Electronic Throttle Control
WARNING: This page is about a different car, the 2004 Mercury Mountaineer and 2004 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
The instrument cluster receives the electronic throttle control status from the PCM over the CAN circuits. When a system concern is detected, the PCM sends the instrument cluster a command signal to turn the electronic throttle control indicator ON.