Engine Control Module: Description and Operation

SYSTEM INPUTS, OUTPUTS, and COMMANDS
The Powertrain Control Module (PCM) 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. Then the PCM outputs a command to the fuel injectors to meter the appropriate quantity of fuel.

The PCM determines and compensates for the age of the vehicle and its uniqueness, it also automatically senses and compensates for changes in altitude (i.e. from sea level to mountains).