Short Term FT Avg

Display shows percentage from -100% to 99%. The center position for the short term fuel trim is 0%. A percentage greater than 0% indicates that time is being added to the MCV pulse width, increasing the amount of fuel to the engine to compensate for a lean condition sensed by the average of both the oxygen sensors. A percentage less than 0% indicates time is being subtracted from the MCV pulse width reducing the amount of fuel to the engine to compensate for a rich condition sensed by the oxygen sensor. A value of 0% indicates no compensation is required to operate the engine at the desired 16.8 to 1 air/fuel ratio.