Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC P0380: Glow Plug CircuitDiagnostic Fault Information
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
Glow Plug Relay Control Circuit | P0380 | P0380 | -- |
Circuit/System Description
The engine control module (ECM) controls the glow relay which supplies power to the glow plugs based on engine coolant temperature. If the ECM detects an open or short circuit at the glow relay control circuit, this DTC will set.
Conditions for Running the DTC
| • | The battery voltage is between 10-16 volts. |
| • | The ignition is ON for longer than 2 seconds. |
Conditions for Setting the DTC
| • | The ECM detects a high voltage condition on the glow relay control circuit for longer than 3 seconds when the glow relay is commanded OFF. |
| • | The ECM detects a low voltage condition on the glow relay control circuit for longer than 3 seconds when the glow relay is commanded ON. |
Action Taken When the DTC Sets
DTC P0380 is a Type A DTC.
Conditions for Clearing the DTC
DTC P0380 is a Type A DTC.
Diagnostic Aids
An incorrectly installed fuel injector, intermediate connector, will cause this DTC to set.
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Verify the integrity of the Glow plug relay control circuit by inspecting for the following conditions:
| • | Damaged components |
| • | Loose or improper installation |
Circuit/System Testing
Important: You must perform Circuit/System Verification before proceeding with Circuit/System Testing.
- Ignition OFF, disconnect the harness connector at the glow plug relay.
- Ignition ON, verify that a test lamp illuminates between the power supply circuit terminal B and ground.
- Ignition OFF, disconnect the harness connector at the ECM.
- Install a 3-amp fused jumper wire between the power supply circuit terminal B and the control circuit A.
- Ignition ON, verify that a test lamp illuminates between the control circuit at ECM terminal 59 and ground.
- Ignition OFF, inspect the glow plug relay.
| ⇒ | If the test lamp does not illuminate, test the power supply circuit for a short to ground or an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test the power supply circuit for a short to ground or an open/high resistance. |
| ⇒ | If the glow plug relay tests normal, replace the ECM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for ECM replacement, setup, and programming |
