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 1 Low VoltageDiagnostic 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/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 the 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 11-18 volts. |
Conditions for Setting the DTC
| • | The sender output is less than 0.5 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. |
Diagnostic Aids
A defective fuel level sensor most likely will not set DTC P0462. The sensor has a 500 ohm default resistor that will prevent it from meeting the code setting criteria of this DTC. Look for problems in the wiring and in the inline and harness connectors at the sensor and ECM.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Instrument Cluster Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for Scan Tool Information
Circuit/System Verification
Ignition ON, verify the scan tool Fuel Tank Level Remaining parameter is between 4-98 percent.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the fuel level sensor.
- Ignition ON, verify that the scan tool Fuel Tank Level Remaining parameter display is less than 4 percent.
- If all circuits test normal, test or replace the fuel level sensor.
| ⇒ | If greater than the specified range, test the signal circuit terminal C for a short to ground. If the circuit tests normal, replace the ECM. |
Component Testing
- Ignition OFF, remove the fuel level sender.
- While sweeping the fuel level sensor through its full range of motion, test for a minimum resistance value of less than 41 ohms and a maximum value greater than 119 ohms between the signal terminal C and the low reference terminal B.
| ⇒ | If not within the specified range, replace the fuel level sensor. |
Component Testing
- Ignition OFF, disconnect the harness connectors at the fuel level sensor.
- 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 the signal terminal C and the low reference terminal B.
| ⇒ | If not within the specified range, replace the fuel level sensor. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Fuel Level Sensor Replacement for the 4.3L engine |
| • | Fuel Level Sensor Replacement for the 4.8L, 5.3L, 6.0L, and 6.2L engines |
| • | Fuel Level Sensor Replacement for the 6.6L engine |
| • | Control Module References for ECM replacement, setup, and programming |
