The powertrain control module, otherwise known as the PCM or computer, is essentially your vehicle’s brain. The PCM in your car or truck is designed to control and regulate all of its functions and parts. Problems in the computer can lead to serious problems with almost every aspect of your car or truck because the computer has to work properly in order for everything else to follow suit.
The PCM is what ultimately controls and regulates your fuel system. Different sensors in the engine send the PCM data about what the engine is doing. The PCM then adjusts the fuel mixture based on this data.