Fuel Indicator Lamp Always on - Bi-Fuel/Alternative Fuels

CIRCUIT DESCRIPTION
The fuel gauge select switch assembly serves 2 purposes. The fuel gauge select switch is used to indicate to the Alternative Fuels ECM that the operator of the vehicle has requested that the fuel gauge display the level of fuel for the DORMANT or non-operating fuel system. The fuel indicator lamp (FIL) is used by the Alternative Fuels ECM to indicate to the operator of the vehicle which fuel system is in use. When illuminated the vehicle is operating on gasoline.

The fuel indicator lamp (FIL) is supplied power by the Alternative Fuels ECM and the ground path is supplied through the alternative fuels engine harness ground. The Alternative Fuels ECM will supply power to the FIL for a two second bulb check at ignition ON during CNG operation or continuously during gasoline operation when the ignition is in the ON or RUN positions.

TEST DESCRIPTION

Steps 1-5:

Steps 6-10:

The number(s) below refer to the step number(s) on the diagnostic table.
1. The System Check MUST be performed before proceeding with this diagnostic table. Failure to perform the System Check will result in mis-diagnosis.
2. This step checks for proper operation of the FIL.
3. The FIL should only stay illuminated when the engine is operating on gasoline.
4. The AFO Signal and AFO Signal Command parameters both indicate the state of the alternative fuels operation circuit. The Signal parameter is the state of the enable circuit as monitored by the gasoline control module. The Command parameter is the state of the enable circuit as commanded by the Alternative Fuels ECM.