Fuel Level Sensor Circuit High Input
Your fuel gauge is reading higher than it should because the sensor is sending a faulty high signal to the engine computer. It's like a thermometer stuck on the hot end—the reading doesn't match reality.
The ECU monitors the fuel level sensor's voltage output, which should vary from low voltage (empty tank) to high voltage (full tank). When the voltage exceeds the maximum threshold for extended periods, the ECU triggers P0464. The sensor uses a variable resistor connected to a float that moves with fuel level.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Fuel Level Sensor Voltage | 0.5V to 4.5V depending on fuel quantity | > 4.7V or continuously at maximum |
| Sensor Resistance | 12 to 250 ohms (varies by tank design) | Stuck at low resistance or open circuit |
Code P0464 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P0464 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.