GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P0461 : Fuel Level Sensor Performance

Diagnostic Fault Information

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

Signal Performance

Fuel Level Sensor Signal

P0462

1

P0463

P0464

P0463

P0461

Fuel Level Sensor Low Reference

--

1

P0463

P0464

P0463

P0461

1. Fuel Gage Inaccurate or Inoperative

Circuit/System Description

The fuel level sender changes resistance based on the fuel level. The engine control module (ECM) monitors the signal circuit of the fuel level sender in order to determine the 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 message via the serial data circuit to the body control module (BCM). The BCM sends the fuel level percent to the instrument panel cluster (IPC) via the serial data circuit to display on the fuel gage.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

The ECM detects a change in fuel level of less than 3 liters (.79 gallons) over a distance of 327 km (203.18 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 the diagnostic 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.

Reference Information

Schematic Reference

Instrument Cluster Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Instrument Cluster Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Component Testing

  1. Ignition OFF, remove the fuel level senders and verify that there are no obstructions interfering with the fuel level senders.
  2. If any interference is present, repair the fuel sender interference.
  3. Ignition OFF, disconnect the harness connector at the fuel level sensor.
  4. While sweeping the primary fuel level sensor through its full range of motion, test for a minimum value less than 41 ohms and a maximum value greater than 119 ohms between signal terminal D and the low reference terminal B.
  5. If not within the specified range, replace the primary fuel level sensor.
  6. While sweeping the secondary fuel level sensor through its full range of motion, test for a minimum value less than 41 ohms and a maximum value greater than 119 ohms between signal terminal E and the low reference terminal B.
  7. If not within the specified range, replace the secondary fuel level sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Primary Fuel Level Sensor Replacement for the 3.6L engine
    •  Secondary Fuel Level Sensor Replacement for the 3.6L engine
    •  Primary Fuel Level Sensor Replacement for the 3.4L engine
    •  Secondary Fuel Level Sensor Replacement for the 3.4L engine
    •  Control Module References for ECM replacement, setup, and programming