P0462

DTC P0462 Fuel Level Sensor Circuit-Low Voltage

Circuit Description
The fuel level sensor is an important input to powertrain control module (PCM) for the enhanced evaporative system diagnostic. Fuel level information is needed for the PCM to know the volume of fuel in the tank. The fuel level affects the rate of change in air pressure in the evaporative system. Several of the enhanced evaporative system diagnostic sub-tests are dependent upon correct fuel level information. The diagnostic will not run when the tank is greater than 85% or less than 15%, full. Fuel level DTCs should be diagnosed before other evaporative system DTCs because they can cause other DTCs to be set.
The sending unit is a float in the fuel tank which moves a wiper arm across a variable resistor. High fuel level causes low resistance in the sending unit. This is recognized by the PCM because the circuit operates at a corresponding high voltage. When the circuit is continuously shorted to a voltage source greater than a specified value, or when the 5 volt signal is shorted to ground, DTC P0463 is set.

Conditions for Setting the DTC
- Fuel tank level slosh test is completed.
- Fuel tank level main test is completed.
- Fuel tank level data is valid.
- Fuel tank level signal is greater than a specified value.
- There are 100 test failures within a 200-test sample.

Action Taken When the DTC Sets
- The PCM will not turn the malfunction indicator lamp (MIL) ON.
- The PCM will store conditions which were present when the DTC set as Failure Records only. This information will not be stored as Freeze Frame data.

Conditions for Clearing the DTC
- The PCM will turn the MIL OFF after three consecutive trips without a fault condition present. A history DTC will be cleared if no fault conditions have been detected for 40 warm-up cycles (engine coolant temperature has risen 4 °C (40 °F) from the start-up ECT, and ECT exceeds 71 °C (160 °F) during that same ignition cycle) or the scan tool clearing function has been used.
- DTC P0463 can be cleared by using the scan tool Clear Into function or by disconnecting the PCM battery feed.

Diagnostic Aids
- Damaged harness-Inspect the wiring harness for damage. If the harness appears to be OK, observe the fuel level display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the display will indicate the location of the fault.
- Damaged harness-Inspect the wiring harness for damage. If the harness appears to be OK, observe the fuel level display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the display will indicate the location of the fault.

Steps 1 - 6:

Steps 7 - 10:

Test Description
Number(s) below refer to the step number(s) on the Diagnostic Chart.
2. The ECT and MAP sensors share a ground at PCM terminal D9.
9. Equates the resistance values at various float positions to the following fuel gauge readings: