P0462

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Engine Controls Schematics: PCM Fuel Tank Inputs:

CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) requires an accurate indication of fuel level for Evaporative Emission (EVAP) system diagnosis. The fuel level in the fuel tank changes the rate of vacuum decay for the EVAP system leak diagnostics.

The fuel level sensor changes resistance based on fuel level. The fuel level sensor has a signal circuit and a ground circuit. The PCM applies about 5 volts on the signal circuit to the sensor. The PCM monitors changes in this voltage caused by changes in the resistance of the sensor to determine fuel level.

When the fuel tank is full, the sensor resistance is high, and the signal voltage is only pulled down a small amount through the sensor to ground. Therefore, the PCM will sense a high signal voltage, or a full fuel tank. When the fuel tank is empty, the sensor resistance is low, and the signal voltage is pulled down a greater amount. This causes the PCM to sense a low signal voltage, or an empty fuel tank.

The PCM uses the input from the fuel level sensor to calculate the fuel level in the fuel tank. Fuel level data is used in the EVAP system diagnostics. Fuel level data is also sent to the Instrument Panel Cluster (IPC) via serial data.

CONDITIONS FOR RUNNING THE DTC
^ DTC P0601 is not set.
^ Vehicle speed is more than 5 km/h.

CONDITIONS FOR SETTING THE DTC
The PCM detects a fuel level sensor signal below the normal operating range.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM stores the DTC information into memory when the diagnostic runs and fails.
^ The Malfunction Indicator Lamp (MIL) will not illuminate.
^ The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records.

The PCM uses a fuel remaining value of 40 percent for the EVAP system diagnostic tests.

CONDITIONS FOR CLEARING THE MIL/DTC
^ A History DTC will clear after forty consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
^ The current DTC will clear when the diagnostic runs and does not fail.
^ Use a scan tool in order to clear the MIL diagnostic trouble code.
^ Interrupting the PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Powertrain Control Module (PCM) Description, Clearing Diagnostic Trouble Codes.

DIAGNOSTIC AIDS

NOTE: Refer to Connector Test Adapter Kit J 35616-A Notice in Service Precautions.

IMPORTANT: Fuel level is used in EVAP system diagnosis. Always diagnose the fuel level sensor before any other EVAP system components or DTCs.

If the fuel level sensor is suspected of being stuck or inaccurate, refer to Fuel Level Sensor Diagnosis. Component Tests and General Diagnostics

If the problem is intermittent, refer to Intermittent Conditions. Intermittent Conditions

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. This step determines if the fault is present.