P0461

DTC P0461

DTC Descriptor

DTC P0461
- Fuel Level Sensor 1 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 primary (left) fuel level sender changes resistance in response to the fuel level. The engine control module (ECM) monitors the signal circuit of the primary (left) fuel level sender in order to determine the fuel level. When the fuel tank is full, the primary (left) fuel level sender resistance is high and the ECM senses a high signal voltage. When the fuel tank is empty, the primary (left) fuel level sender resistance is low and the ECM senses a low signal voltage. The ECM uses the signal circuit of the primary (left) fuel level sender in order to calculate the percentage of remaining fuel in the primary tank. The ECM sends the fuel level information via GMLAN serial data circuit to the instrument panel cluster (IPC) for display in the fuel gage. The fuel information is also used for evaporative emission (EVAP) and other OBD diagnostics.

Conditions for Running the DTC

* The engine is running.
* The fuel level is less than 28.5 L (7.5 gals)
* No VSS DTCs set

Conditions for Setting the DTC

The ECM does not detect a change in fuel level in the primary (left) fuel tank of at least 3 L (0.79 gals) over a distance of 80 km (21.1 miles).

Action Taken When the DTC Sets

* The fuel gage defaults to empty.
* The driver information center (DIC) displays the FUEL LEVEL LOW message.
* 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.

Circuit/System Testing

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

• Repair any fuel level sender interference.

2. Replace the primary (left) fuel level sender.

Repair Instructions

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

* Fuel Level Sensor Replacement - Left Side for the 6.0L engine
* Fuel Level Sensor Replacement - Left Side for the 7.0L engine
* Refer to Programming and Relearning.Programming and Relearning