Vehicle System Controller (VSC)
WARNING: This page is about a different car, the 2006 Mercury Mariner and 2006 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
The powertrain control module (PCM), transaxle control module (TCM), and traction battery control module (TBCM) are connected to a high speed controller area network (CAN) to exchange information messages. The VSC is a software function integrated inside the PCM, and is responsible for vehicle system operation, generating and sending commands to initiate appropriate actions such as limited operation strategy (LOS) modes when serious malfunction is detected. The PCM also stores diagnostic trouble codes (DTCs) along with the freeze frame PID related to the LOS action that was initiated. To retrieve DTCs from the PCM an on-demand and continuous memory self-test must be carried out.