P0462

DTC P0462

DTC Descriptor

DTC P0462
- Fuel Level Sensor Circuit Low Voltage

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Diagnostic System Check - Vehicle






Circuit Description

The engine control module (ECM)/powertrain control module (PCM) monitors the signal circuit of the fuel level sender in order to determine fuel level. The sender consists of a variable resistor that changes resistance based on the fuel level in the tank. The PCM monitors the voltage across the sender resistance in order to determine the fuel level. The ECM/PCM uses the signal circuit of the fuel level sender in order to calculate the total remaining fuel, in percent. The ECM/PCM sends the fuel level percent via the 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, with the engine ON.

Conditions for Setting the DTC

* The fuel level signal is less than 0.39 volt.
* 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 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.
* The ECM/PCM receives the clear code command from the scan tool.

Circuit/System Verification

Ignition ON, observe the scan tool Fuel Tank Level Remaining parameter or the Fuel Level Sensor 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 ON, verify that the scan tool Fuel Tank Level Remaining parameter or the Fuel Level Sensor 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 ECM/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. Verification Tests

* Fuel Level Sensor Replacement for the 4.2L engine
* Fuel Level Sensor Replacement for the 5.3L engine
* Fuel Level Sensor Replacement for the 6.0L engine
* Control Module References for the ECM/PCM replacement, setup, and programming