P0460 indicates the powertrain control module (PCM) has detected an irrational or missing signal from the fuel level sensor circuit. The sensor, usually integrated into the fuel pump module, sends a variable resistance signal that the PCM converts into a fuel-level reading.
The resistive element or float arm inside the tank wears out or corrodes, producing an open, short, or out-of-range signal.
Corroded pins, chafed wires, or broken conductors in the harness between the tank module and the PCM interrupt the sensor signal.
A high-resistance ground path shifts the sensor voltage reference, causing the PCM to read an implausible level.
On some architectures the cluster processes the sensor signal; a cluster failure can set the code even if the sensor is functional.
An internal driver or analog-to-digital converter failure in the PCM can misread a valid sensor signal; this is a last-resort diagnosis after all wiring and sensor tests pass.
The definition is universal; the diagnostics are engine-specific. Open your vehicle for the codes documented for it:
Almost never. The code is almost always caused by the sensor, its wiring, or the ground connection. PCM replacement should only be considered after every circuit and component test has been verified.
The vehicle will run, but the fuel gauge will be unreliable. You risk running out of fuel unexpectedly, and on some vehicles the PCM may disable the fuel pump if it believes the tank is empty.
On most vehicles the fuel pump module (with integrated sender) is accessed through a service port under the rear seat or trunk floor; tank removal is usually not required.
Intermittent contact in the sensor's resistive track, a loose connector, or a wiring break that moves with vibration can cause the signal to come and go.