Low fuel light at 17 gallons

[Duramaxduner]

It think my truck should have a 26 gallon tank. (2008 CCSB). After I hit 17 gallons my low fuel light comes on. The past trucks I've had with 26 gallon tanks I could always pump in 21.5 gallons. I can only ever pump in 17 with this one. How can I fix this?

 

[melms23]

It can be rescaled in your tuning.

 

[N2BRK]

Not easily though. The adjustment is super sensitive.

 

[hondarider552]

Run out of fuel and walk. That would fix it.

 

[roxyfever]

Your lucky. My old lb7 when the low fuel lighy came on it died. Just keep driving when the low fuel light comes on then you will put more in the tank then 17 gallons

 

[TheBac]

Possibly an issue with the sending unit itself? Does the gauge work as it should throughout its range even though the light pops on early?

 

[gamudslinger88]

Mine is the same way. I had it rescaled in my tunes. Mine would be under E mine would take 20 gallons to fill to the brim.

 

[Dozerboy]

When that are that far off I think is the sending unit in the tank. My truck was alway having the light come on at 21 gal. After I quit driving my truck except on the weekend at most the gauge got all kinds screwy. Now the fuel light comes on at 17ish gal.

Sent from my SAMSUNG-SM-G900A using Tapatalk

 

[DAVe3283]

The sending units can wear out. It is just a resistive strip with a wiper, and it can get dirty, corroded, and/or bent, then the gauge does funny things.

Mine did the same thing, and I re-scaled it in the tune, but eventually the pickup tube cracked. I replaced whole sending unit, and put the tune back, and now it works fine.

You can either keep driving after the low fuel light, re-scale it in the tune (I didn't find this to be hard or have any issues), or replace the sending unit.

 

[six5creed]

My light never cuts off and gauge never moves off empty. I need a sending unit. It is aggravating but funny when people ride with you and don't know it's broke.

 

[Duramaxduner]

Do you have to drop the tank to replace this? It does work as it should throughout the range. Just acts like it has a super small tank.

 

[DAVe3283]

You can either drop the tank, or remove the bed. IMO, it is much easier to remove the bed. Just get 3 friends, unbolt the 6 bolts, and lift it off. Takes ~15 minutes, and you don't worry about dropping a fuel tank on your head

 

[ALLY Fox]

GM intentionally scaled the fuel gauge reading so there would be more fuel left in the tank when it showed empty. Nothing worse than having an average ignorant vehicle operator run out of fuel in a diesel truck and call Bubba the tow mechanic to dump something resembling diesel into the tank and light 'er off with a good shot of diesel starting fluid......

 

[Dozerboy]

Don't need to drop the tank or remove the bed. You can tilt it enough to get in there. There is a video on YouTube. You can do it by yourself if your careful.

Sent from my SAMSUNG-SM-G900A using Tapatalk

 

[BigTexas68]

It think my truck should have a 26 gallon tank. (2008 CCSB). After I hit 17 gallons my low fuel light comes on. The past trucks I've had with 26 gallon tanks I could always pump in 21.5 gallons. I can only ever pump in 17 with this one. How can I fix this?

My 08 was the same way. The light would come one and it would have 10-12 gallons left in it.

You can rescale the sensor voltage to correct it.

This is what works for mine and the light comes on with 20 -21 gallons used and 5-6 gallons remaining.

LABELS Fuel Level Sensor Primary (Gallons)

Volts Value
0.000 25.902065
0.703 25.783187
0.782 25.532224
0.860 25.149174
0.938 24.660456
1.016 24.118904
1.094 23.590560
1.173 23.167884
1.251 22.996173
1.329 22.005528
1.407 22.005528
1.485 21.146969
1.564 20.328035
1.642 19.575145
1.720 18.875089
1.798 18.214659
1.876 17.527812
1.955 16.761713
2.033 15.876737
2.111 14.833258
2.189 13.644484
2.267 12.350041
2.346 11.002764
2.502 2.998352
5.000 0.000000