Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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Manifold Pressure/Vacuum Sensor: Description and Operation

The MAP sensor measures manifold vacuum using a frequency. This gives the ECA information on engine load. The ECA used the MAP sensor as a barometric sensor for altitude compensation, updating the ECA during "Key On/Engine Off" and every wide-open throttle. It also supplies information for spark advance, EGR flow and air/fuel ratio.