Glow Plug System: Description and Operation

Glow Plug Location:

DESCRIPTION
In the diesel engine, air alone is compressed in the cylinder; then, after the air has been compressed, a charge of fuel is sprayed into the cylinder and ignition occurs, due to the heat of compression. Eight glow plugs are used to preheat the chamber as an aid to starting.

Control of the Glow Plugs has been accomplished by moving the logic for controlling the heat of the plugs to the Powertrain Control Module (PCM). The new logic can incorporate the higher accuracy of digital processing compared to the previous analog controller. Additionally, logic involving engine speed and estimates of engine combustion can can be added to the traditional time and temperature data used in the previous controller. This capability yields more optimum heat times for the glow plugs, thus pre-glow times can be kept to a minimum for short wait to crank times and maximum glow plug durability.