My 2001 f150 fuel gauge reads E with the low fuel light on most of the time but sometimes it works right. Any ideas?

 

Have you done any changed to the cluster like an overlay ?

Try the DTM ( Dealer test mode ) to see if the fuel sender is showing the same information as the fuel gauge in the cluster.

You will have to fill the tank to know about how much fuel is in the tank ( i.e. just after a fill up ) and have the symptom show up again.

~ 10th item in the list is the digital fuel level value.
If you have just filled up and the gauge fails, and the digital value shows the same as the cluster, I would suspect the fuel level sender in the tank to be the issue. If the digital value shows about what is in the tank, something is going on with the gauge itself.


To enter the HEC Dealer test mode, depress and hold the instrument cluster SELECT/RESET button, turn the ignition switch to the RUN position, and then continue pressing the SELECT/RESET button (5 seconds) until tESt is displayed in the odometer. The SELECT/RESET button must be released within 3 seconds of the odometer tESt display to begin the dealer test mode.

Depress the SELECT/RESET button to advance through the following steps until dtc is displayed. Depressing the SELECT/RESET button will display any stored continuous DTCs before proceeding to the next step.

GAGE
Activates gauge sweep of all gauges, then displays present gauge values. Also carries out the checksum tests on ROM and EE. If the gauge sweep is inoperative, INSTALL a new instrument cluster.

All segments illuminated
lluminates all odometer segments. If any odometer segment is inoperative INSTALL a new instrument cluster.

bulb
lluminates all micro-controlled indicators and LEDs. Install a new indicator or LED as necessary.

r
eturns to normal operation of all micro-controlled indicators and LEDs and displays hexadecimal value for ROM level. (used when requesting assistance from the hotline). If alternating flashes for FAIL and ROM level are displayed, INSTALL a new instrument cluster.

EE
Displays the hexadecimal value for EE level (used when requesting assistance from hotline). If alternating flashes of FAIL and EE level are displayed replace instrument cluster.

dt
Displays hexadecimal coding of final manufacturing test date (used when requesting assistance from hotline).

dtc
Displays continuous DTC's in hexadecimal format. Pressing the SELECT/RESET button will display any DTCs stored before proceeding to the next step.

enG
Displays the English speed in MPH. Speedometer will indicate present speed within tolerances. Display will show 0 if input in not received. If input is invalid for one second or more, or if speed is 0.

m
Displays the metric speed data in kph. Speedometer will indicate present speed within tolerances. Display will show 0 if input in not received. If input is invalid for one second or more, or if speed is 0.

tAc
Displays the tachometer data received from the PCM via the SCP network within tolerances. Tachometer will indicate present RPM. Display will show 0 if input is no received, if input received is invalid for one second or more, or if engine RPM is 0.

FUEL
Displays the code (0-255) for the fuel sender input to the HEC. The fuel gauge will display a filtered fuel level value. This filter will keep the pointer from moving suddenly or erratically.
255 open send +/- 0
232 full stop +/- 0
215 Full mark +/- 10
178 3/4 mark +/- 8
138 1/2 mark +/- 7
93 1/4 mark +/- 5
41 E mark +/- 4
54 Low Fuel (0-59)
0-18 short (0-20 max)

OIL
Displays the code (0-250) for the oil pressure switch input to the HEC. Oil pressure gauge will indicate present oil pressure. Normal oil pressure (greater than 6psi) will display a value between 000 and 176. A low oil pressure or an inoperative engine oil pressure switch (less than 6 psi) will display a value greater than 176.

dEGC
Display of engine temperature in Degrees C input from cylinder head temperature sensor.
49 C "C" mark
60 C Normal band start
120 C Normal band end
-40 C No SCP message for 5 seconds

bAtt
Displays the code (0-255) for the battery voltage input to the HEC. Battery voltage gauge will indicate present battery voltage.
93-102 6.2-9.1 volts, low voltage
115-124 8.5-10.7 volts, Normal band start
215-225 15.8-18 volts, Norm band end
230-241 16.9-19.1 volts, high voltage

rhEo
Displays the present decimal rheostat dimming input, 0-255 (used when requesting assistance from the hotline)

rhi
not used

rhS
not used

rho
not used

Cr
Displays the current RUN/START sense input. Display will show -h for high input with the ignition switch in the START position and -L for low input with the ignition switch in the RUN position.

