Operation CHARM: Car repair manuals for everyone.
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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Barometric Pressure Sensor: Description and Operation


The atmospheric pressure sensor installed on the AFS, senses the atmospheric pressure and converts it into a voltage which is sent to the ECU. The ECU uses this signal to compute the altitude at which the vehicle is operating and adjusts the air/fuel ratio and ignition timing to improve driveability at high altitude.