Single Fuel Tank

DTC P0462 Fuel Level Sensor Circuit Low Voltage (Single Tank)






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 greater than 85% or less than 15% full. (This sensor signal disables the misfire when the fuel levels are less than 15%).

Conditions for Running the DTC

The ignition switch is in the RUN position.

Conditions for Setting the DTC

The fuel level sensor voltage remains below 0.39 volts for more than 20 seconds.

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 or DTC

- 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 temperature exceeds 70°C (160°F) during the same ignition cycle.
- Use the scan tool Clear Information function.

Diagnostic Aids

Check for the following conditions:

- A poor connection or damaged harness - Inspect VCM 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 in the diagnostic table.

4. This step checks the fuel level signal circuit and the VCM.