DTC Descriptor
DTC P0464: Fuel Level Sensor Circuit IntermittentDiagnostic Fault Information
Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
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 1 | P0463 | P0461 |
Fuel Level Sensor Low Reference Circuit | -- | P0463 P0464 1 | P0463 | P0461 |
1. Fuel Gage Inaccurate or Inoperative | ||||
Circuit Description
The fuel level sensor changes resistance based on the fuel level. The engine control module (ECM) monitors the signal circuit of the fuel level sensor in order to determine 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 total remaining fuel percent in the tank. The ECM sends the fuel level message via the class 2 serial data circuit to the instrument panel cluster (IPC) for the fuel gage display. The fuel level information is also used for misfire and evaporative emission (EVAP) diagnostics.
This diagnostic tests for an intermittent fuel level sensor signal. If a change in fuel level is detected, the engine-off natural vacuum small leak test DTC P0442 is aborted due to a refueling event. Before aborting DTC P0442 a refueling event test is executed to confirm that a refueling event has occurred. If refueling is confirmed, the test is considered a pass. Otherwise, the DTC P0464 sets indicating an intermittent signal problem.
Conditions for Running the DTC
| • | The ignition is OFF. |
| • | DTC P0442 is running. |
Conditions for Setting the DTC
| • | The fuel level change is greater than 10 percent during engine off test. |
| • | The above condition is present for greater than 30 seconds. |
Action Taken When the DTC Sets
| • | 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. |
Conditions for Clearing the 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 ECM receives the clear code command from the scan tool. |
Diagnostic Aids
Using the Failure Records data may help locate an intermittent condition. If you cannot duplicate the DTC, the information in the Failure Records can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can help determine how many ignition cycles that the diagnostic test reported a pass and/or a fail.
Reference Information
Fuel Level Specifications
Schematic Reference
Connector End View Reference
Electrical Information Reference
Scan Tool Reference
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the fuel level sensor. Install a signal generator and instrument panel tester between the signal circuit and the low reference circuit.
- Ignition ON, vary the resistance on the signal generator from 40-250 ohms. Verify that the scan tool Fuel Level Sensor parameter displays the correct voltage levels as the resistance is varied from 40 - 250 ohms. Refer to Fuel Level Specifications .
- If all circuits test normal, test or replace the fuel level sensor.
| ⇒ | If the fuel level sensor voltage is incorrect, test the signal circuit and the low reference circuit for an open/high resistance. If the circuits test normal, replace the ECM. |
Repair Instructions
Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for the ECM replacement, setup and programming |
