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. Initial Inspection and Diagnostic Overview






Circuit/System Description

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 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. The fuel information is also used for misfire and evaporative emission (EVAP) diagnostics.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

The ECM/PCM 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/PCM records the operating conditions at the time that the diagnostic test fails. The ECM/PCM 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/PCM receives a clear code command from the scan tool.

Circuit/System Testing

1. Ignition OFF, remove the fuel level sender and verify there are no objects interfering with the fuel level sender.

• Repair any fuel level sender interference.

2. Replace the fuel level sender.

Repair Instructions

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

* Fuel Level Sensor Replacement for the 4.6L engine
* Fuel Level Sensor Replacement (RPO NT7) Fuel Level Sensor Replacement (RPO NU6) for the 3.8L engine
* Control Module References for the ECM/PCM replacement, setup and programming Verification Tests