Barometric Pressure Sensor: Description and Operation

Map And Baro Read Solenoid Location:

LOCATION

Solenoid mounted under hood on passenger side of firewall, near MAP sensor.

PURPOSE

Solenoid switches manifold or barometric (atmospheric) pressure to MAP sensor.

Powertrain Control Module (PCM) uses barometric reference for turbo boost and cold start fuel enrichment at altitudes.

PCM uses manifold vacuum to judge engine load.

OPERATION

Solenoid energized, MAP sensor receives atmospheric pressure.

Solenoid de-energized, MAP sensor receives manifold pressure (vacuum).

PCM energizes solenoid once per throttle closure, but no more than once per three minutes and only within a specified rpm range.