P0462

DTC P0462 (3.8L, 5.3L, 6.0L, 6.2L, 7.0L Engines)

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



DTC Descriptor
DTC P0462
- Fuel Level Sensor Circuit Low Voltage




Diagnostic Fault Information






Circuit/System Description

The fuel level sensor changes resistance in response to the fuel level. The 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 sensor resistance is low and the PCM senses a low signal voltage. When the fuel tank is empty, the sensor resistance is high and the PCM senses a high signal voltage. The PCM uses the signal circuit of the fuel level sensor in order to calculate the percentage of fuel remaining in the tank. The PCM sends the fuel level percentage via serial data circuit to the instrument panel cluster (IPC). The PCM sends a serial data message to the IPC in order to display the fuel level in the fuel gage.


Conditions for Running the DTC

* The ignition is ON, with the engine running.
* The system voltage is between 10-18 volts.



Conditions for Setting the DTC

* The sender output is less than 0.5 volt.
* The total resistance of the circuit is about or below 27.3 ohms.
* The fuel level signal is 0 percent.
* The above condition is present for greater than 10 seconds.



Action Taken When the DTC Sets

* The fuel gage defaults to empty.
* The low fuel indicator displays in the IPC.
* The PCM records the operating conditions at the time that the diagnostic test 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.



Reference Information
Schematic Reference

* Instrument Cluster Schematics (Instrument Cluster Schematics)
* Engine Controls Schematics (Electrical Diagrams)for the 3.8L engine
* Engine Controls Schematics (Electrical Diagrams)for the 4.8L, 5.3L, 6.0L, 6.2L and 7.0L engines

Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

* Instrument Cluster Description and Operation (Description and Operation)
* Fuel System Description (Fuel System Description)for the 3.8L engine

Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning)for Scan Tool Information


Circuit/System Verification

With the scan tool installed and the ignition ON, the Fuel Tank Level Remaining parameter in the PCM EVAP Data List should indicate a value at or greater than 98 percent.


Circuit/System Testing

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

• If the Fuel Tank Level Remaining parameter indicates a value greater than 4 percent, test the fuel level sensor signal circuit terminal B for a short to ground. If the fuel level sensor circuit tests normal, replace the PCM.

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



Component Testing

1. Ignition OFF, disconnect the harness connector at the fuel level sensor.
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 of resistance 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 (Verification Tests) after completing the diagnostic procedure.

* Fuel Level Sensor Replacement (Service and Repair)for the 3.8L engine
* Fuel Level Sensor Replacement (Service and Repair)for the 4.8L, 5.3L, 6.0L, 6.2L and 7.0L engines
* Control Module References (Programming and Relearning)for the PCM replacement, setup, and programming