DTC P0461: Fuel Level Sensor Circuit Performance: Description

The fuel level information is accomplished by using two variable resistance fuel level sensors in series, which vary 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 primary fuel level sensor, which is part of an assembly to the primary fuel pump module (right side of fuel tank). The primary fuel level sensor is electrically connected to the secondary fuel level sensor, which is part of an assembly to the secondary fuel pump module (left side of fuel tank). The secondary fuel level sensor is connected to ground. When the level of fuel in the fuel tank is high, each sensor resistance is low (low voltage on signal line). As the fuel level decreases, the sensor resistances increase (higher voltage on signal line). The ECM monitors the fuel level sensor signal voltage to determine fuel tank level. The fuel level sensor signal voltage ranges between 0.4 to 2.5 volts with each sender arm at the highest and lowest positions. The ECM will send this fuel level information over the CAN link to the BCM. The BCM in turn will average this information with respect to vehicle speed, then send it over the Class II link to the instrument panel cluster which will position the fuel gauge. DTC P0461 will set if the ECM calculated fuel consumption deviates by a certain amount based on the reading from the fuel level sensors.