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 P0462: Fuel Level Sensor Circuit Low Voltage

### 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 serial data messages to the instrument panel cluster (IPC) in order to control the fuel gage and display the fuel level percent.

### Conditions for Running the DTC

• | The ignition is ON, with the engine running.

• | The system voltage is between 9-16 volts.

### Conditions for Setting the DTC

• | The sender output is less than 0.39 volt.

• | The above condition is present for greater than 30 seconds.

### 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.

### Circuit/System Verification

Ignition ON, observe the scan tool Fuel Tank Level Remaining parameter. The reading should be between 4-98 percent.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the fuel level sensor.
2. Ignition ON, verify the Fuel Tank Level remaining parameter is 4 percent or less.

⇒ | If greater than the specified range, test the signal circuit terminal B for a short to ground. If the circuit tests normal, replace the ECM.

3. If all circuits test normal, perform the fuel level sensor component test before replacing the fuel level sensor.

### Component Testing

1. Ignition OFF, remove the fuel level sender.
2. While sweeping the 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 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 for the 2.4L engine

• | Fuel Level Sensor Replacement for the 2.0L engine

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