Powertrain Control Module (PCM)
WARNING: This page is about a different car, the 2003 Mercury Mountaineer and 2003 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
The PCM is on the SCP communication network. The PCM controls the engine for better fuel economy, emissions control, failure mode detection and storage, refer to SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE for diagnosis and testing of the PCM.