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 Circuit Low VoltageDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Fuel Level Sensor Reference Voltage Circuit | P0462 | -- | -- | P0461 |
Fuel Level Sensor Signal Circuit | P0462 | P0463, P0464 | P0463 | P0461 |
Fuel Level Sensor Low Reference Circuit | -- | P0463, P0464 | P0463 | P0461 |
Circuit/System Description
The fuel level sender changes resistance based on the fuel level. The engine control module (ECM) 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 ECM senses a low signal voltage. When the fuel tank is empty, the sender resistance is high and the ECM senses a high signal voltage. The ECM uses the signal circuit of the fuel level sender in order to calculate the total remaining fuel percent in the tank. The ECM sends the fuel level message via the serial data circuit to the instrument panel cluster (IPC) to display on the fuel gage.
This diagnostic tests for a lower than normal fuel level sender signal.
Conditions for Running the DTC
The ignition is ON, with the engine ON.
Conditions for Setting the DTC
| • | The fuel level signal is greater than 98 percent. |
| • | The above condition is present for greater than 20 seconds. |
Action Taken When the DTC Sets
| • | The fuel gage defaults to empty. |
| • | The ECM records the operating conditions at the time the diagnostic 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. |
| • | The ECM receives the clear code command from the scan tool. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Scan Tool Reference
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the fuel level sensors.
- Ignition ON, verify that the scan tool fuel tank level remaining parameter is less than 4 percent
- If all circuits test normal, test or replace the fuel level sensors.
| ⇒ | If greater than 4 percent, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM. |
Component Testing
- Ignition OFF, remove the fuel level senders and verify that there are no obstructions interfering with the fuel level senders.
- Ignition OFF, disconnect the harness connector at the fuel level sensors.
- While sweeping the primary 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 circuit and the low reference circuit.
- While sweeping the secondary 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 circuit and the low reference circuit.
| ⇒ | If any interference is present, repair the fuel sender interference. |
| ⇒ | If not within the specified range, replace the primary fuel level sensor. |
| ⇒ | If not within the specified range, replace the secondary fuel level sensor. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for ECM replacement, setup, and programming |
