Small Pulse Width Correction
Small-pulse correction adjusts the fuel-pulse calculation near the injector's nonlinear low-flow region. It runs before the minimum-pulse clamp and dead-time addition. Use supplier-measured data for the exact injector at its physical differential pressure and voltage, then use one characterized model consistently; do not mix polynomial coefficients, slopes, dead time, and flow ratings measured under different conditions.
Polynomial
Set Small pulse correction mode to Polynomial and define the pulse
threshold with Add nonlinearity below pulse. At or below that pulse width,
the ECU takes the uncorrected base duration x in milliseconds and adds:
c0 + c1*x + c2*x^2 + ... + c7*x^7
The eight coefficients are the constant through x^7 fields. Longer pulses bypass this correction. A supplier polynomial is only valid over its measured pulse range; polynomial extrapolation can produce implausible pulse widths, so move the threshold and coefficients only from measured injector data. Dead time remains a separate battery-voltage curve.
Ford Two-Slope Method
The Ford (dual slope) path models the low-flow kink with two measured slopes. Set injector flow units to mass flow, enter the large-pulse slope (AHISL) as injector flow in g/s, the small-pulse slope (ALOSL) in g/s, and the mass breakpoint (FUEL_BKPT) in mg. Below the breakpoint, duration uses the small slope plus a calculated joining offset; above it, duration uses the large slope. Pressure compensation scales both slopes by the same flow ratio.
The nonlinear selector is disabled on the secondary injector bank in this revision, even if staged injection is enabled.