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.

### 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)/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 fuel level sensor resistance is low and the ECM/PCM senses a low signal voltage. When the fuel tank is empty, the fuel level sensor resistance is high and the ECM/PCM senses a high signal voltage. The ECM/PCM uses the signal circuit of the fuel level sensor in order to calculate the percentage of fuel remaining in the tank. The ECM/PCM sends the fuel level information via the serial data circuit to the body control module (BCM). The BCM sends the fuel information to the instrument panel cluster via the serial data circuit in order to control the fuel gage and display the fuel level.

### 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

#### Special Tools

J 33431-C Signal Generator and Instrument Panel Tester

### 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 OFF, test for less than 1 ohm between the low reference circuit terminal D and ground.

⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuits tests normal, replace the ECM/PCM.

3. Install a Signal Generator and Instrument Panel Tester between the signal circuit terminal C and the low reference circuit terminal D.
4. Ignition ON, vary the signal generator resistance between 40 and 250 ohms. Verify that the scan tool Fuel Tank Level Remaining parameter displays a range that varies between 5 and 95 percent as the signal generator resistance changes.

⇒ | If not displaying the specified range, test the signal circuit for an open/high resistance. If the circuit test normal, replace the ECM/PCM.

5. Vary the signal generator resistance between 40 and 250 ohms. Verify that the fuel gage displays a range that varies between empty and full as the signal generator resistance changes.

⇒ | If the gage is incorrect, replace the IPC.

6. 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 of less than 41 ohms and a maximum value greater than 119 ohms between signal terminal C and the low reference terminal D.

⇒ | 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 Replacementfor the 2.2L or 2.4L engine

• | Fuel Level Sensor Replacement for the 2.0L engine

• | Control Module References