P0380

Diagnostic Chart:

CIRCUIT DESCRIPTION
The glow plug system is used to assist in providing the heat required to begin combustion during engine starting at cold ambient temperatures. The glow plugs are heated before and during cranking, as well as initial engine operation. The Powertrain Control Module (PCM) controls the glow plug ON times by monitoring coolant temperatures and glow plug voltage. This is a type B code.

CONDITIONS FOR SETTING THE DTC
- PCM has commanded glow plugs ON and voltage at the glow plugs is less than 0.8 volts.
or
- PCM has commanded glow plugs OFF and voltage at the glow plugs is greater than 0.8 volts.
or
- PCM has commanded glow plugs ON and there is more than a 2 volt difference between glow plug voltage and ignition voltage.

ACTION TAKEN WHEN THE DTC SETS
Hard start or no start and possible white smoke.

CONDITIONS FOR CLEARING THE MIL/DTC
- The PCM will turn the MIL off after three consecutive trips without a fault condition.
- A History DTC will clear when forty consecutive warm-up cycles that the diagnostic does not fail (coolant temperature has risen 5°C (40°F) from start up coolant temperature and engine coolant temperature exceeds 71°C (16O°F) that same ignition cycle.

DIAGNOSTIC AIDS
If glow plug relay is stuck in the ON position, check for proper operation of glow plugs. When glow plugs are commanded ON by the Scan tool, an internal PCM timer protects the glow plugs from damage by cycling them ON for 3 seconds and the OFF for 12 seconds.

TEST DESCRIPTION
Number(s) below refer to the Step number(s) on the Diagnostic Table.

2. This Step will determine if P0380 is a hard failure.
3. This Step will determine if PCM is requesting the glow plug system ON.
7. This Step will determine if the glow plug relay has been activated, and out put voltage has been seen by the PCM.