CReader Series English User's Manual
RPM, vehicle speed, air flow, engine load, fuel pressure, fuel trim value, engine
coolant temperature, ignition timing advance, or closed loop status.
Fuel Trim (FT) -- Feedback adjustments to the base fuel schedule. Short-term fuel
trim refers to dynamic or instantaneous adjustments. Long-term fuel trim refers to
much more gradual adjustments to the fuel calibration schedule than short-term
trim adjustments. These long-term adjustments compensate for vehicle
differences and gradual changes that occur over time.