GM Service Manual Online
For 1990-2009 cars only

DTC P0461 Sedan

Circuit Description

The fuel level sender changes resistance based on the fuel level. The powertrain control module (PCM) 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 high and the PCM senses a high signal voltage. When the fuel tank is empty, the sender resistance is low and the PCM senses a low signal voltage. The PCM uses the signal circuit of the fuel level sender in order to calculate the total remaining fuel percent in the tank. The PCM sends the GMLAN message to the instrument panel cluster (IPC) in order to display the fuel level percent on 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 PCM 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, with the engine ON.

Conditions for Setting the DTC

The PCM does not detect a change in fuel level of at least 1.6 percent over a distance of 193 km (120 mi).

Action Taken When the DTC Sets

    • The fuel gage defaults to empty.
    • The PCM records the operating conditions at the time the diagnostic fails. The PCM 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 PCM 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, i.e. RPM, engine load, vehicle speed, temperature, etc. This will isolate when the DTC failed.

Refer to Testing for Intermittent Conditions and Poor Connections .

Step

Action

Yes

No

Schematic Reference: Instrument Cluster Schematics

Connector End View Reference: Powertrain Control Module Connector End Views for the 2.2L engine or Powertrain Control Module Connector End Views for the 3.5L engine

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Remove the fuel level sender.
  2. Inspect for the following items:
  3. • A stuck fuel level sender, i.e. the fuel strainer interfering with the sender float arm
    • Foreign material in the fuel tank, i.e. ice

Did you find and correct the condition?

Go to Step 4

Go to Step 3

3

Replace the fuel level sender. Refer to the following:

    •  Fuel Level Sensor Replacement for the 2.2L engine
    •  Fuel Level Sensor Replacement for the 3.5L engine

Did you complete the replacement?

Go to Step 4

--

4

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC, as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK

DTC P0461 Extended Sedan

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.

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Fuel Level Sensor Reference Voltage Circuit

P0462

--

--

P0461

Fuel Level Sensor Signal Circuit

P0462

P0463

1

P0463

P0461

Fuel Level Sensor Low Reference Circuit

--

P0463

1

P0463

P0461

1. Fuel Gage Inaccurate or Inoperative

Circuit/System Description

The fuel level sensor changes resistance in response to the fuel level. The 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 PCM senses a low signal voltage. When the fuel tank is empty, the sensor resistance is high and the PCM senses a high signal voltage. The PCM uses the signal circuit of the fuel level sensor in order to calculate the percentage of remaining fuel in the tank. The PCM sends the fuel level percentage via GMLAN serial data circuit to the instrument panel cluster (IPC) in order to display the fuel level percent on the fuel gage. The fuel information is also used for misfire and evaporative emission (EVAP) diagnostics.

This diagnostic tests for a stuck fuel level sensor signal. The PCM 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 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 PCM records the operating conditions at the time that the diagnostic test fails. The 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 PCM receives a clear code command from the scan tool.

Reference Information

Fuel Level Specifications

Fuel Level Specifications

Schematic Reference

    •  Instrument Cluster Schematics
    •  Emission Hose Routing Diagram for the 2.2L engine
    •  Engine Controls Schematics for the 3.5L engine

Connector End View Reference

    •  Instrument Panel, Gages, and Console Connector End Views
    •  Powertrain Control Module Connector End Views for the 2.2L engine
    •  Powertrain Control Module Connector End Views for the 3.5L engine

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:
  3. • 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 Instructions

    •  Fuel Level Sensor Replacement for the 2.2L engine
    •  Fuel Sender Assembly Replacement for the 3.5L engine
    •  Control Module References for PCM replacement, setup, and programming