Circuit Description
The fuel level sender changes resistance based on fuel level. The engine control module (ECM) monitors the signal circuit of the fuel level sender in order to determine fuel level. When the fuel tank is full, the sender resistance is low and the ECM senses a low signal voltage. When the fuel tank is empty, the sender resistance is high and the ECM senses a high signal voltage. The ECM uses the signal circuit of the fuel level sender in order to calculate the total remaining fuel, percent, in the tank. The ECM sends the fuel level percent via the class 2 serial data circuit to the instrument cluster in order to control the fuel gage. The fuel level information is also used for misfire and evaporative emission (EVAP) diagnostics.
This diagnostic tests for a stuck fuel level sender signal. The ECM sets this DTC if the fuel level sender signal appears to be stuck based on a lack of signal variation expected during normal operation.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0461 Fuel Level Sensor Performance
Conditions for Running the DTC
| • | The ignition is ON. |
| • | The ECM has confirmed that the fuel tank is between 15-85 percent full. |
Conditions for Setting the DTC
The ECM does not detect a change in fuel level of at least 3.0L (0.79 gal) over a distance of 320 km (200 mi).
Action Taken When the DTC Sets
| • | The fuel gage defaults to empty. |
| • | The low fuel indicator illuminates. |
| • | The ECM records the operating conditions at the time the diagnostic fails. The ECM stores 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
| • | Use the Freeze Frame and/or Failure Records data in order to locate an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data may aid in determining the number of miles since the DTC set. The Fail Counter and Pass Counter can also aid in determining the number of ignition cycles that the diagnostic reported a pass and/or fail. Operate the vehicle within the same Freeze Frame conditions (RPM, engine load, vehicle speed, temperature, etc.). This will isolate when the DTC failed. |
Step | Action | Yes | No | ||||
|---|---|---|---|---|---|---|---|
Schematic Reference: Instrument Cluster Schematics Connector End View Reference: Engine Controls Connector End Views for the 5.3L engine or Inline Harness Connector End Views | |||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |||||
2 |
Did you find and correct the condition? | Go to Step 4 | Go to Step 3 | ||||
3 | Replace the fuel level sender. Refer to Fuel Level Sensor Replacement for the 5.3L engine. Did you complete the replacement? | Go to Step 4 | -- | ||||
4 |
Does the DTC reset? | Go to Step 2 | System OK | ||||
