Long Term Fuel Trim (FT) BN 2

RANGE (0-255 COUNTS):
The Long Term FT is derived from the Short Term FT value. The VCM uses the Long Term FT for the long term correction of the fuel delivery. A value of 128 counts indicates that the fuel delivery requires no compensation 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, requiring decreased injector pulse width. A value above 128 counts indicates that a lean condition exists. The VCM compensates by adding fuel, requiring increased injector pulse width.

RANGE (PERCENTAGE OF COMPENSATION REQUIRED):
The Long Term FT is derived from the Short Term FT value. The VCM uses the Long Term FT for the long-term correction of the fuel delivery. A value of 128 counts indicates that the fuel delivery requires no compensation 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, requiring decreased injector pulse width. A value above 128 counts indicates that a lean condition exists. The VCM compensates by adding fuel, requiring increased injector pulse width. As fuel compensation is required, the difference between commanded Long Term FT and 128 counts will be displayed as a percentage.