PA-PE7
not used

GAGE
Repeats the display cycle

Source: Helms 99 manual.

 

it keep jumping from 29 to 30

 

And was the take closer to empty or closer to 1/2 + full ?

The reading from the fuel level sending unit is showing empty.

 

It about half full right now

 

You can check the resistance on the fuel level sender, but the HEC is showing the same info as the gauge, it has an issue.

 

What is the fuel level sender? Its been doing it for a year or two. It does it less when its hot outside. it did the same thing last winter.

 

The float like device in the fuel tank that indicates how full the tank is.

Yours seems to be stuck, either physically as in the float itself or in terms of resistance.

Not going to be fun, comes out from the top of the tank. 2 paths to get to it, drop the tank or pull the bed off.

The wires to it are : Black w/ Orange Stripe wire ( to ground ) & Yellow w/ White stripe wire ( to the cluster ).

Looks to be a 4 pin connector, the other 2 are the fuel pump; Black ( to ground ) and Pink w/ Black Stripe wire ( to the fuel inertia switch -> Fuel Pump relay -> Fuse #10 in the engine compartment Fuse panel ).

 

Is there anything other then that i could try first? I really don't want to pull the tank.

 

Checking the resistance on it.
I do not have a service manual for the MY to know what the values should be for it ( I only have the EVTM ).

Maybe a search in the 99-03 forum there could be similar symptoms that gave the values.

 

What was the end result? Did you figure out your issue?

 

I just fill up every Monday.

 

Awesome

My fuel pump died in my 2000 F150 back in December so I replaced the entire fuel pump and sender unit assembly. It was a pain, especially doing it over a few freezing nights outdoors. When I filled it up the first time, the fuel gauge showed empty, but after a few minutes got up to showing full. It would go down gradually as I used the gas, but when I filled up most times it takes maybe 10-15 minutes before it resets properly. However, in the last week, after filling up, it showed full immediately, then went down to empty for a day or so, then went back to full and showed full for about 100 miles before it came down a little bit. Funny thing was when I started the truck it showed the proper amount (3/4 or so) and then after a few minutes jumped back to full. Week later it started coming down slowly again. Not sure if the sending unit was just bad to begin with or if I have other problems. Any suggestions?

 

After extensive "Discussions" with the Ford Mechanic and service adviser, Mine finally got fixed.
I told them I thought it was a wiring problem, they insisted first that it was the fuel causing corrosion in the sending unit. Since I had Extended insurance, I told them to fix it, even though it was going to cost me the $100 deductible. After replacing the entire unit in the tank, to the tune of over $800, I drove over to the gas station 1 block away, and put in 10 gal.
the gauge was still hard over on EMPTY! Drove immediatly bact the the Dealer, parked in front of the main Service door, went in to the service adviser, and said" Fix the $*#@## thing right"
3 Mechanics(?) and the supervisor Had it immediately up on the rack, and after an additional 30 minutes, came and told me it was fixed. When I asked what was the problem, He said (in a very low voice) " It was a wire shorting to the Frame"
I said, "Noooo??" in My best disbelief voice.
After I got home, I put it up on My hoist, and found out what they did. The problem is in the connector attached to the frame beneath the driver door. Evidently water and what ever is on the road (In our case anti icing spray) can seep into the connector an short various connections. I have since had to repair My ground return wire which caused My Backup, Stop, Turn, and clearance lites to fail.
I highly recommend dielectric grease used freely on all the connections on this connecter. (And maybe an *** kicking to the engineer at Ford that put this connecter at this location.)

 

This post is great, thank you first off. I just want to make sure I interpret it all correctly. I have a 2000 Ford Expedition with 5.4. Fuel guage reads Empty and light is on without exception. I ran the dealer test, and the guage sweep worked. The code coming back is Fuel255. I had a mechanic tell me the sender is registering resistance indicating half/quarter tank(He was not exact). I have checked c148/149 and they look good. There is no identifiable 'anti-slosh' circuit I can find on cluster rear. There has been a 4 inch lift on this thing (I bought it this way). Is there a test either at c148/149 to test connectivity from cluster to sender? This Fuel255 code as I interpret, says open harness? Thank you in advance.