Manifold Absolute Pressure (MAP)

A sensor reading of absolute pressure inside the intake manifold, used as a load input and the key variable in speed-density airflow math.

Manifold absolute pressure (MAP) is the absolute pressure inside the intake manifold, measured in kPa, where roughly 100 kPa is atmospheric, lower is vacuum, and above 100 kPa is boost. The PCM uses MAP as an engine-load signal and, in speed-density mode, as the primary axis for estimating airflow alongside RPM and the VE table. It matters for a safe tune because MAP scaling and sensor range must match the hardware; an undersized MAP sensor that maxes out under boost leaves the model blind exactly when fueling errors are most dangerous. Boosted builds usually require a higher-range MAP sensor and matching calibration. In HP Tuners VCM Editor, MAP sensor configuration and scaling live under Engine > Airflow / Sensors. In VCM Scanner you log MAP (kPa) against RPM, boost, and wideband AFR to confirm the load axis is reading correctly before leaning on it for tuning decisions.