Intake Air Temperature Fuel Multiplier
Open Fuel > IAT multiplier to edit the running-fuel intake-air correction.
The X axis is IAT in °C and the Y axis is a dimensionless multiplier. The ECU
interpolates this curve at the current IAT and includes the result in total
running-fuel correction. 1.0 is neutral; values above or below it add or
remove modeled fuel. If the IAT sensor is invalid, the lookup returns 1.0.
The reset IAT curve is flat at 1.0, using 10 °C-spaced breakpoints from
-40 °C upward. That makes neutral the default rather than an implied hot- or
cold-air correction. Start by validating the IAT sensor
and comparing stable-load behavior with Charge Temperature Estimation,
which is the dedicated air-temperature model for air-mass calculation. This
multiplier is an additional running-fuel term; changing both without
understanding the interaction can compensate the same temperature effect
twice.
Use the Fuel: IAT correction channel to confirm the curve output. Diagnose sensor wiring, calibration, and heat soak before changing the multiplier, and make changes from repeatable steady-state points. This table does not replace injector dead time, fuel-pressure compensation, coolant enrichment, or closed-loop fuel correction. It also does not directly alter cranking fuel.