Normal Operation
WARNING: This page is about a different car, the 2005 Mercury Montego, 2005 Ford Freestyle, and 2005 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.
The instrument cluster receives the electronic throttle control (ETC) status from the powertrain control module (PCM), and the transmission control module (TCM) over the communication network. When a system concern is detected, the PCM or the TCM sets a DTC and sends the instrument cluster a command signal to illuminate the ETC warning indicator.