For 1990-2009 cars

### 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 Circuit 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 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 the serial data circuit to the body control module (BCM). The BCM sends the fuel information to the instrument panel cluster (IPC) via the serial data circuit in order to control the fuel gage and display the fuel level.

### 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.

### 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 sender and verify there are no obstructions interfering with the fuel level sender.

⇒ | If any interference is present, repair the fuel sender interference.

2. Ignition OFF, disconnect the harness connector at the fuel level sensor.
3. While sweeping the fuel level sensor through its full range of motion, test for a minimum resistance value of less than 41 ohms and a maximum value greater than 119 ohms between the signal terminal B and the low reference terminal C.

⇒ | If not within the specified range, replace the fuel level sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Fuel Level Sensor Replacement

• | Control Module References for the ECM replacement, setup and programming