• The GPCM is a unit that controls the glow plugs in order to warm the air in the cylinders.
• The GPCM uses a glow plug enable signal to turn the glow plugs on for a time controlled by the ECM.
• The GPCM is capable of diagnosing a problem with one glow plug and then sending a diagnostic signal to the ECM.
• It also has the ability to turn off one glow plug if a short is detected in that circuit.
• Each bank of glow plugs is connected to the engine wiring harness via a glow plug harness, either left bank or right bank.
• The glow plug harness has four connectors that supply power to the glow plugs and seal oil from escaping through the glow plug access holes.
