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 P0463: Fuel Level Sensor Circuit High 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 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 OFF.

• | DTC P0442 is running.

### Conditions for Setting the DTC

• | The fuel level change is greater than 10 percent.

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

### Action Taken When the DTC Sets

• | DTC P0442 is aborted.

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

### 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 OFF, test for less than 1 ohm between the low reference circuit terminal 3 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 PCM.

3. Install a Signal Generator and Instrument Panel Tester between the signal circuit terminal 2 and the low reference circuit terminal 3.
4. Ignition ON, vary the signal generator resistance between 40 and 250 ohms. Verify that the scan tool Fuel Tank Level Remaining or the Fuel Level Sensor parameter displays a range that varies between 5 and 95 percent as the signal generator resistance changes.

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

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