Fuel Gauge: Description and Operation

When the gauge indicator shows approximately 1/8 tank of fuel remaining, the LED will light, alerting the driver to a low fuel condition.

When the gauge indicator shows engine temperature to be 240-260°F, the LED will light, alerting the driver to an overheating condition.

CIRCUIT OPERATION
The Body Control Module (BCM) calculates the pointer position of the fuel gauge based on the input of the fuel tank gauge level sending unit relative to fuel tank ground. The G4 circuit sends the signal to the BCM.

The fuel pump module, located in the fuel tank, contains the fuel pump and the variable resistor for the fuel gauge. Ground for the resistor is located at the left kick panel. As the position of the float and changes, the resistor changes the current flow through the G4 circuit. The change in current flow is then measured by the BCM and the fuel gauge pointer position is adjusted to reflect the fuel tank level. The signal is sent over the CCD Bus to the instrument cluster.