P0463

DTC P0463

DTC Descriptor

DTC P0463
- Fuel Level Sensor Circuit High Voltage

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview






Circuit Description

The fuel level sender changes resistance based on fuel level. The powertrain control module (PCM) 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 high and the PCM senses a high signal voltage. When the fuel tank is empty, the sender resistance is low and the PCM senses a low signal voltage. The PCM uses the signal circuit of the fuel level sender in order to calculate the total remaining fuel (percent) in the tank. The PCM sends the fuel level percent via the class 2 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 engine is running.
* The system voltage is between 10.5-18 volts.

Conditions for Setting the DTC

* The fuel level signal is greater than 3.2 volts.
* The above condition is present for at least 60 seconds.

Action Taken When the DTC Sets

* The fuel gage defaults to empty.
* The Check Gages indicator illuminates.
* The PCM records the operating conditions at the time the diagnostic fails. The 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 PCM receives the clear code command from the scan tool.

Diagnostic Aids

Use the Freeze Frame and/or Failure Records data in order to locate an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data may aid in determining the number of miles since the DTC set. The Fail Counter and Pass Counter can also aid in determining the number of ignition cycles that the diagnostic reported a pass and/or fail. Operate the vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature, etc.). This will isolate when the DTC failed.

Circuit/System Verification

Ignition ON, observe the scan tool Fuel Level Sensor parameter. The reading should be between 1.0 and 2.5 volts.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the fuel level sensor.
2. Ignition OFF, test for less than 1 ohm of resistance between the low reference circuit and ground.

• If greater than 1 ohm, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the PCM.

3. Ignition ON, install a 3-amp fused jumper between the signal circuit and the low reference circuit. Verify the scan tool Fuel Level Sensor parameter is less than 0.35 volts.

• If greater than 0.35 volts, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the PCM.

4. 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
* Programming and Relearning for PCM or IPC Programming and Relearning