Anytime a DTC code calls out a circuit malfunction it means there is something sooooooooo wrong with the electrical part of the circuit that the PCM can't perform any diagnosis. Think wiring fault or bad sensor.
Do you have an ODB2 scanner? If you did have the ability to monitor the fuel level (FLI) PID it might make short work of trouble shooting this.
Also note that the key to understanding this is NOT to focus on what the cluster fuel level gauge says. It is only reflecting what the PCM is "telling" it to display. The key is to see exactly what the FLI volts are doing. Does it "drop out"? Is it changing rapidly? Is it too high/low?
Without an ODB2 scanner it may be possible to use the Cluster diagnostic mode to monitor the FLI PID. But this may not help with a voltage return that is way outside of what the PCM is expecting.
Cluster diagnostic mode:
To check your engine temp you need to put your car in diagnostic mode. Put the key in the ignition, hold down the odometer reset button, turn the key to the accessory on position, and when the odometer digital readout say's "test", let go of the button. from there if you tap the reset button...
www.allfordmustangs.com
*note, given the amount of help you have been previously been given on other threads it might be useful to others to update the other open threads with "lessons learned".
>>From Ford service manual
P0460 - Fuel Level Sensor Circuit Malfunction
The PCM monitors the fuel level input (FLI) circuit for electrical failure. The test fails when the signal moves outside the minimum or maximum allowable calibrated parameters for a specified fuel fill percentage in the fuel tank.
- Empty fuel tank
- Fuel pump (FP) module stuck open
- Incorrectly installed fuel gauge
- Damaged instrument cluster
- CASE GND circuit open
- FLI shorted to VPWR
- Damaged PCM
- Overfilled fuel tank
- Fuel pump (FP) module stuck closed
- Damaged fuel gauge
- FLI circuit open
- FLI circuit shorted to CASE GND or PWR GND
- CSE GND shorted to VPWR
Monitor FLI PID and FLI V PID in key ON engine RUNNING. FLI PID at 25% fill (with non matching fuel gauge) and FLI V PID less than 0.90 volts [for FLI PID at 75% fill (with non matching fuel gauge) and FLI V PID greater than 2.45 volts] indicates a hard fault. |
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