Glow Plug Control Module

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The glow plug system is composed of solid state glow plug control module (GPCM), glow plugs and the associated wiring harness. The glow plug on-time is controlled by the PCM and is a function of oil temperature, barometric pressure and battery voltage. The PCM enables the GPCM which drives the individual glow plugs. Glow plug on-time normally varies between 1 to 120 seconds. In addition to PCM control, the GPCM internally limits the glow plug operation to 180 seconds regardless of PCM commanded on-time. The power to the glow plugs is provided through the GPCM solid state drivers directly from the vehicle battery. The GPCM monitors and detects individual glow plug functionality, and the control and communication links to the PCM. The failures detected by the GPCM are passed to the PCM using a serial communication signal on the diagnostic line.

NOTE: Wait-to-start lamp on-time is controlled by the PCM and is independent from GPCM on-time.

Fig 1: Identifying Glow Plug Control Module

Courtesy of FORD MOTOR CO.