Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle |
| • | Review Strategy Based Diagnosis |
DTC Descriptor
DTC P0463: Fuel Level Sensor Circuit High InputDiagnostic Fault Information
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
|---|---|---|---|---|---|
Fuel Level Sensor Signal | P0462 | 1 | P0463 P0464 | P0463 | P0461 P0460 |
Fuel Level Sensor Low Reference | -- | 1 | P0463 P0464 | P0463 | P0461 P0460 |
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 fuel level sensor resistance is low and the ECM senses a low signal voltage. When the fuel tank is empty, the fuel level 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 fuel remaining in the tank. The ECM sends the fuel level information via the serial data circuit to the IPC in order to control the fuel gage and display the fuel level.
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 sensor output is greater than 2.9 volts. |
| • | The above condition is present for greater than 30 seconds. |
Action Taken When the DTC Sets
| • | The fuel gage defaults to empty. |
| • | 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
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 Displayed Fuel Level parameter. The reading should be between 4 percent and 98 percent.
Circuit/System Testing
- Ignition OFF, disconnect the X1 harness connector at the fuel pump and sender assembly.
- Ignition OFF, test for less than 1 ohm between the low reference circuit terminal B and ground.
- Ignition ON, install a 3A fused jumper wire between the fuel level sensor signal circuit terminal C and the low reference circuit terminal B. Verify the scan tool Displayed Fuel Level Percent parameter is greater than 98 percent.
- If all circuits test normal, perform the fuel level sensor component test before replacing 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 test 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 value less than 41 ohms and a maximum value greater than 119 ohms between 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.
| • | Control Module References for the ECM replacement, setup and programming. |
