Glow Plug Indicator Lamp
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2004 Ford RV Cutaway, 2004 Ford Pickup, 2004 Ford F550 Super Duty, 2004 Ford F450 Super Duty, and 2004 Ford Excursion. However, it is still accessible from the selected car via links, so may be relevant.
The glow plug indicator lamp (GPIL) is located in the instrument cluster and is used to inform the operator when the engine is ready to be started. The indicator is controlled by the instrument cluster based on an electronic command signal from the PCM through the standard corporate protocol (SCP) communications network. On-time normally varies between 1 and 10 seconds and is independent of glow plug relay on-time. As a prove out, the indicator is commanded on at every key cycle even though the glow plug system may not be required.