joey, GM Customer Service
 

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my old truck did this. and i just acted like it was right. so i hold had to fill up 15 gallons which was easier on the wallet lol
 

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Interesting. I have dual tanks and only the main tank(front one) has the fuel gauge sending unit. Rear tank is pumped into the front tank by a inline pump located inside the frame. Some where there is a sensor to control the pump. Front tank is 26 gal and when the light comes on it will hold 24 gal. Rear is 26 gal also but never holds over 22 when the light comes on.
 

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same problem here... When the light comes on, it will only hold 20 gal. It is indeed a 26 gal. tank, or atleast mine is. aggrivating. but atleast i know i have 6 gallons insurance to make it somewhere.
 

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19 gal. Here kinda a pain but peace of mind when light come on an your in east japip
 

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hmmm---i thought my truck had a 23 gal tank on it, a few weeks ago i was headding home from work and didnt feel like stopping for fuel so I stretched it out and stopped about a 1/4 mile from home. I was below E.When I filled it uo it took 24.5 gallons. IDK!
 

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What about you guys with aftermarket titan tanks......from what I understand they come with a sending unit......do they also have the same issue?
 

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bump....just interested in what the Titan guys have to say.
 

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They use a factory fuel sending unit.
 
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