• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Fuel Level Sensor Reference Voltage Circuit | P0462 | -- | P0461 | |
Fuel Level Sensor Signal Circuit | P0462 | P0463 P0464 | P0463 | P0461 |
Fuel Level Sensor Low Reference Circuit | -- | P0463 P0464 | P0463 | P0461 |
The fuel level sensor changes resistance in response to the fuel level. The engine control module (ECM) monitors the signal circuit of the fuel level sensor in order to determine the fuel level. When the fuel tank is full, the sensor resistance is low and the ECM senses a low signal voltage. When the fuel tank is empty, the sensor resistance is high and the ECM senses a high signal voltage. The ECM uses the signal circuit of the fuel level sensor in order to calculate the percentage of remaining fuel in the tank. The ECM sends the fuel level percentage via serial data circuit to the instrument cluster in order to control the fuel gage.
• | The ignition is ON, with the engine running. |
• | The system voltage is between 9-16 volts. |
• | The sender output is less than 0.39 volt. |
• | The above condition is present for greater than 30 seconds. |
• | The fuel gage defaults to empty. |
• | The low fuel indicator illuminates. |
• | The ECM records the operating conditions at the time that the diagnostic test fails. The ECM displays the failure information in the Failure Records on the scan tool. |
• | 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. |
With the scan tool installed and the ignition ON, the Fuel Tank Level Remaining parameter in the ECM EVAP Data List should indicate a value at or greater than 98 percent.
⇒ | If the Fuel Tank Level Remaining parameter indicates a value greater than the specified, test the fuel level sensor signal circuit for a short to ground. If the fuel level sensor circuit tests normal, replace the ECM. |
⇒ | If not within the specified range, replace the fuel level sensor. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for the ECM replacement, setup and programming |