For 1990-2009 cars

## DTC P0461 3.6L (LY7)

### 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 | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Fuel Level Sensor Reference Voltage Circuit | P0462 | -- | -- | P0461
Fuel Level Sensor Signal Circuit | P0462 | P0463 P0464 | P0463 | P0461
Fuel Level Sensor Low Reference Circuit | -- | P0463 P0464 | P0463 | P0461
¹Fuel Gage Inaccurate or Inoperative

### Circuit/System Description

The primary fuel level sensor and the secondary fuel level sensor change resistance in response to fuel level. The engine control module (ECM) monitors the signal circuit of the primary fuel level sensor and the secondary fuel level sensor in order to determine the fuel level. When the fuel tanks are full, the resistances of both fuel level sensors are high, and the ECM senses a high signal voltage on both the signal circuit of the primary fuel level sensor and the signal circuit of the secondary fuel level sender. When the fuel tanks are empty, the resistances of the fuel level sensors are low and the ECM senses a low signal voltage. The ECM uses the signal circuits of the primary fuel level sensor and the secondary fuel level sensor in order to calculate the percentage of remaining fuel in the tanks. The ECM sends the fuel level percentage via the GMLAN serial data circuit to the instrument cluster in order to control the fuel gage. The fuel information is also used for misfire, evaporative emission (EVAP), and other on-board diagnostics.

### Conditions for Running the DTC

• | The vehicle speed signal DTC is not set.

• | No electronic fuel level sensor failure present.

• | The ignition 1 voltage is between 10.5-18 volts.

• | The engine is running.

• | Fuel level state is stable.

• | The vehicle speed is greater than 0 km/h (0 mph).

• | The inspection is done more than once.

• | The difference between the engine consumed fuel and change of the fuel level signal is greater than 45.6 present for at least 300 seconds.

| OR

• | The primary fuel level is less than 29.4 percent.

• | The secondary fuel level is less than or equal to 10.3 percent.

• | Supply voltage is between 10.5-18 volts.

• | Keep the engine running.

• | Electrical fuel level sensor is not faulty.

• | DTC P0641 runs continuously once the above condition is met.

### Conditions for Setting the DTC

• | The fuel level sensor signal offset is less than the specified value.

• | The accumulated travel distance is more than the specified mileage.

• | The above condition is present for 4 seconds.

### Action Taken When the DTC Sets

• | The fuel gage defaults to empty.

• | The driver information center (DIC) displays the FUEL LEVEL LOW message.

• | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnosis runs and fails.

• | The control module records the operating conditions when the diagnostic is failure. The first time the diagnosis fails, the control module stores this information into the Failure Records. If the diagnosis reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions into the Freeze Frame and updates the Failure Records.

### Conditions for Clearing the DTC

• | The control module turns OFF the malfunction indicator lamp (MIL) after 4 consecutive ignition cycles that the diagnosis runs but does not fail.

• | A current DTC, Last Test Failed, is cleared when the diagnosis runs and passes.

• | A history DTC is cleared after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnosis.

• | Turn OFF the MIL and clear the DTC with a scan tool.

### Reference Information

#### Fuel Level Specifications

Fuel Level Specifications

#### Schematic Reference

• | Instrument Cluster Schematics

• | Engine Controls Schematics

#### Connector End View Reference

• | Component Connector End Views

• | Engine Control Module Connector End Views

#### 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 Test

1. Turn the ignition OFF, remove the fuel level sensor and check if the fuel tank level sensor is stuck.

⇒ | If there is anything stuck, remove the obstruction.

2. If there is nothing stuck, replace the fuel level sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Primary Fuel Level Sensor Replacement

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

## DTC P0461 4.6L (LH2)

### 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 1 Performance

### Diagnostic Fault Information

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 P0464 | P0463 | P0461
Fuel Level Sensor Low Reference Circuit | -- | P0463 ¹ P0464 | P0463 | P0461
¹Fuel Gage Inaccurate or Inoperative

### Circuit/System Description

The primary fuel level sensor and the secondary fuel level sensor changes resistance in response to fuel level. The engine control module (ECM) monitors the signal circuit of the primary fuel level sensor and the secondary fuel level sensor in order to determine the fuel level. When the fuel tanks are full, the resistances of both fuel level sensors are low, and the ECM senses a low signal voltage on both the signal circuit of the primary fuel level sensor and the signal circuit of the secondary fuel level sensor. When the fuel tanks are empty, the resistances of the fuel level sensors are high, and the ECM senses a high signal voltage. The ECM uses the signal circuits of the primary fuel level sensor and the secondary fuel level sensor in order to calculate the percentage of remaining fuel in the tanks. The ECM sends the fuel level percentage via the GMLAN serial data circuit to the instrument cluster in order to control the fuel gage. The fuel information is also used for misfire, evaporative emission (EVAP), and other on-board diagnostics.

### Conditions for Running the DTC

• | The vehicle speed sensor DTC is not set.

• | Engine is running.

• | DTC P0641 runs continuously once the above condition is met.

### Conditions for Setting the DTC

The ECM detects a change in fuel level in the primary fuel tank of less than 3.0L over a distance of 200 km.

### Action Taken When the DTC Sets

• | The fuel gage defaults to empty.

• | The driver information center (DIC) displays the FUEL LEVEL LOW message.

• | DTC P0416 is a type B DTC.

### Conditions for Clearing the DTC

DTC P0416 is a type B DTC.

### Reference Information

Fuel Level Specifications

#### Schematic Reference

• | Instrument Cluster Schematics

• | Engine Controls Schematics

#### Connector End View Reference

• | Component Connector End Views

• | Engine Control Module Connector End Views

#### 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. Ignition OFF, remove the fuel level sensor and check if the fuel tank level sensor is stuck.

⇒ | If there is anything stuck, remove the obstruction.

2. If there is nothing stuck, replace the fuel level sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Refer to Primary Fuel Level Sensor Replacement .

• | Refer to Control Module References for ECM or TCM replacement, setup, and programming