Powertrain Control Module (PCM)
WARNING: This page is about a different car, the 2005 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.
The PCM is on the controller area network (CAN) and the SCP communications network. The PCM uses the CAN to communicate with the diagnostic tool and utilizes the SCP communications network to communicate with other modules. The PCM controls the engine for better fuel economy, emissions control, failure mode detection and storage. See INTRODUCTION - GASOLINE article for diagnosis and testing of the PCM.