• | 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 | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
Fuel Level Sensor Signal | P0462 | 1 | P0463, P0464 | P0463 | P0461 |
Fuel Level Sensor Low Reference | -- | 1 | P0463, P0464 | P0463 | P0461 |
1. Fuel Gage Inaccurate or Inoperative |
The fuel level sensor changes resistance in response to the fuel level. The powertrain control module (PCM) 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 PCM senses a low signal voltage. When the fuel tank is empty, the sensor resistance is high and the PCM senses a high signal voltage. The PCM uses the signal circuit of the fuel level sensor in order to calculate the percentage of fuel remaining in the tank. The PCM sends the fuel level percentage via serial data circuit to the instrument panel cluster (IPC). The PCM sends a serial data message to the IPC in order to display the fuel level in the fuel gage.
• | The ignition is ON, with the engine running. |
• | The system voltage is between 10-18 volts. |
• | The sender output is less than 0.5 volt. |
• | The total resistance of the circuit is about or below 27.3 ohms. |
• | The fuel level signal is 0 percent. |
• | The above condition is present for greater than 10 seconds. |
• | The fuel gage defaults to empty. |
• | The low fuel indicator displays in the IPC. |
• | The PCM records the operating conditions at the time that the diagnostic test fails. The PCM 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. |
Instrument Cluster Description and Operation
Control Module References for Scan Tool Information
Ignition ON, observe the scan tool Fuel Tank Level Remaining parameter. The reading should be between 4 percent and 98 percent.
⇒ | If greater than the specified range, test the signal circuit terminal B for a short to ground. If the circuit tests normal, replace the PCM. |
⇒ | If not within the specified range, replace the fuel level sensor. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Fuel Level Sensor Replacement for the 3.8L engine |
• | Fuel Level Sensor Replacement for the 4.8L, 5.3L, 6.0L, 6.2L and 7.0L engines |
• | Control Module References for the PCM replacement, setup, and programming |