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 P0463: Fuel Level Sensor Circuit High 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 sender changes resistance based on the fuel level. The engine control module (ECM) monitors the signal circuit of the fuel level sender 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 remaining fuel level percent in the tank. The ECM sends the fuel level message via the serial data circuit to the body control module (BCM). The BCM sends the fuel level percent to the instrument panel cluster (IPC) via the serial data circuit for display on the fuel gage.
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 3.5 percent. |
| • | The fuel level sensor output is greater than 2.9 volts |
| • | 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. |
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, observe the scan tool Fuel Tank Level Remaining parameter. The reading should be between 4 percent and 98 percent.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the fuel level sensor.
- Ignition OFF, test for less than 1 ohm between the low reference circuit terminal C and ground.
- Ignition ON, install a 3-amp fused jumper wire between the signal circuit terminal D and the low reference circuit terminal C. Verify the scan tool Fuel Tank Level Remaining parameter is greater than 98 percent.
- If all circuits test normal, test or replace the fuel level sensor.
| ⇒ | If greater than the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM. |
| ⇒ | If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. 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 D and the low reference terminal C.
| ⇒ | If not within the specified range, replace the fuel level sensor. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for ECM replacement, setup, and programming |
