Glow Plugs - PCM-Controlled
WARNING: This page is about a different car, the 2008 Ford Econoline, 2008 Ford E450 Super Duty, and 2008 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
The glow plugs are located in the cylinder heads, under the glow plug wiring harness.
The glow plugs are self-regulating. If the engine oil temperature is above 55°C (131°F), the PCM will bulb-check the WAIT TO START lamp but not energize the glow plug relay.
The glow plug ON time varies from 0-120 seconds depending on battery voltage, engine oil temperature and barometric pressure.
The glow plug ON time is independent of the wait to start lamp ON time.
The glow plug control monitor (GPCM) system is designed to find failed glow plugs or failed wiring in the glow plug system.