The glow plug controller is a solid state device which operates the glow plugs. The temperature and the power consumption is controlled between the engine control module (ECM) and the glow plug controller within a wide range to suit the engine's pre-heating requirements. The ECM controls the glow plug module with a pulse-width modulated (PWM) control circuit. The glow plug initial ON time will vary based on the system voltage and temperature. Lower temperatures cause longer ON times.

P0380 00

P0383 02 or P0384 00

The ECM detects an open, short to ground, or a short to voltage on the glow plug module control circuit for greater than 0.5 s.

DTC P0380, P0383 and P0384 are Type C DTCs.

DTC P0380, P0383 and P0384 are Type C DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, observe the DTC information with a scan tool. DTC P0380, P0383 or P0384 should not set.
2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness connector X1 at the K34 Glow Plug Control Module (GPCM).
2. Test for less than 5 Ω between the ground circuit terminal 3 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Connect a test lamp between the B+ circuit terminal 5 and ground.

⇒	If the test lamp is OFF, test the B+ circuit for a short to ground or an open/high resistance.

4. Ignition ON, connect a test lamp between the ignition circuit terminal 4 and ground.

⇒	If the test lamp is OFF, test the ignition circuit for a short to ground or an open/high resistance.

5. Test for less than 0.3 V between the signal circuit terminal 1 and ground.

⇒	If greater than the specified range, test the signal circuit for a short to voltage.

6. Ignition OFF, disconnect the harness connector X1 at the K20 Engine Control Module (ECM).
7. Test for greater than 500 kΩ between the K34 Glow Plug Control Module (GPCM) signal circuit terminal 1 and ground.

⇒	If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

8. Test for less than 5 Ω between the signal circuit terminal 1 at the K34 Glow Plug Control Module (GPCM) harness connector and terminal 57 at the K20 Engine Control Module (ECM) harness connector.

⇒	If greater than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

9. If the circuit tests normal, replace the K34 Glow Plug Control Module (GPCM).

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.