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
If it fails: lemon-manuals.org.ua

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General Description and Operation

The PCM performs the following functions:
^ accepts input from various engine sensors to compute the required fuel flow rate necessary to maintain a prescribed air/fuel ratio throughout the entire engine operational range.
^ outputs a command to the fuel injectors to meter the appropriate quantity of fuel.
^ determines and compensates for the age of the vehicle and its uniqueness, also automatically senses and compensates for changes in altitude.