• | 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)/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 ECM/PCM senses a low signal voltage. When the fuel tank is empty, the sensor resistance is high and the ECM/PCM senses a high signal voltage. The ECM/PCM uses the signal circuit of the fuel level sensor in order to calculate the percentage of remaining fuel in the tank. The ECM/PCM sends the fuel level percentage via serial data circuit to the body control module (BCM). The BCM sends the fuel level information via serial data messages to the instrument panel cluster (IPC) in order to control the fuel gage.
This diagnostic tests for an intermittent fuel level sensor signal. If a change in fuel level is detected, DTC P0442 is aborted due to a possible refueling event. If refueling is confirmed, the test for DTC P0464 is considered a pass. The refueling event test must pass 2 out of 3 times, otherwise, the DTC P0464 will set indicating an intermittent signal problem.
• | The ignition is OFF. |
• | DTC P0442 is running. |
• | DTC P0464 runs and fails 2 out of 3 test cycles. |
• | The fuel level change is greater than 10 percent. |
• | The above condition is present for less than 30 seconds. |
• | DTC P0442 is aborted. |
• | The ECM records the operating conditions at the time the diagnostic 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. |
• | Powertrain Control Module Connector End Views for the 3.8L engine |
• | Engine Controls Connector End Views for the 4.6L engine |
⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuits tests normal, replace the ECM. |
⇒ | If not displaying the specified range, test the signal circuit for an open/high resistance. If the circuit test 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 ECM replacement, setup, and programming |