Fuel Level Sensing

The PZM calculates fuel level and sends a serial data message to the IPC and PCM indicating fuel level. The IPC receives "filtered" data to account for fuel slosh except while the computer system is in "service" mode (On-Board Diagnostics). The PCM Always receives "unfiltered" data. The fuel level is calculated as a ratiometric reading between the fuel level sensor and an Ignition 1 reference voltage. By using this method, changes in system voltage will have no effect on fuel level. The PZM sends changes in fuel level information to the IPC each time there is a change of at least five tenths of a liter. The PZM sends changes in fuel level information to the PCM each time there is a change of at least one liter.