P0461

DTC P0461

DTC DESCRIPTOR
DTC P0461
Fuel Level Sensor Circuit Performance.

DIAGNOSTIC FAULT INFORMATION

IMPORTANT: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Testing and Inspection

CIRCUIT/SYSTEM DESCRIPTION




The fuel level sensor changes resistance in response to the fuel level. The engine control module (ECM) 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 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 percentage of remaining fuel in the tank. The ECM sends the fuel level percentage via GMLAN serial data circuit to the body control module (BCM). the BCM sends the GMLAN message to the instrument panel cluster (IPC) in order to control the fuel gage and display the fuel level percent. Then fuel information is also used for misfire and evaporative emission (EVAP) diagnostics.

This diagnostic tests for a stuck fuel level sensor signal. The ECM sets this DTC if the fuel level sensor signal appears to be stuck based on a lack of signal variation expected during normal operation.

CONDITIONS FOR RUNNING THE DTC
The engine is running.

CONDITIONS FOR SETTING THE DTC
The ECM does not detect a change in fuel level of at least 1.6 percent over a distance of 193 km (120 miles).

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 that the diagnostic test 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 a clear code command from the scan tool.

REFERENCE INFORMATION

Fuel Level Specifications
Fuel Level Specifications (2.0L and 2.2L) Fuel Level Specifications (2.4L)

Schematic Reference
- Instrument Cluster Schematics
- Computers and Control Systems Schematics

Connector End View Reference
- Instrument Panel, Gages, and Console Connector End Views.
- Engine Control Module (ECM) Connector End Views.

Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs

Scan Tool Reference
Scan Tool Data List

CIRCUIT/SYSTEM TESTING
1. With the ignition OFF, remove the fuel level sender.
2. Inspect for the following conditions:
- The fuel level sensor is stuck, perhaps due to an interference with the fuel strainer.
- The fuel tank contains foreign material for instance, ice.
- If any of the above condition is not present, replace the fuel level sensor.

REPAIR INSTRUCTION

IMPORTANT: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.

- Fuel Level Sensor Replacement
- Control Module References for the ECM replacement, setup and programming.