Principles of Operation (How Does It Work)

NOTE: If the bi-fuel vehicle does not operate correctly in alternative fuel mode, refer to Powertrain Management.

As a technician, it is very important to understand:
1. where the input (command) originates from
2. all information (messages) necessary in order for a feature to operate
3. which module (s) receives (s) the input or command message
4. does the module which received the input (message), control the output of the feature, or does it output a message over the SCP communication network to another module
5. which module controls the output of the feature

Fuel Gauge Indication
A single fuel gauge is used for both alternative fuel and gasoline level indication. The fuel indication system uses an aftermarket fuel pump intercept harness, compuvalve, dash reset relay, compressed natural gas fuel tank pressure sensor, and other circuits, along with the Ford gasoline fuel pump module. The components and circuits together produce accurate fuel gauge indication in both alternative fuel and gasoline operating modes. Depending upon the operating mode selected, alternative fuel or gasoline, the FTPS, or the fuel pump module will send a resistance value over the fuel pump intercept harness to the compuvalve. The compuvalve sends the resistance value to the instrument cluster through the fuel pump intercept harness and Ford circuits where it is utilized by the fuel gauge.