P0384 Fault Code

Glow Plug/Heater Circuit B

• What does that mean?
• Symptoms
• Causes
• Solutions

The P0384 fault code indicates a problem with the Glow Plug/Heater Circuit B, which is part of the engine’s starting system in diesel engines. Glow plugs heat the combustion chamber to ensure proper ignition of the fuel, especially in cold conditions. A fault in this circuit can lead to starting issues and poor engine performance.

What are the symptoms of the P0384 code?

Symptoms associated with the P0384 code may include:

• Difficulty starting the engine, particularly in cold weather
• Rough idling or misfiring during warm-up
• Decreased fuel efficiency
• Engine warning light illuminated on the dashboard
• Smoke from the exhaust during startup

What causes the P0384 code?

Common causes of P0384 include:

• Faulty glow plug in Circuit B
• Open or short circuit in the glow plug wiring
• Malfunctioning glow plug relay
• Issues with the engine control module (ECM)
• Poor electrical connections or corrosion in the circuit

How to fix P0384?

To remedy the P0384 code, follow these steps:

• Inspect and test the glow plugs in Circuit B for proper functionality; replace any faulty plugs.
• Check the wiring and connectors for damage, wear, or corrosion. Repair or replace as necessary.
• Test the glow plug relay and replace it if it's malfunctioning.
• Scan for additional codes that might indicate ECM issues or related faults and address them accordingly.
• Clear the fault codes and perform a test drive to ensure the issue has been resolved.