Fuel Management

Fuel system basics

THE best outline about the fuel system can be found in the following thread.

Flexfuel

The ECU will do automatic mass fuel flow (mff) compensation based on ethanol content. It can do this both with a sensor or sensorless.

By default, the calibration is set up to leverage a "manual" ethanol setting (which is what the ED code short circuits for the slider). When configured in automatic mode, the ECU will use algorithmic based flex fuel adaptation. By enabling a sensor (pinned to pin 71 [need to verify]), the ecu will instead use the sensor unless the sensor fails.

Switch to use manual alternative fuel ratio
lc_fac_afu_ratio_man_act - set to [00] to disable

Logical value to indicate AFU sensor configuration
lc_fac_afu_ratio_conf - set to [00] to enable the sensor (not a typo)

It also might be helpful to enable the PID output for e-content (PID 52) Details start on page 23709 of the FR. c_state_srv_1_pid[n][10] is the bit field that includes pid 52.