P0463

CIRCUIT DESCRIPTION
The left fuel level sensor measures fuel level changes within the left fuel tank and changes resistance based on fuel level. The PCM monitors changes in the resistance of the sensor to determine fuel level.

When the fuel tank is full, the sensor resistance is high, and the PCM senses high signal voltage. When the fuel tank is empty, the sensor resistance is low, and the PCM senses a low signal voltage.

The PCM uses inputs from the fuel level sensor to calculate the total fuel remaining in the fuel tanks. This information is then sent to the IPC via the class 2 serial data circuit.

When the PCM senses a signal voltage higher than the normal operating range of the sensor, this DTC sets.

CONDITIONS FOR RUNNING THE DTC
The ignition is ON.

CONDITIONS FOR SETTING THE DTC
^ Fuel level sensor voltage for the left level sensor is above 2.9 V.
^ The fuel level signal is greater than 98 percent.
^ The above conditions are present for greater than 2 minutes.

ACTION TAKEN WHEN THE DTC SETS
^ The DIC displays a LOW FUEL message.
^ The fuel gage defaults to empty.
^ The check gages indicator illuminates.
^ The PCM records the operating conditions at the time the diagnostic fails. The PCM displays the failure information in the Failure Records on the scan tool.

CONDITIONS FOR CLEARING THE DTC
^ The DTC becomes history when the conditions for setting the DTC are no longer present.
^ The history DTC clears after 40 malfunction free warm-up cycles.
^ The PCM receives the clear code command from the scan tool.

DIAGNOSTIC AIDS
Use the Freeze Frame and/or Failure Records data in order to locate an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data may aid in determining the number of miles since the DTC set. The Fail Counter and Pass Counter can also aid in determining the number of ignition cycles that the diagnostic reported a pass and/or fail. Operate the vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature, etc.). This will isolate when the DTC failed.

Refer to Testing for intermittent and Poor Connections in Diagnostic Aids.

IMPORTANT: When inspecting for a deformed or warped fuel tank, measure the resistance of the suspect fuel level sensor at empty, with the sensor in the fuel tank, and again with the sensor removed from the fuel tank. The measured resistance values should be the same at empty. If the measured resistance values are not the same, refer to Fuel Tank Replacement (Right) or Fuel Tank Replacement (Left) in Computers and Controls Systems.

TEST DESCRIPTION

Steps 1-2:

Steps 3-12:

The number(s) below refer to the step number(s) on the diagnostic table.
3. Tests for the proper operation of the circuit in the low voltage range.