Fuel Level Very Low

Fuel Level Sensor Circuit:

CIRCUIT DESCRIPTION:
Fuse "A9" in the console fuse block supplies the fuel gage (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 "2B7" (CKT 30) of the BCM, and when the fuel tank is empty pin "2137" (CKT 30) should be grounded. The voltage at pin "2137" of the BCM should decrease as the fuel tank level goes from full to empty. A fuel level reference voltage, at pin "3D1" (CKT 139) 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 "3D1") and the fuel level sensor voltage (pin "2137") 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 GAGE" message to the driver information center. When the average calculated fuel level reaches 2.2 gallon the BCM will send the "FUEL LEVEL LOW" message to the driver information center. When the average calculated fuel level reaches 1.5 gallon the BCM will send the "FUEL LEVEL VERY LOW" message to the driver information center.

TEST CONDITION(S):
1. Ignition 3 voltage is present.

FAILURE CONDITION(S):
1. Calculated fuel level less than 1.5 gallons.

ACTION TAKEN:
1. Display the "FUEL LEVEL VERY LOW" message on the CCDIC.