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

### Circuit Description

The fuel level sender changes resistance based on fuel level. The powertrain control module (PCM) monitors the signal circuit of the fuel level sender in order to determine fuel level. When the fuel tank is full, the sender resistance is low and the PCM senses a low signal voltage. When the fuel tank is empty, the sender resistance is high, and the PCM senses a high signal voltage. The PCM uses the signal circuit of the fuel level sender in order to calculate the total remaining fuel percentage in the tank. The PCM sends the fuel level percent via the class 2 serial data circuit to the instrument cluster in order to control the fuel gage. The fuel level information is also used for misfire and evaporative emission (EVAP) diagnostics.

### Conditions for Running the DTC

The ignition is ON.

### Conditions for Setting the DTC

• | The fuel level signal is greater than 99 percent.

• | The above condition is present for greater than 20 seconds.

### Action Taken When the DTC Sets

• | The fuel gage defaults to empty.

• | The LOW FUEL indicator illuminates.

• | The PCM records the operating conditions at the time the diagnostic fails. The PCM 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.

• | The PCM receives the clear code command from the scan tool.

### Reference Information

#### Fuel Level Specifications

Fuel Level Specifications

#### Schematic Reference

• | Instrument Cluster Schematics

• | Engine Controls Schematics for the 2.9L engine

• | Engine Controls Schematics for the 3.7L engine

#### Connector End View Reference

• | Displays and Gages Connector End Views

• | Powertrain Control Module Connector End Views for the 2.9L engine

• | Powertrain Control Module Connector End Views for the 3.7L engine

#### 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, disconnect the harness connector at the fuel level sensor.
2. Ignition ON, verify that the scan tool Fuel Tank Level Remaining parameter is less than 4 percent.

⇒ | If greater than 4 percent, test the signal circuit for a short to ground. If the circuit tests normal, replace the PCM.

3. If all circuits test normal, test or replace the fuel level sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Fuel Level Sensor Replacement for the 2.9L engine

• | Fuel Level Sensor Replacement for the 3.7L engine

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