P0461 Fuel Level Sensor Performance (Dual Tanks)

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Schematic:

CIRCUIT DESCRIPTION
The Fuel Level sensor is an important input to the VCM for the Enhanced Evaporative System Diagnostic. The VCM needs the fuel level information in order to know the volume of fuel in the tank. The fuel level affects the rate of change in the air pressure in the EVAP system. Several of the Enhanced Evaporative System Diagnostic sub-test are dependent upon the correct fuel level information. The diagnostic will not run when the tank is more than 85% or less than 15% full. (This sensor signal disables the misfire when the fuel levels are less than 15%).

CONDITIONS FOR SETTING THE DTC
^ The fuel tank level slosh test is completed
^ The tank level main test is completed
^ The fuel tank level data is valid
^ The fuel level signal is unchanged over a distance of 200 miles

ACTION TAKEN WHEN THE DTC SETS
^ The control module stores the DTC in history after the first failure but will not illuminate the Malfunction Indicator Lamp (MIL).
^ The control module records the operating conditions at the time the diagnostic fails. The control module stores the failure information in the scan tools Freeze Frame/Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The control module turns OFF the MIL after 3 consecutive drive trips when the test has Run and Passed
^ A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles. A warm up cycle occurs when the coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant reaches a temperature that is more than 70°C (158°F) during the same ignition cycle.
^ A scan tool can clear the DTCs.

DIAGNOSTIC AIDS
Check for the following conditions:
^ A poor connection or damaged harness - Inspect VCR harness connectors for the following:
- Backed out terminals
- Improper mating
- Broken locks
- Poor wire to terminal connections
^ Intermittent test - monitor a scan tool or digital voltmeter connected between the related circuits while moving the connectors and harnesses. If the failure is induced, the voltage reading will change. This will help locate a circuit problem.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. This step determines it sender is responding correctly.
6. This step determines if the VCR is functioning correctly.