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Glow Plug System: Description and Operation

DESCRIPTION
The glow plug system preheats air in the combustion chamber to improve cold engine starting.

OPERATION
The glow plug system is electronically controlled by the Powertrain Control Module (PCM). The PCM energizes the intake manifold glow plugs immediately after the ignition switch is placed in the ON position and then determines how long the intake manifold glow plugs will be on according to the engine oil temperature and the barometric pressure. The required time for the glow plugs to be energized decreases as the engine oil temperature and barometric pressure increase. The intake manifold glow plugs are self-regulating, and the PCM controls relay ON time. The PCM protects the intake manifold glow plugs by energizing them for short durations if the battery voltage is abnormally high.


CONSTRUCTION
The system consists of eight intake manifold glow plugs, the glow plug control module, PCM Engine Oil Temperature (EOT) sensor, and Barometric Pressure (BARO) sensor.