Barometric Pressure Sensing
Barometric pressure is the actual ambient absolute pressure at the sensor's elevation, not sea-level-corrected weather pressure, manifold boost, or vacuum. This revision supports an external analog barometric sensor and an onboard LPS2x sensor where the board target provides one (external setup, onboard setup).
Open Sensors > Baro sensor. For an analog sensor, assign Baro ADC input, choose Type, and enter the low/high points. Analog baro uses the same pressure decoder presets and custom linear endpoints as MAP. For a board-supported LPS2x, assign LPS2x Baro SCL and SDA with the analog channel disabled. The external analog sensor takes priority: onboard initialization is skipped if a barometric provider is already registered.
Calibration and correction
For an analog sensor, select the exact device preset where available; otherwise enter pressure and voltage endpoints from its datasheet. Compare the barometric reading with a known local absolute-pressure reference, or convert a weather report to station pressure using the local elevation. At key-on with the engine stopped, the reading should be plausible for the location, but do not enter a sea-level-corrected weather value or a universal sea-level value.
Fuel > Barometric pressure correction applies a three-dimensional correction by pressure and RPM in Speed Density. Its default table is unity, not a calibration shortcut (default table). Correct the sensor first, then change this table only when the engine model needs a validated elevation correction.
Use fixed baro corr from MAP reads the MAP sensor once at initialization and holds it as barometric pressure. An invalid initial value is rejected and generates P2226; the fixed override is then disabled (startup validation).
Diagnostics and wiring
Use the Baro pressure log gauge and the MAP/baro raw diagnostic gauges. If baro is absent, fuel barometric correction returns 1, while several injector and actuator calculations use 101.325 kPa as a fallback (fuel correction). There is no generic barometric-pressure value check equivalent to the MAP DTCs in this revision.
The Atlas documents an onboard barometer; the Universal 112 v1.2 pinout should be used for an external analog input only on that board revision.