Description & Operation

WARNING: This page is about a different car, the 2002 Ford Pickup, 2001 Ford Pickup, and 2000 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.

WARNING: Do not modify system configuration or components. Do not replace components with parts not specifically designed for use with alternative fuel. Alternative fuel components and gasoline fuel components are not interchangeable. Use of improper parts or materials could result in fire, personal injury or engine damage.

NOTE: This article concerns unique features of Bi-Fuel, fuel level indication system. For instrument cluster functions and diagnostics not covered in this article, see ANALOG INSTRUMENT PANELS - F150 PICKUP - GASOLINE article.

Bi-Fuel indication system consists of fuel pump module, fuel gauge, fuel selector switch, fuel pump intercept (jumper) harness, Alternative Fuel Control Module (AFCM, also called Compuvalve), Compressed Natural Gas (CNG) fuel tank pressure sensor or Liquid Petroleum Gas (LPG) sensor and related circuitry. AFCM is able to perform self-diagnostics on alternative fuel system. AFCM Diagnostic Trouble Codes (DTCs) may be retrieved with New Generation Star (NGS) tester, or equivalent scan tool. Instrument cluster is Hybrid Electronic Cluster (HEC) with self-diagnostic capability. HEC DTCs may be displayed on HEC or retrieved with NGS tester.

A single fuel gauge is used for both alternative fuel and gasoline fuel level indication. To switch between fuel modes, the driver can change the position on the fuel selector switch from GAS to ALT. On all Bi-Fuel vehicles, the gasoline fuel pump information is passed through the AFCM (compuvalve). While operating in gasoline mode, the fuel pump sending unit information goes through the compuvalve and then to the instrument cluster. While operating in alternative fuel mode, the gasoline fuel pump sending unit information is still received by AFCM (compuvalve) but the signal sent out from the AFCM (compuvalve) is replaced with information from the alternative fuel sensors which is then sent to the HEC module. If operating in alternative fuel, the LPG sensor or CNG fuel tank pressure sensor will send a resistance value through the fuel pump intercept harness to the AFCM (compuvalve). The AFCM (compuvalve) sends that value to the HEC through the fuel pump intercept harness where it is used by the fuel gauge. Fuel tank pressure sensor is located in the rear in-bed fuel tank solenoid valve and can range from 50-4000 psi (345-27,580 kPa). Fuel tank temperature sensor is also located in the rear in-bed fuel tank solenoid valve. Fuel tank temperature sensor sends a voltage signal to HEC. When temperature increases in fuel tank, resistance at fuel temperature sensor decreases. If operating in gasoline mode the fuel pump sends a resistance value through the fuel pump intercept harness to the AFCM (compuvalve). The AFCM (compuvalve) sends that value to the HEC through the fuel pump intercept harness where it is used by the fuel gauge.