DTC P0461: Fuel Level Sensor Circuit Performance: Description

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