Fuel gauge inaccurate

[jdm_sixtwo]

As the title states, my 6.2 2010s fuel gauge is about 8 gallons off. When the tank is full the gauge doesn’t go to the F, and when it hits E I have about 8 gallons left. Is there any way to recalibrate the gauge or the sending unit? Or does this mean I’d need a new sending unit to get an accurate gauge again? I can also just live with the gauge and know that it’s 8ish gallons off.

 

[Ruger]

Back in the day you could just rotate the gauge in the bezel, but that was before the world became digital.

What about Forscan? I don't know anything about it, but some FRF members are quite knowledgeable. A solution might be had that way, which would be way, way better than having to drop the fuel tank.

Is your Miles To Empty indicator off, too?

 

[jdm_sixtwo]

Yep. It says I’m at 0 miles when it hits E, but there’s really 8 gallons left. And when I fill up the gauge only goes to 3/4 full and that reflects on the miles to empty.

 

[Ruger]

Well, I hope an adjustment may be made in some way. Dropping the fuel tank to get to the sender is risky work, and perhaps left to somebody with factory training and who has done it before.

 

[FordTechOne]

Fuel level is measured by a variable resistor on the sending unit float. Resistance varies between 180 ohms ± 4 ohms when fuel level is low and 10 ohms ± 2 ohms the fuel level is high. The resistance reading is a direct input from the sending unit to the Instrument Cluster over 2 circuits. So possible causes include a faulty Instrument Cluster, circuit issue, or faulty sending unit.

Start by visually inspecting the fuel tank for deformation; if the purge valve sticks open it can apply enough vacuum to the tank to cause it to collapse, which can push the sending unit arm upward and skew the readings. ForScan is a good suggestion as mentioned above to check for DTCs and gauge operation.

 

[EricM]

There were two fuel tank sizes available in 2010 F150s.

The programming could be incorrect. Did you buy it new or used?

Edit:
Link to check with Forscan https://forscan.org/forum/viewtopic.php?t=14698

 

[ratty]

If there's any damage or corrosion to the wire from the sender to the gauge, or to a ground wire, the resistance in the wire will increase, telling your gauge there's less fuel in the tank than there really is (less resistance = more fuel, more resistance = less fuel). Before replacing anything, do an ohm (resistance) check on the wiring from the sender to the gauge.

 

[jdm_sixtwo]

Those are the only non engine codes on FORScan

 

[Dane]

Soooooo.. you can actually just open up the gauge and move the needle. I've had to do this with both my tach and my fuel gauge. Beware of ever doing a gauge sweep though... mine will "decalibrate". I don't know what's actually wrong, but it has been fine for years, so I'm not motivated to mess with it.

 

[jdm_sixtwo]

You mean like opening up the whole gauge cluster? I didn’t see any way to get into it last time I had it out