Learned Voltage Feedback and Target Air Fuel Ratio

Although Long FT, Target A/F, and LVF (Learned Voltage Feedback) are essentially the same, there is a difference in how this data parameter is displayed on OBD engines. LVF and Target A/F are displayed as a voltage signal with a range of 0 to 5 volts. The signal, which varies in fixed 1.25 volt increments, has a nominal value of 2.50 volts.

When LVF is at 2.50 volts, it indicates that basic injection duration calculation is within ± 10% of required injection duration (to achieve 14.7 to 1 AFR). If basic injection duration deviates more than ± 10% of required injection, LVF will shift to correct the excessively lean or rich condition.

Lower voltage indicates decreased injection duration to correct for a rich condition. Higher voltage indicates increased injection duration to correct for a lean condition.

Lower voltage indicates decreased injection duration to correct for a rich condition. Higher voltage indicates increased injection duration to correct for a lean condition.

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