For 1990-2009 cars

The fuel level sensor is a variable resistor that varies resistance according to changes in the level of fuel in the fuel tank. The powertrain control module (PCM) supplies ignition voltage reference through a series of pull-up resistors to the sensor, which is connected to ground. When the level in the fuel tank is high, the sensor resistance is high, low voltage on signal line. As the fuel level decreases, the sensor resistance decreases, voltage increases on the signal line. The PCM uses the signal voltage to determine fuel tank level. The PCM sends the fuel level over the class 2 link to the body control module (BCM). The BCM averages the signal over time then sends a message to the instrument panel (I/P) cluster over the link to position the gage. DTC P0462 sets when the fuel level sensor signal voltage at the PCM is below the calibrated voltage value.

### DTC Parameters

DTC P0462 will set if fuel level voltage is less than 0.2 volts when:

• | The condition exists for longer than 1 second.

• | The ignition voltage is greater than 9 volts.

DTC P0462 diagnostic runs continuously with ignition ON.

DTC P0462 is a type D DTC.

### Diagnostic Aids

To locate an intermittent problem, use a scan tool to monitor the FUEL LEVEL SENSOR voltage with ignition ON, engine OFF. Wiggling the wires while watching for a change in the FUEL LEVEL SENSOR voltage may locate the area where a short to ground in the wiring could lie.

The voltage measured with a DVOM on the signal line with the ignition ON and sensor disconnected should read very close to ignition voltage, within 0.2 volts. The scan tool, however, is scaled 0-5 volts.

Check for corrosion in the harness connectors. Corrosion will cause a short to the return circuit and may set this DTC.

If DTC P0462 is active, the fuel gage will read EMPTY and the Low Fuel telltale will be commanded ON.