2004 Ford F150 Bi-fuel Supplement 2nd Printing - Page 14

Instrumentation and controls The vehicle's fuel system will NOT automatically change to the gaseous fuel mode (CNG or LPG , depending upon application), if the level of the unleaded gasoline runs low. FUEL GAUGE The fuel gauge in your CNG or LPG Bi-fuel vehicle (depending upon application) behaves similarly to a standard gasoline fuel gauge. The fuel gauge will provide a linear reading from Full down to Empty. • Fuel gauge operation for a LPG Bi-fuel vehicle is based on a float type sensor measuring the level of the liquid propane in the fuel tank(s). • Fuel gauge operation for a CNG Bi-fuel vehicle is based on the pressure and temperature of the natural gas in the fuel tank(s). Depending upon the application, a full fuel gauge reading will occur at a pressure of approximately 20 700 kPa (3 000 psi) or 24 800 kPa (3 600 psi) at a temperature of approximately 21°C (70°F). For more information on fuel gauge performance during the fast-fill method of CNG fueling, refer to Refueling your Bi-fuel vehicle in the Maintenance and care chapter of this supplement. WARNING LIGHTS With the engine running, the "Check Engine/Service Engine Soon" indicator light (depending upon application) will illuminate on the instrument cluster when the On Board Diagnostics System and/or the Gaseous Fuel Injection System detects a malfunction in one of the engine's emission controls. For more information, refer to Warning light and chimes in the Instrumentation chapter of your Owner's Guide and this supplement. If a malfunction of the LPG Gaseous Fuel Injection System is detected with the engine running in the ALT gaseous fuel mode, the green indicator light on the fuel selector GAS switch will flash on and off. The warning lights may illuminate or flash on and off (depending upon application) without a driveability concern being noted. The vehicle will usually be drivable and will not require towing. Contact a qualified Ford dealership at the first available opportunity. 14