Powertrain Malfunction (Wrench) Warning Indicator
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 PCM monitors the electronic throttle control and the transmission system and provides the instrument cluster with the operating status over the CAN. When a system concern is detected, the PCM provides the instrument cluster with a signal commanding the instrument cluster to illuminate the powertrain malfunction (wrench) warning indicator.