Manifold Absolute Pressure Sensor (MAP)
This sensor is mounted in engine compartment or under instrument panel. It measures changes in manifold pressure (vacuum). The MAP sensor sends electrical signals to ECM, reflecting need for adjustment in air/fuel mixture and spark timing under various operating conditions.
NOTE:
The MAP sensor is not used on all engine applications. The 3.8L turbo engine uses a special MAP sensor that also detects altitude changes.