02 XLT fuel gauge reads 3/4 when tank full

[OTB]

I have an 02 XLT 4x4, 153k miles.

Last week, gauge read fuel down to 1/4 tank. Went to gas station and filled up, but the pump shut off after only about 10 gallons. Sure enough, when I started car the gauge read as only 3/4 full, so I figured it was a problem with the gas station pump.

Filled up again last night, different gas station, and same thing happened. Gauge was at 1/2 tank and was taking a long drive so figured I would fill up first. Pump shut off after 3 gallons and I kept trying to top off thinking it was a pump problem again, but it was full.. Started car and gauge reads only 3/4 again.

I put a bottle of techron in the fuel this morning to see if that would help clean up the sending unit, but no help yet.

My SES light is NOT on.

Thanks in advance.

 

[DLinkOZ]

Do you have the digital dash? If so, put it into diagnostic mode and see what signal it's receiving for fuel level. At the very least, you can say if it's the gauge or not - if the signal is full (I believe 250 or 255) then the gauge is faulty. If the signal isn't full, then the problem is likely in whatever sort of sending unit/whatever it uses to measure the fuel.