Circuit Description
The fuel level sensor is a device used to determine the level of fuel in the tank. The IPC applies an ignition voltage to the sensor. The sensor varies the voltage based on the level of fuel in the tank. The sensor resistance is high when the tank is full, and the IPC senses a high signal voltage. As the fuel level in the tank decreases, the sensor resistance drops, and the signal voltage at the IPC is pulled low.
The IPC also sends the fuel level information via class 2 serial data to the PCM.
The PCM requires an accurate indictation of fuel level for EVAP system diagnosis. The IPC monitors the fuel level sensor for signal voltages outside the normal range of the sensor. If the IPC detects a signal voltage below the calibrated range of the sensor, the PCM is notified via class 2 and DTC P0462 will set.
Conditions for Running the DTC
| • | The ignition is ON. |
| • | System voltage is between 11-16 volts. |
Conditions for Setting the DTC
The PCM is notified via class 2 that the IPC detects a fuel level sensor voltage that is less than 0.4 volt for at least 10 seconds.
Action Taken When the DTC Sets
The PCM stores conditions which were present when the DTC set as Failure Records only. This information will not be stored as Freeze Frame Records.
Conditions for Clearing the MIL/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 a clear code command from the scan tool. |
Diagnostic Aids
Important: Fuel level is used to determine EVAP system diagnosis. Always diagnose the fuel level sensor before any other EVAP system components or DTCs.
Refer to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges and Console for additional diagnostic information.
| • | Check for poor connections at the IPC and/or the fuel level sensor. |
| Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
| • | Damage harness. |
| Inspect the wiring harnesses for damage. |
Reviewing the Failure Records vehicle mileage since the diagnostic test last failed may assist in diagnosing the condition. The information may help determine how often the condition that set the DTC occurs.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check ? | -- | Go to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges and Console |
