Normal Operation
WARNING: This page is about a different car, the 2006 Mercury Grand Marquis and 2006 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.
The instrument cluster receives the powertrain status from the powertrain control module (PCM) over the controller area network (CAN). When a system concern is detected, the PCM sends the instrument cluster a command signal to illuminate the powertrain malfunction (wrench) warning indicator.