I'm sorry, I should have said the first and last line values are trouble values.
Values of 0 to 18 indicate an short circuit trouble.
255 value indicates an open circuit trouble.

 

This is very true, I have left my radio on and had the same results and this is very common with these trucks. Basically when your truck is on the processor cannot read in open loop mode. Your truck had to have time to re calculate the fuel in the tank and i have seen mine take up to 1 hour of driving before it registered.

 

Thanks Bluegrass.... I guess I'll be chasing problems wiring soon or replacing the sender/pump.http://images.ibsrv.net/ibsrv/res/sr...lies/frown.gif

 

I know it's an old thread but maybe i can get some answers to a similar problem.

I have an '01 screw with roughly 175K miles on it. The problem i have is that the fuel gauge needle will run and read correctly but will stop at right above the 1/4 mark and will remain at this point even when the truck is turned off. I know the gauge or the sytem is still reading correctly bc if i continue to drive the truck, the low fuel light will come on at the correct time (i'm basing that off of what amount of fuel should be left in the tank, my mpg, and how many miles i've driven and have left on the tank).

This issue has been going on for quite some time now and isn't causing any problems other than being extremely annoying. If any of you F-150/Expo experts can lend some knowledge, I would greatly appreciate it.

 

See if you can follow along with the discription.
The Fuel gage, coolant gage, oil pressure, tach, voltmeter, low oil and low fuel are all powered common full time from fuse #29.
All these indicators are seperately activated from a solidstate chip device that takes individual inputs to address these indicators.
If only the gas level is acting faulty, it may be the solidstate device driveing it.
Otherwise a leakage path to ground would have to exist to keep the gas indicator off normal or rest with ignition off or the gage is sticking.
Remove the fuse to see what happens to the gas gage position.

If it drops, you could have either a problem on the circuit board or the dash has to be replaced for faulty device.
.
Next, trigger the dash diagnostics and step through the tests to the fuel level indication that appears in the speedo display and see what that tells you.
If the dash would need to be replaced, you may need to have your keys reprogrammed and the PATS/PCM possibly addressed for programming.
.
To trigger the dash HEC diagnostics.
Press and hold the speedo reset 'in' , turn ignition to 'run', then start the engine, then release the reset button.
Next step slowly to an indication of 'dtc' using the reset button.
.
Come back with any number you see at this position.
Continue to step to the word 'fuel' and read out what the display says. It should read the present level in the tank as determined by the solidstate logic.
This readout will be an 'octal' number between 0 and 255.
For example a #54 will = the low fuel signal.
If there is indeed low fuel lamp on but the gage does not read 1/8 or less near zero, there is an issue as discribed above.
138= 1/2 level.
215=full etc.
When you turn off the igntion, the dash diagnostics is exited back to normal.
You can see from all this that the whole system converts the analoge tank level indication to a digital value for moving the gage position by outputting a resistance value.
Sorry it's so complex but that's the way things are done.
All the other positions are displaying other system information so I only take you to the DTC and Fuel level indicator positions.
Hope you can 'intu' this and get the answer you need.
Let us know how it goes.
Good luck.

 

Bluegrass I am having a similar problem with my 2003 F150 Supercrew. The gauge seems to work normal except it never goes above 3/4. I just filled up yesterday and ran through the dash diagnostic and my fuel indicates 167. I'm assuming this indicates a bad sending unit.
Can the sending unit be tested WITHOUT dropping the tank?

 

Octal 167 is in the 3/4 full range.
My guess is the float level is unable to rise above that level.
If you fill the tank to the point it shows at the filler neck flapper, and gauge shows only 3/4, I would a assume the float can't get above that level.
Here is a case the microprocessor does not run out of 'numbers'.
You can't measure the float range without taking the pump out of a low tank level to get the tank down far enough.
Your lucky the float stops at the 3/4 level. Could be worse if it stopped at the1/8 or 1/4 point or stuck at a high level and don't know what you have.
If the red light comes on, normally there is about 5 gallon left to get more or to where your going.
At least you can get some idea what's left from the dash test display.
Good luck.

 

Thank you for your reply. Yes, I am luckier than some in regards to where the float level stops. I always reset my mileage so I have a good indicator of how much fuel I have. I was always curious how much fuel was left when the light comes on, so that's good to know.

Again, thank you.

 

All I've seen on this whole page is talking but no solutions on how to fix the issue... Just references.... Wtf is up with that.... Can someone just write the way to fix the issue.... NOT REFERENCES!!!!

 

Mine ended up being the fuel sending unit.

 

I changed the entire pump assembly and it still did nothing