Circuit Description

Glow plug system assists in providing heat required to begin combustion during engine starting at cold ambient temperatures. Glow plugs are heated before and during cranking as well as initial engine operation. PCM controls glow plug on-time by monitoring coolant temperatures and glow plug voltage.

DTC will set when PCM has commanded glow plugs on and voltage at glow plugs is less than 4 volts, or PCM has commanded glow plugs off and voltage at glow plugs is greater than 4 volts, or PCM has commanded glow plugs on and a greater than 2 volt difference exists between glow plug voltage and ignition voltage.