F 150 Heritage 4WD Pickup V8-5.4L SOHC VIN Z Bi-fuel (2004)
Alternative Fuel Selector Switch: Description and Operation
Bi-Fuel CNG Models
ALTERNATIVE FUEL SELECTOR INDICATOR/SWITCH
ALT/GAS Switch
The ALT/GAS switch is located on the instrument panel and allows the driver to pre-select the operating fuel before starting the vehicle. The switch
only operates with the ignition switch in the OFF position. If the switch is pressed while the vehicle is running, the input is ignored. The gaseous fuel
system will NOT automatically change fuel modes with the vehicle running.
The ALT/GAS switch has two operating positions:
-
GAS
-
ALT
When the GAS position is selected, the engine will operate in the gasoline mode. Selecting the ALT position sends a signal to the alternative fuel
control module (AFCM) requesting ALT fuel mode. If the temperature and pressure conditions are correct, the vehicle will switch to the gaseous fuel
mode. A green indicator will also illuminate on the switch to verify the vehicle is operating in the CNG mode. If no signal is received by the AFCM,
the system defaults to gasoline mode.