Fuel Level Very Low

Fuel Level Circuit:

DESCRIPTION:

The ignition 1 fuse #15 supplies the fuel gauge (CKT #139) and fuel level reference (CKT #30) 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 1C12 (CKT #350) 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 1C12) 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. Several driver warnings are triggered off of the calculated fuel level. If the auxiliary displays are turned off using the display ON/OFF button on the IPC and the average calculated fuel level reaches 1/4 tank, the BCM will turn on the auxiliary displays and send the "Check Fuel Gauge" message to the driver information center. When the average calculated fuel level reaches 2.7 gallons the BCM will turn ton the "Low Fuel" telltale. When the average calculated fuel level reaches 1.5 gallons the BCM will send the "Fuel Level Very Low" message to the driver information center.

TEST CONDITION:

Ignition 1 voltage is present.

FAILURE CONDITION:

Calculated fuel level less than 1.5 gallon.

ACTION TAKEN:

Display the "Fuel Level Very Low" message on the CCDIC.