Circuit Description
The fuel level sensor changes resistance based on fuel level. The fuel level sensor has a signal circuit and a ground circuit. The engine control module (ECM) applies 5 volts on the signal circuit to the sensor. The ECM monitors the changes in this voltage caused by changes in the resistance of the sensor in order to determine fuel level.
When the fuel tank is full, the sensor resistance is low, and the ECM signal voltage is high. When the fuel tank is empty, the sensor resistance is high, and the signal voltage is low.
The ECM uses inputs from the fuel level sensor in order to calculate the total fuel percentage remaining in the fuel tank. The ECM uses the fuel level information for the evaporative emission (EVAP) and misfire diagnostics. The fuel level information is sent to the instrument panel cluster (IPC).
If the ECM detects that the fuel level sensor signal changes more than a calibrated amount within a certain time, this DTC sets.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0464 Fuel Level Circuit Intermittent
Conditions for Running the DTC
| • | DTCs P0107, P0108, P0112, P0113, P0122, P0123, and P0502 are not set. |
| • | The engine is running. |
| • | This diagnostic will be delayed for 5 seconds if one or more of the following occurs: |
| - | The change in manifold absolute pressure (MAP) sensor is more than 10 kPa. |
| - | The change in engine speed is more than 50 RPM. |
| - | The change in throttle position (TP) sensor is less than 2 percent. |
| - | The intake air temperature (IAT) sensor is more than -10°C (50°F). |
Conditions for Setting the DTC
The ECM detects that the fuel level changes more than 3.9 percent for 7.5 seconds.
Action Taken When the DTC Sets
| • | The control module stores the DTC information into memory when the diagnostic runs and fails. |
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records. |
| • | The driver information center, if equipped, may display a message. |
Conditions for Clearing the DTC
| • | A current DTC Last Test Failed clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic. |
| • | Clear the DTC with a scan tool. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Instrument Cluster Schematics Connector End View Reference: Component Connector End Views | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 |
Are DTCs P0461, P0462, and P0463 also set? | Go to Step 3 | |
Observe the Fuel Level Sensor voltage parameter with a scan tool while moving the fuel level sensor connector and the engine control module (ECM) connector. Refer to Inducing Intermittent Fault Conditions. Does the scan tool indicate an abrupt change in value? | Go to Step 5 | Go to Step 4 | |
Observe the fuel level sensor voltage with a scan tool while moving the wiring harness between the fuel level sensor connector and the ECM. Refer to Inducing Intermittent Fault Conditions. Does the scan tool indicate an abrupt change in value? | Go to Step 6 | ||
5 | Repair the connector terminal as necessary. Refer to Connector Repairs. Did you complete the repair? | Go to Step 7 | -- |
6 | Repair the harness/wiring as necessary. Refer to Wiring Repairs. Did you complete the repair? | Go to Step 7 | -- |
7 |
Did the DTC fail this ignition? | Go to Step 2 | Go to Step 8 |
8 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | System OK | |
