The fuel level sensor is a variable resistor that varies resistance according to changes in the level of fuel in the fuel tank. The ECM supplies a 5 volt reference through a pull-up resistor to the sensor, which is connected to ground. When the level in the fuel tank is high, the sensor resistance is low (low voltage on signal line). As the fuel level decreases, the sensor resistance increases (voltage increases on the signal line). The ECM uses the signal voltage to determine fuel tank level. The ECM averages the fuel level over time then sends it over the Class II link to the BCM. The BCM averages the fuel level with respect to vehicle speed then sends out a message to the I/P cluster for the fuel gauge over the link. DTC P0461 sets when the signal voltage at the ECM does not change a calibrated amount after the vehicle has been driving a long distance.

DTC P0461 will set if fuel level doe not change more than 3.95 gallons (15 liters) when the ECM calculates 5.26 gallons (20 liters) of fuel consumption.

DTC P0461 diagnostic runs once per ignition cycle.

P0461 is a (type D) DTC.

DTC P0461 sets due to a fuel level that does not change by an expected amount the ECM calculates over a period of driving time.

Use Scan tool to monitor FUEL LEVEL while raising the vehicle from the back. Percentage should change indicating a moving float.

Note: The FUEL LEVEL voltage reading on Scan tool is averaged over time. An instantaneous updated FUEL LEVEL voltage reading can be achieved by turning the ignition Off than then back On.

Possible causes of static fuel level:

Fuel level sensor resistance: 19 ohms with float at top position (full tank) through 251 ohms with float at bottom position (empty tank).