P0463

DTC P0463 (WITH RPO CODE L81)

CIRCUIT 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 CAN serial data circuit to the body control module (BCM). The BCM sends the fuel level percent to the instrument panel cluster (IPC) via the class 2 data circuit to display on the fuel gage. The fuel level information is also used for misfire and evaporative emission (EVAP) diagnostics.

This diagnostic tests for a higher than normal fuel level sender signal.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P0463 Fuel Level Sensor Circuit High Voltage

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 4.7 volts.
- The above condition is present for greater than 20 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The fuel gage defaults to empty.
- The IPC illuminates the low fuel warning light.
- The driver's information display (DID) displays the Low Fuel message.
- 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.

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, i.e. RPM, load, vehicle speed, temperature, etc. This will isolate when the DTC failed.

TEST DESCRIPTION

Steps 1 - 12:

The number below refers to the step number on the diagnostic table.
3. Tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.