Fuel Level Is Low Message

TEST CONDITION(S)
1. Ignition 1 voltage is present.

FAILURE CONDITION(S)
1. Calculated fuel level less than 1.9 gallons.

ACTION TAKEN
1. Display the FUEL LEVEL IS LOW message on the IPC.
2. Activate the slow paced chime on the chime module.

DESCRIPTION
The ignition 1 fuse #14 supplies the fuel gauge (CKT 239) and fuel level reference (CKT 39) circuits with system voltage. When the fuel tank is full there should be system voltage present at pin 3C10 (CKT 30) of the BCM, and when the fuel tank is empty pin 3C10 (CKT 30) should be grounded. The voltage at pin 3C10 of the BCM should decrease as the fuel tank level goes from full to empty. A fuel level reference voltage, at pin 3C4 (CKT 39) of the BCM, is received by the BCM from the same Ignition 1 source as the fuel level sensor. The BCM will then create a ratio between the fuel level reference voltage (pin 3C4) and the fuel level sensor voltage (pin 3C10) to determine how much fuel is in the tank. The BCM will then send the averaged calculated amount of fuel to the IPC to be displayed as gallons or liters of fuel remaining in the fuel tank. When the average calculated fuel level reaches 1.9 gallons or less, the BCM will send the FUEL LEVEL IS LOW message to the driver information center.

DIAGNOSIS
Refer to Engine for fuel gage diagnosis. Engine