P0462
DTC P0462
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 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 serial data circuit to the instrument cluster in order to control the fuel gage.
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 (Instrument Cluster Schematics)
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 4.8L, 5.3L, 6.0L, 6.2L, or 7.0L engine
* Fuel System Description (Fuel System Description) for the 3.5L engine
* Fuel System Description (Fuel System Description) for the 3.9L 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 ECM 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, verify that the scan tool Fuel Tank Level Remaining parameter display is less than 4 percent.
• 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, test or replace 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 (Verification Tests) after completing the diagnostic procedure.
* Fuel Level Sensor Replacement (Service and Repair) for the 4.8L, 5.3L, 6.0L, 6.2L, or 7.0L engine
* Fuel Level Sensor Replacement (Service and Repair) for the 3.5L engine
* Fuel Level Sensor Replacement (Service and Repair) for the 3.9L engine
* Control Module References (Programming and Relearning) for the ECM replacement, setup, and programming