Glow Plug Control Module (GPCM)
The glow plug system consists of a solid state 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 to power the individual glow plugs by providing direct battery voltage to the glow plugs. The GPCM monitors the individual glow plug operation. Concerns detected by the GPCM are transmitted to the PCM using a serial communication signal on a diagnostic line. 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 the 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.