Operation CHARM: Car repair manuals for everyone.

P0463

Diagnostic Chart:




Schematic:




The fuel tank level sensor is a variable resistor that varies resistance according to changes in the level of fuel in the fuel tank. The PCM supplies ignition voltage reference through a series of pull-up resistors to the sensor, which is connected to ground. When the level in the fuel tank is low, the sensor resistance is low (low voltage on signal line). As the fuel level increases, the sensor resistance increases (voltage increases on the signal line). The PCM uses the signal voltage to determine fuel tank level. The PCM sends the fuel tank level over the Class II link to the BCM. The BCM averages the signal over time then sends out a message to the I/P cluster for the fuel gauge over the link. DTC P0463 sets when the signal voltage at the PCM is above the calibrated voltage value.

DTC PARAMETERS
DTC P0463 will set if fuel level voltage is greater than 4.86 volts when:
^ Condition exists for longer than 1 second
^ Ignition voltage is greater than 9 volts

DTC P0463 diagnostic runs continuously with ignition On.

DTC P0463 is a type D DTC.

DIAGNOSTIC AIDS
To locate an intermittent problem, use Scan tool to monitor FUEL LEVEL voltage with ignition On, engine Off. Wiggling wires while watching for a change in FUEL LEVEL voltage may locate the area where an open or short to voltage in the wiring could lie.

The voltage measured with a DVOM on the signal line with the ignition On and sensor disconnected should read very close to ignition voltage (within 0.2 volts). The Scan tool, however, is scaled 0 to 5 volts.

If DTC P0463 is active, the fuel gauge will read EMPTY and the LOW FUEL telltale will be commanded On.