P0382

DTC P0382

CIRCUIT DESCRIPTION
The engine control module (ECM) controls the glow relay which supplies power to the glow plugs based on engine coolant temperature. In the after glow phase, the glow indicator light is not illuminated but glow plugs remain active for a certain period. If the ECM detects an open circuit or short circuit on the glow relay control circuit, this DTC will set.

Condition for Running the DTC
- The battery voltage is between 10-16 volts.
- The ignition switch is ON.

Condition for Setting the DTC
- The ECM detects a low voltage condition on the glow relay control circuit for longer than 10 seconds when the glow relay is commanded OFF.

OR
- The ECM detects a high voltage condition on the glow relay control circuit for longer than 10 seconds when the glow relay is commanded ON.

Action Taken When the DTC Sets
- The ECM illuminates the malfunction indicator lamp (MIL) on the second consecutive driving cycle when the diagnostic runs and fails.
- The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Freeze Frame/Failure Records on the second consecutive driving cycle when the diagnostic runs and fails.

Condition for Clearing the MIL/DTC
- The ECM turns OFF the MIL when the diagnostic runs and does not fail.
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes after the key is cycled.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic after the ECM turns OFF the MIL.
- Clear the MIL and the DTC with a scan tool.

Diagnostic Aids
If an intermittent condition is suspected, the following may cause an intermittent:
- Faulty relay
- Poor connections
- Misrouted harness
- Rubbed through wire insulation
- Broken wire inside the insulation

Check for the following conditions:
- Poor connection at the ECM: Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
- Damaged harness: Inspect the wiring harness for damage. If the harness appears to be OK, observe the "DTC P0382" display on the scan tool with the ignition ON and engine OFF while moving connectors and the wiring harness related to the relay. A change in the display will indicate the location of the fault.

Test Description
The numbers below refers to the step number on the diagnostic table.
2. Listen for an audible click when the glow relay operates. Command both the ON and OFF states.
3. Tests for voltage at the coil side of the glow relay. The Gauges 10 A fuse supplies power to the coil side of the glow relay.
4. Verifies that the engine control module (ECM) is providing ground to the glow relay.
5. Tests if ground is constantly being applied to the glow relay.

DTC P0382
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls Connector End Views or Engine Control Module (ECM) Connector End Views

Step 3 - 8:

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