Long Term FT

Range 0-255 (-100 Percent to 100 Percent): The Long Term Fuel Trim (FT) is derived from the Short Term FT value. The Long Term FT is used for the long term correction of the fuel delivery. A value of the 128 counts (0 percent) indicates that the fuel delivery requires no compensation in order to maintain a 14.7:1 air to fuel ratio. A value below 128 counts means that the fuel system is too rich and the fuel delivery is being reduced. The PCM is decreasing the injector pulse width. A value above 128 counts indicates that a lean condition exists for which the PCM is compensating